'Megascale' structures that humans could one day build(bbc.com)
bbc.com
'Megascale' structures that humans could one day build
https://www.bbc.com/future/article/20210113-the-megascale-structures-that-humans-could-one-day-build
134 コメント
You would need to capture the ENTIRE energy output of the sun for about 5 years to generate that much energy.
If you can do that, terraforming Mars is nothing, you could just grab a bunch of nearby asteroids or a planet or two and combine.
And just think about how much material you need in order to build a collector large enough to entirely encompass the sun - it's WAY WAY WAY larger than your added Mars mass.
Also you would need a magical strength material just to hold those lightspeed objects in place (think of the huge centrifugal force they are generating). There's nothing in the world that could hold them in place.
I assume they are charged - or how are they keeping them in their "track"? No physical material could handle it. So they have to be charged, well the Synchrotron radiation generated would be enough to sterilize anything nearby.
So "known physics" is a bit of a stretch.......... :)
If you can do that, terraforming Mars is nothing, you could just grab a bunch of nearby asteroids or a planet or two and combine.
And just think about how much material you need in order to build a collector large enough to entirely encompass the sun - it's WAY WAY WAY larger than your added Mars mass.
Also you would need a magical strength material just to hold those lightspeed objects in place (think of the huge centrifugal force they are generating). There's nothing in the world that could hold them in place.
I assume they are charged - or how are they keeping them in their "track"? No physical material could handle it. So they have to be charged, well the Synchrotron radiation generated would be enough to sterilize anything nearby.
So "known physics" is a bit of a stretch.......... :)
Story whise there is a caste of underground dwelling engineers who rarely venture to the surface who are taking care of that - via a giant pipe organ like musical instrument/control console!
They effectively play the whole planet using their inner understanding of the system and perfect musical hearing, keeping everything in perfect balance and harmony.
(There are actually some other "engineer castes" such as the Salamanders that live on the floating islands and keep the ppanet warm. They are much less baddass but still rather hot blooded for some reason.)
They effectively play the whole planet using their inner understanding of the system and perfect musical hearing, keeping everything in perfect balance and harmony.
(There are actually some other "engineer castes" such as the Salamanders that live on the floating islands and keep the ppanet warm. They are much less baddass but still rather hot blooded for some reason.)
Not practical at all, but an unusual idea for sure.
My favorite thing about this is that it's completely irrelevant to the show. It's a healing-type show about the daily life of a gondola driver. It could have taken place in actual Venice with no real changes.
Is this really how objects interact with the environment? I am aware of what it means to speed up such an object, as you approach c you need more and more energy, it "feels" as your mass is increasing. What surprises me is that this effect would extend to objects outside?
This seems surprising to me. By the same logic, if an object moved at speed of light it would have infinite mass and unless gravity is not proportional to mass, you would have infinite gravity.
This seems surprising to me. By the same logic, if an object moved at speed of light it would have infinite mass and unless gravity is not proportional to mass, you would have infinite gravity.
Hence it is impossible for an object (with mass) to reach c.
Only progressively closer - 0.99c, 0.999c, 0.9999c etc.
Only progressively closer - 0.99c, 0.999c, 0.9999c etc.
It's impossible yes, but does it generate a gravitational field?
Yes it does!
Gravity is generated by energy, and mass is just one type of energy. For example photons produce a gravitational field of their own, and are influenced by gravitational fields.
So yes, energy in the form of velocity does produce gravity.
It can get complicated to calculate though, because velocity in the same direction as the observer doesn't exist, only in other directions (including perpendicular).
A thought experiment: Two huge identical masses are traveling toward each other, and perpendicular to an observer. They collide and "stick" to each other. All their velocity is now rest energy, which obviously has gravity.
But this means that even before they collided they also had gravity (since you can never create or destroy gravity, only move it).
Now rotate the experiment - one mass is traveling toward the observer, and the other is traveling with the observer. This time when they collide part of it is rest energy, and the rest is kinetic (since the observer is still moving, while the two objects stopped each other dead still at a point in space).
But this time, the mass that was with the observer had zero gravity (from the POV of the observer), but the mass traveling toward the observer had more gravity.
But it means that gravity is not a "global" phenomenon, it depends on your POV. And that makes for some difficult calculations if you must account for multiple objects all moving. (For example in cosmology. From my understanding the calculations are so complicated that they are mostly just ignored because few objects are moving fast enough for it to matter.)
Gravity is generated by energy, and mass is just one type of energy. For example photons produce a gravitational field of their own, and are influenced by gravitational fields.
So yes, energy in the form of velocity does produce gravity.
It can get complicated to calculate though, because velocity in the same direction as the observer doesn't exist, only in other directions (including perpendicular).
A thought experiment: Two huge identical masses are traveling toward each other, and perpendicular to an observer. They collide and "stick" to each other. All their velocity is now rest energy, which obviously has gravity.
But this means that even before they collided they also had gravity (since you can never create or destroy gravity, only move it).
Now rotate the experiment - one mass is traveling toward the observer, and the other is traveling with the observer. This time when they collide part of it is rest energy, and the rest is kinetic (since the observer is still moving, while the two objects stopped each other dead still at a point in space).
But this time, the mass that was with the observer had zero gravity (from the POV of the observer), but the mass traveling toward the observer had more gravity.
But it means that gravity is not a "global" phenomenon, it depends on your POV. And that makes for some difficult calculations if you must account for multiple objects all moving. (For example in cosmology. From my understanding the calculations are so complicated that they are mostly just ignored because few objects are moving fast enough for it to matter.)
Thank you for the answer. I am humbled. I have decent understanding of Newtonian physics, but when it goes to relativistic levels I am out of my depth.
Fascinating stuff. So effectively, with "infinite energy" and "unbreakable materials" we could have artificial gravity.
Fascinating stuff. So effectively, with "infinite energy" and "unbreakable materials" we could have artificial gravity.
Artificial gravity implies you could turn it on and off. But you can't - if you have infinite energy, you also have infinite gravity, the two are bound together.
Whenever you have energy, you have gravity. I suppose you could send the energy from elsewhere, then send it back when you don't want the gravity anymore.
Whenever you have energy, you have gravity. I suppose you could send the energy from elsewhere, then send it back when you don't want the gravity anymore.
There's no "generating" gravity. Energy is Mass. They didn't pack atoms, they packed energy, but it is the same stuff.
Firefly also included gravity in terraforming:
All those moons - just like the central planets, they're as close to Earth-That-Was as we could make 'em: gravity, atmosphere, and such
but never provided any explanation. In that medium (live-action TV) it's just handwaving around the production difficulties of showing low-G; Joss by his own admission will cry if you ask him science questions.
All those moons - just like the central planets, they're as close to Earth-That-Was as we could make 'em: gravity, atmosphere, and such
but never provided any explanation. In that medium (live-action TV) it's just handwaving around the production difficulties of showing low-G; Joss by his own admission will cry if you ask him science questions.
While I loved the show, the science was particularly bad.
For example, in the pilot episode, they pass by a Reaver ship while enroute to another planet. The encounter occurs slowly enough for the crew to get a long look at the Reaver ship as it passes. The closing speed seemed to be about 100mph at best.
Whereas with the Apollo mission to the moon, the capsule was traveling 25,000 mph, or ten times the speed of a bullet. And even then it took three days to get to the moon.
And even 25k mph is slow if we're talking about crossing actual interplanetary distances.
For example, in the pilot episode, they pass by a Reaver ship while enroute to another planet. The encounter occurs slowly enough for the crew to get a long look at the Reaver ship as it passes. The closing speed seemed to be about 100mph at best.
Whereas with the Apollo mission to the moon, the capsule was traveling 25,000 mph, or ten times the speed of a bullet. And even then it took three days to get to the moon.
And even 25k mph is slow if we're talking about crossing actual interplanetary distances.
Yeah, Joss 'fesses up to that one in the episode commentary.
I don't know if it's "particularly bad" by the standards of screen SF. No shows do it well, and the vast majority don't even try.
I don't know if it's "particularly bad" by the standards of screen SF. No shows do it well, and the vast majority don't even try.
What about The Expanse?
From the little I've seen of it, much better than most but still not great.
There are things like the Epstein drive that is nearly "magic". It is as if you had some device that could do direct matter-energy conversion with 99.999999999999999999999% efficiency.
Beyond that, they do treat maneuvering in space with greater realism that most shows.
Beyond that, they do treat maneuvering in space with greater realism that most shows.
I don't really remember enough about that show to comment, but the usual failure mode of Newtonian flight models in visual media is that they're extremely reluctant to depict a ship doing a sustained thrust in the opposite direction to its velocity vector, which should logically be ~50% of its time under thrust. They just don't trust audiences to be able to grok it.
Frontier: Elite II (the 1993 game) was the same; it was pretty hardcore Newtonian, but the autopilot would only use the front-facing thrusters to decelerate, even though the main thrusters were much more powerful. If you were under time pressure and needed an efficient flight plan, you had to do turnover and deceleration manually and by eye.
Frontier: Elite II (the 1993 game) was the same; it was pretty hardcore Newtonian, but the autopilot would only use the front-facing thrusters to decelerate, even though the main thrusters were much more powerful. If you were under time pressure and needed an efficient flight plan, you had to do turnover and deceleration manually and by eye.
The Expanse does show deceleration explicitly many times. It's called a flip and burn in the show.
Expanse is really interesting that there is basically just one super science item and thats the Epstein drive (well, if you don't count the near magic the protomolecule does). Everything else is pretty much slightly improved current tech (transparent smartphones, better medical tech, practical implants, advanced life support systems).
One could even say some things aere kess advanced than one would expect - quite a few autonomous weapons, big rotating space colonies (oneil island 3, standfor torus, clarke wheel, etc) or worldhouses. Also no laser/gracer/xaser weapons or long range kinetic energy weapons. And no nuclear bomb pumped lasers.
One could even say some things aere kess advanced than one would expect - quite a few autonomous weapons, big rotating space colonies (oneil island 3, standfor torus, clarke wheel, etc) or worldhouses. Also no laser/gracer/xaser weapons or long range kinetic energy weapons. And no nuclear bomb pumped lasers.
Ouch, that’s one of those painfully bad ideas that makes it obvious most people lack a basic understanding of physics.
Creating enough mass from energy to hit ~2/3 earths total mass is several orders of magnitude larger than the Death Stars main weapon. And as you point out if basically anything fails all that energy gets released on Mars.
Creating enough mass from energy to hit ~2/3 earths total mass is several orders of magnitude larger than the Death Stars main weapon. And as you point out if basically anything fails all that energy gets released on Mars.
> Ouch, that’s one of those painfully bad ideas that makes it obvious most people lack a basic understanding of physics.
I disagree. That's the fun thing about scifi. As long as your idea could theoretically work (which you seem to agree), you can decide whether the theoretical risks manifest or not, or handwave uninvented solutions to those.
Scifi is about dreaming within our universe beyond our current knowledge or limitations.
At least that's my two cents.
Edit: Not familiar with this specific book, but just in general terms.
I disagree. That's the fun thing about scifi. As long as your idea could theoretically work (which you seem to agree), you can decide whether the theoretical risks manifest or not, or handwave uninvented solutions to those.
Scifi is about dreaming within our universe beyond our current knowledge or limitations.
At least that's my two cents.
Edit: Not familiar with this specific book, but just in general terms.
> Which you seem to agree
Well no their are a host of issues beyond safety and energy requirements. You’re not going to be able to contain that much virtual mass moving at near light speed. We also don’t know if virtual mass produces gravity, etc etc.
Well no their are a host of issues beyond safety and energy requirements. You’re not going to be able to contain that much virtual mass moving at near light speed. We also don’t know if virtual mass produces gravity, etc etc.
> We also don’t know if virtual mass produces gravity
Yes we do. It does.
Gravity is produced by energy, of which mass is only one type.
Yes we do. It does.
Gravity is produced by energy, of which mass is only one type.
Last I checked there was zero experimental support for this.
Unless you have a citation?
Unless you have a citation?
See my other post here: https://news.ycombinator.com/item?id=25793668
Basically any other answer would be a violation of a whole bunch of conservation laws. In short: It's easy to convert velocity energy to rest energy, rest energy obviously has gravity, so velocity energy must as well.
Basically any other answer would be a violation of a whole bunch of conservation laws. In short: It's easy to convert velocity energy to rest energy, rest energy obviously has gravity, so velocity energy must as well.
The issue as I understand it is neutron stars would form black holes in some reference frames. It really breaks relativity for all forms of energy to produce gravity.
Which is completely ok as long as there is some experimental support.
Which is completely ok as long as there is some experimental support.
That's a flaw of the theories of black holes, not relativity.
> It really breaks relativity for all forms of energy to produce gravity.
It does not, quite the opposite: It's a fundamental feature of it.
> Which is completely ok as long as there is some experimental support.
There is no experimental support for black holes either, it breaks physics far less for black holes not to exist. (Note black holes are not the same as super massive objects, which do have experimental support. An event horizon has never been observed, just assumed.)
> It really breaks relativity for all forms of energy to produce gravity.
It does not, quite the opposite: It's a fundamental feature of it.
> Which is completely ok as long as there is some experimental support.
There is no experimental support for black holes either, it breaks physics far less for black holes not to exist. (Note black holes are not the same as super massive objects, which do have experimental support. An event horizon has never been observed, just assumed.)
The existence of black holes is part of the general consensus at this point. It’s fine to suggest they don’t exist, just realize you’re disagreeing with the vast majority of physicists and evidence we have.
I don’t mean this as an appeal to authority, just a suggestion you likely have some fundamental misunderstandings. Especially if you never worked through the actual equations.
I don’t mean this as an appeal to authority, just a suggestion you likely have some fundamental misunderstandings. Especially if you never worked through the actual equations.
> The existence of black holes is part of the general consensus at this point.
Yes it is, but the lack of understanding of black holes is also part of general understanding. Physicists know quite well they don't fully understand what happens in every black hole situation.
> It’s fine to suggest they don’t exist, just realize you’re disagreeing with the vast majority of physicists and evidence we have.
We don't have any evidence, only conjecture and [incomplete] math.
Two things that might prevent black holes: Quark degeneracy pressure (unknown, not even the magnitude is known), and time dilation, which leads to "frozen stars" which hover just before becoming black holes, but never do because that last bit of mass that takes them over the edge takes an infinite time to arrive.
Neither of those two are "fringe" theories mind you, they have both been discussed by prominent theorists (I also get to appeal to authority :)
Yes it is, but the lack of understanding of black holes is also part of general understanding. Physicists know quite well they don't fully understand what happens in every black hole situation.
> It’s fine to suggest they don’t exist, just realize you’re disagreeing with the vast majority of physicists and evidence we have.
We don't have any evidence, only conjecture and [incomplete] math.
Two things that might prevent black holes: Quark degeneracy pressure (unknown, not even the magnitude is known), and time dilation, which leads to "frozen stars" which hover just before becoming black holes, but never do because that last bit of mass that takes them over the edge takes an infinite time to arrive.
Neither of those two are "fringe" theories mind you, they have both been discussed by prominent theorists (I also get to appeal to authority :)
There is quite a bit of evidence, it’s mostly indirect evidence though.
First, a quark degeneracy pressure is irrelevant for the existence of black holes as they have lower density requirements the larger the event horizon. A large enough uniform density sphere of say styrofoam would form an event horizon.
In terms of evidence, “Frozen stars” don’t match up with the Laser Interferometer Gravitational-Wave Observatory’s observations that suggest a collision between a black hole and a neutron star.
That said, the Messier 87 black hole image is the closest thing to a direct observation we have. It’s possible that some mistakes where made, but many would argue it’s solid evidence on it’s own.
PS: Anyway, I am not suggesting this as some statement from on high. I am saying if most people that take serious time and effort looking into something all come to the same conclusion it’s prudent to dig deep before coming to a different conclusion. That’s especially true of physics where actually understanding the math behind existing models is difficult. Essentially you should be able to point to some math and say see this, this is wrong and then justify that statement.
First, a quark degeneracy pressure is irrelevant for the existence of black holes as they have lower density requirements the larger the event horizon. A large enough uniform density sphere of say styrofoam would form an event horizon.
In terms of evidence, “Frozen stars” don’t match up with the Laser Interferometer Gravitational-Wave Observatory’s observations that suggest a collision between a black hole and a neutron star.
That said, the Messier 87 black hole image is the closest thing to a direct observation we have. It’s possible that some mistakes where made, but many would argue it’s solid evidence on it’s own.
PS: Anyway, I am not suggesting this as some statement from on high. I am saying if most people that take serious time and effort looking into something all come to the same conclusion it’s prudent to dig deep before coming to a different conclusion. That’s especially true of physics where actually understanding the math behind existing models is difficult. Essentially you should be able to point to some math and say see this, this is wrong and then justify that statement.
It's a minor detail of the setting of a story. I doesn't matter if it's practical in real life, it just has to be not be in contradiction with the fictional world of the story. Kind of like Star Trek allowing faster-than-light travel due to imagined discoveries in the fields of physics.
I like hard science fiction that's based in known physics, but I can still enjoy science fiction that's not totally realistic as long as it's at least consistent with itself and doesn't contradict known physics out of pure laziness or ignorance.
I think it's a better solution than just saying "Mars is at full gravity because of magic we won't explain."
I like hard science fiction that's based in known physics, but I can still enjoy science fiction that's not totally realistic as long as it's at least consistent with itself and doesn't contradict known physics out of pure laziness or ignorance.
I think it's a better solution than just saying "Mars is at full gravity because of magic we won't explain."
The advantage of saying magic we can’t explain is you have fewer uses of other magic we can’t explain. Having that much mass moving near light speed requires absurdly strong materials etc. You need a silly energy source, etc etc.
Similarly, you get a lot of knock on effects from the other hand waves.
Similarly, you get a lot of knock on effects from the other hand waves.
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it's ok, the engineers learned enough from the previous 3 failures to make sure it really doesn't happen again with this one :)
So the energy they need to bring is the energy equivalent of the matter they would have needed to bring to get the same result.
Or an other way to see it : they have to annihilate two Mars planet to get enough energy to create gravity on the third one.
Or an other way to see it : they have to annihilate two Mars planet to get enough energy to create gravity on the third one.
Yep, pretty much - but tourist from Earth will feel gravity just as at himo and gondola rides will be 100% authentic! ;-)
No wonder Aria is a perfect slice of life / healing series - any aggressive aliens or other evildoers don't stand a chance agains their rather low profile yet insanely high tech level! :)
No wonder Aria is a perfect slice of life / healing series - any aggressive aliens or other evildoers don't stand a chance agains their rather low profile yet insanely high tech level! :)
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BLAME! Could be an example of megastructures gone haywire.
I still remeber that one episode when the main character goes up a stairwell for quite a while (possibly weeks+) then finally reaches the top, opens a manhole cover basically, enetering a huge room - for one he can't see the ceiling and it goes in all directions and seems flat.
After wandering around for an unspecified while he encounters a cyborg scientist looking through some sort of instrument. He tells him this "room" in the megastructure is a spehrical empty space and has the inner diameter of Jupiter.
So if you ever wondered where to Von Neumann construction bots that got a little haywire got all the raw materials...
After wandering around for an unspecified while he encounters a cyborg scientist looking through some sort of instrument. He tells him this "room" in the megastructure is a spehrical empty space and has the inner diameter of Jupiter.
So if you ever wondered where to Von Neumann construction bots that got a little haywire got all the raw materials...
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Huh, that's clever and terrifying.
Anyone remember SimCity 2000's arcologies?
https://simcity.fandom.com/wiki/Arcology
https://en.wikipedia.org/wiki/Arcology
https://simcity.fandom.com/wiki/Arcology
https://en.wikipedia.org/wiki/Arcology
Oh yeah. Along the same lines I also have a fond place in my heart for Buckminster Fuller's tensegrity spheres.
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For some scale of structures, it may be too dangerous to be done here on Earth, at least in the short-middle term. Some systems are very complex and not well understood yet (climate, ecosystems, food chain, etc) and the risk of disrupting something we depend on and not have alternative place to live on if something unexpected happens.
We are kind of living that scenario already, the global transport and energy "megastructures" are causing global warming, maybe not as construction but as system with many components. Imagine building something planned 100 years ago when the people of that time wasn't aware of the polar vortex, the gulf stream or positive reinforcement loops, or were not aware of their importance.
Limited impact, controlled/limited side effects, composable for a planned/measured growth, instead of a big cathedral that must be all of it or nothing, may be factors that make some future projects be safe enough.
It is not just being able to draw it and that have an sound math on its factibility. With big enough things, you may have to factor the impact for all of us, on things that are outside the construction itself.
We are kind of living that scenario already, the global transport and energy "megastructures" are causing global warming, maybe not as construction but as system with many components. Imagine building something planned 100 years ago when the people of that time wasn't aware of the polar vortex, the gulf stream or positive reinforcement loops, or were not aware of their importance.
Limited impact, controlled/limited side effects, composable for a planned/measured growth, instead of a big cathedral that must be all of it or nothing, may be factors that make some future projects be safe enough.
It is not just being able to draw it and that have an sound math on its factibility. With big enough things, you may have to factor the impact for all of us, on things that are outside the construction itself.
It is fair to consider a road network to be a megastructure. After all, the roads are all continuously connected to each other and if you were to sabotage some of the roads you can split the entire megastructure.
The second part of Neal Stephenson's Seveneves is filled with megastructures in space. I wish he made some videos to explain them better than with words.
https://en.wikipedia.org/wiki/Seveneves
https://en.wikipedia.org/wiki/Seveneves
This is something I’ve always appreciated about Greg Egan; his personal website is filled with pages and pages of exposition about the physics of the worlds he comes up with, down to the level of simulating what certain phenomena would look like and turning it into a video. Huge fan of the guy’s work.
Both halves of Seveneves are crying out for TV adaptation
There's a fantastic amount of untapped cinematic material in the last 30 years of science fiction. Stephenson, Egan, Banks, ... Half-life...
I have to think the budget, even with the megabudgets TV shows have today, would be tough to manage. There is a lot that takes place in zero G, and that is not cheap to fake.
You could do something similar to what the Expanse has done and have 'mag boots' so everyone just kind of walks around in zero g and they'll occasionally put someone walking on the 'ceiling' to sell the zero g.
I think you could probably figure out some decent excuse why most of the space stuff had gravity while leaving much of the plot intact
All of Stephenson's books are crying out for TV or Movie adaptation! (hint: esp. Snowcrash & Zodiac!).
Zodiac might make a better film, but actually I guess you can just transplant the protagonist into a variety of wacky adventures over a number of seasons. I think Snowcrash (like Cryptonomicon or Anathema) relies a bit too much on explanations for it to work on the screen. Diamond Age feels like it comes to too much of a conclusion, maybe it’s a mini series
I think the right director(s) could make Snowcrash work -- e.g. the Wachowskis'. They did a really good job adapting V for Vendetta from the original Alan Moore and David Lloyd comics/stories.
Reading Snow Crash and IMO it could be a fantastic series. However, I must say I would hate a poor adaptation much more than no adaptation at all. Hopefully in my lifetime someone takes it on and gets it right.
(Off-topic) I liked the first half of Seveneves, but the second half with megastructures... felt like a let-down, especially after the brilliant first half. The future civilization can hitch an entire city on a space elevator, but an aircraft pilot wears a catheter - because they somehow can't create an aircraft with a regular toilet.
(I'm half convinced that Stephenson is aroused by future humanoids wearing cool technology and nothing else.)
> Christoph Grienberger oversaw all mathematical works written by Jesuit authors, a role akin to an editor at a modern scientific journal. He was modest and productive, and could not resist solving problems. He reasoned that since a 1:10 gear could allow one person to lift 10 times as much as one unassisted, if one had 24 gears linked to a treadmill then one could lift the Earth… very slowly.
Someone kinda did this; a 1 to 10^100 gear reduction.
https://www.youtube.com/watch?v=nFslB0AcVmM
Someone kinda did this; a 1 to 10^100 gear reduction.
https://www.youtube.com/watch?v=nFslB0AcVmM
Reminds me of this one (the final gear is embedded in concrete):
https://www.youtube.com/watch?v=5q-BH-tvxEg
I always wanted to make this for micrometer moves, but the mechanical play I can't model
Can we build deep into the Earth? Probably not... but it's funny to think about. The mantle is less than 4000 degrees C. Yet there are known materials with a melting point above that: https://www.asminternational.org/web/cmdnetwork/home/-/journ...
Even regular Tungsten would apparently get you through most of the mantle without melting.
Alright, so what can be done about the extreme pressure that deep?
It seems like bulk nanotubes are perhaps the only theoretical material that could withstand the pressure (100GPa)?
Even regular Tungsten would apparently get you through most of the mantle without melting.
Alright, so what can be done about the extreme pressure that deep?
It seems like bulk nanotubes are perhaps the only theoretical material that could withstand the pressure (100GPa)?
> Alright, so what can be done about the extreme pressure that deep?
Don't have any compressible gases. If we're just sending machines and infrastructure into the mantle, maybe that's possible. If we want to send people it's harder. I don't know if anything like the oxygenated fluid from the Abyss (or the LCL from Evangelion which was more or less the same thing) does or can exist in reality. Or if other problems would arise at extreme pressures.
Your mention of high melting point materials makes me wonder if fiber optic cables could be made that survive in that environment. It'd be an expensive undertaking just to reduce, say, the network latency from North America to Asia.
If we ignore the mantle, building into the shallow crust where it's still cool seems like a reasonable thing to do. I suspect the main reason it's usually not done are the cost of earth removal and reinforcement being higher than above-ground structures, and having to deal with water. It's fun to think about what an underground megastructure would be like, though. Could be as simple as turning an old pit mine or quarry into a below-ground urban center.
In Portland, OR out towards Gresham there's a huge hole in the ground next to the Multnomah County land use planning department that I suppose is probably an old quarry. I like to imagine what it'd look like with apartment complexes along the sides and a park with a lake at the bottom. Maybe a shopping center with a farmer's market, and a light rail stop. Keeping it from flooding would be a huge logistical challenge, though.
Don't have any compressible gases. If we're just sending machines and infrastructure into the mantle, maybe that's possible. If we want to send people it's harder. I don't know if anything like the oxygenated fluid from the Abyss (or the LCL from Evangelion which was more or less the same thing) does or can exist in reality. Or if other problems would arise at extreme pressures.
Your mention of high melting point materials makes me wonder if fiber optic cables could be made that survive in that environment. It'd be an expensive undertaking just to reduce, say, the network latency from North America to Asia.
If we ignore the mantle, building into the shallow crust where it's still cool seems like a reasonable thing to do. I suspect the main reason it's usually not done are the cost of earth removal and reinforcement being higher than above-ground structures, and having to deal with water. It's fun to think about what an underground megastructure would be like, though. Could be as simple as turning an old pit mine or quarry into a below-ground urban center.
In Portland, OR out towards Gresham there's a huge hole in the ground next to the Multnomah County land use planning department that I suppose is probably an old quarry. I like to imagine what it'd look like with apartment complexes along the sides and a park with a lake at the bottom. Maybe a shopping center with a farmer's market, and a light rail stop. Keeping it from flooding would be a huge logistical challenge, though.
The oxygenated fluid from the Abyss is a real thing
https://en.wikipedia.org/wiki/Liquid_breathing
https://en.wikipedia.org/wiki/Liquid_breathing
Only sort of real. So far no one has made it practical for humans.
There is something like that in China, a luxury hotel in a quarry: https://www.ihg.com/intercontinental/hotels/us/en/shanghai/s...
Wow, that's pretty cool.
We just need a few nuclear powered tunnel borers going. Then earth removal,water, and reinforcement aren't that big of issues. I've often wondered if there aren't already some of them crisscrossing the US already.
> If we consider megascale engineering that has actually happened – the terracing of parts of South East Asia, the land reclamation of the Netherlands, the US Interstate Highway System, the internet – it consists of projects that can be implemented piecemeal, where work can cease and resume after learning experiences, and where the system is not dependent on every part functioning perfectly. They can be maintained, and it usually makes sense for the people involved to maintain their homes and servers.
This is a really good quote.
Some estimates put Kowloon Walled City the most densely populated place ever. It's where I think seasteading has it's best chance.
A contrary opinion would be Elon Musks Starlink or GPS.
This is a really good quote.
Some estimates put Kowloon Walled City the most densely populated place ever. It's where I think seasteading has it's best chance.
A contrary opinion would be Elon Musks Starlink or GPS.
The Panama and Suez canals are also counter-examples. They were almost useless before they were completed
I have had two structures in mind for some time.
One would be a solar powered water elevator that pumped water from the Pacific into the various endorheic basins in Nevada. These could then be drained during cloudy times or peak hours to supplement solar power.
The other is a causeway along the Antilles islands from Miami to Trinidad that would act as an eastern connection point between north and south America.
One would be a solar powered water elevator that pumped water from the Pacific into the various endorheic basins in Nevada. These could then be drained during cloudy times or peak hours to supplement solar power.
The other is a causeway along the Antilles islands from Miami to Trinidad that would act as an eastern connection point between north and south America.
There is (was?) a project to do your first structure in the Atacama Desert in Chile:
> Espejo de Tarapacá (EdT) – one of the most innovative infrastructure projects in the world – is comprised of a 300 MW pumped hydro storage plant that operates with seawater, located approximately 100 kilometers south of Iquique. This project is essentially a large electricity storage system which will eliminate, at a low cost, the intermittency of non-conventional renewable energy – such as solar energy.
http://valhalla.cl/espejo-de-tarapaca/
> Espejo de Tarapacá (EdT) – one of the most innovative infrastructure projects in the world – is comprised of a 300 MW pumped hydro storage plant that operates with seawater, located approximately 100 kilometers south of Iquique. This project is essentially a large electricity storage system which will eliminate, at a low cost, the intermittency of non-conventional renewable energy – such as solar energy.
http://valhalla.cl/espejo-de-tarapaca/
There’s one in the mountains of Virginia too: https://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Sta...
> One would be a solar powered water elevator that pumped water from the Pacific into the various endorheic basins in Nevada. These could then be drained during cloudy times or peak hours to supplement solar power.
Interesting. I've thought similarly, but for a slightly different purpose. Inland Australia is a massive desert, but there are theories that it was once (at least significantly more of it) a large grassland. Apparently it was mostly destroyed with the introduction of hoofed animals, which pull the roots of grass out as they eat it, as opposed to kangaroo's and other native animals which eat grass without removing the root.
I haven't explored the hard science behind this, but the theory is discussed in the book 'Dark Emu'.
Regardless, it gives hope that the desert could be cultivated in order to support more plants & animals (I'm thinking native rather than for farming purposes).
To realistically kick this off tho it would require huge amounts of fresh water, which Australia sorely lacks.
But we could produce plenty of electricity from solar power, wind power and nuclear power (Australia has enormous uranium reserves and plenty of sun). With cheap power, we could pump and desalinate water into the center of Australia.
Unlike death valley, it's not down hill tho, so it would require long distance pumping.
Interesting to find this project mentioned here which bares some similarities: https://en.wikipedia.org/wiki/Red_Sea%E2%80%93Dead_Sea_Water...
Interesting. I've thought similarly, but for a slightly different purpose. Inland Australia is a massive desert, but there are theories that it was once (at least significantly more of it) a large grassland. Apparently it was mostly destroyed with the introduction of hoofed animals, which pull the roots of grass out as they eat it, as opposed to kangaroo's and other native animals which eat grass without removing the root.
I haven't explored the hard science behind this, but the theory is discussed in the book 'Dark Emu'.
Regardless, it gives hope that the desert could be cultivated in order to support more plants & animals (I'm thinking native rather than for farming purposes).
To realistically kick this off tho it would require huge amounts of fresh water, which Australia sorely lacks.
But we could produce plenty of electricity from solar power, wind power and nuclear power (Australia has enormous uranium reserves and plenty of sun). With cheap power, we could pump and desalinate water into the center of Australia.
Unlike death valley, it's not down hill tho, so it would require long distance pumping.
Interesting to find this project mentioned here which bares some similarities: https://en.wikipedia.org/wiki/Red_Sea%E2%80%93Dead_Sea_Water...
I was thinking about how to do some climate engineering of Australia or Africa, and came up with a megastructure to do it.
I was thinking of putting several hundred square miles of something dark (black felt or something similar maybe) in the ocean just upwind of a region. The goal is to concentrate solar energy near the surface.
Increased evaporation would increase air humidity, and rain downwind would increase a lot. Seemed like the lowest tech, lowest cost way to convert solar into rain/fresh water on a massive scale.
I was thinking of putting several hundred square miles of something dark (black felt or something similar maybe) in the ocean just upwind of a region. The goal is to concentrate solar energy near the surface.
Increased evaporation would increase air humidity, and rain downwind would increase a lot. Seemed like the lowest tech, lowest cost way to convert solar into rain/fresh water on a massive scale.
That's so far why not use two closer bodies of water and just cycle it endlessly like the smaller scale pumped storage already being build?
Xkcd what-if did an article about what would happen if you flooded death valley: https://what-if.xkcd.com/152/
I feel like Kurzgesagt does this so much better:
https://www.youtube.com/watch?v=pP44EPBMb8A
https://www.youtube.com/watch?v=pP44EPBMb8A
You might find Isaac Arthur’s Megastructures playlist interesting: https://m.youtube.com/playlist?list=PLIIOUpOge0LtW77TNvgrWWu...
Man, this guy has great content and I've tried to get past his speech impediment for literally years but I can't. It really taints his videos unfortunately.
I think it's fine if you have an issue, but just so others no I have never had any issues understanding him, and he has gotten a lot better.
Issac Arthur is a treasure, I wish high schoolers could take a semester of him.
Issac Arthur is a treasure, I wish high schoolers could take a semester of him.
At first, I just thought it was some kind of exotic accent but I have had no problem understanding him and english is not my first language. In fact, I find his speech quite enjoyable.
So to anyone unfamiliar with his work, do not let this stop you from watching, it's awesome if you are in to this kind of stuff.
So to anyone unfamiliar with his work, do not let this stop you from watching, it's awesome if you are in to this kind of stuff.
His newer stuff has improved somewhat, he was working with a speech therapy group apparently in the last year or so.
It's still not perfect but much better than it used to be.
It's still not perfect but much better than it used to be.
That's great news! I'll check out his newer videos.
He has closed captioning on all his videos to help viewers.
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Play it faster. 2X or more.
Yeah, the Dyson sphere was my first thought when opening the article. Crazy to think that it's a "solved problem" with the only issue being the politics and people not coming together. As is it with the most things, unfortunately
Nuclear detonations are very effective earth movers, perhaps capable tools in an Megascale structure project. See project plowshare. I'm not sure if the energy to make a weapon (enrichment primarily) is less than using conventional diggers and haulers. That is, are nuclear detonations efficient relative to other earth moving methods? Almost certainly.
https://en.wikipedia.org/wiki/Project_Plowshare
https://en.wikipedia.org/wiki/Project_Plowshare
Far-fetched projects like the ones discussed in the article have always piqued my imagination. As the article semi-mentions, we may at some point be forced into geoengineering and other "megascale" projects (see [0] for superconducting rings to boost Earth's magnetic field as it flips).
Maybe it's just overconfidence in humanity, but I can't help but believe that we are capable of such feats if sufficiently motivated and able to work together on the required scales.
[0] http://large.stanford.edu/courses/2016/ph240/mclaughlin2/doc...
Maybe it's just overconfidence in humanity, but I can't help but believe that we are capable of such feats if sufficiently motivated and able to work together on the required scales.
[0] http://large.stanford.edu/courses/2016/ph240/mclaughlin2/doc...
Wikipedia has some great content on megastructures. It's a good place to find some sci-fi book recommendations as well. I've ended up there more than once on late nights.
Here are a few good starting points:
https://en.wikipedia.org/wiki/Megastructure
https://en.wikipedia.org/wiki/Astronomical_engineering
https://en.wikipedia.org/wiki/Kardashev_scale
Here are a few good starting points:
https://en.wikipedia.org/wiki/Megastructure
https://en.wikipedia.org/wiki/Astronomical_engineering
https://en.wikipedia.org/wiki/Kardashev_scale
About that Canon...Before the Iraq war, A Canadian Inventor was building a giant canon for them, possibly capable of shooting missiles at Israel and even the USA.
After the war, he was assassinated by Mossad. https://en.wikipedia.org/wiki/Gerald_Bull
After the war, he was assassinated by Mossad. https://en.wikipedia.org/wiki/Gerald_Bull
If you find yourself in Barbados you can go and visit Project HARP Space Gun.
PS: only the Pope’s allowed to use the canon. Perhaps you meant cannon?
PS: only the Pope’s allowed to use the canon. Perhaps you meant cannon?
Haha, yeah. I met the pope. But I'm the worse speller.
Thanks, I'll definitely check it out if I visit Barbados one day.
Had a fixed aimpoint - Tel Aviv. Can't blame Mossad one bit.
> Had a fixed aimpoint
Source for that? See plenty about it being as a defense against Iran also. I can't find anything for your claim made.
And I'd be very interested at where you draw the line for the extrajudicial murder of Western military scientists getting their face blown apart in a Belguim street by foreign governments?
Hazarding a wild guess here but if an Iraqi intel agent did this to someone out the front of their house in Langley it would be completely immoral and evil right?
Surely the justification you've made here can be applied to thousands of current and former government employees along with private contractors across the planet?
I'm truly interested if you think this is how civilised societies should interact with each other? The man could have been arrested at any time, he was not in hiding nor unknown to world.
Source for that? See plenty about it being as a defense against Iran also. I can't find anything for your claim made.
And I'd be very interested at where you draw the line for the extrajudicial murder of Western military scientists getting their face blown apart in a Belguim street by foreign governments?
Hazarding a wild guess here but if an Iraqi intel agent did this to someone out the front of their house in Langley it would be completely immoral and evil right?
Surely the justification you've made here can be applied to thousands of current and former government employees along with private contractors across the planet?
I'm truly interested if you think this is how civilised societies should interact with each other? The man could have been arrested at any time, he was not in hiding nor unknown to world.
Whether it's how states should act is a wholly different question. No, preferably but what do you want? There has been quite a few chechens assassinated in western Europe, the sanctions haven't prevented Russian hit squads.
So instead here is a question to you, what should be done? I ask for a realistic answer.
So instead here is a question to you, what should be done? I ask for a realistic answer.
> In 1920, the New York Times famously mocked the proponents of the idea [the rocket], implying that they lacked the physics education of a high-school student. (In 1969, the newspaper issued a light-hearted retraction a day after the Apollo 11 astronauts lifted off towards the Moon.)
Is there any technological opinion people had in 1972 that would be considered embarrassing by today's standards?
The only thing that comes to mind is that Simpsons quote: "I predict that within 10 years, computers will be twice as powerful, ten thousand times larger, and so expensive that only the 5 richest kings of Europe will own them"
Is there any technological opinion people had in 1972 that would be considered embarrassing by today's standards?
The only thing that comes to mind is that Simpsons quote: "I predict that within 10 years, computers will be twice as powerful, ten thousand times larger, and so expensive that only the 5 richest kings of Europe will own them"
Paul Krugman's prediction that the impact of the internet will be "no greater than that of the fax machine."[0]
This is not by the way a specific criticism of Krugman (though I do think too many people, including Krugman himself, wrongly think his Nobel Prize for trade theory gives him expertise in every other subject he pontificates about).
As usual, the non-doers (commenters or critics, places like the NYT) have little perspective on things that can change the world. It's up to us in tech to always have that bright-eyed optimism for what is possible, because we're the ones building it day-in-day-out. Observer critics don't really have a place in this, unless that criticism is coming directly from folks who are meant to be the initial customers/users of technology.
[0]https://www.laphamsquarterly.org/revolutions/miscellany/paul...
This is not by the way a specific criticism of Krugman (though I do think too many people, including Krugman himself, wrongly think his Nobel Prize for trade theory gives him expertise in every other subject he pontificates about).
As usual, the non-doers (commenters or critics, places like the NYT) have little perspective on things that can change the world. It's up to us in tech to always have that bright-eyed optimism for what is possible, because we're the ones building it day-in-day-out. Observer critics don't really have a place in this, unless that criticism is coming directly from folks who are meant to be the initial customers/users of technology.
[0]https://www.laphamsquarterly.org/revolutions/miscellany/paul...
I've always felt the reverse, it's the doer that are in knee deep in the guts of various technological endeavor that display the most technological skepticism.
Peak oil.
It'll obviously happen at some point, but they were very wrong about the timing.
There's probably lots of examples on the optimistic side too. AI probably counts there.
It'll obviously happen at some point, but they were very wrong about the timing.
There's probably lots of examples on the optimistic side too. AI probably counts there.
Peak oil will never happen. The Alberta and Venezuela tar sands contain hundreds of years of supply, yet in a decade or so it'll be cheaper to make oil using cheap renewable energy than it will be to pull it out of the tar sands.
So then we've already peaked? I thought peak oil referred to related to the rate of extraction, not the reserve levels.
How much barrel of oil do we need to get one barrel of oil from tar sands?
I can't remember where I read it, but "We may one day fit 65k transistors on a chip" is a classic
Here's a fun compilation of side-by-side renderings of smallest to largest fictional buildings (not only scifi). It really helps get a sense of the scale of the imagined structures.
https://www.youtube.com/watch?v=hjIci91FRX4
Edit, starships, much larger than buildings above: https://www.youtube.com/watch?v=aTPwbVqU6lc
No affiliation, but fun channel.
https://www.youtube.com/watch?v=hjIci91FRX4
Edit, starships, much larger than buildings above: https://www.youtube.com/watch?v=aTPwbVqU6lc
No affiliation, but fun channel.
Relatedly, there was just an infographic going around of "Megascale" spaceships from science-fiction movies:
https://www.deviantart.com/dirkloechel/art/Size-Comparison-S...
https://www.deviantart.com/dirkloechel/art/Size-Comparison-S...
I'm a little sad that the webring on that page doesn't work.
I also appreciate the role-playing game settings of the author of this article.
http://www.aleph.se/Nada/Game/BigIdeas/index.html
http://www.aleph.se/Nada/Game/BigIdeas/index.html
The probably biggest current project: https://en.wikipedia.org/wiki/Red_Sea–Dead_Sea_Water_Conveya...
Isaac Arthur also has a great series on Megastructures
https://youtube.com/playlist?list=PLIIOUpOge0LtW77TNvgrWWu5O...
https://youtube.com/playlist?list=PLIIOUpOge0LtW77TNvgrWWu5O...
I've always thought that a practical use of mega-structures like Niven's Ringworld (or Halo from the video games), besides colonisation, would be to reach higher energy levels in particle physics, like with the LHC. To reach higher energy levels they need a larger circumference... so if you follow that research to extremes... maybe our descendants in the far future will live on what's essentially a massive science experiment.
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All of that and not one mention of O'Neil cylinders? A bit less mega, perhaps, but more feasible than even a Dyson Swarm because of it.
https://en.m.wikipedia.org/wiki/O%27Neill_cylinder
https://en.m.wikipedia.org/wiki/O%27Neill_cylinder
My favorite candidate is the Chott el-Djerid. A canal to the Mediterranean would create a huge inland sea in a largely abandoned Tunisian desert. The resulting increase in precipitation could irrigate the northern half of the country, boosting Africa's youngest democracy.
A ginormous space-based sunshade for the Earth would be pretty useful.
Not nearly as useful as a swarm of small shades/mirrors that would allow a more fine grained control over the local weather.
But there are also other alternatives that could either achieve some level of control over the wether or help the mirror swarm, like aerostats, or ocean heat exchange energy generators [1]. If we build large enough number of them, we can increase convection between equator and pole regions of the ocean reducing hurricanes and increasing rain over Sahara.
[1] https://en.m.wikipedia.org/wiki/Ocean_thermal_energy_convers...
But there are also other alternatives that could either achieve some level of control over the wether or help the mirror swarm, like aerostats, or ocean heat exchange energy generators [1]. If we build large enough number of them, we can increase convection between equator and pole regions of the ocean reducing hurricanes and increasing rain over Sahara.
[1] https://en.m.wikipedia.org/wiki/Ocean_thermal_energy_convers...
It would be.
Anything space based and big enough to rival or exceed planet sizes would take some very interesting engineering and management.
They would take a long time. Technology would advance tremendously during their construction. In fact, their construction might be planned to never end.
The first bits might not even be functional; their only purpose might be to act as a place to build the next bits on to.
Even when we get to the functional bits, they might be designed and built to be replaced, or built over, like Mike Mulligan's steam shovel.
They would also have to be designed and built to be safe even if civilization collapses. An interesting challenge would be to leave behind instructions, constantly updated while we're still around, to any future civilization to be able to "take up the tools" when they're ready.
Anything space based and big enough to rival or exceed planet sizes would take some very interesting engineering and management.
They would take a long time. Technology would advance tremendously during their construction. In fact, their construction might be planned to never end.
The first bits might not even be functional; their only purpose might be to act as a place to build the next bits on to.
Even when we get to the functional bits, they might be designed and built to be replaced, or built over, like Mike Mulligan's steam shovel.
They would also have to be designed and built to be safe even if civilization collapses. An interesting challenge would be to leave behind instructions, constantly updated while we're still around, to any future civilization to be able to "take up the tools" when they're ready.
"Anything space based and big enough to rival or exceed planet sizes would take some very interesting engineering and management."
Actually I think this would be quite small and manageable.
A space shade shades more area as it moves further away from the Earth. Further, the percentage of solar energy we would want to mitigate would be relatively small.
A modest sized shade made of reflective foil, in a solar orbit interior to the Earths orbit, could probably be done quite cheaply.
Actually I think this would be quite small and manageable.
A space shade shades more area as it moves further away from the Earth. Further, the percentage of solar energy we would want to mitigate would be relatively small.
A modest sized shade made of reflective foil, in a solar orbit interior to the Earths orbit, could probably be done quite cheaply.
> A space shade shades more area as it moves further away from the Earth.
The moon can eclipse the sun in its entirety.
Mercury is larger, yet barely visible with a telescope when it transits the sun.
I think the opposite of what you said is true.
(What you said I believe is correct in the case that the sun is much smaller than the Earth.)
The moon can eclipse the sun in its entirety.
Mercury is larger, yet barely visible with a telescope when it transits the sun.
I think the opposite of what you said is true.
(What you said I believe is correct in the case that the sun is much smaller than the Earth.)
Yes, it's a essentially a cone with the point at Earth. The circular cross sections only get bigger as you move towards the sun. Only reason it works with the moon is b/c it's 400x smaller and 400x closer. Cool fact is that won't happen forever, the moon's orbit is slowly increasing.
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Most of the actual build and design will be done by robots and AI systems, humans will have a very little role to play.
How will the robots be powered perpetually?
when we reach Kardashev Type I civilization...
I always wondered if it would be possible to run flexible pipelines floating close to the bottom of the ocean which could transport fresh water between far flung areas. Imagine if you could siphon some of the freshwater outflow of, say, the Columbia River and send it down to SoCal or AZ farmland.
It'd be easier to build and maintain a canal. If you're worried about evaporation, then just build a canal to the ocean and desalinate the water. It'd probably consume much less energy than a mega pipeline.
https://en.m.wikipedia.org/wiki/Aria_(manga)
It is a slice of life story about a grouo of gonodoli riding turist guides in a replica Venice on terraformed Mars. You can see terraformed mars quite often in SF, that's not what I'm talking about. Not even the flying islands that hist the power sources keeping the planet warm.
You see in tgis story, there is one thing kinda hiding in plain sight - it's terraformed Mars with Earth strength gravity.
Yes, not 1/3 g but full 1 g and they did it during the terraforming, it's not a mistake by the author.
So how exactly do you triplicate planets gravity withou importing 2 times of it's mass in the proccess ?
By buikding a Mars spanning series of particle accelerators that accelerate dense macroscale objects to near lightspeed under the surface.
Thanks to the theory of relativity things behave as they had much more mass as they approach lightspeed, which is exactly what you need to simulate two more Marses of mass needed to achieve 1 g like on Earth - bam, artificial gravity using known physics! :-)
Just don't thing about the insane amount of energy requured to accelerate so much muss in your accelerator racetracks to lightspeed. Or what would happen if even just one of these superlaminar dense capsules anaged to collide with the accelerator wall, making all other crash as well. Very close supernova might seem like a firecracker in comparison.