8 ms·

Most people get baked, wonder if we're alone in the universe, and take a nap. Astrophysicists get baked, wonder if we're alone in the universe, and publish pape

by nyx 5y ago

Most people get baked, wonder if we're alone in the universe, and take a nap. Astrophysicists get baked, wonder if we're alone in the universe, and publish papers like this. Jokes aside, is there really any practical value in this sort of research, or is it the kind of thing that we do because it's interesting and kinda cool? Don't get me wrong, I think it's valuable for that alone, but...

JuettnerDistrib 5y ago
> is there really any practical value in this sort of research In many ways it is too early to do this research, so it is a kind of art (as is a lot of research, imho). As long as only a few people do it, it's cool and useful so we can be aware of our potential future. On the other hand, since we have no credible evidence of extraterrestrials, it would be surprising to find a civilisation so advanced to build a Dyson sphere. If they can build Dyson spheres, wouldn't they already be all over the place? Ok, I suppose I should actually go read the paper now...
- bryanrasmussen 5y ago
  Being able to build Dyson spheres does not make them capable of going faster than the speed of light, so any civilization capable of building a Dyson sphere would probably still be clustered around a couple stars and that's it. Would such a civilization spread to more than one star is actually also a question, or would they control their population rationally stay on their Dyson sphere and only start to move when the star had less than 100,000 years left to go. Only some Dyson sphere variants, like Shkadov thrusters, are primarily conceived as ways to move around. Which personally seems to me less likely, is a civilization, as well as the ability to construct these objects, also going to have a species level interest in going exploring?
  - perihelions 5y ago
    > "Being able to build Dyson spheres does not make them capable of going faster than the speed of light, so any civilization capable of building a Dyson sphere would probably still be clustered around a couple stars and that's it." Check your math: this galaxy is ~10^5 light-years in size and ~10^10 years in age.
    - bryanrasmussen 5y ago
      what does that have to do with anything I said? Yes, I guess they would be everywhere if their civilization was able to make Dyson spheres 1 year after the creation of the galaxy, also if they decided to 1. Not control their population for some reason. 2. Had some sort of interest in exploring. 3. Implicit also in the speed of light thing, would find it really interesting to send a portion of their population to the next available and suitable star which might be enough light years away to make communication impractical. I mean for our civilization there is some level of argument that says it would be a ridiculous idea to move to a new solar system and we have an intellectual exploratory streak in our species. I mean we are currently not at the level of being able to do a Dyson sphere, it took us 4.543 billion years (age of earth) to get to the part that somebody could conceive of it. There is also some discussion as to whether or not our civilization is going to last, so given that and the other things I said it seems unlikely to me that any Dyson sphere civilization would actually build more than one, but maybe some build two because binary stars or some other weird circumstance which makes it worthwhile to do. on edit: if we get to Dyson sphere building capabilities which seems really unlikely, will we build more than one? How many more?
      - MattPalmer1086 5y ago
        The point is that you don't need to go faster than the speed of light. There's more than enough time to cover the entire galaxy in a relatively short period of time at sublight speeds. A few million years is sufficient.
        bryanrasmussen 5y ago
        yeah, sure, enough time to GO everywhere but not enough time to BE everywhere, which is a different thing entirely, even if all the other things I brought up as to why the aliens weren't everywhere were not things to take into consideration. So again, still haven't heard any argument why an alien civilization achieving the ability to build Dyson spheres, even if they did so far enough in the past that they would then have adequate time to traverse the galaxy afterwards, would then have to be everywhere?
  - caf 5y ago
    They may not be moving around to explore so much as to keep their solar system safe. Galactic orbits are far more chaotic than the sedate stable orbits within the solar system - stars closely approach each other on a somewhat regular basis.
    - bryanrasmussen 5y ago
      that's a good point, but I guess at Dyson sphere level a star approaching is like discovering oil on your property.
- dave_sullivan 5y ago
  No Dyson spheres, but there are black holes all over the place. Some people think those would make great computing devices, many of their origins are not well explained as super nova remnants, and they efficiently harness energy from companion stars. They have all the properties of Dyson spheres but they actually exist. Maybe with advanced enough physics, intelligent civilizations learn to manufacture and harness black holes, neutron stars, and other dense objects for societal benefit.
  - jonathankoren 5y ago
    > No Dyson spheres, but there are black holes all over the place. Some people think those would make great computing devices They’re crappy computing devices. Even if you figured out how to program one — and that’s an “if” that would make Sagittarius A* look like a neutrino — there’s no way to read the information out except Hawking Radiation, and that would take 10^70 years. https://youtu.be/0GLgZvTCbaA https://youtu.be/0GLgZvTCbaA (8:36)
  - alfiedotwtf 5y ago
    This is the first time I've heard of this. Wow, yes! A blackhole is far more efficient at consuming energy than a Dyson Sphere... the hard part though is kickstarting the process I guess
- ohyeshedid 5y ago
  > If they can build Dyson spheres, wouldn't they already be all over the place? I figure they'd have to be. They'd need more than a solar system's worth of raw resources to build the sphere. They may need more than a solar system's worth of resources just to build the tools and craft to be able to build the sphere. They're going to need an insane amount of production facilities for various components, and that's going to take a massive amount of resources. That's going to require exploring quite a bit of a galaxy.
- awb 5y ago
  > If they can build Dyson spheres, wouldn't they already be all over the place? The number I’ve seen quoted is 50M years to colonize the galaxy: http://www.sentientdevelopments.com/2012/01/new-mathematical-study-reveals-that-our.html http://www.sentientdevelopments.com/2012/01/new-mathematical... > they calculated that any galactic empire would have spread outwards from its home planet at about 0.25% of the speed of light. The result is that after 50m years it would extend over 130,000 light years, with zealous colonisers moving in a relatively uniform cloud and more reticent ones protruding from a central blob. Since the Milky Way is estimated to be 100,000-120,000 light years across, outposts would be sprinkled throughout the galaxy, even if the home planet were, like Earth, located on the periphery. It’s actually so fast that advanced civilizations would have had time to colonize the galaxy and go extinct many times over without us noticing. Or maybe their spheres were built so long ago they’ve already collapsed and been consumed by the stars again. It’s a great mystery and interesting thought experiment though.
  - denton-scratch 5y ago
    > 50M years to colonize the galaxy Our ancestors from 50M years ago are all extinct. So a civilisation spreading through the galaxy would have evolved in all kinds of different ways. It's not obvious to me that these diverse evolutionary strands would all still be interested in Dyson spheres, or space travel, or even astronomy. There's a belief that's hard to shake off, that the properties humans have that we think most important represent some kind of evolutionary pinnacle. Typically, those properties are language, and a large brain for processing language. But if language and a large brain are really such great evolutionary advantages, why are humans the only creatures on Earth that have evolved those properties? Possibly language and a large brain are an evolutionary backwater. At 0.25% of the speed of light, it would take us 1,600 years to reach Proxima Centauri; but it might take a lot longer to reach a star with habitable planets. We'd definitely need generation ships. After (say) a million years, we'd presumably have evolved to adapt to life on generation ships. It's not obvious to me that such adaptations would leave us fit to inhabit a planet. And perhaps adaptation to life on a generation ship means adapting to eating your fellow passengers. Given the history of humanity, I find it hard to believe that the population of a generation ship could survive as long as 100 years without war breaking out on-board. We've had large brains and language for about 50,000 years, as far as I can tell; we've been warring the whole time. Maybe large brains and language pre-dispose us to war? If that's right, then it seems unlikely that intelligent life would ever spread far from it's planet of origin. I'm very sceptical of the idea that any "civilisation" could ever spread far from its home planet. There are two things that we refeer to as a civilisation: a culture, and a species. Culture changes very quickly - over a single lifetime. But on a scale of millions of years, speciation is also pretty quick. So I can't see how any kind of homogenous civilisation or species could spread through a galaxy. They would have diversified before the train even reached its first stop. So I don't have any insurance against being kidnapped by aliens.
dnsco 5y ago
It depends on how you define practical value. Immediately capitalizable? Probably not outside of Hollywood. Building a theoretical underpinning for the future of our species? I hope so.
TheDudeMan 5y ago
This probably has implications around the Fermi paradox and the great filter(s). We would like to pass whatever filters are ahead of us.
wesleywt 5y ago
Research should NEVER be limited by whether it has practical value or not. Because we don't know if future generations will make it practical.
- XorNot 5y ago
  Exactly. Any research which takes something we don't know, and turns it into something we now know, is valuable.
- ncmncm 5y ago
  Research is ALWAYS limited to what the person performing it considered practical. Getting a paper published is as practical as most researchers need to get. (Some do more.) If they don't publish, they soon don't get to do research anymore, and have to start doing what somebody else considers practical.
  - wesleywt 5y ago
    You missed the word I wrote "should". Funding agencies want to fund only "practical" research. But studying the migratory patterns of a single species of butterfly should be funded as much as the latest biotech fad that supposedly is of "practical value".
tapas73 5y ago
All fundamental research is reaserch for the sake of knowledge, for the sake of satisfying curiosity. Once it is done, possibly much much much later, somebody may stumble upon it and use it in some creative (and unforseen) ways for other research. On the other hand if you give any probability to alien existence, then this is very much practical already in the search for them.
Apocryphon 5y ago
You could possibly win an Ig Nobel Award out of it.
captainmuon 5y ago
Searching for Dyson spheres is not too different from searching for other hypothetical astronomical objects. Maybe it is a low-stakes analysis you could put some students on, so they learn something. Data collection, statistical methods, paper writing is all identical to "traditional" searches. I come from particle physics, and we did quite a few searches for very weird particles that, I admit, didn't believe in. But it was quick to retool the search for more plausible models. Also I think science works the way that you use your fantasy to come up with outlandish things, and then try to rule them out with logic.
- dillondoyle 5y ago
  How do you find one? Is it similar to a black hole where you can detect the gravity, but can't see any of the energy coming from the covered sun?
  - terramex 5y ago
    Dyson sphere would emit significant amount of infrared light but no visible light. Original Freeman Dyson's paper from 1960 was titled "Search for Artificial Stellar Sources of Infrared Radiation" https://sci-hub.ee/10.1126/science.131.3414.1667 https://sci-hub.ee/10.1126/science.131.3414.1667
    - ncmncm 5y ago
      When somebody got a telescope that could, they found there were way more sources of infrared radiation than visible stars.
    - dillondoyle 5y ago
      Cool. maybe James Webb will find one ;)
kragen 5y ago
Was there any practical value in Columbus discovering America? If the Aztecs had instead sailed to Europe or Africa and discovered them, would that have been of any practical value to them? It's difficult to imagine a discovery that would have more practical import than the discovery of an extraterrestrial civilization.
- ncmncm 5y ago
  Hint: Columbus didn't discover America. Millions of people already lived there, and knew all about it. But anyway looking for Dyson spheres will not reveal any extraterrestrial civilizations.
  - zzt123 5y ago
    I believe the person you are replying to is saying “discover” relatively rather than Euro-centrically, as they mention a hypothetical Aztecs “discovering” Europe and Africa.
  - vasco 5y ago
    A discovery doesn't have to imply that no living being knew about said thing/ place. It can imply only that the person or the group of people the person is from learns about this new thing. At some point in time nobody in Europe had definite proof of how to get to America. You can call "europeans learning how to get to America" something else other than "discovered America", but what phrasing should one use instead? To make the point, literally nothing can be classified as "discovered" under your rules because any alien civilization may know about everything we'll ever find or figure out, and if they know about it we can't have discovered it. Columbus was a murderer and people in America before he got there deserved way better but this type of nitpicking correction is just noise if you don't even say what is a more appropriate phrase.
  - kragen 5y ago
    Are you saying that, even if extraterrestrial civilizations existed, looking for Dyson spheres wouldn't reveal them? Or are you saying that they don't exist, so nothing will reveal them? In either case, why?
tannhauser23 5y ago
It's a low cost, low probability way to look for advanced civilizations. Chances are low that you'll find anything, but hey the data's already here and we have powerful computers so let's run some calculations. And occasionally you find weird and interesting anomalies that push science forward: https://www.space.com/alien-megastructure-mysteriously-dimming-stars.html https://www.space.com/alien-megastructure-mysteriously-dimmi...

by nyx 5y ago

JuettnerDistrib 5y ago

> is there really any practical value in this sort of research In many ways it is too early to do this research, so it is a kind of art (as is a lot of research, imho). As long as only a few people do it, it's cool and useful so we can be aware of our potential future. On the other hand, since we have no credible evidence of extraterrestrials, it would be surprising to find a civilisation so advanced to build a Dyson sphere. If they can build Dyson spheres, wouldn't they already be all over the place? Ok, I suppose I should actually go read the paper now...

bryanrasmussen 5y ago
Being able to build Dyson spheres does not make them capable of going faster than the speed of light, so any civilization capable of building a Dyson sphere would probably still be clustered around a couple stars and that's it. Would such a civilization spread to more than one star is actually also a question, or would they control their population rationally stay on their Dyson sphere and only start to move when the star had less than 100,000 years left to go. Only some Dyson sphere variants, like Shkadov thrusters, are primarily conceived as ways to move around. Which personally seems to me less likely, is a civilization, as well as the ability to construct these objects, also going to have a species level interest in going exploring?
- perihelions 5y ago
  > "Being able to build Dyson spheres does not make them capable of going faster than the speed of light, so any civilization capable of building a Dyson sphere would probably still be clustered around a couple stars and that's it." Check your math: this galaxy is ~10^5 light-years in size and ~10^10 years in age.
  - bryanrasmussen 5y ago
    what does that have to do with anything I said? Yes, I guess they would be everywhere if their civilization was able to make Dyson spheres 1 year after the creation of the galaxy, also if they decided to 1. Not control their population for some reason. 2. Had some sort of interest in exploring. 3. Implicit also in the speed of light thing, would find it really interesting to send a portion of their population to the next available and suitable star which might be enough light years away to make communication impractical. I mean for our civilization there is some level of argument that says it would be a ridiculous idea to move to a new solar system and we have an intellectual exploratory streak in our species. I mean we are currently not at the level of being able to do a Dyson sphere, it took us 4.543 billion years (age of earth) to get to the part that somebody could conceive of it. There is also some discussion as to whether or not our civilization is going to last, so given that and the other things I said it seems unlikely to me that any Dyson sphere civilization would actually build more than one, but maybe some build two because binary stars or some other weird circumstance which makes it worthwhile to do. on edit: if we get to Dyson sphere building capabilities which seems really unlikely, will we build more than one? How many more?
    - MattPalmer1086 5y ago
      The point is that you don't need to go faster than the speed of light. There's more than enough time to cover the entire galaxy in a relatively short period of time at sublight speeds. A few million years is sufficient.
      - bryanrasmussen 5y ago
        yeah, sure, enough time to GO everywhere but not enough time to BE everywhere, which is a different thing entirely, even if all the other things I brought up as to why the aliens weren't everywhere were not things to take into consideration. So again, still haven't heard any argument why an alien civilization achieving the ability to build Dyson spheres, even if they did so far enough in the past that they would then have adequate time to traverse the galaxy afterwards, would then have to be everywhere?
- caf 5y ago
  They may not be moving around to explore so much as to keep their solar system safe. Galactic orbits are far more chaotic than the sedate stable orbits within the solar system - stars closely approach each other on a somewhat regular basis.
  - bryanrasmussen 5y ago
    that's a good point, but I guess at Dyson sphere level a star approaching is like discovering oil on your property.
dave_sullivan 5y ago
No Dyson spheres, but there are black holes all over the place. Some people think those would make great computing devices, many of their origins are not well explained as super nova remnants, and they efficiently harness energy from companion stars. They have all the properties of Dyson spheres but they actually exist. Maybe with advanced enough physics, intelligent civilizations learn to manufacture and harness black holes, neutron stars, and other dense objects for societal benefit.
- jonathankoren 5y ago
  > No Dyson spheres, but there are black holes all over the place. Some people think those would make great computing devices They’re crappy computing devices. Even if you figured out how to program one — and that’s an “if” that would make Sagittarius A* look like a neutrino — there’s no way to read the information out except Hawking Radiation, and that would take 10^70 years. https://youtu.be/0GLgZvTCbaA https://youtu.be/0GLgZvTCbaA (8:36)
- alfiedotwtf 5y ago
  This is the first time I've heard of this. Wow, yes! A blackhole is far more efficient at consuming energy than a Dyson Sphere... the hard part though is kickstarting the process I guess
ohyeshedid 5y ago
> If they can build Dyson spheres, wouldn't they already be all over the place? I figure they'd have to be. They'd need more than a solar system's worth of raw resources to build the sphere. They may need more than a solar system's worth of resources just to build the tools and craft to be able to build the sphere. They're going to need an insane amount of production facilities for various components, and that's going to take a massive amount of resources. That's going to require exploring quite a bit of a galaxy.
awb 5y ago
> If they can build Dyson spheres, wouldn't they already be all over the place? The number I’ve seen quoted is 50M years to colonize the galaxy: http://www.sentientdevelopments.com/2012/01/new-mathematical-study-reveals-that-our.html http://www.sentientdevelopments.com/2012/01/new-mathematical... > they calculated that any galactic empire would have spread outwards from its home planet at about 0.25% of the speed of light. The result is that after 50m years it would extend over 130,000 light years, with zealous colonisers moving in a relatively uniform cloud and more reticent ones protruding from a central blob. Since the Milky Way is estimated to be 100,000-120,000 light years across, outposts would be sprinkled throughout the galaxy, even if the home planet were, like Earth, located on the periphery. It’s actually so fast that advanced civilizations would have had time to colonize the galaxy and go extinct many times over without us noticing. Or maybe their spheres were built so long ago they’ve already collapsed and been consumed by the stars again. It’s a great mystery and interesting thought experiment though.
- denton-scratch 5y ago
  > 50M years to colonize the galaxy Our ancestors from 50M years ago are all extinct. So a civilisation spreading through the galaxy would have evolved in all kinds of different ways. It's not obvious to me that these diverse evolutionary strands would all still be interested in Dyson spheres, or space travel, or even astronomy. There's a belief that's hard to shake off, that the properties humans have that we think most important represent some kind of evolutionary pinnacle. Typically, those properties are language, and a large brain for processing language. But if language and a large brain are really such great evolutionary advantages, why are humans the only creatures on Earth that have evolved those properties? Possibly language and a large brain are an evolutionary backwater. At 0.25% of the speed of light, it would take us 1,600 years to reach Proxima Centauri; but it might take a lot longer to reach a star with habitable planets. We'd definitely need generation ships. After (say) a million years, we'd presumably have evolved to adapt to life on generation ships. It's not obvious to me that such adaptations would leave us fit to inhabit a planet. And perhaps adaptation to life on a generation ship means adapting to eating your fellow passengers. Given the history of humanity, I find it hard to believe that the population of a generation ship could survive as long as 100 years without war breaking out on-board. We've had large brains and language for about 50,000 years, as far as I can tell; we've been warring the whole time. Maybe large brains and language pre-dispose us to war? If that's right, then it seems unlikely that intelligent life would ever spread far from it's planet of origin. I'm very sceptical of the idea that any "civilisation" could ever spread far from its home planet. There are two things that we refeer to as a civilisation: a culture, and a species. Culture changes very quickly - over a single lifetime. But on a scale of millions of years, speciation is also pretty quick. So I can't see how any kind of homogenous civilisation or species could spread through a galaxy. They would have diversified before the train even reached its first stop. So I don't have any insurance against being kidnapped by aliens.

dnsco 5y ago

It depends on how you define practical value. Immediately capitalizable? Probably not outside of Hollywood. Building a theoretical underpinning for the future of our species? I hope so.

TheDudeMan 5y ago

This probably has implications around the Fermi paradox and the great filter(s). We would like to pass whatever filters are ahead of us.

wesleywt 5y ago

Research should NEVER be limited by whether it has practical value or not. Because we don't know if future generations will make it practical.

XorNot 5y ago
Exactly. Any research which takes something we don't know, and turns it into something we now know, is valuable.
ncmncm 5y ago
Research is ALWAYS limited to what the person performing it considered practical. Getting a paper published is as practical as most researchers need to get. (Some do more.) If they don't publish, they soon don't get to do research anymore, and have to start doing what somebody else considers practical.
- wesleywt 5y ago
  You missed the word I wrote "should". Funding agencies want to fund only "practical" research. But studying the migratory patterns of a single species of butterfly should be funded as much as the latest biotech fad that supposedly is of "practical value".

tapas73 5y ago

All fundamental research is reaserch for the sake of knowledge, for the sake of satisfying curiosity. Once it is done, possibly much much much later, somebody may stumble upon it and use it in some creative (and unforseen) ways for other research. On the other hand if you give any probability to alien existence, then this is very much practical already in the search for them.

Apocryphon 5y ago

You could possibly win an Ig Nobel Award out of it.

captainmuon 5y ago

Searching for Dyson spheres is not too different from searching for other hypothetical astronomical objects. Maybe it is a low-stakes analysis you could put some students on, so they learn something. Data collection, statistical methods, paper writing is all identical to "traditional" searches. I come from particle physics, and we did quite a few searches for very weird particles that, I admit, didn't believe in. But it was quick to retool the search for more plausible models. Also I think science works the way that you use your fantasy to come up with outlandish things, and then try to rule them out with logic.

dillondoyle 5y ago
How do you find one? Is it similar to a black hole where you can detect the gravity, but can't see any of the energy coming from the covered sun?
- terramex 5y ago
  Dyson sphere would emit significant amount of infrared light but no visible light. Original Freeman Dyson's paper from 1960 was titled "Search for Artificial Stellar Sources of Infrared Radiation" https://sci-hub.ee/10.1126/science.131.3414.1667 https://sci-hub.ee/10.1126/science.131.3414.1667
  - ncmncm 5y ago
    When somebody got a telescope that could, they found there were way more sources of infrared radiation than visible stars.
  - dillondoyle 5y ago
    Cool. maybe James Webb will find one ;)

kragen 5y ago

Was there any practical value in Columbus discovering America? If the Aztecs had instead sailed to Europe or Africa and discovered them, would that have been of any practical value to them? It's difficult to imagine a discovery that would have more practical import than the discovery of an extraterrestrial civilization.

ncmncm 5y ago
Hint: Columbus didn't discover America. Millions of people already lived there, and knew all about it. But anyway looking for Dyson spheres will not reveal any extraterrestrial civilizations.
- zzt123 5y ago
  I believe the person you are replying to is saying “discover” relatively rather than Euro-centrically, as they mention a hypothetical Aztecs “discovering” Europe and Africa.
- vasco 5y ago
  A discovery doesn't have to imply that no living being knew about said thing/ place. It can imply only that the person or the group of people the person is from learns about this new thing. At some point in time nobody in Europe had definite proof of how to get to America. You can call "europeans learning how to get to America" something else other than "discovered America", but what phrasing should one use instead? To make the point, literally nothing can be classified as "discovered" under your rules because any alien civilization may know about everything we'll ever find or figure out, and if they know about it we can't have discovered it. Columbus was a murderer and people in America before he got there deserved way better but this type of nitpicking correction is just noise if you don't even say what is a more appropriate phrase.
- kragen 5y ago
  Are you saying that, even if extraterrestrial civilizations existed, looking for Dyson spheres wouldn't reveal them? Or are you saying that they don't exist, so nothing will reveal them? In either case, why?

tannhauser23 5y ago

It's a low cost, low probability way to look for advanced civilizations. Chances are low that you'll find anything, but hey the data's already here and we have powerful computers so let's run some calculations. And occasionally you find weird and interesting anomalies that push science forward: https://www.space.com/alien-megastructure-mysteriously-dimming-stars.html https://www.space.com/alien-megastructure-mysteriously-dimmi...