Astronomers discover super-Earth around Barnard's star(phys.org)
phys.org
Astronomers discover super-Earth around Barnard's star
https://phys.org/news/2018-11-astronomers-super-earth-barnard-star.html
131 comments
How many years is such a discovery away?
The Extremely Large Telescope in Chile, which fits the "30 meter class" description, is scheduled to be operational in 2024.
Luvoir is expected to launch in the mid-2030s. It is one of at least two exoplanet detection-and-characterization missions that is under study by NASA.
> Luvoir is expected to launch in the mid-2030s
For others who are not familiar with the NASA studies, "expected" is probably too strong a word and "proposed" is probably more accurate. LUVOIR is one of four flagship mission concepts which NASA has provided with seed money. They will all be evaluated during the coming 2020 Decadal Survey of Astronomy and Astrophysics. The recommendations from that survey will then be used as guidance for NASA. So if the Decadal Survey ranks LUVOIR as a top priority (the missions are all so large that it is unlikely more than one would be funded), and if they meet their proposed timeline, then it would launch in the mid-2030s. So it's not yet a given that LUVOIR will happen (another mission could be more highly ranked), and the timeline should be taken with a grain of salt.
For others who are not familiar with the NASA studies, "expected" is probably too strong a word and "proposed" is probably more accurate. LUVOIR is one of four flagship mission concepts which NASA has provided with seed money. They will all be evaluated during the coming 2020 Decadal Survey of Astronomy and Astrophysics. The recommendations from that survey will then be used as guidance for NASA. So if the Decadal Survey ranks LUVOIR as a top priority (the missions are all so large that it is unlikely more than one would be funded), and if they meet their proposed timeline, then it would launch in the mid-2030s. So it's not yet a given that LUVOIR will happen (another mission could be more highly ranked), and the timeline should be taken with a grain of salt.
This is 100% accurate.
In fact, given the timeline, I’d be surprised if either Luvoir or HabEx, as currently envisioned, actually flies. There is a lot of technical innovation that will happen between now and then, even if the Decadal recommends one or the other.
(I work on yield modeling for the study. I make plots and animations of observations, and the times on the plot labels have disconcertingly-far-off times like 2036.)
In fact, given the timeline, I’d be surprised if either Luvoir or HabEx, as currently envisioned, actually flies. There is a lot of technical innovation that will happen between now and then, even if the Decadal recommends one or the other.
(I work on yield modeling for the study. I make plots and animations of observations, and the times on the plot labels have disconcertingly-far-off times like 2036.)
It all depends on jwst. If that flops, or even if it only goes as planned, without the spectacular over-performance expected of nasa stuff these days, future large space telescopes will be shelved for a generation
At least the optical ones.
My worry is that jwst will be too short-lived. It cannot become the fixture for decades that hubble has been.
My worry is that jwst will be too short-lived. It cannot become the fixture for decades that hubble has been.
I imagine that an image of a planet around another star would have similar global impact as the Earth-rise picture from the Apollo missions did / does - sort of uniting people from different nations by giving them a visceral reaction from a totally new pov.
Is such an "image" why we are discussing here?
Is such an "image" why we are discussing here?
Personally I'm most looking forward to the James Webb Telescope [1]. It's expected to be launched as soon as 2007!
https://en.wikipedia.org/wiki/James_Webb_Space_Telescope
https://en.wikipedia.org/wiki/James_Webb_Space_Telescope
I'd love to see a simple, 2D map of our corner of the galaxy now that we've discovered so many planets.
Something like the closest 25-50 stars, color coded by type of star and planets (cool/hot/gassy).
Something like the closest 25-50 stars, color coded by type of star and planets (cool/hot/gassy).
Here is a slightly older overview of our neighbourhood (the stars haven‘t moved much since then, but you‘d have to add the more recent planet information): https://zompist.com/nearstars.html
Neat, thanks for the link!
What I'm really thinking though, is a simpler looking map. Like a political map of the world, the kinds you had hanging up in your 2nd grade classroom. I'm surprised no one has made one yet of our starry neighborhood.
I'd make one, but I unfortunately cannot draw or do any graphic design to save my life.
What I'm really thinking though, is a simpler looking map. Like a political map of the world, the kinds you had hanging up in your 2nd grade classroom. I'm surprised no one has made one yet of our starry neighborhood.
I'd make one, but I unfortunately cannot draw or do any graphic design to save my life.
If Jack Williamson was correct then we probably shouldn't probe deeper, lest the Medusae find us...
Would be interesting to see if it could bear life despite being frozen.
Would be interesting to see if it could bear life despite being frozen.
Well tardigrades wouldn't mind that much, but it would be hard to evolve to that point. The point is, evolution seems to find a way no matter how harsh the environment is, as long as the life already started
its only a matter of time we find other living organisms. The odds are staked so high against not finding any.
Finding living organisms would in general be bad news, but it depends on the type of life. It would tell us about why we don't see a universe filled with intelligent life. It would increase the probability though that the great filter is ahead of us, especially if the life is multi-cellular.
[deleted]
Let's say we'd eventually find those other living organisms. What then? (BTW, the odds of that life to be a sentient one are much lower.)
Start investing more heavily in becoming a space-faring civilization? Also, try to learn about these other life forms.
I argue that space-faring civilization goal should be independent of alien encountering.
If the Great Filter is ahead of us, becoming a space-faring civilization sooner increases the odds of surviving it.
(And that's the main argument for the Great Filter being behind us, it is hard to imagine that we are fighting against astronomical odds to become space-faring.)
(And that's the main argument for the Great Filter being behind us, it is hard to imagine that we are fighting against astronomical odds to become space-faring.)
The argument the great filter is ahead of us though is based on the observation that even with slower then light spacetravel, over the timeframes of the existing universe a species could still colonize the entire Milky Way in something like a 100,000 years with von Neumann probes (of which organic life would be a good basis for building one).
There should be life everywhere it's possible by technological panspermia - but we don't seem to observe that. What stops elder civilizations from doing this, is the big mystery.
Unless of course, as a poster above notes, if we fire up the JWST and discover chlorophyll-fringes in the spectra of just about every rocky planet we can see. That'd imply a lot.
There should be life everywhere it's possible by technological panspermia - but we don't seem to observe that. What stops elder civilizations from doing this, is the big mystery.
Unless of course, as a poster above notes, if we fire up the JWST and discover chlorophyll-fringes in the spectra of just about every rocky planet we can see. That'd imply a lot.
That is the argument for a filter existing. It says nothing about it's position.
I agree. But I imagine it would help some people get more excited about it.
I posted this above, but it's a good answer to you as well.
I think that most people, be them scientists, religious leaders, politicians, or even laymen, will have their lives changed forever by the discovery of extra-terrestrial life. For the religious, discovery of even extra-terrestrial bacteria will upend most of the interpretations of their holy books. Those books are the foundation of modern Western society (Do not kill, do not steal, do not take another man's wife, etc). By upending the basis of society we have no idea how humanity will end up. Will we throw everything based on the bible away? Reinterpret them? Will the Jews and Muslims reconcile? Will the Christians set out on another crusade? Will that crusade be to the extra-terrestrial bacteria to wipe them out as well?
I think that most people, be them scientists, religious leaders, politicians, or even laymen, will have their lives changed forever by the discovery of extra-terrestrial life. For the religious, discovery of even extra-terrestrial bacteria will upend most of the interpretations of their holy books. Those books are the foundation of modern Western society (Do not kill, do not steal, do not take another man's wife, etc). By upending the basis of society we have no idea how humanity will end up. Will we throw everything based on the bible away? Reinterpret them? Will the Jews and Muslims reconcile? Will the Christians set out on another crusade? Will that crusade be to the extra-terrestrial bacteria to wipe them out as well?
Some will outright deny the existence of the new information about extra-terrestrial life.
But, for most believers, I bet there will be a re-articulation of the tenets of the faith, a transformation of their existing doctrine into something that seems compatible with the new information.
Maybe this is not quite the right way to look at it, but it seems to me that, taken together, these religious faiths have already survived many, many highly traumatic historical and informational challenges and persecutions (e.g. invasion of the "sea peoples" in the Eastern Mediterranean, rise and fall of the Greek Empire, rise of the Roman Empire, destruction of the temple in Jerusalem, Constantine's conversion, religious councils which redefined Jesus, fall of the Roman Empire, Galileo, Copernicus, Reformation, Magellan, Enlightenment, British Empire, Darwin/Evolution, Napoleon, Hubble–Lemaître and modern cosmology, the Holocaust, etc ...)
For example, it seems to me like modern astronomy has drastically challenged and damaged the very notion of a saintly or holy figure "ascending into heaven," but believers whose holy books explicitly describe such an event have not abandoned their faiths in large numbers because of it.
Another example is modern biology and theories about the origin of humanity. That didn't stop religions based on the book of Genesis.
IMHO, hard evidence of extra terrestrial life will be just one more speed bump in the history of these faiths.
But, for most believers, I bet there will be a re-articulation of the tenets of the faith, a transformation of their existing doctrine into something that seems compatible with the new information.
Maybe this is not quite the right way to look at it, but it seems to me that, taken together, these religious faiths have already survived many, many highly traumatic historical and informational challenges and persecutions (e.g. invasion of the "sea peoples" in the Eastern Mediterranean, rise and fall of the Greek Empire, rise of the Roman Empire, destruction of the temple in Jerusalem, Constantine's conversion, religious councils which redefined Jesus, fall of the Roman Empire, Galileo, Copernicus, Reformation, Magellan, Enlightenment, British Empire, Darwin/Evolution, Napoleon, Hubble–Lemaître and modern cosmology, the Holocaust, etc ...)
For example, it seems to me like modern astronomy has drastically challenged and damaged the very notion of a saintly or holy figure "ascending into heaven," but believers whose holy books explicitly describe such an event have not abandoned their faiths in large numbers because of it.
Another example is modern biology and theories about the origin of humanity. That didn't stop religions based on the book of Genesis.
IMHO, hard evidence of extra terrestrial life will be just one more speed bump in the history of these faiths.
> For the religious, discovery of even extra-terrestrial bacteria will upend most of the interpretations of their holy books
The religious might surprise you.
https://www.vofoundation.org/faith-and-science/life-in-the-u...
The religious might surprise you.
https://www.vofoundation.org/faith-and-science/life-in-the-u...
Doesn't surprise me at all. There are a multitude of opinions. But the question was "what will change", discussing those that accept the new findings and have no need to change is orthogonal to answering the question.
Start worrying that a great filter might be in our future rather than our past.
I, for one, plan on eating them. (Not the sentient ones)
study, eat, destroy. In no particular order.
Honestly, nothing much will happen. Self-plug, ahead.
http://winestockwebdesign.com/Essays/Alien_Life.html
Long story, short: It would have to be sentient life in order to get any long-lasting attention. In the recent past, plenty of scientists were sure that simple life (e.g., lichens) existed even on Mars. The general public didn't go nuts over that. So finding simple life—for sure, this time—wouldn't change anything this time around, either.
http://winestockwebdesign.com/Essays/Alien_Life.html
Long story, short: It would have to be sentient life in order to get any long-lasting attention. In the recent past, plenty of scientists were sure that simple life (e.g., lichens) existed even on Mars. The general public didn't go nuts over that. So finding simple life—for sure, this time—wouldn't change anything this time around, either.
Non-living organisms would be even more interesting!
How do you figure? The distances are tremendous, and it seems like we ate guessing at what the climate is like on the nearest exoplanets. How would we spot life? Wed need probes to travel near the speed of light to have any chance. That's a long way off.
We have spectroscopy. Complex biological molecules can be identified through spectrographic analysis of starlight passing through the exoplanet’s atmosphere. JWST is equipped with a near infrared spectrograph to do exactly this.
Traveling near the speed of light or at it will never happen. Infinite energy / mass problem. Plus everyone back at earth will have aged equivalent to the number of light years away, while it may feel only like a couple weeks on the ship. Unless we develop some type of wormhole technology, we're pretty much confined to our immediate system for any realistic exploration and communications.
I think the comment was made in relation to star's age, as it is one of the oldest in our galaxy. If life requires time to develop, this planet gave it a good shot at that. Also, the planet's climate may have been more favorable to life in the star's heyday, which means that even if nothing living will be around when we'll get there, that still makes it a very promising archeological place.
We should send palaeontologists, not archaeologists.
My recurring dream for the JWST is that we switch it on and get immediately overwhelmed with indirect spectroscopic evidence of biology within multiple exoplanets, ushering in a whole new era of science. Watching that launch will be the most heartstopping moment of my life.
My recurring dream for the JWST is that it actually ever launches. :(
>Watching that launch will be the most heartstopping moment of my life.
You got that right. When Elon launched the car I was like "eh this will be just like any other launch" then as the launch started I was perched on the edge of my chair shouting "CLIMB CLIMB CLIMB BABY CLIMB" at my phone. JWST will be one of the most nerve-racking moments of my life if I watch the launch due to it's many delays.
>Watching that launch will be the most heartstopping moment of my life.
You got that right. When Elon launched the car I was like "eh this will be just like any other launch" then as the launch started I was perched on the edge of my chair shouting "CLIMB CLIMB CLIMB BABY CLIMB" at my phone. JWST will be one of the most nerve-racking moments of my life if I watch the launch due to it's many delays.
I can see why people would focus on the risk of a flashy explosion, but I think the real risk will be with the deployment process and having gotten everything right with JWST. ESA launches are very reliably, JWST is a one time design.
I think as long as we are using rockets to lift things from our world, there will be some level of fear of failure. After all, rockets are essentially an explosion attempting to be controlled.
> JWST is a one time design.
I wish they've invented notebooks or something. So we could build a second JWST at a smaller cost.
I wish they've invented notebooks or something. So we could build a second JWST at a smaller cost.
The problem is that the technology that JWST is built with is no longer available. The development cycle moved so fast that the industrial bits needed to manufacture JWST are no longer there, even if we have complete and detailed plans.
Very similar with how building a Saturn V today is logistically impossible, even if we can build more modern, efficient and cheaper rockets.
Very similar with how building a Saturn V today is logistically impossible, even if we can build more modern, efficient and cheaper rockets.
On the bright side, a failed deployment might make us expedite deep space manned mission tech in order to go fix it.
There is not a single crewed vehicle in operation or even planned that supports spacewalks. If it's not next to the ISS, people aren't going to be able to fix it.
At best we could send a robot, which would probably be more easily operated from the ground.
At best we could send a robot, which would probably be more easily operated from the ground.
There've been several proposals for an Orion-mated orbital module with an airlock, as well as an ESA one based around their ATV. After all, the eventual goal of Orion is to allow deep-space missions to asteroids etc.
Even coming up with something from scratch is unlikely to cost the $10B we'd lose from a failed JWST.
Even coming up with something from scratch is unlikely to cost the $10B we'd lose from a failed JWST.
[deleted]
I dream to be there during the launch as well. Could you enlighten me on how JWST could find the evidence of life?
>Could you enlighten me on how JWST could find the evidence of life?
Near Infrared Spectroscopy [0]. JWST will be the first instrument in space capable of performing NIR spectroscopy, which will be used to analyze the starlight shining through exoplanets' atmospheres for evidence of biological molecules.
[0] https://dms.cosmos.esa.int/COSMOS/doc_fetch.php?id=3372219
Near Infrared Spectroscopy [0]. JWST will be the first instrument in space capable of performing NIR spectroscopy, which will be used to analyze the starlight shining through exoplanets' atmospheres for evidence of biological molecules.
[0] https://dms.cosmos.esa.int/COSMOS/doc_fetch.php?id=3372219
Citation needed?
If the odds of life spontaneously starting and then surviving are really low, then there really may be no other life in our galaxy (<1 trillion stars) or even the observable universe (<1 trillion trillion stars).
If the odds of life spontaneously starting and then surviving are really low, then there really may be no other life in our galaxy (<1 trillion stars) or even the observable universe (<1 trillion trillion stars).
Citation needed?
We have a sample size of just one (our solar system). But we already know that life on Earth began very soon after it cooled enough to have liquid water - that gives us some confidence that it can't be that hard for life to start.
We know life's been around on Earth for ~4 billion years, surviving multiple insane climate swings from subtropical vegetation and species living in the Arctic to the entire planet freezing over, multiple massive impacts from space, insane volcanism that people today just would not even recognize as volcanism. Hopefully that means life's somewhat durable.
We have a sample size of just one (our solar system). But we already know that life on Earth began very soon after it cooled enough to have liquid water - that gives us some confidence that it can't be that hard for life to start.
We know life's been around on Earth for ~4 billion years, surviving multiple insane climate swings from subtropical vegetation and species living in the Arctic to the entire planet freezing over, multiple massive impacts from space, insane volcanism that people today just would not even recognize as volcanism. Hopefully that means life's somewhat durable.
If what you mean by 'life' is bacterium, sure. That's all that was here for 3 billion years. I don't think we'd find that very exciting.
Eukaryotes are basically a fluke. The symbiosis event that created Eukaryotes from a random combination of Archaea and Bacteria appears to have happened only _once_ in the entire history of the earth.
It's arrogant to assume that life as we know it is both inevitable and inevitably complex in a manner similar to our complexity.
A practically infinite universe means potentially infinite diversity, including phenomenon that may not recognize as life at all to us, but should be equally interesting.
Eukaryotes are basically a fluke. The symbiosis event that created Eukaryotes from a random combination of Archaea and Bacteria appears to have happened only _once_ in the entire history of the earth.
It's arrogant to assume that life as we know it is both inevitable and inevitably complex in a manner similar to our complexity.
A practically infinite universe means potentially infinite diversity, including phenomenon that may not recognize as life at all to us, but should be equally interesting.
"Eukaryotes are basically a fluke. The symbiosis event that created Eukaryotes from a random combination of Archaea and Bacteria appears to have happened only _once_ in the entire history of the earth."
Isn't it possible that once it happened, it filled a niche that prevented something similar from happening again? Thus, the fact it only happened once doesn't tell you how probable it was to happen at all.
I have the impression other similar things may have happened as well. Recent articles about a viral-like protein that may be crucial to how long term memory works suggest that chance combinations of life that melded may be a theme.
Isn't it possible that once it happened, it filled a niche that prevented something similar from happening again? Thus, the fact it only happened once doesn't tell you how probable it was to happen at all.
I have the impression other similar things may have happened as well. Recent articles about a viral-like protein that may be crucial to how long term memory works suggest that chance combinations of life that melded may be a theme.
>Isn't it possible that once it happened, it filled a niche that prevented something similar from happening again?
Except it did happen again. Chloroplasts and mitochondria organelles are so different they are considered to have been generated from separate events.
Assuming that there are niches though is dangerous, because it assumes the evolution is guided, which it isn't. It's entirely possible that this has happened many times throughout history, but the resulting new organisms couldn't compete and died off without a leaving a trace.
That's why assuming it only happened twice is survivor bias.
Except it did happen again. Chloroplasts and mitochondria organelles are so different they are considered to have been generated from separate events.
Assuming that there are niches though is dangerous, because it assumes the evolution is guided, which it isn't. It's entirely possible that this has happened many times throughout history, but the resulting new organisms couldn't compete and died off without a leaving a trace.
That's why assuming it only happened twice is survivor bias.
"Assuming that there are niches though is dangerous, because it assumes the evolution is guided, which it isn't"
No, I wasn't suggesting that evolution is guided. If something evolves, and it ends up in the way of anything evolving similarly, it's not purposeful. It just is, as long as some catastrophe doesn't clear the way.
Edit: your comment "It's entirely possible that this has happened many times throughout history, but the resulting new organisms couldn't compete and died off without a leaving a trace." is a distinction without a difference to me. That's what I meant by it not happening, and the existing organisms occupying a niche.
No, I wasn't suggesting that evolution is guided. If something evolves, and it ends up in the way of anything evolving similarly, it's not purposeful. It just is, as long as some catastrophe doesn't clear the way.
Edit: your comment "It's entirely possible that this has happened many times throughout history, but the resulting new organisms couldn't compete and died off without a leaving a trace." is a distinction without a difference to me. That's what I meant by it not happening, and the existing organisms occupying a niche.
I think finding life on any other world would be very exciting even if uni-cellular. While we know which organic compounds are common in the nearby universe, we have no idea what other "architectures" are feasible, even granted an environment (temperature, pressure, solar spectrum) roughly like ours (including extremophiles). Life optimizes, but it's also path-dependent. Surely Earth's genetic code is accidental and path-dependent, but how constrained is the protein design space? For example, given a star like ours, do we have optimum chlorophyll? Or if you make your living as a sulfate reducing prokaryote, how many different ways can you do that?
No telescope will tell us what the ribosomes of Barnard b look like, of course.
But if only macroscopic life excites you, is it clear that you need eukaryotes for complex (multi-cellular) life? And how can you know it happened only once? It could also be that it happened multiple times, but one strain outcompeted (or just ate) every other. There could be undiscovered alternate "eukaryotes" if they remained single-cellular, too.
No telescope will tell us what the ribosomes of Barnard b look like, of course.
But if only macroscopic life excites you, is it clear that you need eukaryotes for complex (multi-cellular) life? And how can you know it happened only once? It could also be that it happened multiple times, but one strain outcompeted (or just ate) every other. There could be undiscovered alternate "eukaryotes" if they remained single-cellular, too.
Actually, cell-level endosymbiosis seems to have happened a bunch of times. Chloroplasts in plants are basically the same deal. The amoeboid paulinella chromatophora seems to have an independent lineage of chloroplasts. The Wikipedia page on endosymbiosis has more examples. It's starting to look pretty common.
Also, complex multicellularity (IIRC defined as differentiated cells) has evolved (according to the latest theory) six times. So that looks pretty likely to happen eventually, as well.
Human-level technological civilization, yeah, that looks like a one-time thing so far.
Edit: check out this article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3910982/ They just casually mention "diatom-derived plastids", which are basically organelles that used to be diatoms, eukaryotic organisms in themselves!
Also, complex multicellularity (IIRC defined as differentiated cells) has evolved (according to the latest theory) six times. So that looks pretty likely to happen eventually, as well.
Human-level technological civilization, yeah, that looks like a one-time thing so far.
Edit: check out this article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3910982/ They just casually mention "diatom-derived plastids", which are basically organelles that used to be diatoms, eukaryotic organisms in themselves!
> I don't think we'd find that very exciting.
Uh, that would be absolutely, positively very exciting to find microbes that originated someplace other than Earth. If you expect we'll find little green humanoid-looking things, you're going to be highly disappointed for likely centuries.
Uh, that would be absolutely, positively very exciting to find microbes that originated someplace other than Earth. If you expect we'll find little green humanoid-looking things, you're going to be highly disappointed for likely centuries.
> microbes that originated someplace other than Earth
Well we could never be sure of that without real samples. Who's to say it's not all the result of panspermia?
Well we could never be sure of that without real samples. Who's to say it's not all the result of panspermia?
> bacterium, sure... I don't think we'd find that very exciting.
I think that most people, be them scientists, religious leaders, politicians, or even laymen, will have their lives changed forever. For the religious, discovery of extra-terrestrial bacteria will upend most of the interpretations of their holy books. Those books are the foundation of modern Western society (Do not kill, do not steal, do not take another man's wife, etc). By upending the basis of society we have no idea how humanity will end up. Will we throw everything based on the bible away? Reinterpret them? Will the Jews and Muslims reconcile? Will the Christians set out on another crusade? Will that crusade be to the extra-terrestrial bacteria to sterilize them?
> event that created Eukaryotes ... happened only once.
The insemination event which led to your birth also happened only once. However, it is does happen often enough in systems that have the right conditions. And there are trillions of available planets, right here in the Milky Way.
I think that most people, be them scientists, religious leaders, politicians, or even laymen, will have their lives changed forever. For the religious, discovery of extra-terrestrial bacteria will upend most of the interpretations of their holy books. Those books are the foundation of modern Western society (Do not kill, do not steal, do not take another man's wife, etc). By upending the basis of society we have no idea how humanity will end up. Will we throw everything based on the bible away? Reinterpret them? Will the Jews and Muslims reconcile? Will the Christians set out on another crusade? Will that crusade be to the extra-terrestrial bacteria to sterilize them?
> event that created Eukaryotes ... happened only once.
The insemination event which led to your birth also happened only once. However, it is does happen often enough in systems that have the right conditions. And there are trillions of available planets, right here in the Milky Way.
> I think that most people, be them scientists, religious leaders, politicians, or even laymen, will have their lives changed forever.
Scientists yes, the rest won't care that much. It'll make the news sure but it'll be out of the headlines within a week. Maybe I'm a cynic but I'd put money on that being the case.
Additionally speaking as a religious person, it wouldn't change any of my beliefs. And I'm struggling to see how it would for others of my faith really.
Scientists yes, the rest won't care that much. It'll make the news sure but it'll be out of the headlines within a week. Maybe I'm a cynic but I'd put money on that being the case.
Additionally speaking as a religious person, it wouldn't change any of my beliefs. And I'm struggling to see how it would for others of my faith really.
Except the universe isn't infinite.
It's true the universe is very large and feels infinite, but we know that it's about 25 billion galaxies (the size of the Milky Way) and that it has finite mass.
Sure, these numbers are incredibly large, but like you said, we're dealing with probabilities that are also incredibly small. There should be a cutoff somewhere for the observable universe as to what it is probable or improbable of producing.
It's true the universe is very large and feels infinite, but we know that it's about 25 billion galaxies (the size of the Milky Way) and that it has finite mass.
Sure, these numbers are incredibly large, but like you said, we're dealing with probabilities that are also incredibly small. There should be a cutoff somewhere for the observable universe as to what it is probable or improbable of producing.
The universe and the observable universe are different things. As far as we can measure, the universe appears to be flat (by measuring the observable universe). With finite mass, but expanding space, how is it not infinite?
You just said it yourself - infinite space but finite mass. "Life" by most definitions is made of mass, not space.
Claiming infinite space has infinite possibilities for life is quite literally a Celestial Teapot argument.
Claiming infinite space has infinite possibilities for life is quite literally a Celestial Teapot argument.
I didn't make any claim about life. I just wanted to challenge the statement about the universe being finite. I also agree with the other commenter that I'm not sure we can even be sure the mass is finite, but also happy to be enlightened.
The context of this conversation is probability of generating life. Debating theories on dark energy isn't relevant since it's not dense enough to generate life.
The context isn't relevant when I'm correcting a fact, at least as we/I currently understand it - the universe is infinite. I'm wasn't making a statement about dark energy, or life.
You're misinterpreting the semantics of finite mass in this conversation about abiogenesis by taking it out of context of conversation.
You are ignoring the spacetime part of the universe, which in definitions of the universe being finite or not, is probably far more relevant than the mass.
Is it that simple? Empty space has energy (dark energy) and E=MC^2 means energy and mass are interchangeable. Hence infinite space does imply infinite mass.
Not a physicist, so I'm probably dead wrong. But I would like to be enlightened.
Not a physicist, so I'm probably dead wrong. But I would like to be enlightened.
It is that simple, unless you think dark energy is dense enough to create a single celled organism (it's not).
We were talking about life, I didn't presume to say anything about intelligent or multi-cellular life. I agree with what you're saying though.
> The symbiosis event that created Eukaryotes from a random combination of Archaea and Bacteria appears to have happened only _once_ in the entire history of the earth.
That story is very much in flux still. We're not very certain on how that occurred, let alone how many times over those billions of years.It's linked to the Great Oxygenation Event, likely, but we're still in the very early stages of understanding that era.
> A practically infinite universe means potentially infinite diversity, including phenomenon that may not recognize as life at all to us, but should be equally interesting.
As is usual in science, it depends. If you are dealing with matter like us, then there are only a few universal solvents (5? I can't find the citation). In those solvents, there are a countable amount of ways that the chemistry will allow for 'life' to 'evolve'. The ways that the life can then evolve are really complicated and diverse, but there does seem to be a evolution/development trade-off, where you have to go through developmental 'keyholes' to get to a new level of complexity. Is that infinite? I've no idea, but it feels like a different ordinal of infinity.
https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_h...
That story is very much in flux still. We're not very certain on how that occurred, let alone how many times over those billions of years.It's linked to the Great Oxygenation Event, likely, but we're still in the very early stages of understanding that era.
> A practically infinite universe means potentially infinite diversity, including phenomenon that may not recognize as life at all to us, but should be equally interesting.
As is usual in science, it depends. If you are dealing with matter like us, then there are only a few universal solvents (5? I can't find the citation). In those solvents, there are a countable amount of ways that the chemistry will allow for 'life' to 'evolve'. The ways that the life can then evolve are really complicated and diverse, but there does seem to be a evolution/development trade-off, where you have to go through developmental 'keyholes' to get to a new level of complexity. Is that infinite? I've no idea, but it feels like a different ordinal of infinity.
https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_h...
If it were the case that is incredibly unlikely for life to get started in general, we would still be making those observations, give that we are here. This is the problem with only having one poorly understood data point that we ourselves are part of.
I'm optimistic that there is life out there. And if so, we should be able to get hard evidence by studying exoplanet atmospheres in the next few decades. Until then, it is very difficult to assess.
I'm optimistic that there is life out there. And if so, we should be able to get hard evidence by studying exoplanet atmospheres in the next few decades. Until then, it is very difficult to assess.
Essentially "The Anthropic Principle" if people want to read more about it.
Agreed that a sample size of 1 doesn't tell us much - but it does tell us something, which is my point.
> it can't be that hard for life to start.
We have a selection bias happening here. We observe life because if life didn't appear as soon as the Earth was cool enough, the odds of us being here and able to reason about that would be small. We shouldn't consider it particularly abundant until we find a separate biosphere where life developed independently.
I personally think it's really easy to get molecules making copies of themselves, but we don't have enough data to claim that.
We have a selection bias happening here. We observe life because if life didn't appear as soon as the Earth was cool enough, the odds of us being here and able to reason about that would be small. We shouldn't consider it particularly abundant until we find a separate biosphere where life developed independently.
I personally think it's really easy to get molecules making copies of themselves, but we don't have enough data to claim that.
No, we can actually gain some statistical confidence here that life can't be that hard to start. That doesn't mean it's true to reality, just that with the information we have at sample size = 1, we do actually know something.
The fact that we're not on some planet around a red-dwarf a trillion years from now discussing this, but on a relatively young world does in fact tell us something.
The fact that we're not on some planet around a red-dwarf a trillion years from now discussing this, but on a relatively young world does in fact tell us something.
Further, the speed at which it happened here is very compelling.
This planet is 4.6B years old Life is at least 3.5B years old. Maybe older. And for the first few hundred million, Earth was a fireball. So it happened almost as soon as it was possible to.
This planet is 4.6B years old Life is at least 3.5B years old. Maybe older. And for the first few hundred million, Earth was a fireball. So it happened almost as soon as it was possible to.
Other thing to keep in mind though is that, an ocean is a big places so there are lots of events where life has a chance to start. So even if the individual chance for an event to spawn life is low, you have a lot of chances. Way, way bigger than 1 trillion chances per planet I'd bet.
And after life reaches a certain point, wiping it out is incredibly hard. I don't know what it would take to wipe out all life, as in every last bacteria too, on Earth...
So while I might accede intelligent (especially technological) life might be rare, I sincerely doubt life itself is.
And after life reaches a certain point, wiping it out is incredibly hard. I don't know what it would take to wipe out all life, as in every last bacteria too, on Earth...
So while I might accede intelligent (especially technological) life might be rare, I sincerely doubt life itself is.
> 1 trillion chances per planet
Not meaning to be condescending, that's not how probability works or is expressed.
Also, the fact that the ocean "is a large place" says nothing about how probable or not the events to create and sustain life are.
I understand most people have this gut feeling that because the universe is vast and ancient there must be something out there (and I have it too), but we just don't know.
We just have no idea exactly how hard life is to develop and be sustained. We just started having theories (a handful at that) about how we transcended from chemistry to biology. The prevalent theory for example is that the moon's unusually big size and proximity was the catalyst for that to happen. How many planets have extremely big moons in such close proximity? How many million other factors played a role assuming the tide theory is even close to accurate?
It's just an infinitely complex problem and we just don't know.
Not meaning to be condescending, that's not how probability works or is expressed.
Also, the fact that the ocean "is a large place" says nothing about how probable or not the events to create and sustain life are.
I understand most people have this gut feeling that because the universe is vast and ancient there must be something out there (and I have it too), but we just don't know.
We just have no idea exactly how hard life is to develop and be sustained. We just started having theories (a handful at that) about how we transcended from chemistry to biology. The prevalent theory for example is that the moon's unusually big size and proximity was the catalyst for that to happen. How many planets have extremely big moons in such close proximity? How many million other factors played a role assuming the tide theory is even close to accurate?
It's just an infinitely complex problem and we just don't know.
I'd love to know more about these moon theories. Got a good layman's article to cite?
There are a few effects but we don't know what is important and what isn't.
The moon stabilizes the earths rotation (due to orbital mechanics I don't understand), that's probably important for complex life.
Tides are probably important because they help mix up all the elements. Tidal pools also may have been critical for abiogenesis.
The creation of the moon be a huge planetoid hitting us may be responsible for plate tectonics that provide enough volcanism.
The moon stabilizes the earths rotation (due to orbital mechanics I don't understand), that's probably important for complex life.
Tides are probably important because they help mix up all the elements. Tidal pools also may have been critical for abiogenesis.
The creation of the moon be a huge planetoid hitting us may be responsible for plate tectonics that provide enough volcanism.
Not quite, it's the opposite. We're having a hard enough time theoreticizing how self-replicating nucelotides with adequate lipid-bilayer maintaining molecular machinery occurred naturally on our volcanic, reducing-atmosphere of a planet.
Abiogenesis isn't the same as evolution, and given what limited knowledge we have of prebiotic Earth, life shouldn't have naturally occurred here. Ocean size doesn't matter in this case when the ocean isn't able to form a single self-replicating cell. The dice being rolled don't even have the number you need.
Abiogenesis isn't the same as evolution, and given what limited knowledge we have of prebiotic Earth, life shouldn't have naturally occurred here. Ocean size doesn't matter in this case when the ocean isn't able to form a single self-replicating cell. The dice being rolled don't even have the number you need.
This same argument can be applied to argue that aliens speak English.
The reason we know that aliens don’t speak English is that, as vast as the universe is, the set of possible languages is much larger and so rich with possibility that it need never repeat.
So why do we think the set of languages spoken by chemistry is any different?
The reason we know that aliens don’t speak English is that, as vast as the universe is, the set of possible languages is much larger and so rich with possibility that it need never repeat.
So why do we think the set of languages spoken by chemistry is any different?
Remember, it's not that you're rolling 1 billion dice expecting to get all sixes. It's that you're constantly re-rolling the dice that aren't sixes to get sixes.
I don't get this point. The probability argued would take this into account. It could be that the probability is _that_ small that even if you keep rolling you don't reach it.
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Barnard's star is a flare star so the surface probably gets randomly fried.
Because of its age, Barnard's star has less flare activity [1]. Also, from the Nature article [2] we read "Barnard’s star is also among the least magnetically active red dwarfs known..."
[1] https://en.wikipedia.org/wiki/Barnard%27s_Star
[2] https://www.nature.com/articles/s41586-018-0677-y
[1] https://en.wikipedia.org/wiki/Barnard%27s_Star
[2] https://www.nature.com/articles/s41586-018-0677-y
It would only take ~50 years to reach Barnard's star with a theoretical fusion engine according to a research study named Project Daedalus. Someone shoot a probe at the planet and maybe our kids can see some cool imagery!
I think fission fragment rockets might be more promising. Doable with current tech, they can have exhaust velocities of a few percent the speed of light (specific impulse in the 6 figures), comparable or better than fusion engines.
https://en.wikipedia.org/wiki/Fission-fragment_rocket
https://en.wikipedia.org/wiki/Fission-fragment_rocket
With 100 tons of propellant and the best imaginable VASIMR engine we could send a 10 ton payload (mostly nuclear reactor) there in...
2600 years.
We need better engines. A Daedalus-class fusion drive would be a great option, but first we'd need to develop it.
2600 years.
We need better engines. A Daedalus-class fusion drive would be a great option, but first we'd need to develop it.
Minor details - let’s roll
Ok, I'll just nip off to Jupiter to mine 50,000 tones of deuterium/Helium-3 fuel from the atmosphere. I'll be back in a jiffy.
Also just a minor detail - let's roll
If we wait a few thousand years, it'll get just a little closer to us:
> Barnard's Star will make its closest approach to the Sun around 11,800 AD, when it will approach to within about 3.75 light-year
https://en.wikipedia.org/wiki/Barnard%27s_Star#Overview
> Barnard's Star will make its closest approach to the Sun around 11,800 AD, when it will approach to within about 3.75 light-year
https://en.wikipedia.org/wiki/Barnard%27s_Star#Overview
The most realistic current proposal for an interstellar science mission is to avoid onboard propulsion altogether using a fleet of tiny laser-accelerated probes. Each one would be a very thin mirror, shot from orbit to the stars by a ground-based laser array. httpss://en.m.wikipedia.org/wiki/Breakthrough_Starshot
Something like this would look to the Barnard's star inhabitants a lot like 'Oumuamua
Except only a few tens of centimetres across. There might be thousands of them streaming past us all the time and we'd never know.
You could also do it with existing nuclear fission technology (Project Orion). 3% speed of light seems to be quite feasible with that. If there‘d be no other way to save humanity, a generation ship with that technology would probably be built today.
Project Orion, the one that can hypothetically do 3% light speed, is definitely fusion as well. And the very high Isp versions of it are incredibly challenging to build (as you need like a magnetic shield to deflect the nuclear plasma ball). The more modest Isp versions are more realistic, but won't get you there.
I see, but still, at least the energy source itself would be proven technology in the form of H-bombs right? As for the shielding, do you mean the pusher plate or the nuclear shape charge in the bombs themselves? Does going from fission to fission+fusion bomb make such a big difference that couldn’t be overcome just with more/stronger material and/or ablative shields?
"Super-Earths" are among the most numerous planet type in the galaxy. The term just means they mass somewhere between 1 and 10 Earths, and says literally nothing else about the planet.
Why is this interesting news?
Why is this interesting news?
Because it's right in our backyard? At about 6 light years, this star and its planet(s) are the second closest extrasolar star system to Earth, after Alpha Centauri.
And since it rotates around a relatively dim star, imaging it directly is much easier than a planet much further away.
Also, super earths are more common only because we can find them with the tools we have. By looking at our own backyard, I can tell you round rocks smaller than Earth are much more numerous than any other roughly spherical thing orbiting the Sun.
Also, super earths are more common only because we can find them with the tools we have. By looking at our own backyard, I can tell you round rocks smaller than Earth are much more numerous than any other roughly spherical thing orbiting the Sun.
> "Super-Earths" are among the most numerous planet type in the galaxy
Source? Just because our limited technology for detecting exoplanets tells us in the results that "X is most common" does not mean that X is really the most common.
It could be that planets smaller than Earth are the most numerous types, but we just cannot see many of them because they are, well, relatively small.
Source? Just because our limited technology for detecting exoplanets tells us in the results that "X is most common" does not mean that X is really the most common.
It could be that planets smaller than Earth are the most numerous types, but we just cannot see many of them because they are, well, relatively small.
> "Super-Earths" are among the most numerous planet type in the galaxy.
Ehhh, not so much. We don't have reliable statistics for planetary abundance outside of a very narrow zone, due to limitations in our detection systems.
Among planets with short orbital periods lower than a few years, super-earths are the most abundant, much more so than Earth-size planets. But that doesn't tell us much about their absolute abundance.
Also, it's interesting because Barnard's star is one of the closest stars to Earth.
Ehhh, not so much. We don't have reliable statistics for planetary abundance outside of a very narrow zone, due to limitations in our detection systems.
Among planets with short orbital periods lower than a few years, super-earths are the most abundant, much more so than Earth-size planets. But that doesn't tell us much about their absolute abundance.
Also, it's interesting because Barnard's star is one of the closest stars to Earth.
thank you for defining that. i was wondering about that term.
it made me think the planet was also in Earth's temperature range. but it's not. it orbits so far from Barnard that it's very cold and unlikely to have any liquid water. and they can say only that it's "potentially" rocky (so therefore also potentially gaseous?).
it doesn't seem very much like earth.
it made me think the planet was also in Earth's temperature range. but it's not. it orbits so far from Barnard that it's very cold and unlikely to have any liquid water. and they can say only that it's "potentially" rocky (so therefore also potentially gaseous?).
it doesn't seem very much like earth.
Most of them also seem to be either small or failed ice giants like Neptune or Uranus which makes them even more “boring”.
And likely lifeless without liquid water, hmmm...
*on the surface.
It's beyond the frost line, so probably has deep icy oceans.
It's beyond the frost line, so probably has deep icy oceans.
[1] Ss opposed to the thermal infrared, which works best for young planets which have substantial residual heat from their formation. [2] Such as when an exoplanet transits in front of it's host star, the atmosphere will absorb some light. However it appears this technique is only sensitive to the very thin upper parts of the atmosphere, and we don't learn much about the rest.