Earth-like planet spotted orbiting Sun’s closest star(nature.com)
nature.com
Earth-like planet spotted orbiting Sun’s closest star
https://www.nature.com/articles/d41586-022-00400-3
333 comments
Here's a good collection of details about the entire star system of Proxima Centauri, including its planets.
https://www.star-facts.com/proxima-centauri/
Also fascinating, a relative distance vs time graph of close stars. It turns out we'll have closer distances for 6 in the next 10,000 - 50,000 years.
https://www.star-facts.com/wp-content/uploads/2020/08/Neares...
Somehow I feel like Elon Musk has a print out of that graph on his office wall.
https://www.star-facts.com/proxima-centauri/
Also fascinating, a relative distance vs time graph of close stars. It turns out we'll have closer distances for 6 in the next 10,000 - 50,000 years.
https://www.star-facts.com/wp-content/uploads/2020/08/Neares...
Somehow I feel like Elon Musk has a print out of that graph on his office wall.
"Unlike the Sun, which will evolve into a red giant in 6.5 billion years and reach the end of its life at an age of about 10 billion years, Proxima will stay on the main sequence for another four trillion years due to its low mass and low energy production."
They laughed at me when I bought investment property on Proxima Centauri b, but who'll be the one laughing in 10.000000001 billion years?
They laughed at me when I bought investment property on Proxima Centauri b, but who'll be the one laughing in 10.000000001 billion years?
“Stars with a mass of less than 0.25 solar masses do not evolve into red giants.… Toward the end of the blue dwarf phase, Proxima will become considerably more luminous, reaching up to 2.5% of the Sun’s luminosity. Once it runs out of hydrogen fuel, it will evolve into a white dwarf, skipping the red giant phase, and gradually lose all its heat energy.”
So we just need to tackle climate change and learn to live sustainably on Earth, then we’ll have a few billion years to figure out how to get to Proxima Centauri.
So we just need to tackle climate change and learn to live sustainably on Earth, then we’ll have a few billion years to figure out how to get to Proxima Centauri.
I thought that was interesting. Especially when the next news article I read called it a "dying star" (presumably their literary license on red dwarf). Everything's relative!
Making an assumption here about Proxima Centauri's own Oort Cloud, but seems like if it's the same size as ours, they'd overlap? Seems like a potentially interesting way for "stuff" to get transferred from one solar system to another.
I believe we are discovering that space isn’t as empty as we once imagined. Rock-hopping could be a viable method of (slow) interstellar travel.
Isn't that how you end up in an endless Solar System war?
Belta-lowda! Belta-lowda! Belta-lowda!
Belta-lowda! Belta-lowda! Belta-lowda!
Eh, we're talking about a section of an arm on a galaxy that we're in. I'm pretty sure there's nothing in between most galaxies.
If you take long enough at it, you get comfortable out there and don't need stars anymore.
I only counted 5 (including Proxima Centauri). What are the six that you see?
Barnards Star, Lalande 21185, then Alpha Centauri, then Proxima Centauri, then Ross 248, then Gliese 445 makes 6.
There are 6 if you count Proxima Centauri and Alpha Centauri separately; 7 if you count both stars in the Alpha Centauri pair separately, and 5 if you count Alpha and Proxima Centauri separately.
Alpha Centauri is the binary system of Alpha Centauri A and Alpha Centauri B, which are separated by about 10-30 AU. It's very, very close in terms of interstellar distances to Proxima Centauri, which is a red dwarf that orbits Alpha Centauri A and B at a distance of 13000 AU, or 0.2 LY - a remote enough orbit that it makes sense to keep track of whether it's on the near side or far side of the triple-star system.
There are 6 if you count Proxima Centauri and Alpha Centauri separately; 7 if you count both stars in the Alpha Centauri pair separately, and 5 if you count Alpha and Proxima Centauri separately.
Alpha Centauri is the binary system of Alpha Centauri A and Alpha Centauri B, which are separated by about 10-30 AU. It's very, very close in terms of interstellar distances to Proxima Centauri, which is a red dwarf that orbits Alpha Centauri A and B at a distance of 13000 AU, or 0.2 LY - a remote enough orbit that it makes sense to keep track of whether it's on the near side or far side of the triple-star system.
For reference, Saturn is about 9-10 AU from the Sun.
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Thanks for that chart, that site is really worth checking out! There is a ton of cool stuff there, like the nearest starts, when we computed their distances, and other thing.
Good catch
"With the small stellar radius, Proxima d ... equilibrium temperature may reach 360K,"
NB: Earth's is 255K. Venus 260K, Mars 215K. So this doesn't tell the whole story, but is probably quite hot.
"With the small stellar radius, Proxima d ... equilibrium temperature may reach 360K,"
NB: Earth's is 255K. Venus 260K, Mars 215K. So this doesn't tell the whole story, but is probably quite hot.
It is certainly tidally locked.
So it has a hot side, a cold side, and an intermediate ring at the terminator.
Probably not very comfortable.
So it has a hot side, a cold side, and an intermediate ring at the terminator.
Probably not very comfortable.
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Why is it certainly tidally locked when Mercury is not?
Mercury orbits in 88 days. This other place orbits in 5 days.
And Mercury is almost tidally locked. Venus will be, before long.
And Mercury is almost tidally locked. Venus will be, before long.
For us kids at the back of the class, how are those two facts related?
Why couldn't something orbit the star fast without being tidally locked?
Why couldn't something orbit the star fast without being tidally locked?
Rotational drag depends on distance between the star and planet.
Planets with fast orbits are closer to the star and get more drag- hence more likely to be locked.
Planets with fast orbits are closer to the star and get more drag- hence more likely to be locked.
Thx
hmm seems like a good candidate for paradise/hell /s
There's also the consideration of the host star to take into account.
I dislike the term "Earth-like" in these publications because it conjures images of a strange alien world able to support (human) life. Even assuming there were life capable of withstanding the constant flares from the host star, I suspect it would have to look very different in color and likely composition to the plant life here due to needing to capture a different part of the spectrum.
I dislike the term "Earth-like" in these publications because it conjures images of a strange alien world able to support (human) life. Even assuming there were life capable of withstanding the constant flares from the host star, I suspect it would have to look very different in color and likely composition to the plant life here due to needing to capture a different part of the spectrum.
My education was in chemistry, I've wondered about this topic before. Visible light is actually special after removing the happenstance of DNA-based visual systems from the picture: IR tends to twist or translate bonds (warming) and UV tends to ionize.
Visible light being right in the middle is the trick which gives us photosynthesis, and sight, because in both cases a photon can be captured by a photosensitive bond. It's harder to come up with plausible photosensitive bonds for IR light, and most anything is photosensitive once you get far enough into UV.
Visible light being right in the middle is the trick which gives us photosynthesis, and sight, because in both cases a photon can be captured by a photosensitive bond. It's harder to come up with plausible photosensitive bonds for IR light, and most anything is photosensitive once you get far enough into UV.
There is a strong selection bias at work: molecules made and operated on by living systems are chosen according to available energy.
A world evolved under lower energies and temperatures would select chemicals with weaker bonds. Other worlds evolved under higher energies and temperatures would select chemicals with stronger bonds.
Visible light is visible to us because it is important for molecules we use.
This is not to say that all points on the energy continuum are equally favorable to potential metabolic processes, but life adapts to conditions, even where they are not optimal. I don't know of any reason to assume the regime where Earth life has landed is optimal, but it has proven more than adequate.
A world evolved under lower energies and temperatures would select chemicals with weaker bonds. Other worlds evolved under higher energies and temperatures would select chemicals with stronger bonds.
Visible light is visible to us because it is important for molecules we use.
This is not to say that all points on the energy continuum are equally favorable to potential metabolic processes, but life adapts to conditions, even where they are not optimal. I don't know of any reason to assume the regime where Earth life has landed is optimal, but it has proven more than adequate.
> IR tends to twist or translate bonds (warming)
Is this unique to IR?
Is this unique to IR?
It's almost definitional of IR in fact, but not quite.
Waves which are relaxed enough to pass through ordinary matter, but interact in interesting ways with metals and other electron clouds, we call radio. Microwaves start out doing this: usefully, they spin water molecules around, hence microwave ovens. What we call microwaves 'bottom out' on not doing so, it's a useful but somewhat artificial category which I would split between radio and IR if you gave me the gavel.
Unlike visible, which is 'visible' because it has distinct properties.
Waves which are relaxed enough to pass through ordinary matter, but interact in interesting ways with metals and other electron clouds, we call radio. Microwaves start out doing this: usefully, they spin water molecules around, hence microwave ovens. What we call microwaves 'bottom out' on not doing so, it's a useful but somewhat artificial category which I would split between radio and IR if you gave me the gavel.
Unlike visible, which is 'visible' because it has distinct properties.
Yes, "Earth-like" caught my attention too because red dwarfs are flare stars. I wanted to check my facts before commenting which led me down the rabbit hole of the history of Proximas flare activity, which is quite interesting.
Fun fact: Go outside on a clear night, and you can see 5-10,000 stars. There are 8 times that many red dwarfs in your field of view, and none of them are visible to the naked eye. But in 2016 Proxima was for a few minutes.
In March 2016 we saw a superflare: Proxima briefly became nearly a factor of 100 brighter, reaching a brightness just visible to the naked eye from dark sites.
Fun fact: Go outside on a clear night, and you can see 5-10,000 stars. There are 8 times that many red dwarfs in your field of view, and none of them are visible to the naked eye. But in 2016 Proxima was for a few minutes.
In March 2016 we saw a superflare: Proxima briefly became nearly a factor of 100 brighter, reaching a brightness just visible to the naked eye from dark sites.
Another point for anyone considering whether we should send a space-probe there...
The current fastest man-man object is the Helios 2 space-probe, reaching something like 25 000 kilometres per hour. Proxima Centauri is 1.3020 parsecs away from Earth.
So, just diving one by the other, we'd looking at something like 18 000 years as a rough order of magnitude for sending something from Earth to Proxima Centauri.
You'd be much better off waiting, well, even a thousand years for technology to improve rather than sending something now.
Note: this is a very dodgy line of reasoning. The Helios probe got a massive speed boost from a close encounter with the sun. But even if the speed is wrong by a factor of ten, we're still looking at somewhere between a thousand and a hundred-thousand years.
The current fastest man-man object is the Helios 2 space-probe, reaching something like 25 000 kilometres per hour. Proxima Centauri is 1.3020 parsecs away from Earth.
So, just diving one by the other, we'd looking at something like 18 000 years as a rough order of magnitude for sending something from Earth to Proxima Centauri.
You'd be much better off waiting, well, even a thousand years for technology to improve rather than sending something now.
Note: this is a very dodgy line of reasoning. The Helios probe got a massive speed boost from a close encounter with the sun. But even if the speed is wrong by a factor of ten, we're still looking at somewhere between a thousand and a hundred-thousand years.
A probe based on nuclear pulse propulsion could do it in around 50 years, with today's technology. It's not that we can't do it fast (within one average human lifespan), it's that the project would be very expensive and something like Nasa has a relatively tight budget.
I mean we, as humanity, have to have an eccentric billionaire start a Martian fire (SpaceX Starship) under our lazy asses to even start to think about getting to Mars in a reasonable timeframe and in reasonable numbers (to start a colony). We are not funding making our species multiplanetary for the last few decades because we were too lazy, how can anyone expect us sending anything to the closest star (other than the sun)... You can't.
I mean we, as humanity, have to have an eccentric billionaire start a Martian fire (SpaceX Starship) under our lazy asses to even start to think about getting to Mars in a reasonable timeframe and in reasonable numbers (to start a colony). We are not funding making our species multiplanetary for the last few decades because we were too lazy, how can anyone expect us sending anything to the closest star (other than the sun)... You can't.
Going to Mars seems pretty useless to me at this time. It’s a super hostile environment and we don’t have the technology yet to have a self sustaining base there. Give it a few decades and progress in robotics will make a Mars base much easier. There is plenty of work to be done on Earth. We have to solve clean energy production and in general reduce pollution. These are massive technological challenges that deserve massive funding.
Going to {the Middle East, Europe / Asia, Australia, the New World, interior South America, the North American West) seems pretty useless to me at this time. It’s a super hostile environment and we don’t have the technology yet to have a self sustaining base there. Give it a few decades and progress in {insert technology} will make a base much easier. There is plenty of work to be done on {current place}. We have to solve {current problems}. These are massive technological challenges that deserve massive funding.
... has been said for the entirety of human history. And in all that time, they've only ever been right about Australia. (J/k Aussies!)
Only one technology matters: that which enables transportation.
Animal husbandry. Sailing. Railroads.
In the end, humans are plentiful. As long as it's done in full disclosure and as an uncoerced individual choice, who the hell are we to stand in the way of adventurers taking a chance on a better life?
... has been said for the entirety of human history. And in all that time, they've only ever been right about Australia. (J/k Aussies!)
Only one technology matters: that which enables transportation.
Animal husbandry. Sailing. Railroads.
In the end, humans are plentiful. As long as it's done in full disclosure and as an uncoerced individual choice, who the hell are we to stand in the way of adventurers taking a chance on a better life?
This is absolutely, objectively, incorrect.
You might as well argue that you can build a self-sustaining base on Antarctica.
Of course you can't, because Antarctica can't support life. No amount of shouting into a bullhorn about adventure will change that.
It might be possible with an absolutely epic effort to airlift soil, nuclear reactors, nuclear and other fuels, machinery for every eventually (including chip fabs), raw materials that aren't locally available (which means almost all of them), and habitable structures.
At the end of that epic effort you'll have something that will barely have a toe-hold on long-term survivability. Possibly. If you're lucky.
Not only is Mars far colder, it also doesn't have air. Or surface water. So all the challenges are at least an order of magnitude harder.
And it's much much further away.
Rhetoric and wishful thinking are not going to give you a better life if you can't deal with the reality of the challenges.
You might as well argue that you can build a self-sustaining base on Antarctica.
Of course you can't, because Antarctica can't support life. No amount of shouting into a bullhorn about adventure will change that.
It might be possible with an absolutely epic effort to airlift soil, nuclear reactors, nuclear and other fuels, machinery for every eventually (including chip fabs), raw materials that aren't locally available (which means almost all of them), and habitable structures.
At the end of that epic effort you'll have something that will barely have a toe-hold on long-term survivability. Possibly. If you're lucky.
Not only is Mars far colder, it also doesn't have air. Or surface water. So all the challenges are at least an order of magnitude harder.
And it's much much further away.
Rhetoric and wishful thinking are not going to give you a better life if you can't deal with the reality of the challenges.
At the end of the day, profit determines reality. And that's where futurists have always screwed up, because profit funds solutions.
Nobody has colonized Antarctica not because it's impossible, but because it's difficult enough and useless enough that we all agreed on a treaty prohibiting it.
In contrast, we constructed the 63 radars (some with bases) of the DEW line in the late 1950s in under 3 years, with part of the Air Force's budget. Because it was useful.
Establishing a Mars colony is not impossible, it's just extremely hard. Which means expensive. Which means it needs a justification. Which is what I think the knee-jerk is really about.
And is a fair opinion. You may think interplanetary colonization should not be a priority. I think it should.
Nobody has colonized Antarctica not because it's impossible, but because it's difficult enough and useless enough that we all agreed on a treaty prohibiting it.
In contrast, we constructed the 63 radars (some with bases) of the DEW line in the late 1950s in under 3 years, with part of the Air Force's budget. Because it was useful.
Establishing a Mars colony is not impossible, it's just extremely hard. Which means expensive. Which means it needs a justification. Which is what I think the knee-jerk is really about.
And is a fair opinion. You may think interplanetary colonization should not be a priority. I think it should.
Seems to me we are nowhere near the level of maturity needed to even suggest colonization.
Our basic priorities are not in order and that is true for a lot of the world.
Tons of people need solutions now to problems we can solve, and we do not solve them because those priorities are not in order.
And with that, there goes that justification.
Higher priority items include:
Not shitting where we eat,
A much reduced focus on killing one another.
There are many others.
I agree with the other commenter.
It may be very frustrating and disappointing to get married to those ideas. No one reading here is going to see them.
Our basic priorities are not in order and that is true for a lot of the world.
Tons of people need solutions now to problems we can solve, and we do not solve them because those priorities are not in order.
And with that, there goes that justification.
Higher priority items include:
Not shitting where we eat,
A much reduced focus on killing one another.
There are many others.
I agree with the other commenter.
It may be very frustrating and disappointing to get married to those ideas. No one reading here is going to see them.
Fantasies. None of us will be known or remembered. We will never colonize the universe in these bodies.
> soil
Both aquaponics and aeroponics provide ways to grow plants without soil. Breeding insects or algae may provide nutrition with very small amounts of mass needing to be transported.
> nuclear reactors
Yes, these are a necessity but we've sent one to Antarctica before and we could send a more modern one to Mars.
> nuclear and other fuels
The good thing about nuclear fuel is that you need a very small amount of it to produce a lot of energy for a long time.
> machinery for every eventuality (including chip fabs)
Colonists by necessity must make do with less and that does mean a lower standard of living and higher mortality but you know what they do it anyways because some things are worth trading comfort and a decade or two of life for. English colonists didn't bring the entire industrial infrastructure with them to the New World. They brought what would fit on the boats and had to make do with what they could create from local resources or do without. They had the benefit of subsequent voyages but I don't think anyone here is imagining colonizing Mars or Antarctica with a single expedition.
> raw materials
Mars (and Antarctica for the most part) do lack anything biological in origin, no oil or wood or crops as feedstock for chemical reactions but there are always alternatives. We usually don't use those alternate sources here because they are too labour or energetically or materially expensive but when they are your only option price and effort become less of a concern.
> all the challenges are at least an order of magnitude harder
No one who is attempting to work towards this is doing it because it is easy. I remember there being a speech about that which ended up with some pretty spectacular results.
Both aquaponics and aeroponics provide ways to grow plants without soil. Breeding insects or algae may provide nutrition with very small amounts of mass needing to be transported.
> nuclear reactors
Yes, these are a necessity but we've sent one to Antarctica before and we could send a more modern one to Mars.
> nuclear and other fuels
The good thing about nuclear fuel is that you need a very small amount of it to produce a lot of energy for a long time.
> machinery for every eventuality (including chip fabs)
Colonists by necessity must make do with less and that does mean a lower standard of living and higher mortality but you know what they do it anyways because some things are worth trading comfort and a decade or two of life for. English colonists didn't bring the entire industrial infrastructure with them to the New World. They brought what would fit on the boats and had to make do with what they could create from local resources or do without. They had the benefit of subsequent voyages but I don't think anyone here is imagining colonizing Mars or Antarctica with a single expedition.
> raw materials
Mars (and Antarctica for the most part) do lack anything biological in origin, no oil or wood or crops as feedstock for chemical reactions but there are always alternatives. We usually don't use those alternate sources here because they are too labour or energetically or materially expensive but when they are your only option price and effort become less of a concern.
> all the challenges are at least an order of magnitude harder
No one who is attempting to work towards this is doing it because it is easy. I remember there being a speech about that which ended up with some pretty spectacular results.
> Mars (and Antarctica for the most part) do lack anything biological in origin, no oil or wood or crops as feedstock for chemical reactions but there are always alternatives.
Ignoring energy sources (solvable using by a fission reactor), the entire Earth has a similar feedstock problem as Antarctica. There's plenty of hydrogen and oxygen there. CO2 can be mined from the atmosphere by plants. Nitrogen is the remaining building block of life. At this point, most of the nitrogen in human tissue was extracted from the atmosphere using the Haber-Bosch method (which, roughly speaking, converts atmospheric Nitrogen and energy to fertilizer).
I agree that Antarctica would be an easier (and safer) place to build the first self-sustained "moon base"
Ignoring energy sources (solvable using by a fission reactor), the entire Earth has a similar feedstock problem as Antarctica. There's plenty of hydrogen and oxygen there. CO2 can be mined from the atmosphere by plants. Nitrogen is the remaining building block of life. At this point, most of the nitrogen in human tissue was extracted from the atmosphere using the Haber-Bosch method (which, roughly speaking, converts atmospheric Nitrogen and energy to fertilizer).
I agree that Antarctica would be an easier (and safer) place to build the first self-sustained "moon base"
"We go to the moon not because it is easy, but because if we don't then some commie bastards will get there first."
I am all for exploration and science for the sake of science, but any talk of colonies is just wasted breath at this stage. We need to first explore how to live within our means on earth.
I am all for exploration and science for the sake of science, but any talk of colonies is just wasted breath at this stage. We need to first explore how to live within our means on earth.
I'm of the opposite opinion. I think we need to spread out as soon as possible because it's not clear we can ever completely future proof our civilization here. There are simply too many things that can go wrong, many of which are not within our control. Take the pandemic for example, if it had been 10x worse it could have collapsed our current global civilization. There's no way of preventing it from spreading to every corner of the Earth without also destroying civilization as we know it. Same goes for asteroid impacts, super volcanos (consider Tonga a warning), tsunamis, solar flares, CMEs. Then there are the man-made disasters that we may or may not be able to keep under control such as war, terrorism, religious fanaticism, industrial accidents, pollution or even just apathy and hedonism.
I'm not saying we should ignore all the other things in favour of escaping to space. The Earth is the largest volume of habitable space that we have right now but it is also the only one and that's the problem. We should be building other habitats in parallel with solving our current problems. We need a literal backup plan in case things go seriously wrong.
I'm not saying we should ignore all the other things in favour of escaping to space. The Earth is the largest volume of habitable space that we have right now but it is also the only one and that's the problem. We should be building other habitats in parallel with solving our current problems. We need a literal backup plan in case things go seriously wrong.
Big picture, I think all this pushing to make everything perfect for every person on the entire planet Earth before expanding to space is a TERRIBLE strategy
Imagine a StarCraft/Factorio player who hides out in his starting base, building it up more and more and more forever, while talking about "living within his means".
There are effectively unlimited resources right there for the taking! Let's go take them!
Imagine a StarCraft/Factorio player who hides out in his starting base, building it up more and more and more forever, while talking about "living within his means".
There are effectively unlimited resources right there for the taking! Let's go take them!
Bit of a straw man - nobody said anything about pushing for perfection at home, just "we can do better than this".
Also - "right there for the taking" gets to the heart of my objection as it is nowhere near true. Space is vast and delta-v is expensive - even if we get past the problem of deadly radiation outside the ionosphere, we are incredibly far from being able to make space travel anything other than an enormous sink for money and resources.
Also - "right there for the taking" gets to the heart of my objection as it is nowhere near true. Space is vast and delta-v is expensive - even if we get past the problem of deadly radiation outside the ionosphere, we are incredibly far from being able to make space travel anything other than an enormous sink for money and resources.
Maybe I'm optimistic, but these are just problems to be solved. Space exploration is a big risk / big reward investment. Yes it would require a comparatively huge investment to mine an asteroid vs. open a pit mine in Brazil but "mining" an asteroid likely means carving off hunks of solid metal for transit back to the Earth's surface rather than processing megatons of rock by blasting, trucking, and smelting. Like many things about space, it boggles the mind that a single asteroid mining mission could produce more platinum group metals than have ever been mined on Earth throughout human history. How does the total amount of money and resources spent on mining those metals on Earth stack up against the cost of a single successful asteroid mining operation?
I think this argument extends to colonization efforts as well. What is the economic and cultural benefit of founding a new nation? It's not something that we are familiar with at this point in history so we are relatively blind to it. We just take it for granted that the nations in which we live have always been there since they have always been there for us. I have no doubt that once we begin colonizing Mars or the Moon or even just Earth orbit it will have as great of an impact as the colonization of the New World.
I think this argument extends to colonization efforts as well. What is the economic and cultural benefit of founding a new nation? It's not something that we are familiar with at this point in history so we are relatively blind to it. We just take it for granted that the nations in which we live have always been there since they have always been there for us. I have no doubt that once we begin colonizing Mars or the Moon or even just Earth orbit it will have as great of an impact as the colonization of the New World.
If we really wanted to, i don't see why we couldn't establish a self-sustaining base in Antarctica. Of course, it's forbidden.
Then create one in the Sahara or the Atacana desert at 5000m elevation. Still way easier than Mars.
They are certainly easier, but how useful are they? A base on Mars will bring down the fuel requirements to exploring and exploiting the belt and outer planets tremendously. Missions that are impossible or uneconomical to do from Earth could be made possible and cheap if launched from Mars.
Anything that seems easier from Mars is overwhelmingly easier without stopping at Mars first. Even Phobos would be a better choice.
The only thing Mars has going for it is hype.
The only thing Mars has going for it is hype.
Mars offers quite a few things that make it more inviting for a manned base:
- 38% of Earth's gravity
- 24.5 hour days
- lots of resources such as iron, carbon, oxygen, water (ice)
- aerobraking in the atmosphere saves fuel
- it's big (same land mass as Earth's). There's enough room for growth.
- temperatures are better than elsewhere in space (-63°C to +20°C at the equator)
- Lava tubes that could offer protection against radiation and meteorites for habitats
- good potential of life / former life
- 38% of Earth's gravity
- 24.5 hour days
- lots of resources such as iron, carbon, oxygen, water (ice)
- aerobraking in the atmosphere saves fuel
- it's big (same land mass as Earth's). There's enough room for growth.
- temperatures are better than elsewhere in space (-63°C to +20°C at the equator)
- Lava tubes that could offer protection against radiation and meteorites for habitats
- good potential of life / former life
You need some way to make fuel and propellant, though. Phobos would be a great choice for a launchpad, but in such a scenario you would do ISRU on Mars and lift fuel and propellant there - which will be much more efficient than on Earth, since there's less gravity and less atmosphere.
Any fuel you could generate on Mars would be overwhelmingly easier and cheaper to ship in from Earth; and you wouldn't need to land a million tons of freight on Mars first. A million tons of fuel delivered to LEO would take you quite a long way, and you could start immediately.
If you want to go somewhere beyond Mars, stopping there and then starting again just sets you back. (Same goes for the moon, or lunar orbit.) "Stepping stones" have strongly negative value in space transport.
If you want to go somewhere beyond Mars, stopping there and then starting again just sets you back. (Same goes for the moon, or lunar orbit.) "Stepping stones" have strongly negative value in space transport.
A million tons of fuel doesn't cut the delta v requirements down. You'd have to ship the required fuel to Mars orbit (or wherever you plan on doing refuelling) still.
> Any fuel you could generate on Mars would be overwhelmingly easier and cheaper to ship in from Earth
Source?
Source?
Also exploring Mars itself and establishing a base there (anywhere off Earth really).
If you are concerned about a launchpad for other missions the moon is much better. Lower gravity, easy to reach.
How would you produce fuel and propellant on the Moon? SpaceX plans on producing methane and lox from water and CO2 on Mars.
You could produce oxygen and hydrogen from the water ice and the carbon dioxide cold traps on the Moon.
There may also be more carbon below the surface, see https://phys.org/news/2020-05-carbon-emissions-moon-theory-b...
There may also be more carbon below the surface, see https://phys.org/news/2020-05-carbon-emissions-moon-theory-b...
Linear Reasoning
Mars is multiple orders of magnitude more difficult to survive on than the Middle East. Its not really comparable at all.
I like to think we've improved our technology a few orders of magnitude in the last 1.8 million years.
And so you think you can just mush those two claims together and come to the conclusion that sustaining life on mars must be achievable?
Not must be. Is probably achievable, and is worth attempting, even at the cost of lives.
You can argue from either the perspective of futility of attempt (no chance of success) or futility of outcome (success wouldn't be worth it), but I'm pretty convinced both would be weak arguments, both logically and historically.
You can argue from either the perspective of futility of attempt (no chance of success) or futility of outcome (success wouldn't be worth it), but I'm pretty convinced both would be weak arguments, both logically and historically.
I'm probably an optimist on Mars travel. I think, with a fuck ton of starships, you could get people living on Mars. But there's some big asterisks on that. You'd more or less have to live in the starships, dependent on shipments from earth, with self sufficiency failing on pretty much every category. Over a very long period, most people would probably die a bit earlier from radiation and dust. Not much would be produced of value. It would cost hundreds of billions of dollars, at least. And interest in it would rapidly decline.
The suspicion I have about self sufficiency pessimism is that it's an apples to oranges comparison. Are there any modern analogies? As near as I can tell, it hasn't been required after the 16th century, due to access to relatively timely transportation.
And if it hasn't been required, then how are we to look at existing practice and say we're bad at or incapable of it?
And if it hasn't been required, then how are we to look at existing practice and say we're bad at or incapable of it?
Comparison to what? We don't need an analogy. This is a novel environment and it can be evaluated on its own.
Self sufficiency failing on Mars vs what kind of self sufficiency we can manage now (while living on Earth and no needing to prioritize it)
Sounds like the early days of Australia. Maybe build a new Botany Bay? (Only half joking.)
There is no survival advantage to us on Mars. What are we all arguing about? This site is staring to feel a bit unhinged when it comes colonizing the solar system. Like SGC Ori unhinged.
Nobody ever believed that America is a super-hostile environment.
Roanoke, Ajacan, Fort Caroline, Sable Island, Charlesfort, Pensacola, San Miguel de Gualdape, Charlesbourg-Royal, France-Roy, Pensacola?
False equivalence, of course.
The fact that random groups people from the Old World decided to start colonies without any prior experience or preparation precisely shows that they didn't consider America to be "super-hostile".
The fact that random groups people from the Old World decided to start colonies without any prior experience or preparation precisely shows that they didn't consider America to be "super-hostile".
> Only one technology matters: that which enables transportation.
Is this tongue-in-cheek? I genuinely hope so.
Is this tongue-in-cheek? I genuinely hope so.
It sounds like a very chicken or egg problem to me, who's to say that progress in robotics doesn't come from trying to establish a base on Mars? Progress is often times non-linear, I mean here we using computers and communication technology based on Integrated Circuits technology furthered by the Apollo program; say we never went to the moon, computing technology and Moore's law might have been set back a decade or two.
I am not against Mars but I just think it’s premature. Build up robotics for a while and Mars will be much easier. There is no rush to become a multi planetary species. There is no credible threat of a big asteroid or volcano in the next decades. All threats we may be facing are self made.
My favorite moonshot project would be to create robotics that can clean up the environment and handle recycling. Having the technology to pick up dog poop and plastic bags in an efficient and affordable manner or separating recycling items would be a huge technological challenge that would create a ton of spin-off opportunities including a base on Mars. Or clean up the pacific garbage patch with robots.
My favorite moonshot project would be to create robotics that can clean up the environment and handle recycling. Having the technology to pick up dog poop and plastic bags in an efficient and affordable manner or separating recycling items would be a huge technological challenge that would create a ton of spin-off opportunities including a base on Mars. Or clean up the pacific garbage patch with robots.
I think all of this is premature. Focusing on life extension technology and life science would see a lot of other technological benefit, and in the worst case just mean we can wait it out.
Mars can already be useful as a springboard for space exploration. It's a literal stepping stone, both closer to the belt and outer planets in terms of distance, but also in terms of delta-v, since both the gravity well on Mars is smaller, and it's higher up in the Sun's gravity well, too. Any future space exploration and exploitation will be made tremendously easier if you can launch from Mars instead of Earth.
Mars is, even at absolute best, a dump: dry, cold, airless, at the bottom of a gravity well, and subject to dust storms besides.
We can build much better outside of gravity wells. Whatever you would land on Mars is more useful in solar orbit, parked next to any convenient asteroid.
We can build much better outside of gravity wells. Whatever you would land on Mars is more useful in solar orbit, parked next to any convenient asteroid.
Admittedly my knowledge on this matter derives from KSP, but I've found that rendezvous is much trickier outside of gravity wells.
And there's still the problem of ISRU.
And there's still the problem of ISRU.
We have ISRU right here, right now.
You can't do ISRU in orbit. I don't know of any resources available on the Moon that would allow you to do ISRU there either. Ceres might work, but the inclined orbit may make that impractical as a stop.
We do ISRU all day, every day right here, in the millions of tons.
"A stop" is not just useless, but is actively harmful in space transportation. You go, for free, until you get there, and then use up fuel stopping. Starting and stopping are exactly what costs. Stopping halfway makes the whole trip cost literally twice as much.
"A stop" is not just useless, but is actively harmful in space transportation. You go, for free, until you get there, and then use up fuel stopping. Starting and stopping are exactly what costs. Stopping halfway makes the whole trip cost literally twice as much.
It's also 'for free' to continue from LEO to anywhere else, but it can still make sense to refuel in LEO rather than launch with all the fuel requirements you need for the mission from Earth surface. The delta v required from LEO to another body is lower than that from Earth surface there. Delta v required from lunar orbit to some non-terrestrial body is also lower than that from LEO, and it could potentially make sense to do refuelling from there in order to get the maximum possible delta v leaving Earth's gravity well. Finally, the delta v required to reach the belt and Jupiter from low Mars orbit is lower than that to reach them from Earth. That means bigger payloads can be sent to these destinations, or even potentially any payload at all; it is only barely possible to reach a Hohmann transfer to Jupiter from Earth with SpaceX's Starship's claimed delta-v, whereas from Mars there should be several km/s of extra delta-v to spare.
Refueling in LEO or high earth orbit is fundamentally different, in every single particular, from stopping somewhere halfway.
Until you understand this, everything you say about space travel will make zero sense, and furthermore will deeply embarrass you for long after you finally catch on. You make a fool of yourself by continuing in this vein.
Until you understand this, everything you say about space travel will make zero sense, and furthermore will deeply embarrass you for long after you finally catch on. You make a fool of yourself by continuing in this vein.
You can do the calculations yourselves. Refueling in LEO is energetically more costly than a launch from the Earth surface to escape. You will end up using more fuel overall if you launch into LEO vs. if you take all the fuel you need from the Earth's surface in a single launch. If there is a difference, you haven't explained it.
agree, extreme temp variations and a toxic atmosphere would make living there very difficult(not to mention the journey!). Much better to try a moon station first as its a few days travel and then compare what went right/wrong and then think about replicating that for mars. Having water on mars does help its case though..
Not to mention that you would need to figure out how to keep the humans from having a mental breakdown. Myself, I would probably be clawing at the windows for a look at a non-existent tree in about two days.
Do you expect traveling multiple light years to an alien world to be easier or less hostile? You have to start somewhere, and the selection is pretty thin.
Traveling multiple light years is out of the question. You can think about some concepts but it’s simple not doable at this point no matter the budget.
Tbf, it'll also take us a few decades to get human Mars transit figured out so sounds like we're on schedule.
Totally agree!
However, it's likely that one task (going to Mars, even sending a couple rich bozos there) is small enough that you can probably do that and work on fixing things "at home".
In fact, one could argue that one set of big companies that exist this decade that didn't exist last decade is just a shopping list of "Crap I'll need for my martian condo"
However, it's likely that one task (going to Mars, even sending a couple rich bozos there) is small enough that you can probably do that and work on fixing things "at home".
In fact, one could argue that one set of big companies that exist this decade that didn't exist last decade is just a shopping list of "Crap I'll need for my martian condo"
Because it's there
https://blog.theclymb.com/out-there/because-its-there-the-qu...
https://blog.theclymb.com/out-there/because-its-there-the-qu...
Did you know NASA only get 0.36% of the US Federal budget? Everything else gets "massive funding".
Makes sense though because earth is a dump and extremely corrupt. Even if you were able to substantially decrease military funding (the usual scapegoat) without massively changing the world order we still probably wouldn’t spend more on nasa, we would spend it on healthcare, infrastructure, economic bailouts, education, green tech, etc.
If you think going to Mars is useless, don't go.
Just don't stand in the way of those who chose to go.
Just don't stand in the way of those who chose to go.
By all means, go. But pay for it yourself. If you can't personally afford Mars, the middle of the Sahara Desert is unoccupied and overwhelmingly easier and cheaper to get established in. Or, under the ice in Greenland. Or, revitalize an abandoned whaling station on an island off Antarctica. If those seem uninviting, I promise Mars will be a thousand times moreso.
Your "golly I'm on Mars!" euphoria would thin out very, very fast. "This place f'n sucks!" malaise would grow steadily and without bound.
Your "golly I'm on Mars!" euphoria would thin out very, very fast. "This place f'n sucks!" malaise would grow steadily and without bound.
I'm definitely not going. But I'm very glad others will go!
Maybe that's a confusing distinction for some.
Maybe that's a confusing distinction for some.
I would not mind if they went somewhere. If they went to Mars they would immediately stop talking about what a great idea it was, even if they still had air. They would shortly thereafter try to get somebody to bring them back home.
So we have this thing called a government that we give money too. Different people want it to do different things. You can recognize that while you may pay for things you dont want, other people are paying for the things that you want but they dont.
Maybe an unpopular opinion, but Musk is just plain wrong when he thinks there is any urgency to Mars exploration (or it's just vicarious arguments because rockets are cool).
Basically, the tech you need to make a Mars colony truly self sufficient is something like a compact fusion powerplant.
Before we have that, no point in worrying about using Mars as a "backup plan", because if Earth was screwed, Mars would have a couple of years to live at most.
And obviously it would be vastly better for humanity if Musk spent money on zero-emission large scale energy production, than on rockets.
Basically, the tech you need to make a Mars colony truly self sufficient is something like a compact fusion powerplant.
Before we have that, no point in worrying about using Mars as a "backup plan", because if Earth was screwed, Mars would have a couple of years to live at most.
And obviously it would be vastly better for humanity if Musk spent money on zero-emission large scale energy production, than on rockets.
This is hopeful negativism.
- They don't need fusion. A StarShip can deposit hundreds of solar panels and put them on the ground. No, dust isn't an issue because they'll bring a roomba. No, this isn't a joke, NASA martian probes' solar panels were cleaned by a light Martian breeze.
- They will be able to become self-sufficient rapidly. They're not going to send 1M tons of cargo to Mars without a deployment plan. SpaceX and Tesla have already demonstrated effective vertically integrated supply chains and manufacturing. They have the institutional knowledge to mine raw materials and build factories that build complex parts.
- There are plenty of other Earth-bound governments and billionaires that could devote funds to zero-emission large scale energy production projects. Musk, his companies and assets amount to a very small fraction of the global economy. Your ire is misdirected: your anger about the situation is properly directed at the rule of corrupt imbeciles and their questionable resource allocation decisions (Netflix, coal, etc.) here on Earth rather than one team of folks who seem extraordinarily mission driven and effective.
- They don't need fusion. A StarShip can deposit hundreds of solar panels and put them on the ground. No, dust isn't an issue because they'll bring a roomba. No, this isn't a joke, NASA martian probes' solar panels were cleaned by a light Martian breeze.
- They will be able to become self-sufficient rapidly. They're not going to send 1M tons of cargo to Mars without a deployment plan. SpaceX and Tesla have already demonstrated effective vertically integrated supply chains and manufacturing. They have the institutional knowledge to mine raw materials and build factories that build complex parts.
- There are plenty of other Earth-bound governments and billionaires that could devote funds to zero-emission large scale energy production projects. Musk, his companies and assets amount to a very small fraction of the global economy. Your ire is misdirected: your anger about the situation is properly directed at the rule of corrupt imbeciles and their questionable resource allocation decisions (Netflix, coal, etc.) here on Earth rather than one team of folks who seem extraordinarily mission driven and effective.
Mars has dust storms which last months or years, it has no ionosphere, and that dust contains enough perchlorates to poison anything we could eat, including us. Ok, that sentence went somewhere odd at the end but, it's true.
A large asteroid has only one of these problems, by virtue of not coming with any atmosphere, ionic or otherwise.
I kinda hope Elon is bluffing and actually plans to head to the Belt. I've penciled it out and and he'd have to be insane not to. Surely he has pencils as well.
A large asteroid has only one of these problems, by virtue of not coming with any atmosphere, ionic or otherwise.
I kinda hope Elon is bluffing and actually plans to head to the Belt. I've penciled it out and and he'd have to be insane not to. Surely he has pencils as well.
The Martian dust storms are pretty tame. Nothing like portrayed in the movies. The atmosphere is 1% of what it is here on earth.
So while it is a “storm” it isn’t like a tropical force hurricane or anything. More like a very minor annoyance that deposits a bit more Martian dust on your stuff over time.
So while it is a “storm” it isn’t like a tropical force hurricane or anything. More like a very minor annoyance that deposits a bit more Martian dust on your stuff over time.
Isn't long term zero-g pretty hostile to our biology?
Mars is 0.3 G, which is just as hostile for long-term habitation. No human child conceived, born, and raised in that environment would have the ability to stand on Earth without an Aliens-style rigid exosuit. Their heart might not even be capable of pumping blood to their head.
Nobody knows what 0.3 g does to the body because we've spent 20 years on the ISS doing zero-g "science" even after the most important question was answered:
Q: What does zero-g do to the human body?
A: It's really really unhealthy.
Q: What does zero-g do to the human body?
A: It's really really unhealthy.
Hollow out the asteroid and spin it.
This wouldn’t work, asteroids are like gravel there isn’t really anything to hollow out and even if you did when you spun it the asteroid would just shoot these rocks out in all directions.
What's the story on navigating in the belt? Approach specific target from above or reasonably safe to traverse it and explore?
>They're not going to send 1M tons of cargo to Mars without a deployment plan.
Can this happen? I imagine before we can settle on Mars we first should be comfortable flying there, and the latter should be sufficient for asteroid mining. But, right, our technology is just not at a comfortable level yet.
Can this happen? I imagine before we can settle on Mars we first should be comfortable flying there, and the latter should be sufficient for asteroid mining. But, right, our technology is just not at a comfortable level yet.
Comfortable comes much later than possible. When it's possible to go, that's the time to go. The early Atlantic crossings weren't comfortable, just possible.
Unlike Atlantic, Mars isn't habitable, you can't settle there with merely possible crossing. Maybe first establish a colony at 1km depth in the ocean; we are relatively comfortable going there, but what it takes to run a colony there and would it be possible with only possible crossing?
The Mars backup plan seems kinda dumb to me because Mars is worse as is than all but the very worst post-apocalyptic Earth scenarios.
Just build bunkers here and staff them in shifts. Much cheaper.
Your remaining threats for which Mars would be better than "ruined" Earth are something like a grey goo event, or an asteroid so large that it liquefies much of the crust (killing everyone in all your bunkers). So, a fair bit bigger than the one that killed the Dinosaurs.
I am very interested in watching people try to colonize Mars, but find the "backup for Earth" argument ridiculous, especially if presented as something urgent.
Just build bunkers here and staff them in shifts. Much cheaper.
Your remaining threats for which Mars would be better than "ruined" Earth are something like a grey goo event, or an asteroid so large that it liquefies much of the crust (killing everyone in all your bunkers). So, a fair bit bigger than the one that killed the Dinosaurs.
I am very interested in watching people try to colonize Mars, but find the "backup for Earth" argument ridiculous, especially if presented as something urgent.
>And obviously it would be vastly better for humanity if Musk spent money on zero-emission large scale energy production, than on rockets.
Classic zero sum thinking. Spacex doesn't cost money, it makes it. How much money do you think Musk put into it? The answer is ~100 million seed. It is now worth 35,000 million.
How far do you think that 100m would go to develop fusion. The ITER project alone costs 65,000 million.
Classic zero sum thinking. Spacex doesn't cost money, it makes it. How much money do you think Musk put into it? The answer is ~100 million seed. It is now worth 35,000 million.
How far do you think that 100m would go to develop fusion. The ITER project alone costs 65,000 million.
While US gov't put in $billions. But who kept ownership? Mars hype turns out to be good for drawing money out of governments.
ITER is a dead end, no matter what, so not a useful data point.
ITER is a dead end, no matter what, so not a useful data point.
>While US gov't put in $billions.
There is a difference between buying something and putting in money. If I buy a cheeseburger, I can't say I "put in" $5 to McDonalds and should have some ownership. If I pay my contract plumber to fix my toilet, I don't own their business either.
I think you will be hard-pressed to find any substantial examples where the US gov wasn't buying something from SpaceX.
There is a difference between buying something and putting in money. If I buy a cheeseburger, I can't say I "put in" $5 to McDonalds and should have some ownership. If I pay my contract plumber to fix my toilet, I don't own their business either.
I think you will be hard-pressed to find any substantial examples where the US gov wasn't buying something from SpaceX.
McDonald's won't go bankrupt if you elect not to get the large fries. SpaceX would have gone bankrupt several times if NASA hadn't kicked in at a crucial moment.
So they deserve equity for being a critical customer? I still don't follow the logic.
You won't.
> Musk is just plain wrong when he thinks there is any urgency to Mars exploration (or it's just vicarious arguments
because rockets are cool).
Mars might not be sustainable in our lifetime but in a century or two? I think it's within the realm of possibility.
As for the urgency, the last two years has demonstrated the exact opposite to me. Modern civilization is a hop, skip, and a jump away from instability and disaster. When you say that we should instead spend resources on large zero-emissions energy production, well, we've had Nuclear Fission for half a century. The reason we didn't use it to prevent Climate Change is 90% political, not technical, another problem that having a self-sustaining colony, outside the sphere of Earth's influence, would solve.
Mars might not be sustainable in our lifetime but in a century or two? I think it's within the realm of possibility.
As for the urgency, the last two years has demonstrated the exact opposite to me. Modern civilization is a hop, skip, and a jump away from instability and disaster. When you say that we should instead spend resources on large zero-emissions energy production, well, we've had Nuclear Fission for half a century. The reason we didn't use it to prevent Climate Change is 90% political, not technical, another problem that having a self-sustaining colony, outside the sphere of Earth's influence, would solve.
Even if we completely screw up liveability on earth, it's probably still going to be way more hospitable then most planets we can reach.
In addition to the fact that there's almost nothing you could do to Earth that would make it less liveable than Mars, any political problem that plagues the Earth is going to plague Mars just as easily. Earth didn't create human political problems, humans did. The only way to keep political problems from plaguing Mars would be to keep humans off of it.
> The reason we didn't use [Nuclear Fission] to prevent Climate Change is 90% political, not technical
Eh. The physics and proliferation risk are pretty intertwined.
Who's to say we would have been better off with greater historical nuclear weapon proliferation risk but lower climate risk?
We know the path we chose, limited global use of fission power, mostly avoided nuclear weapons proliferation, and did avoid nuclear exchanges. So it's provably a successful (or probably successful) path. Whether an alternative would have gotten the same outcome?
Eh. The physics and proliferation risk are pretty intertwined.
Who's to say we would have been better off with greater historical nuclear weapon proliferation risk but lower climate risk?
We know the path we chose, limited global use of fission power, mostly avoided nuclear weapons proliferation, and did avoid nuclear exchanges. So it's provably a successful (or probably successful) path. Whether an alternative would have gotten the same outcome?
>We know the path we chose, limited global use of fission power, mostly avoided nuclear weapons proliferation, and did avoid nuclear exchanges. So it's provably a successful (or probably successful) path.
Only if you value the lack of nuclear exchanges over the impacts of climate change. Which one of the two is more likely to cause a mass extinction type issue on the planet, one puts the control in the hands of people and the other the forces of nature.
Only if you value the lack of nuclear exchanges over the impacts of climate change. Which one of the two is more likely to cause a mass extinction type issue on the planet, one puts the control in the hands of people and the other the forces of nature.
I'd say I do. Climate change is colossal in problem magnitude, but temporally slow and distributed in impact. Nuclear weapons are terrifying fast and centralized in impact.
Unfortunately, our civilization is also mostly centralized. Cities, ports, highly productive land : total land area.
If you're talking persistent radioactive effects for a decade+, it doesn't take many to severely cripple the world.
As an example, a 100kt weapon (or smaller dirty) could knock a port out of action. Now look at a list of ports [0] and imagine what would happen if one or more of them dropped off the global trade grid for multiple years.
[0] https://en.m.wikipedia.org/wiki/List_of_busiest_container_po...
Unfortunately, our civilization is also mostly centralized. Cities, ports, highly productive land : total land area.
If you're talking persistent radioactive effects for a decade+, it doesn't take many to severely cripple the world.
As an example, a 100kt weapon (or smaller dirty) could knock a port out of action. Now look at a list of ports [0] and imagine what would happen if one or more of them dropped off the global trade grid for multiple years.
[0] https://en.m.wikipedia.org/wiki/List_of_busiest_container_po...
How would the increase in the number of nuclear power plants lead to more nuclear weapons? There is no direct connection besides edge cases like Iran using it as a cover to develop nuclear weapons.
Someone please correct me if I'm speaking inaccurately, but early reactor design (1950s/60s/70s) focused on light water reactors, which meant enriched U-235 fuel (@ ~3%?). By design, these reactors also convert a portion of their U-238 to P-239, only some of which is then consumed in the reactor.
Consequently, for widespread nuclear reactors (read: in many countries), you also had widespread proliferation of lightly enriched uranium (in the fuel) and proliferation of plutonium (produced in the fuel as the reactor runs).
Both of these remove the most time and energy consuming step (low level enrichment) as an obstacle to state nuclear weapons development.
And they're fundamental to the way light water reactor technology works, especially with the limitations of the period. So the only way you could have had proliferation-resistance would have been to have some sort of global fuel-control and -custody agreement (presumably run by the United States, USSR, and maybe France, depending on the time period). Which sovereign countries would have likely felt some kind of way about.
Consequently, for widespread nuclear reactors (read: in many countries), you also had widespread proliferation of lightly enriched uranium (in the fuel) and proliferation of plutonium (produced in the fuel as the reactor runs).
Both of these remove the most time and energy consuming step (low level enrichment) as an obstacle to state nuclear weapons development.
And they're fundamental to the way light water reactor technology works, especially with the limitations of the period. So the only way you could have had proliferation-resistance would have been to have some sort of global fuel-control and -custody agreement (presumably run by the United States, USSR, and maybe France, depending on the time period). Which sovereign countries would have likely felt some kind of way about.
The number of new nuclear reactors only stopped growing in the 80's. In any case I don't think access to material is the limiting factor in nuclear proliferation. If we're talking about the US and USSR, it's completely irrelevant, even if they had 100x more reactors since they already have more than enough bombs to more or less to blow up the entire world. Other western countries either have enough nukes already or don't need or want them and I don't see why would they export technology or material to countries which are hostile to them.
It's not obvious to me that having more nuclear reactors in the US, Britain or Germany would had made it significantly easier for rogue states like Iraq, Iran or North Korea to developed nuclear weapons.
It's not obvious to me that having more nuclear reactors in the US, Britain or Germany would had made it significantly easier for rogue states like Iraq, Iran or North Korea to developed nuclear weapons.
So you're talking about having more nuclear power, but only in First World economies?
That seems... ethically dubious.
That seems... ethically dubious.
Why is it anymore ethically dubious than having more solar or wind power in first world countries? But no, I'm not necessarily saying that. I just disagree with the claim that if nuclear power continued growing at the same rate as it did prior to 1979 that would somehow have lead to higher proliferation of nuclear weapons.
> As for the urgency, the last two years has demonstrated the exact opposite to me. Modern civilization is a hop, skip, and a jump away from instability and disaster.
I mean, you would somehow have to make Earth less hospitable than Mars to make the effort worth it.
I mean, you would somehow have to make Earth less hospitable than Mars to make the effort worth it.
There is an inherent urgency in all of his plans, mainly because he wants to see it done within his lifetime. He's got 40 years left tops, but more like 20 during which he could still theoretically do anything significant in. Rockets take decades to develop.
The urgency is because you can fool enough people only so long before they catch on and recognize what they are being sold.
He should really thing about making a company to do solar, and maybe an Electric Car company that outsells every other USA EV company 10:1
One conceivable reason to colonize Mars is real estate.
Perhaps in the near future life extension technology will become common place, people may continue to have kids, but natural deaths may be rare; the human population will increase exponentially and need somewhere to live and something to do -- terraforming Mars in exchange for property may be reasonable.
Perhaps in the near future life extension technology will become common place, people may continue to have kids, but natural deaths may be rare; the human population will increase exponentially and need somewhere to live and something to do -- terraforming Mars in exchange for property may be reasonable.
I don't think that a compact fusion powerplant specifically is needed. But I do agree that a truly self-sufficient Martian colony (I.E. able to exist for more than a few years without ships coming from Earth) would need a gargantuan level of infrastructure to have even a small chance of being viable.
From a standpoint of reducing emissions on Earth, it would be cool to see Elon Musk's best take on how to build a practical fusion generator though. I've heard of a few potential paths that could lead to net power much faster and cheaper than ITER. Supposedly superconducting magnets have gotten considerably better since ITER was proposed, and since power output in a tokamak reactor is something like the third or fourth power of the magnet strength IIRC, there's potential for a newer and smaller reactor design to outdo it in both timeline and cost.
From a standpoint of reducing emissions on Earth, it would be cool to see Elon Musk's best take on how to build a practical fusion generator though. I've heard of a few potential paths that could lead to net power much faster and cheaper than ITER. Supposedly superconducting magnets have gotten considerably better since ITER was proposed, and since power output in a tokamak reactor is something like the third or fourth power of the magnet strength IIRC, there's potential for a newer and smaller reactor design to outdo it in both timeline and cost.
It is not possible to conceive of a path that would not lead to net power before ITER. ITER has no intention of generating so much as a milliwatt, ever.
Why is it weird that a private corporation is doing space exploration & technology? Most of the biggest sailing expeditions were undertaken by private individuals and companies (although often under the funding of a royal family). Locomotives and airplanes were also created and perfected by private individuals / companies.
The 1950s-2000s NASA model for space exploration was unusual in its centralized approach.
The 1950s-2000s NASA model for space exploration was unusual in its centralized approach.
Most of those private expeditions were seeking short term profit (of course there exceptions like the Arctic/Antarctic expeditions but their budgets were relatively insignificant compared to the resources required to send several ships to India or the Americas in the 15th century or a spaceship to Mars. Even if colonizing and exploiting the mineral resources on Mars could be profitable in the longterm being the first on Mars (unlike being the first to sail to India) is definitely going to cost more than it's worth (in financial terms) so no rational private company would do this.
There's an argument to be made that some of the current largest market cap companies in the world are analogous to royal families, in terms of centralization of capital vs freedom of decision making.
The notable difference is that they don't have a monopoly on violence
Most premodern states (at least) in Europe didn't really have a monopoly on violence in the strict sense either. Kings were constrained by a variety of laws and customs which they couldn't easily change without triggering violent opposition and had to co-opt the local elites (who usually acted as independent actors) whenever they wanted to impose their will outside of the area they directly controlled. Even an 'absolute' ruler like Louis XVI had very limited direct power compared to many modern governments.
Fair enough, it seems that you are primarily attacking the word Monopoly. What if we were to soften the claim to dominance. Rulers always maintained power based on their ability to resist violence from within and without. Economic leverage only existed as long as one could protect themselves from violent opposition. A trade embargo meant nothing if the opposition can seize your assets and production by force.
In today's world, mega corporations have no defense if a government actor decides to use force against them.
This utter defenselessness against violence is the main difference between a modern corporation and a feudal actor.
In today's world, mega corporations have no defense if a government actor decides to use force against them.
This utter defenselessness against violence is the main difference between a modern corporation and a feudal actor.
I feel this is only a partially true, at least in democratic countries governed by rule of law, because the threat is mostly only theoretical. While modern states are significantly more powerful they are generally governed by more rational actors who (both because of that and better access to information) are much better at estimating the consequences of their actions compared to medieval kings or other autocrats. While the government could go ahead and take all the assets of Apple, Google, Facebook etc. both the government and the people in charge of those corporations know that that's extremely unlikely to happen, especially in a violent way, since the government has very little to gain and a lot to lose by doing that. So while modern corporations are technically utterly defenselessness against violence as you say, arguably this is by choice. Unlike feudal actors corporations have no reason to invest any resources in changing this since they are in a much safer position.
I think I totally agree, and see this as a substantial difference between corporations and feudal lords. They have entirely capitulated on force and are comfortable in this position. You say they only maintain this position by choice, but what choice do they have otherwise? It is hard to imagine Apple, Google, Facebook having any success if they changed their mind and decided to challenge national governments like US or China with direct force.
It has pros on both sides. MAMAA wouldn't have their profit margins if they had to fund a private security force to enforce their contracts and protect their assets.
They get the freedom to focus on their business, within the bounds of the law, by ceding violence authority to the government. And in return, the government establishes and enforces those laws.
They get the freedom to focus on their business, within the bounds of the law, by ceding violence authority to the government. And in return, the government establishes and enforces those laws.
Good point. See: ARM China
Do you have any suggested reading about:
"A probe based on nuclear pulse propulsion could do it in around 50 years, with today's technology."
I was always under the impression that these vast distances were basically entire unreachable in several human lifetimes.
"A probe based on nuclear pulse propulsion could do it in around 50 years, with today's technology."
I was always under the impression that these vast distances were basically entire unreachable in several human lifetimes.
The canonical reference is Project Daedalus:
https://en.wikipedia.org/wiki/Project_Daedalus
https://en.wikipedia.org/wiki/Project_Daedalus
Is talking about detonating nukes behind a ship with a big shield behind it.
We do in fact have another billionaire, Yuri Millner, to push humanity towards the goal of reaching other stars with his "Breakthrough Starshot" initiative.
As far as I know this would be cell phone sized with no way of slowing down. It would cross entire solar systems within a few hours.
There's no way to slow down, true.
Let's see... Neptune's orbital diameter 8.3 light hours.
At 10% c (speed of light) you would need 83 hours. Yes, insane speed, yet hopefully enough time to take quite a few pictures.
Also the plan is not to send a single "disc", but many (thousands?). Together they could potentially provide a treasure trove of data from within the alien solar system.
Let's see... Neptune's orbital diameter 8.3 light hours.
At 10% c (speed of light) you would need 83 hours. Yes, insane speed, yet hopefully enough time to take quite a few pictures.
Also the plan is not to send a single "disc", but many (thousands?). Together they could potentially provide a treasure trove of data from within the alien solar system.
The best thing we could do for space exploration is to figure out terrestrial fusion.
"...with today's technology..."
So we have the ability today to move 50K tons of parts into orbit, and come up with vast quantities of helium-3?
So we have the ability today to move 50K tons of parts into orbit, and come up with vast quantities of helium-3?
The only humans who will be utilizing space in earnest are the Martians. Terrans will be confined to their local space with overwatch on the Moon.
> ... overwatch on the Moon.
I'm pretty sure not even that.
I'm pretty sure not even that.
Isn't Parker Solar Probe much faster than that? It's supposed to be going hundreds of thousands of km/h. [1]
[1] https://en.wikipedia.org/wiki/Parker_Solar_Probe
[1] https://en.wikipedia.org/wiki/Parker_Solar_Probe
Yes, Parker breaks the 40+ year old record set by Helios. OP is using stale data.
The fastest crewed spaceship was Apollo 10 at 39,705km/h before reentry. After orbiting the moon they had lots of fuel left over so they just floored the engine on the way home. Not just falling back towards the planet but actively flying towards the ground for longer than any other Apollo mission.
This record can be broken with current technology, we just have to go back to the moon.
The fastest crewed spaceship was Apollo 10 at 39,705km/h before reentry. After orbiting the moon they had lots of fuel left over so they just floored the engine on the way home. Not just falling back towards the planet but actively flying towards the ground for longer than any other Apollo mission.
This record can be broken with current technology, we just have to go back to the moon.
It achieved those speeds by falling into a gravity well. Reaching Alpha Centauri requires escaping one.
I very well may be wrong about this, but I believe thats not exactly true. Parker required the fasted launch as of its time because it had to shed the momentum of the earth that it started with to be able to fall into that gravity well.
quoting from reddit:
> You may be thinking of the Sun as a big gravity well and how you can just drop things in a well. But orbits don't work anything like that at all. Sure if you are stationary relative to the Sun then you'll fall right into it. But anything that leaves Earth is very far from stationary. You're going at 30 km/s 90 degrees off your target. Possibly the first idea many people think of if they want to hit the Sun is to cancel that 30 km/s of speed, and sure it'll work. But you need 30 km/s of delta-v. On the other hand, to escape the solar system from Earth you only need a velocity of 42 km/s relative to the Sun, of which you already have 30 km/s. So you only need to increase your speed by about 12 km/s. (And for both cases add one or two km/s to counter Earth's gravity.)
https://www.reddit.com/r/askscience/comments/wjv87/comment/c...
https://www.forbes.com/sites/startswithabang/2019/09/20/this...
quoting from reddit:
> You may be thinking of the Sun as a big gravity well and how you can just drop things in a well. But orbits don't work anything like that at all. Sure if you are stationary relative to the Sun then you'll fall right into it. But anything that leaves Earth is very far from stationary. You're going at 30 km/s 90 degrees off your target. Possibly the first idea many people think of if they want to hit the Sun is to cancel that 30 km/s of speed, and sure it'll work. But you need 30 km/s of delta-v. On the other hand, to escape the solar system from Earth you only need a velocity of 42 km/s relative to the Sun, of which you already have 30 km/s. So you only need to increase your speed by about 12 km/s. (And for both cases add one or two km/s to counter Earth's gravity.)
https://www.reddit.com/r/askscience/comments/wjv87/comment/c...
https://www.forbes.com/sites/startswithabang/2019/09/20/this...
[deleted]
I find it enjoyable to think about the technologies that might just be in the cards further into the future.
If we ever figure out light-weight fusion drives, we could build light hugger space ships that accelerate to a decent fraction of the speed of light. At 1g acceleration it takes about one year to get to 0.9c, which would make the Proxima system accessible with a travel time of about 6 years. Or 8 years at 0.5g. Or 9 years if we 'only' get to 0.5c.
The same goes for laser-driven light sails if we just wanted to send a probe, although deceleration would be an issue. (There is currently an aspirational research project for this called Breakthrough Starshot)
The exciting thing about these technologies is that they don't require new physics in principle, just a lot of engineering. Of course, uploaded minds would probably always be better suited for space travel, but it's neat to know that even biological people could in theory make these trips.
If we ever figure out light-weight fusion drives, we could build light hugger space ships that accelerate to a decent fraction of the speed of light. At 1g acceleration it takes about one year to get to 0.9c, which would make the Proxima system accessible with a travel time of about 6 years. Or 8 years at 0.5g. Or 9 years if we 'only' get to 0.5c.
The same goes for laser-driven light sails if we just wanted to send a probe, although deceleration would be an issue. (There is currently an aspirational research project for this called Breakthrough Starshot)
The exciting thing about these technologies is that they don't require new physics in principle, just a lot of engineering. Of course, uploaded minds would probably always be better suited for space travel, but it's neat to know that even biological people could in theory make these trips.
IIRC, the limit with humans on-board is like .3c due to the red/blue shifting of the background radiation of the universe. At about .3c, it turns into microwaves/radar/x-rays and such, becoming quite bad for humans. There’s so much background radiation, there may be no way to adequately shield from it and/or travel may be limited only in the direction of less background radiation.
Maybe someone has a link to more information, that’s just what I remember from years ago.
Maybe someone has a link to more information, that’s just what I remember from years ago.
Right, also the hull must resist the impact against hidrogen atoms at near the speed of light, which would apply tremendous forces. Dust will be like exploding nukes.
That's a good point. I have no idea actually where the practical limits would be, especially considering options that arise if the ship has access to a lot of electrical power to generate a protective magnetic field. But even at 0.3c, the trip to Proxima could still be worthwhile for an unmodified human.
You still have the deceleration issue.
You need to use the same amount of energy and time to decelerate, as you did to accelerate.
So you'd only be able to sustain constant acceleration for half the distance. Then deceleration for the second half of the journey.
That would make the travel time much, much longer than your calculations, since you'd be traveling at relatively slow speed for both the first & last 20-25% of the distance.
You need to use the same amount of energy and time to decelerate, as you did to accelerate.
So you'd only be able to sustain constant acceleration for half the distance. Then deceleration for the second half of the journey.
That would make the travel time much, much longer than your calculations, since you'd be traveling at relatively slow speed for both the first & last 20-25% of the distance.
[deleted]
Here’s a link to a Gizmodo article talking about the study… unfortunately I can’t get the original study to load: https://gizmodo.com/this-is-what-it-would-really-look-like-t...
> If we ever figure out light-weight fusion drives, we could build light hugger space ships that accelerate to a decent fraction of the speed of light. At 1g acceleration it takes about one year to get to 0.9c, which would make the Proxima system accessible with a travel time of about 6 years. Or 8 years at 0.5g. Or 9 years if we 'only' get to 0.5c.
No, we couldn't. The energy density of fusion isn't anywhere near close enough to make a lighthugger, you'd need insane mass ratios[1] and ramjets are probably unfeasible (as in, even-if-your-a-Kardeshev-II-civilization-unfeasible[2]).
[1]: http://www.projectrho.com/public_html/rocket/slowerlight3.ph...
[2]: https://www.sciencedirect.com/science/article/pii/S009457652...
No, we couldn't. The energy density of fusion isn't anywhere near close enough to make a lighthugger, you'd need insane mass ratios[1] and ramjets are probably unfeasible (as in, even-if-your-a-Kardeshev-II-civilization-unfeasible[2]).
[1]: http://www.projectrho.com/public_html/rocket/slowerlight3.ph...
[2]: https://www.sciencedirect.com/science/article/pii/S009457652...
Another atomic rockets enjoyer. I've killed so much time on that site. I don't agree with every one of Winchell's conclusions. But they are small things. And I don't know of a more comprehensive and grounded take on future spaceflight technologies.
I was saddened to hear about Winchell's cancer diagnosis last year[1]. I've wasted a ton of time there too, it's an oddity compared to the rest of the modern internet. I know very few other useful sites like it, and I love it all the more for its strange aesthetic.
I don't agree with everything there either, but usually it's only very minor gripes. In this case though, it's hard to argue with the reality of the rocket equation.
[1]: https://twitter.com/nyrath/status/1436010987086286853?s=20
I don't agree with everything there either, but usually it's only very minor gripes. In this case though, it's hard to argue with the reality of the rocket equation.
[1]: https://twitter.com/nyrath/status/1436010987086286853?s=20
Oh man, I hadn't heard about that. Best of luck to him but he's right prostate cancer is a pretty bad one.
What are the other few sites you do know of?
And you are absolutely right about the rocket equation. You can't really get around it.
What are the other few sites you do know of?
And you are absolutely right about the rocket equation. You can't really get around it.
I'm sure there's more but the first few that come to mind are Greg Egan's homepage[1], Xenology[2], and on a completely different topic "Gramadach na Gaeilge"[3] (Irish Grammar).
[1]: https://gregegan.net
[2]: https://xenology.info
[3]: http://nualeargais.ie/gnag/gram.htm
[1]: https://gregegan.net
[2]: https://xenology.info
[3]: http://nualeargais.ie/gnag/gram.htm
It's too late to edit, but the link to xenology should be http and not https:
[2]: http://xenology.info
[2]: http://xenology.info
This is exciting stuff indeed. Imagine a year-4,000 spaceship reaching Centauri before another spaceship dispatched 1,000 years before it?
For the cynical or pessimists: I'm not optimistic about humanity reaching year-4,000, I'm just possibilistic about it (as in the philosophical meaning [1]).
[1] https://en.wikipedia.org/wiki/Actualism#:~:text=possibilism,...
For the cynical or pessimists: I'm not optimistic about humanity reaching year-4,000, I'm just possibilistic about it (as in the philosophical meaning [1]).
[1] https://en.wikipedia.org/wiki/Actualism#:~:text=possibilism,...
I can't imagine humanity not making it to 4000. There are very few true existential threats.
This is literally the plot of a very old computer game Alien Legacy. [0]
[0]: https://en.m.wikipedia.org/wiki/Alien_Legacy
[0]: https://en.m.wikipedia.org/wiki/Alien_Legacy
Thank you for your optimism, now let me balance that out a little.
Propulsion maybe the easier part of engineering. Afaik we are nowhere near to life support and environment control that could be considered stable for a time period of maybe 10 years or more.
The biggest biological advantage, adaptation is meaningless for large organism on such a timescale and maybe dangerous on a microbial level.
Propulsion maybe the easier part of engineering. Afaik we are nowhere near to life support and environment control that could be considered stable for a time period of maybe 10 years or more.
The biggest biological advantage, adaptation is meaningless for large organism on such a timescale and maybe dangerous on a microbial level.
You are correct that we are nowhere near that in life support technology, however, there don't seem to be an fundamental hurdles there. If we end up opting for a biological life support system, adaptation would not even enter the equation - it'd be a matter of genetic engineering. An obvious danger would always be onboard ecosystem collapse, of course.
Whenever I read discussions about space travel and trying to approach the speed of light for human travel I have the feeling there's a lot of tunnel vision (excuse the pun). It always seems to assume travelling along a linear path through space.
In my mind, using the admittedly poor analogy of space-time as a membrane that is distorted by gravity, my thinking is we'll find some way to effectively bring two points in space-time adjacent to each other and 'step' between them. Wormholes, Warp, or whatever you want to call it.
Think of a flexible membrane 10 meters long and we are going to travel from one end to the other. We can either travel in a linear fashion over its surface for 10 meters or we can wrap the membrane so both ends are next to each other and travel 0.01m across the gap between them.
Yes, I know there are all sorts of obstacles and arguments against this simplistic visualisation but this is how I've always imagined the physics of any science fiction faster-than-light travel - worm-holes, warp drives, etc.
If you want an actual, real, possible-right-now analogy, think of our current situation where the fastest way to travel from London, UK to Sydney, Australia (1/2 way around the world) is through the atmosphere in an aeroplane travelling ~17000 kilometers and taking at best 19.5 hours.
SpaceX (Musk) Virgin Galactic (Branson), other companies [0], and space agencies [1] have talked about, and are actively working toward, stepping outside the atmosphere into space to reduce the time element to around an hour.
So just like with supposedly faster-than-light travel, by 'stepping outside' the linear/conventional thinking/physics we reduce the time of travel element dramatically. The start and end points don't move but the distance travelled by the transport vehicle itself changes in order to enable the reduction in time.
[0] https://www.telegraph.co.uk/travel/news/new-flights-space-lo...
[1] https://edition.cnn.com/travel/article/hypersonic-flight-air...
In my mind, using the admittedly poor analogy of space-time as a membrane that is distorted by gravity, my thinking is we'll find some way to effectively bring two points in space-time adjacent to each other and 'step' between them. Wormholes, Warp, or whatever you want to call it.
Think of a flexible membrane 10 meters long and we are going to travel from one end to the other. We can either travel in a linear fashion over its surface for 10 meters or we can wrap the membrane so both ends are next to each other and travel 0.01m across the gap between them.
Yes, I know there are all sorts of obstacles and arguments against this simplistic visualisation but this is how I've always imagined the physics of any science fiction faster-than-light travel - worm-holes, warp drives, etc.
If you want an actual, real, possible-right-now analogy, think of our current situation where the fastest way to travel from London, UK to Sydney, Australia (1/2 way around the world) is through the atmosphere in an aeroplane travelling ~17000 kilometers and taking at best 19.5 hours.
SpaceX (Musk) Virgin Galactic (Branson), other companies [0], and space agencies [1] have talked about, and are actively working toward, stepping outside the atmosphere into space to reduce the time element to around an hour.
So just like with supposedly faster-than-light travel, by 'stepping outside' the linear/conventional thinking/physics we reduce the time of travel element dramatically. The start and end points don't move but the distance travelled by the transport vehicle itself changes in order to enable the reduction in time.
[0] https://www.telegraph.co.uk/travel/news/new-flights-space-lo...
[1] https://edition.cnn.com/travel/article/hypersonic-flight-air...
I've never bought it. It will still involve being able to transfer information FTL, and then you're on to the Grandfather Paradox.
On top of it, let's handwave all of this away, poof. Any aliens anywhere in the Universe would also be using it once their technology got to that level. Just from the lack of visitors, we have three possibilities that are immediately evident:
1) Humans are among the first intelligent species to get to this technology in the entire Universe.
2) Other species have it, but all of them, every last far-flung one of them, even the renegade civilizations or the mad scientists at the individual level, abide by not using it around humans. Despite all of their numerous reasoning capacities and utterly inhuman motivations, every last sophont with access to the tech has agreed upon this, and has for thousands of years.
3) That tech can't exist.
The first and second are unlikely, statistically.
On top of it, let's handwave all of this away, poof. Any aliens anywhere in the Universe would also be using it once their technology got to that level. Just from the lack of visitors, we have three possibilities that are immediately evident:
1) Humans are among the first intelligent species to get to this technology in the entire Universe.
2) Other species have it, but all of them, every last far-flung one of them, even the renegade civilizations or the mad scientists at the individual level, abide by not using it around humans. Despite all of their numerous reasoning capacities and utterly inhuman motivations, every last sophont with access to the tech has agreed upon this, and has for thousands of years.
3) That tech can't exist.
The first and second are unlikely, statistically.
[deleted]
Bits of dust or a pebble hitting ship at 0.5c would make for a bad day.
Is the 6 years measured in the time-frame of a passenger on the spacecraft, or as observed from Earth?
At 0.9c the relativistic time dilation is such that 2.3 days on Earth pass for every day shipboard time, meaning the crew would experience less than 4 years of travel in total: https://www.fourmilab.ch/cship/timedial.html
Since we aren't too fast yet, it would basically be the same.
>something like 18 000 years
this is why we don't see any signs of life out there. there really isn't any point in trying to venture beyond your home. universe is just too big even at the speed of light when you start venturing beyond your local group.
this is why we don't see any signs of life out there. there really isn't any point in trying to venture beyond your home. universe is just too big even at the speed of light when you start venturing beyond your local group.
That is assuming that the speed of light truly is the end-all-be-all. It is quite possible there are other ways of travel that we’ve yet to discover. I have no idea what they’d be but humans have really only been doing this space / astronomy thing for a few hundred years at most.
We have barely scratched the surface of what is truly going on out there. It would be incredibly “human centric” to think our current understanding of the universe is “it”, in my opinion.
We have barely scratched the surface of what is truly going on out there. It would be incredibly “human centric” to think our current understanding of the universe is “it”, in my opinion.
I think you would need a kind of power that would have obvious hallmarks, like literally rewriting the rules that underlie the universe. But's that just my cynical perspective.
I guess that's why arthur c clarke said sufficiently advanced technology is indistinguishable from magic. I just think that kind of magic would be visible to us. Or maybe it is, but we just can't tell.
I guess that's why arthur c clarke said sufficiently advanced technology is indistinguishable from magic. I just think that kind of magic would be visible to us. Or maybe it is, but we just can't tell.
> even at the speed of light
If you get really close to the speed of light (which is not really practical from a materials engineering standpoint) your time of transit is significantly shorter.
Once these (extremely hard) engineering problems are solved, a trip to the next star can be a week-long affair from your point of view, but your friends back on Earth won't see you for about a decade.
If you get really close to the speed of light (which is not really practical from a materials engineering standpoint) your time of transit is significantly shorter.
Once these (extremely hard) engineering problems are solved, a trip to the next star can be a week-long affair from your point of view, but your friends back on Earth won't see you for about a decade.
You'd have to get very close to the speed of light, before you'd see any really significant relativistic effects.
That just isn't practically doable with any technology within humanity's reach, probably for centuries. If it ever will be at all.
The amount of energy needed to propel anything at that speed is enormous.
That just isn't practically doable with any technology within humanity's reach, probably for centuries. If it ever will be at all.
The amount of energy needed to propel anything at that speed is enormous.
Unless my math is very wrong, at 0.9c the passenger perceived time is more or less half the perceived time from the departure point. That's already quite significant, although not something I could do over a vacation ;-)
In order to spend a leisurely "cruise-ship" week to Proxima you'd need to go very close to c. At that speed, even friction with a non-ideal vacuum is a problem :-D.
In order to spend a leisurely "cruise-ship" week to Proxima you'd need to go very close to c. At that speed, even friction with a non-ideal vacuum is a problem :-D.
> a trip to the next star can be a week-long affair from your point of view
You’d need to travel at around 233x the speed of light to make getting to the nearest star be a week trip, no?
You’d need to travel at around 233x the speed of light to make getting to the nearest star be a week trip, no?
The effect is called time dilation. The section of interest here is „Time dilation caused by a relative velocity“:
https://en.m.wikipedia.org/wiki/Time_dilation
https://en.m.wikipedia.org/wiki/Time_dilation
I’m aware of time dilation, my point was that a “week vacation” to something “over 4 light years” away is just hyperbolic.
Nope! If you obtain the full speed of light then a) you're not made of baryons anymore so congratulations on that and b) no time passes whatsoever between your being emitted in some tight laser beam on planet A, and being transcribed on planet B, from your perspective.
None. Photons don't experience time, they are time.
None. Photons don't experience time, they are time.
Not exactly. For you to think you are traveling 20x faster than light, your friends that stayed at home would have to see you traveling at 0.99995c. For 233x faster than light, that's a lot of 9's in that number.
I get 0.999c for 20x and 0.99999c for 220+
I'll trust your numbers more than mine.
But, for all intents and purposes, this is impossibly fast ;-)
Unless you are on the Bistromath, that is.
But, for all intents and purposes, this is impossibly fast ;-)
Unless you are on the Bistromath, that is.
[deleted]
There is no faster than light, I can't parse this statement.
Distance divided by [time experienced by traveler]. GP is not saying that traveler went faster than light.
[deleted]
I guess the assumption is their life span is similar to that on our planet. If the life span measured in thousand of years, it will be a different story.
Lifespan is one thing, but also the "cadence" of life. For a mammal, spending a year in a spaceship is hard. For a brick, spending a thousand years as part of a wall is the natural order of things.
The formal name for this is the https://en.wikipedia.org/wiki/Interstellar_travel#Wait_calcu...
with how small you can make a probe today there isn’t any barrier to making something 100x faster or more. throw up a small camera and transmitter with a huge ion thruster thank on top of a saturn v sized rocket of your choice and you will get going very fast
[deleted]
The other problem with sending a space probe is that the devs will have to actually deliver the Proxima Centauri mod on time and on budget, which, let's be honest, probably isn't going to happen for another few years. Think about it, you have to skin the whole planet, make sure the AI isn't weird, make sure it doesn't conflict with the existing storyline or retcon all the earth NPC memories. It's a HUGE project. Right now we just literally return a light curve from the function when someone looks at it.
And even if we could get the adversial networks to model all this garbage, etc it needs to line up with the plan of the rest of the Universe from the franchise and the managers can't even decide whether the photon is going to be a wave or a particle. Jeez. Vaporware like HL2.
And even if we could get the adversial networks to model all this garbage, etc it needs to line up with the plan of the rest of the Universe from the franchise and the managers can't even decide whether the photon is going to be a wave or a particle. Jeez. Vaporware like HL2.
Another point for anyone considering whether we should send a space-probe there...
We should and do send probes anywhere that's practical. The question is more like when it will be practical to build star probes.
The current fastest man-man object is the...
The current fastest man-made object wasn't intended to reach the stars.
On the other hand, there are many challenges that make more sense to undertake as previous steps to develop the needed technology.
We should and do send probes anywhere that's practical. The question is more like when it will be practical to build star probes.
The current fastest man-man object is the...
The current fastest man-made object wasn't intended to reach the stars.
On the other hand, there are many challenges that make more sense to undertake as previous steps to develop the needed technology.
> 25 000 kilometres per hour
252 792 km/h
252 792 km/h
Sadly, as discussed here, the technical problems with propulsion systems for interstellar travel are non-trivial:
https://news.ycombinator.com/item?id=29638529
Of course that doesn't necessarily preclude a nearby higher level Kardashev Civilization becoming interested in all the noise we're making and heading over.
As we put up systems beyond Webb, it may be possible to observe a hypothetical inbound craft / fleet some years off, which would have interesting effects on our current human society, once it became generally known..
My suspicion is that the social media generation would react a lot worse than the radio generation did to the 1938 broadcast of H. G. Wells' War of the Worlds:
https://www.space.com/40435-finding-aliens-humanity-reaction...
https://news.ycombinator.com/item?id=29638529
Of course that doesn't necessarily preclude a nearby higher level Kardashev Civilization becoming interested in all the noise we're making and heading over.
As we put up systems beyond Webb, it may be possible to observe a hypothetical inbound craft / fleet some years off, which would have interesting effects on our current human society, once it became generally known..
My suspicion is that the social media generation would react a lot worse than the radio generation did to the 1938 broadcast of H. G. Wells' War of the Worlds:
https://www.space.com/40435-finding-aliens-humanity-reaction...
If Breakthrough Starshot happens some of us may get to at least see it in our lifetimes.
I don’t think we will or should be trying for interstellar at this time; but something being non-trivial doesn’t mean we shouldn’t do it.
I thought the nuclear propulsion options were viable and relative simple.
All of the descriptions I've seen were "viable" in the sense of "we could hypothetically accomplish this in a few decades a for around $100 trillion". At least that was the estimate for Project Daedalus, which designed a nuclear pulse propulsion probe to do a 50-year flyby of Barnard's Star. Fun to think about but it's going to be a while before even the largest governments can afford to fund a project that most of its creators will never see completed.
Even if you get a very high specific impulse, you still need to pack a lot of reaction mass. You'll also need a lot of supplies (or a biome) because even if you get to 0.1 c, it's still 40 years to get there.
I'm not losing hope that there are ways to travel faster than the speed of light that we haven't yet discovered, like bending the spacetime around the spacecraft, or wormholes, or something else of that kind. If various forms of rapidly ejecting matter out of a nozzle really are the only physically viable option for spaceflight, it would be an extremely disappointing universe.
> If various forms of rapidly ejecting matter out of a nozzle really are the only physically viable option for spaceflight, it would be an extremely disappointing universe.
Indeed. If that's the case, the universe is an infinitely big and infinitely boring place.
OTOH, our future uploaded selves may be able to slow down their clock rates and make the trip so much shorter.
And you don't need to leave your dear ones on Earth - just bring forks of them along you (chances are a fork of you will remain on Earth anyway).
Indeed. If that's the case, the universe is an infinitely big and infinitely boring place.
OTOH, our future uploaded selves may be able to slow down their clock rates and make the trip so much shorter.
And you don't need to leave your dear ones on Earth - just bring forks of them along you (chances are a fork of you will remain on Earth anyway).
At the moment I have more faith that our AI overlords - or, future self-replicating robots, insert various levels of intelligence and self-reliance here - will be the ones going interstellar, not so much us unless we revolutionize spaceflight. That said, the picture of the future that The Expanse investigates seems to be the most realistic, just minus the somewhat magic propulsion system.
Not a huge problem if, after the robots terraform the planet and build our settlements, I can opt to be printed into a new organic body.
We'll still need some form of magical propulsion or, worse, some magical power source. There aren't many things that can keep providing energy for thousands of years. I'm pretty sure fission is a non-starter here and even nuclear fusion designs would need a source of tritium because, after a couple thousand years, there won't be much left of the initial fuel.
We'll still need some form of magical propulsion or, worse, some magical power source. There aren't many things that can keep providing energy for thousands of years. I'm pretty sure fission is a non-starter here and even nuclear fusion designs would need a source of tritium because, after a couple thousand years, there won't be much left of the initial fuel.
What would that fork think of it?
If I were to fork myself in this situation, I'd make one fork who thinks that making the trip will be awesome and another that will think that staying home is the coolest thing.
If we can, from time to time, merge our memories and refork, this wouldn't be a big issue, as both forks would experience both lives.
I think that, at this point, we wouldn't be that much human anymore.
If we can, from time to time, merge our memories and refork, this wouldn't be a big issue, as both forks would experience both lives.
I think that, at this point, we wouldn't be that much human anymore.
You don't even have to modify it. If you are a person that thinks going and leaving a fork would be cool, and also thinks staying and sending a fork would be cool, the job is done.
Frankly, I believe that any form of mind upload or consciousness transfer is a much harder problem than both rejuvenation and interstellar spaceflight.
Looking at current aging research, there's a good possibility we'll see rejuvenation in the next decade or two and it'll profoundly change our society. In 20 years, everyone will be looking 25 years old and pointing at frail people with wrinkly faces and laughing, same way we do today with antivaxxers.
Once that's out of the way, we'll eventually get comfortable with building arbitrarily large objects on orbit, and we could as well build a huge spaceship with an onboard self-sustaining ecosystem and fly that to other stars, the boring way. Yes, it will be a very long journey, but it's possible without the reliance on yet to be discovered new physics.
Looking at current aging research, there's a good possibility we'll see rejuvenation in the next decade or two and it'll profoundly change our society. In 20 years, everyone will be looking 25 years old and pointing at frail people with wrinkly faces and laughing, same way we do today with antivaxxers.
Once that's out of the way, we'll eventually get comfortable with building arbitrarily large objects on orbit, and we could as well build a huge spaceship with an onboard self-sustaining ecosystem and fly that to other stars, the boring way. Yes, it will be a very long journey, but it's possible without the reliance on yet to be discovered new physics.
That's insane optimism to me. We don't even know how to get a nail to re-attach to a nail bed. We can't put some crystals on a tooth. We can't create a single hair follicle. We have zero non-surgical ways to repair arteries. Etc, etc, etc. We have made zero progress in anti-aging other than controlling blood pressure and identifying harmful chemicals in an environment.
We ARE good at extreme, surgical and or heavy medicating intervention. Doesn't go hand-in-hand with life extension at all.
We ARE good at extreme, surgical and or heavy medicating intervention. Doesn't go hand-in-hand with life extension at all.
At least there is such a thing as growing tissues from stem cells. Nothing at all in the category of "uploading" one's consciousness anywhere exists. Not "uploading a memory", not "uploading a thought process", those are abstract concepts we've made to describe what the extremely strange organs that brains are do, anyway, and we're nowhere near close to understanding its biology much less replicating what it actually does with a machine.
We're now capable of programming cells to produce arbitrary proteins at will, how cool is that?
Also please do look through the playlist in a sibling comment. Michael Levin's research is truly badass. He has grown tadpoles with an extra working eye on the back, and recently he has regrown an amputated leg on a frog.
There's an astonishing amount of untapped possibilities in biology that are opening up only now as we finally have the right tools.
Also please do look through the playlist in a sibling comment. Michael Levin's research is truly badass. He has grown tadpoles with an extra working eye on the back, and recently he has regrown an amputated leg on a frog.
There's an astonishing amount of untapped possibilities in biology that are opening up only now as we finally have the right tools.
Right, CRISPR is ok, but they haven't figured out that many real applications. This approach to vaccines has actually been around forever.
I bookmarked this thread specifically to watch your links later. I appreciate them and will watch, as I am really interested in the topic.
My hope is that biotech is the next step, but as I mentioned, for now I am highly pessimistic. We can't seem to treat virtually anything in any real sense, despite the experiments you mention. If anything, the progress in prosthetics (including the spinal bypass) has been great, but nothing to do with life extension or genuine recovery of lost functionality without surgical intervention.
Personally, it seems to be me that the closest thing we can do so far as individuals is reduce risk factors and try to stay high on Death Clocks: https://www.lifespan.io/news/grimage-is-the-best-clock-for-p...
Completely unrelated, but this reminded me that we can't seem to regrow cartilage either. This is a huge issue after cancers and cardiac deaths. Any falls, excessive wear and tear, etc all destroy quality of life with the joints. Latest efforts here: https://www.studyfinds.org/arthritis-pain-regrowing-cartilag...
I bookmarked this thread specifically to watch your links later. I appreciate them and will watch, as I am really interested in the topic.
My hope is that biotech is the next step, but as I mentioned, for now I am highly pessimistic. We can't seem to treat virtually anything in any real sense, despite the experiments you mention. If anything, the progress in prosthetics (including the spinal bypass) has been great, but nothing to do with life extension or genuine recovery of lost functionality without surgical intervention.
Personally, it seems to be me that the closest thing we can do so far as individuals is reduce risk factors and try to stay high on Death Clocks: https://www.lifespan.io/news/grimage-is-the-best-clock-for-p...
Completely unrelated, but this reminded me that we can't seem to regrow cartilage either. This is a huge issue after cancers and cardiac deaths. Any falls, excessive wear and tear, etc all destroy quality of life with the joints. Latest efforts here: https://www.studyfinds.org/arthritis-pain-regrowing-cartilag...
We can now treat a lot of conditions we couldn't before. People used to die all the time of infections or any number of other conditions we now consider fully curable. Medicine as we know it is a relatively young science compared to physics or mathematics for example. We can treat most bacterial infections. We can manage most virus infections. We can perform life-saving, high-precision surgeries. We couldn't do any of these things just 100 years ago — that's nothing on a historical timescale.
Thing is, medicine/biology is a unique field because it relies quite a lot on advancements in other fields for its tools. You couldn't research cells before microscope was invented. You can't begin figuring out what each part of a genome does before you've sequenced it. You can't begin to research functions of specific proteins before you've solved their structures and got the ability to manipulate their production and/or attach markers to them. And so on, and so forth. Not so long ago the main approach in medical research was basically "try stuff randomly on lab animals and see what has a beneficial effect". Now that we can peek into the internal workings of biological systems we can use a more direct, more engineering-like approach.
Thing is, medicine/biology is a unique field because it relies quite a lot on advancements in other fields for its tools. You couldn't research cells before microscope was invented. You can't begin figuring out what each part of a genome does before you've sequenced it. You can't begin to research functions of specific proteins before you've solved their structures and got the ability to manipulate their production and/or attach markers to them. And so on, and so forth. Not so long ago the main approach in medical research was basically "try stuff randomly on lab animals and see what has a beneficial effect". Now that we can peek into the internal workings of biological systems we can use a more direct, more engineering-like approach.
Any chance you could link to some stuff that's making you so optimistic about rejuvenation on that timeline?
Look up the stuff David Sinclair is doing with his team. They are already rejuvenating and regrowing severed optic nerves with Yamanaka factors in mice and are preparing to start human trials.
It's not rock-solid that this is going to happen for the whole body soon, but some truly breakthrough things are happening right now in this field, nothing like the previous decades.
It's not rock-solid that this is going to happen for the whole body soon, but some truly breakthrough things are happening right now in this field, nothing like the previous decades.
That doesn’t solve the issue that the passengers will need to live on the ship for a thousand years, even if their relatives will be on Earth for twice as long.
Even a very big ship can be boring after a sufficiently long time.
Even a very big ship can be boring after a sufficiently long time.
https://old.reddit.com/r/longevity has a lot of links to various articles and papers, and I also collect relevant videos and talks into a playlist: https://www.youtube.com/playlist?list=PLLvA7pB41pDk27XOjqbXi...
> pointing at frail people with wrinkly faces and laughing, same way we do today with antivaxxers.
Except those people are more likely to be too poor to afford it instead of unwilling to take it.
Except those people are more likely to be too poor to afford it instead of unwilling to take it.
Or, worse, the young will never get any power because the old will not relinquish control.
Then you have the "surfeit of princes" problem.
This isn't just grand political power: imagine being unable to progress in your career because geriatrics above you aren't retiring.
That's just one possible secondary effect. We could enumerate many others.
Then you have the "surfeit of princes" problem.
This isn't just grand political power: imagine being unable to progress in your career because geriatrics above you aren't retiring.
That's just one possible secondary effect. We could enumerate many others.
Oh yes. That's a very clear concern. I'm reacting to the "people who decline will he like antivaxers" comment. But it seems far more likely people will be priced out as opposed to voluntarily refuse treatment.
This logic is flawed. It would be much more economically sensible to just rejuvenate everyone regularly instead of doing what we do today — try, and eventually fail, to manage all the conditions related to old age. Since aging affects literally everyone, this huge scale would drive the cost of that intervention down to pennies.
Just to be clear: I'm not from the US, we do have not a very good but nevertheless somewhat working public health system over here.
Just to be clear: I'm not from the US, we do have not a very good but nevertheless somewhat working public health system over here.
> It would be much more economically sensible to just rejuvenate everyone regularly instead of doing what we do today — try, and eventually fail, to manage all the conditions related to old age.
In the US, we just will do neither for the majority of Americans. If you're too poor to afford rejuvenation, you'll be too poor to afford other treatments. And you'll just die.
Sure the cost of each treatment might be pennies (although it probably will cost a lot and not have those economies of scale) but total profit is not maximized by a smaller markup. Better to get Gates/Bezos/Musk/other billionaires to give you 90% of their fortunes.
In the US, we just will do neither for the majority of Americans. If you're too poor to afford rejuvenation, you'll be too poor to afford other treatments. And you'll just die.
Sure the cost of each treatment might be pennies (although it probably will cost a lot and not have those economies of scale) but total profit is not maximized by a smaller markup. Better to get Gates/Bezos/Musk/other billionaires to give you 90% of their fortunes.
They’ll sneer at the masses without eternal youth anyway.
Unless, of course, living a thousand years brings some wisdom with it.
Unless, of course, living a thousand years brings some wisdom with it.
I’m guessing we have to choose between capitalism and eternal youth.
I’m totally ok with a post-scarcity socialist society.
I’m totally ok with a post-scarcity socialist society.
With all the messages we’re sending I’m sure a curvature propulsion drive is just around the corner ;)
"Earth-like planet"?
It orbits the star every 5 days; it's a quarter of the earth's mass. It's also a tenth the distance from its star that Mercury is from the Sun. It's earth-like only in that its temperature is consistent with there being liquid water.
It orbits the star every 5 days; it's a quarter of the earth's mass. It's also a tenth the distance from its star that Mercury is from the Sun. It's earth-like only in that its temperature is consistent with there being liquid water.
"Earth-like" just means terrestrial, as opposed to jovian. It means it has a rocky surface.
Venus is also classified as Earth like, but it's rocky surface looks more like hell than the mythological descriptions of it. ;-)
Terrestrial and rocky are both far better choices to communicate the concept.
Then they should have just called it a rocky planet. Earth-like is a massive misnomer/clickbait here.
It is the term used in planetary science. Not understanding something doesn't mean clickbait
Being the accepted term in the field doesn't it make it not click-bait. That just comes down to whether or not using the term in the headline baits people to click.
The abstract refers to it as "sub-Earth", and a "Earth-mass".
The abstract refers to it as "sub-Earth", and a "Earth-mass".
Thanks - I didn't know it was a technical term.
So even if the thing's tidelocked, and has no atmosphere because stellar flare-ups, it still counts as earth-like. TIL.
So even if the thing's tidelocked, and has no atmosphere because stellar flare-ups, it still counts as earth-like. TIL.
IIRC from other publications, they expect something between .26 and 1.1 Earth masses, so it may well be a reasonably big rock. Surface gravity, composition and atmosphere are also big factors in being Earth like - Titan has a lower gravity, but a much thicker atmosphere than Earth.
Well, Proxima Centauri isn't really "Sun-like" either, so what constitutes an "Earth-like" planet for a different type of star is debatable...
Could you please stop ruining cool science journalism headlines with your facts?
"The team used a state-of-the art spectrograph called ESPRESSO"
And suddenly i am imagining lots of very smart people drinking lots of caffeine.
"To find the wobble.."
this is not helping :)
"ESPRESSO is kept in a special room at the observatory, inside a tank "
oh come on ..
And suddenly i am imagining lots of very smart people drinking lots of caffeine.
"To find the wobble.."
this is not helping :)
"ESPRESSO is kept in a special room at the observatory, inside a tank "
oh come on ..
Astronomers go to great lengths to name their stuff for good abbreviations. ESPRESSO is actually “Echelle Spectrograph for Rocky Exoplanet- and Stable Spectroscopic Observations”
Astronomers are known to backronymise: https://en.wikipedia.org/wiki/STEVE
That is pretty exciting. Some say life would be difficult because Proxima Centauri is a flare star, which has violent outbursts of radiation. Not more than the sun though, even if it is so much smaller. But the habitable zone would also be much closer to the star.
It has a significant life span of about 4 trillion years and could easily outlive the present universe several times.
It has a significant life span of about 4 trillion years and could easily outlive the present universe several times.
Hey, we also got a weird signal from this area not too long ago!
https://en.wikipedia.org/wiki/BLC1
https://en.wikipedia.org/wiki/BLC1
Sweet let's crank up the generation ships. Of course picking a suitably inspiring name should be the first priority. Unity? Terra Nova? Gaia?
On a more serious note is this a good candidate for JWST, would it be able to infer chemical composition from the planet's spectrum or something?
Awesome though we went from (in my lifetime) learning at school that other planets have never been observed, to finding them sprinkled around basically every star just like our own. I feel like it won't be long before we detect the first potential chemical markers of alien life, if it's out there. Keep doing your thing space science folk!
On a more serious note is this a good candidate for JWST, would it be able to infer chemical composition from the planet's spectrum or something?
Awesome though we went from (in my lifetime) learning at school that other planets have never been observed, to finding them sprinkled around basically every star just like our own. I feel like it won't be long before we detect the first potential chemical markers of alien life, if it's out there. Keep doing your thing space science folk!
Before anyone gets too excited I'd just point out that all they have found is a rocky world within Proxima's habitable zone. That doesn't mean that world necessarily has a breathable atmosphere, water, sufficient gravity, a geomagnetic field, rotation sufficient to distribute heat equitably across its surface (as opposed to it being tidally locked facing Proxima), or any of a dozen other features requisite to support life.
Oh... and did I mention that Proxima is a known flare star?
Wake me up when they find a terrestrial world in the habitable zone of Alpha Centauri instead.
Oh... and did I mention that Proxima is a known flare star?
Wake me up when they find a terrestrial world in the habitable zone of Alpha Centauri instead.
Yeah I was being a little tongue in cheek with the excitement, still it's pretty crazy we're actually seeing and cataloguing exoplanets now which was still in the realms of science fiction less than half a century ago.
Anyway if Stellaris has taught me anything it's that the flares will add additional energy credits to the system... what's not to like?
Anyway if Stellaris has taught me anything it's that the flares will add additional energy credits to the system... what's not to like?
Easier to add water to Mars, or fix Venus, all possible to have well underway by end of century.
>> Sweet let's crank up the generation ships. Of course picking a suitably inspiring name should be the first priority. Unity? Terra Nova? Gaia?
Titanic. Moribund. Lethe. Purgatory I-X. etc.
Titanic. Moribund. Lethe. Purgatory I-X. etc.
Titanic sounds good. We should also call it an unexplodable space ship.
Generation ships will take some time to get ready. We can railgun tardigrades and aphanizomenon flos-aquae there this year and let evolution do the rest. By the time we (or, more likely, the descendants of cockroaches) get there, it will be teeming with DNA-based life.
We should perhaps be extra sure that there isn't life there already, before starting to attack a distant planet with terraforming weaponry.
Why bother, even if there is no life there now that doesn't mean their won't be when we finally arrive. Or contrary if there is life there now that doesn't mean it will survive until we get there.
The odds that there is life on our generational ship when we arrive are not that great either.
The odds that there is life on our generational ship when we arrive are not that great either.
I seem to remember in an Iain M. Banks novel that there was some controversy about terraforming, like there was an other civilisation that considered it an atrocity and hated The Culture fot that?
It would be even more exciting if we detect industrial processes.
> Of course picking a suitably inspiring name should be the first priority. Unity? Terra Nova? Gaia?
It’ll be Spacey McSpaceface if we put it to a vote.
It’ll be Spacey McSpaceface if we put it to a vote.
Perhaps it's too soon after reading The Dark Forest, but uh oh.
I just finished the book yesterday. I rank it #1 on my all-time SciFi list. I would say A Fire Upon the Deep is #2 and Dune #3.
I had the same exact thought the moment I finished it.
After a week of reflection, I think it was a slight overreaction -- the book is still very very good but i dont think #1 for me.
But something about the way the story took shape and culminated in the final third of the book was so engaging, and so satisfying. I think I stayed up until 4 or 5AM the night I finished the last 200 pages.
After a week of reflection, I think it was a slight overreaction -- the book is still very very good but i dont think #1 for me.
But something about the way the story took shape and culminated in the final third of the book was so engaging, and so satisfying. I think I stayed up until 4 or 5AM the night I finished the last 200 pages.
Really? A Fire Upon the Deep and Dune are masterpieces, yes, but The Dark Forest although good isn't in the same league IMO.
- - - -
Tangent: Have you read Gene Wolfe's Book of the New Sun? It's less famous than the books above, but (IMO) it's in the same rarefied company as Dune and J.R.R. Tolkien's work.
- - - -
Tangent: Have you read Gene Wolfe's Book of the New Sun? It's less famous than the books above, but (IMO) it's in the same rarefied company as Dune and J.R.R. Tolkien's work.
I definitely think The Dark Forest ranks up there with those.
I haven't even heard of Wolfe's book. Will check it out, thanks.
I haven't even heard of Wolfe's book. Will check it out, thanks.
Let's send them a ping. What could go wrong?
Fantastic Sci-Fi book series, btw.
Full name is A Remembrance of Earth's Past.
Full name is A Remembrance of Earth's Past.
I bet the sophons are already on their way
https://en.wikipedia.org/wiki/Breakthrough_Starshot
Quite a nice concept - accelerate the probe with lasers- no plans for deceleration though
Quite a nice concept - accelerate the probe with lasers- no plans for deceleration though
Other commenters (rightly) pointed out this is a stretch to the term "habitable".
What's becoming clear though is the only thing stopping us from lots of Earth-mass planets is the abilities of our detectors to detect ever-smaller gravitational wobbles and ever-smaller transits. Bear in mind we only tend to find planets around stars where we're on their ecliptic planes.
So planets seem to be really common. If they weren't the odds of finding planetary systems on our nearest stellar neighbour would be quite low.
But the distances are still so vast that the energy expenditure and timelines are completely impractical (if you assume the speed of light of a hard cosmic limit, which I do).
So if planets are common and interstellar travel is impractical, the only way to expand really is around your own star. This is the Dyson Swarm. This would actually solve the energy issue of interstellar travel (ie"stellar highways") so it's almost a prerequisite. Thing is, Dyson Swarms are likely detectable from vast distances due to their IR emissions (ie the only way to get rid of heat is to radiate it into space and that has a specific frequency depending on the temperature of the radiating object).
But if planets are really common and we don't see any Dyson Swarms it seems that spacefaring life is extremely rare and the most likely number of such civilizations in the Milky Way is 1 including us.
What's becoming clear though is the only thing stopping us from lots of Earth-mass planets is the abilities of our detectors to detect ever-smaller gravitational wobbles and ever-smaller transits. Bear in mind we only tend to find planets around stars where we're on their ecliptic planes.
So planets seem to be really common. If they weren't the odds of finding planetary systems on our nearest stellar neighbour would be quite low.
But the distances are still so vast that the energy expenditure and timelines are completely impractical (if you assume the speed of light of a hard cosmic limit, which I do).
So if planets are common and interstellar travel is impractical, the only way to expand really is around your own star. This is the Dyson Swarm. This would actually solve the energy issue of interstellar travel (ie"stellar highways") so it's almost a prerequisite. Thing is, Dyson Swarms are likely detectable from vast distances due to their IR emissions (ie the only way to get rid of heat is to radiate it into space and that has a specific frequency depending on the temperature of the radiating object).
But if planets are really common and we don't see any Dyson Swarms it seems that spacefaring life is extremely rare and the most likely number of such civilizations in the Milky Way is 1 including us.
I will start off by saying I have very little knowledge of physics or astronomy, but reading comments like these feels like I'm watching a 13th century British sailor confidently state what's on the other side of the Atlantic ocean...
Do we really know enough to be able to say if a planet is habitable? Or could there be other forms of life that we don't know of yet... We have only recently put a man on the moon, and now we're saying we would be able to detect dyson spheres...?
Do we really know enough to be able to say if a planet is habitable? Or could there be other forms of life that we don't know of yet... We have only recently put a man on the moon, and now we're saying we would be able to detect dyson spheres...?
> We have only recently put a man on the moon, and now we're saying we would be able to detect dyson spheres...?
A moth doesn't even have electricity, but it can detect a lampshade. A Dyson sphere is basically a stellar lampshade; we can detect it if the laws of thermodynamics hold, and we're pretty sure they do. (A Dyson swarm is similar, though a bit harder to detect.)
A moth doesn't even have electricity, but it can detect a lampshade. A Dyson sphere is basically a stellar lampshade; we can detect it if the laws of thermodynamics hold, and we're pretty sure they do. (A Dyson swarm is similar, though a bit harder to detect.)
Maybe stars are the Dyson spheres, and their emissions are the waste energy that wasn't worth harvesting.
The spectral signature would be different if that happened. If all of the stars are Dyson spheres, then… maybe our models about stars are fundamentally wrong. But I doubt it; the maths to work out what the signature should be (given the composition) is pretty simple. Take a blackbody, put spectral lines as measured in the lab onto it, then redshift it.
People bring this up a lot. It's fair to ask. I do often find it comes from a place of wishful thinking. I mean I'd like to have FTL at my disposal true. But what we're dealing with now seem to be either hard physical limits or such close approximations to be effectively the same. The key two are:
1. The speed of light is a hard limit; and
2. Thermodynamics (particularly the Second Law) applies. Specifically, you can't get energy from nothing.
From this you can draw a few conclusions:
1. The likely sources of future energy are solar (most likely IMHO) and nuclear fusion. I hope fusion is viable. I'm not yet convinced it is. More exotic far-future options include antimatter and black holes. Antimatter is something you'd make. Think of it like a battery. So you still need the energy to make it. Black holes as propulsion are the same way. Generating power around a large black hole is theoretically possible but has a bunch of issues;
2. Reaction mass is a huge problem for traveling large distances, so much so that using photos to impart momentum seems the most practical. Fusion could be viable here. Antimatter and black hole propulsion are theoretically possible;
3. Because of energy demands, capturing the Sun's energy makes the most sense and doesn't require any "magical" or exotic science or technology;
4. Because of thermodynamics, eventually heat will radiate into space. It's really the only way of dissipating heat, ultimately.
5. Like I said, the IR signature is purely a function of temperature; and
6. A star with a Dyson Swarm will have a very strange (to us) spectrum. Very little visible light. High amounts of IR. There is really no hiding such a megastructure.
So this is essentially a natural conclusion based on physical laws we have no evidence for that they're false or meaningfully incomplete. Thing is, if the speed of light isn't a hard limit that actually makes it more likely we'd find spacefaring life not less because the reach of such a civilization would be so much farther.
1. The speed of light is a hard limit; and
2. Thermodynamics (particularly the Second Law) applies. Specifically, you can't get energy from nothing.
From this you can draw a few conclusions:
1. The likely sources of future energy are solar (most likely IMHO) and nuclear fusion. I hope fusion is viable. I'm not yet convinced it is. More exotic far-future options include antimatter and black holes. Antimatter is something you'd make. Think of it like a battery. So you still need the energy to make it. Black holes as propulsion are the same way. Generating power around a large black hole is theoretically possible but has a bunch of issues;
2. Reaction mass is a huge problem for traveling large distances, so much so that using photos to impart momentum seems the most practical. Fusion could be viable here. Antimatter and black hole propulsion are theoretically possible;
3. Because of energy demands, capturing the Sun's energy makes the most sense and doesn't require any "magical" or exotic science or technology;
4. Because of thermodynamics, eventually heat will radiate into space. It's really the only way of dissipating heat, ultimately.
5. Like I said, the IR signature is purely a function of temperature; and
6. A star with a Dyson Swarm will have a very strange (to us) spectrum. Very little visible light. High amounts of IR. There is really no hiding such a megastructure.
So this is essentially a natural conclusion based on physical laws we have no evidence for that they're false or meaningfully incomplete. Thing is, if the speed of light isn't a hard limit that actually makes it more likely we'd find spacefaring life not less because the reach of such a civilization would be so much farther.
And it's also assuming that any life is like us, with no other technology or way to cycle/recycle heat other than to radiate it into space.
I mean, I know the proof of life is us, but the human-centered view of the universe does reek of prior historical "knowledge" that the earth was the center of the universe. I understand searching for life like us, as that is what we can extrapolate from current data. But to use that to infer that we're it, it's just too much for me.
I mean, I know the proof of life is us, but the human-centered view of the universe does reek of prior historical "knowledge" that the earth was the center of the universe. I understand searching for life like us, as that is what we can extrapolate from current data. But to use that to infer that we're it, it's just too much for me.
This is the realm of the Fermi Paradox (which is a misnomer because it's not really a paradox at all).
The key question is that if planets are so common and space is so big, why does it seem to be so empty of life? You bring up an argument that maybe life is so different as to be undetectable. It's a fair question to ask but the beauty of the Fermi Paradox is that you don't need to argue about what's most likely. You simply have to be concerned with what's possible.
Let me put it this way. let's say that there is 1 other spacefaring civilization in the Milky Way and they've evolved like you said in a way completely alien to us and as such don't follow a path we can easily detect or at least we don't think to look for it. I can buy that as entirely possible.
But now let's assume there are 1,000 spacefaring civilizations in the Milky Way. What are the odds that every one them falls in this category? What are the odds that none of them follow a similar evolutionary path to us and what we consider highly likely? It becomes increasingly incredulous as you scale up the number of civilizations.
So what's more likely? 1,000 civilizations followed a path alien to us independently? Or that there are few to no other civilizations out there to detect?
To say we're the only 1 of 1,000 to follow this path is really a different kind of human-centric hubris.
Extracting energy from a star is so low-tech it defies logic to think we're the only ones who will (likely) do it.
The key question is that if planets are so common and space is so big, why does it seem to be so empty of life? You bring up an argument that maybe life is so different as to be undetectable. It's a fair question to ask but the beauty of the Fermi Paradox is that you don't need to argue about what's most likely. You simply have to be concerned with what's possible.
Let me put it this way. let's say that there is 1 other spacefaring civilization in the Milky Way and they've evolved like you said in a way completely alien to us and as such don't follow a path we can easily detect or at least we don't think to look for it. I can buy that as entirely possible.
But now let's assume there are 1,000 spacefaring civilizations in the Milky Way. What are the odds that every one them falls in this category? What are the odds that none of them follow a similar evolutionary path to us and what we consider highly likely? It becomes increasingly incredulous as you scale up the number of civilizations.
So what's more likely? 1,000 civilizations followed a path alien to us independently? Or that there are few to no other civilizations out there to detect?
To say we're the only 1 of 1,000 to follow this path is really a different kind of human-centric hubris.
Extracting energy from a star is so low-tech it defies logic to think we're the only ones who will (likely) do it.
There is a major logical flaw in your argument.
Space travel is only considered to be impractical for humans, or similarly large organic entities within their limited lifespan.
The time constraint and the mass constraint may not be particularly relevant to intelligence that no longer has organic form.
An artificial lifeform may not have a defined life span and thus taking 100,000 years to travel the stars may be acceptable.
Additionally, they may only need to make the trip once to establish the receiving antenna, in order to transmit their "progeny" around the galaxy.
Tldr; We are like ants thinking that we need to figure out how to make really long tunnels to cross the Atlantic, instead of focusing on the limitations of our physical bodies.
Space travel is only considered to be impractical for humans, or similarly large organic entities within their limited lifespan.
The time constraint and the mass constraint may not be particularly relevant to intelligence that no longer has organic form.
An artificial lifeform may not have a defined life span and thus taking 100,000 years to travel the stars may be acceptable.
Additionally, they may only need to make the trip once to establish the receiving antenna, in order to transmit their "progeny" around the galaxy.
Tldr; We are like ants thinking that we need to figure out how to make really long tunnels to cross the Atlantic, instead of focusing on the limitations of our physical bodies.
I'm reminded of the wonderful book "Blindsight" which features vampire astronauts because they can put themselves into states of suspended animation
Time is still a problem because how do you keep such a spacecraft in good repair?. If anything breaks it needs a fair amount of intelligence to fix. same for parts that wear out.
Rocks though space, but that doesn't help learn much. Rocks bring up the other issue is we don't know how many high velocity things might be between starts, numbers below the noise limits of our current sensors is enough to destroy anything we could send out.
Rocks though space, but that doesn't help learn much. Rocks bring up the other issue is we don't know how many high velocity things might be between starts, numbers below the noise limits of our current sensors is enough to destroy anything we could send out.
Your body breaks constantly in minor ways, yet it's automagically repaired to a degree. This evolved naturally, but after sufficient breakthroughs in material sciences we could evolve/design materials that are indestructible.
If you haven't already, give Rendezvous with Rama a read.
If you haven't already, give Rendezvous with Rama a read.
Just for reference, the planet is 4.0×10^13 kilometres away, if we send our fastest ever probe, and assume it averages the top speed of 586,800 km/h all the way there, it will still take 7,781 years to reach the planet.
Under 1g acceleration about 3.5 years
https://www.omnicalculator.com/physics/space-travel
https://www.omnicalculator.com/physics/space-travel
1) you also need time decelerate
2) speed of light is a hard limit, you cannot keep accelerating and you need more energy the closer you get to that limit
2) speed of light is a hard limit, you cannot keep accelerating and you need more energy the closer you get to that limit
> 1) you also need time decelerate
No that would be a waste of effort. A flyby mission definitely makes the most sense. The 3.5 years are with deceleration though.
No that would be a waste of effort. A flyby mission definitely makes the most sense. The 3.5 years are with deceleration though.
You mean flyby at almost the speed of light?
For interstellar travel, I think usable flyby speed is almost the same as stop and look around speed.
I found this little ditty in a linked article way way way more fascinating:
> Humanity’s first chance to explore this nearby world may come from the recently announced Breakthrough Starshot initiative, which plans to build fleets of tiny laser-propelled interstellar probes in the coming decades. Travelling at 20% of the speed of light, they would take about 20 years to cover the 1.3 parsecs from Earth to Proxima Centauri.
> Humanity’s first chance to explore this nearby world may come from the recently announced Breakthrough Starshot initiative, which plans to build fleets of tiny laser-propelled interstellar probes in the coming decades. Travelling at 20% of the speed of light, they would take about 20 years to cover the 1.3 parsecs from Earth to Proxima Centauri.
> Unlike the Sun, which will evolve into a red giant in 6.5 billion years and reach the end of its life at an age of about 10 billion years, Proxima will stay on the main sequence for another four trillion years due to its low mass and low energy production.
4 trillion years. Wow. If there was life on one of the planets, it would have a long time to evolve.
4 trillion years. Wow. If there was life on one of the planets, it would have a long time to evolve.
I feel like there is definitely a trend of astronomy articles low key alluding to or hinting at life on other planets in their titles. Presumably to garner clicks and be bait, but when you read the article invariably it's good old science and no life to be found yet.
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If there are three known planets in the Proxima Centauri, why are they called b, c and d — why is there no Proxima Centauri a?
Now, we need to have some advanced technologies to have a shot at going there.
If it's the third planet why are they calling it Proxima Centauri d?
Maybe 'Proxima Centauri a' refers to the star itself? I'm not sure.
Has it been spotted though? Indirect evidence shows something is there. But no one has seen it, not any image has been produced.
'detected' would be more accurate, but this is a pop sci take on a press release that says "New planet detected around star closest to the Sun" [1] of a paper called "A candidate short-period sub-Earth orbiting Proxima Centauri" [2]. That's often how it goes, each new medium picking it up adding more and more embellishment, graphics of green-and-blue planets, and breathless fantasizing about one day colonizing the stars.
"Earth-like planet spotted orbiting Sun's closest star" is a lot sexier than "We detect a signal at 5.12 ± 0.04 days with a semi-amplitude of 39 ± 7 cm s−1. The analysis of subsets of the ESPRESSO data, the activity indicators, and chromatic RVs suggest that this signal is not caused by stellar variability but instead by a planetary companion with a minimum mass of 0.26 ± 0.05 M⊕ (about twice the mass of Mars) orbiting at 0.029 au from the star. The orbital eccentricity is well constrained and compatible with a circular orbit."
[1] https://www.eso.org/public/news/eso2202/
[2] https://www.aanda.org/10.1051/0004-6361/202142337
"Earth-like planet spotted orbiting Sun's closest star" is a lot sexier than "We detect a signal at 5.12 ± 0.04 days with a semi-amplitude of 39 ± 7 cm s−1. The analysis of subsets of the ESPRESSO data, the activity indicators, and chromatic RVs suggest that this signal is not caused by stellar variability but instead by a planetary companion with a minimum mass of 0.26 ± 0.05 M⊕ (about twice the mass of Mars) orbiting at 0.029 au from the star. The orbital eccentricity is well constrained and compatible with a circular orbit."
[1] https://www.eso.org/public/news/eso2202/
[2] https://www.aanda.org/10.1051/0004-6361/202142337
ROAD TRIP!!!
We can't even work out how to run our own planet in a consistent and consensual way, I say leave it to the other more civil aliens to inhabit, otherwise we'll end up with another broken planet.
I don't think space is so crowded and we got enough empty rocks up there.
What is there to break on a lifeless planet?
Clearly the implication is that it is another habitable planet and the other comments talking about going there etc. It isn't the rock I am worried about, it would be community that decides to move there and then starts exploiting each other leaving a planet depleted of resources and a rather long journey home!
This is basically the entire plot of Sid Meier's Alpha Centauri.
From the paper (Introduction and Conclusions, respectively) [1]:
The habitability conditions of Proxima b, which orbits within the HZ of the star, have been extensively studied (e.g. Barnes et al. 2017; Ribas et al. 2016; Turbet et al. 2016; Meadows & Barnes 2018). On the other hand, the candidate Proxima d orbits much closer to the star and outside the HZ range.
In particular, the discovery of an Earth-mass planet orbiting Proxima Centauri (Anglada-Escudé et al. 2016), our closest stellar neighbour, was one of the most significant results in the field, in part because the planet orbits inside the habitable zone (HZ) of the star (e.g. Kopparapu et al. 2013).
So, Proxima d is too close to the star to be inside the HZ; it's within the HZ in the sense that the HZ is further out from the star.
The author of the Nature commentary, which claims that "it could have oceans of liquid water that can potentially harbour life", apparently didn't read the paper.
[1] https://www.eso.org/public/archives/releases/sciencepapers/e...