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Maybe one reason we can't detect advanced civilizations is because they're capturing and recycling all their waste heat & waste EM. We could start looking for

Maybe one reason we can't detect advanced civilizations is because they're capturing and recycling all their waste heat & waste EM. We could start looking for cold spots that should be warm.

raverbashing 7y ago
Could be. I never bought the whole Dyson spheres idea. A truly advanced civilization wouldn't need that much energy (they would be very efficient), and certainly wouldn't need to "kidnap" a start for that. A single digit percent of the Earth would need to be covered with solar panels with today's technology for our energetic consumption, I don't see why advanced civilizations would need let's say 10% of the energy of a star (let alone need to capture it)
- newsbinator 7y ago
  One reason to harness a star might be replicator or transporter technology. It takes a lot of energy to make an omelette. Or a lot more energy to make a person-sized person.
- ajuc 7y ago
  > they would be very efficient https://en.wikipedia.org/wiki/Jevons_paradox https://en.wikipedia.org/wiki/Jevons_paradox > In economics, the Jevons paradox (/ˈdʒɛvənz/; sometimes Jevons effect) occurs when technological progress or government policy increases the efficiency with which a resource is used (reducing the amount necessary for any one use), but the rate of consumption of that resource rises due to increasing demand.[1] > In 1865, the English economist William Stanley Jevons observed that technological improvements that increased the efficiency of coal-use led to the increased consumption of coal in a wide range of industries. He argued that, contrary to common intuition, technological progress could not be relied upon to reduce fuel consumption.[4][5] With enough energy crazy things are possible. Terraforming planets, human-lifespan interstellar travel, swarms of space habitats allowing everybody to have their own ecosystem changing to their will. Assuming people won't do it because they don't do it now (when energy is limited) is unwise. Don't you think some rich people would like to have their own space habitat where they can change gravity, day-night cycle, and the whole ecosystem at will? It's possible with current technology, just very expansive. It creates new real estate from scratch. With enough energy everybody could have one. I don't see any point at which people decide "this is enough". Always there will be some people that want more. BTW I agree it won't be a Dyson sphere, it will probably be a Dyson swarm. Much easier to start, cheaper, and has all the benefits of a sphere.
  - raverbashing 7y ago
    That's a good comeback The counterproblem is: capturing energy from a star is one thing, transporting it to where it can be used a different problem (as we even see today with electric cars) Or maybe they will just mine bitcoin with it, who knows
    - TeMPOraL 7y ago
      Transporting energy from a star is simple: concentrating the light. The most basic incremental design for a Dyson sphere would be a swarm of mirror satellites. How do we see energy transport problem with electric cars? That's only a matter of the right sockets not being available. The power grid is there.
      - raverbashing 7y ago
        Can the grid handle 10% of cars moving from gas to electricity? 50%? 90%? Not to mention battery issues (range, charge time, safety, etc) which are getting better, no doubt about it It's not only a matter of having the right socket
        ajuc 7y ago
        It's complicated, for sure, and will need changes in the infrastructure. But it has some advantages as well. Imagine 10 000 000 cars with 50 kWh battry capacity each connected to the grid and letting 10% of their capacity to be used for balancing of the network. If the grid has excess power - charge to 100%. If the grid lacks power - discharge to 90%. That's 50 GWh of balancing capacity. It basically solves the problems with unpredictability of most of the renewable power sources.
- BuckRogers 7y ago
  Glad to hear I'm not the only Dyson doubter. Seems too primitive to me. Any advanced civilization will have advanced knowledge on the truth to our reality, and will find ways to manipulate the laws of nature in this or other universes. We're already getting an initial grasp on that with our own developments and we're way behind. Mega structures around a star is just too basic to make sense at the stage where you could build one.
  - TeMPOraL 7y ago
    Why? Basic things usually work well. Chemical rockets, firearms, water wheels, wind generators, pumping water for energy storage - these are just few random examples of the extremely basic, brute-force approaches that work really well for us, and see no sign of being replaced. Complexity beyond the point of what's needed is usually sign of bad design.
    - BuckRogers 7y ago
      Your question forces me to restate the original post again in other words, but you're correct, if understanding and manipulating the substrate of our reality is a sign of "bad design". Nothing you mentioned is basic from the viewpoint of a mere single planet species. But it's all basic enough to ensure we've remained a single planet species. Thus, if you can build a Dyson sphere, you probably won't need one because at that point your fundamental knowledge will be much greater than "bigger gun". In fact, we stopped building bigger firearms long ago due to greater understanding.
- TeMPOraL 7y ago
  > I don't see why advanced civilizations would need let's say 10% of the energy of a star (let alone need to capture it) Because you're thinking about maintaining status quo of early XXI century Earth (and not that, solar panels won't be enough for that), not about future possibilities. Space travel, for one, is a huge energy sink if you want to do it in reasonable timeframes. A probe to Mars in a year? Sure, usual chemical rockets will do. A passenger ship in 2 weeks? Now we're talking absurd amounts of energy. If human history teaches us anything, it's that there's always use for more energy. Hell, recently we've been inventing some potentially infinite energy sinks - like the idea of running the economy on cryptocurrencies. I'm still not sure whether Bitcoin is a conspiracy to have humanity cook itself on Earth, or to force humans to start building a Dyson sphere in the next 100 years...
  - raverbashing 7y ago
    But you see, the problem with space travel is not the lack of energy, it's how to transport it efficiently (rocket equation) and how to use it efficiently to increase speed (specific velocity, etc) You can throw all the fuel you want at a chemical rocket and it won't take you to Mars in less than a year (more or less).
    - TeMPOraL 7y ago
      > it's how to transport it efficiently (rocket equation) This applies only if you have to carry chemical fuel with you; you can cheat a lot if you have lots of raw energy available. Chemical rockets won't open up the outer Solar System to us, but beamed power just might. Hell, at the Dyson sphere technology level, you could just push things around the system with giant lasers. (Yes, that same technology could also be used as a powerful weapon, but it's the unfortunate feature of distances in space - anything interesting you'd like to do in timescales we're used to from daily lives requires handling energy in levels and forms that could be used as weapons of mass destruction.)
- xondono 7y ago
  You do realize that covering 10% of the planet in solar panels is the start of a Dyson sphere right? Just push it up to 100% and start adding "fake" planets until a sphere is formed. :) Jokes aside, "A truly advanced civilization wouldn't need that much energy" reminds me of "640K ought to be enough for anybody", energy is in some sense like RAM, the more you have, the more you can do with it.
dTal 7y ago
It's impossible to capture and recycle all waste heat. It's an inevitable consequence of the second law of thermodynamics. Life, an anomalously low-entropy state, must survive by dumping its entropy somewhere else. Relatedly: stealth as shown in The Expanse is impossible. https://www.forbes.com/sites/chadorzel/2015/12/22/the-expanse-and-the-physics-of-stealth-in-space/ https://www.forbes.com/sites/chadorzel/2015/12/22/the-expans... (the article also tackles Dyson spheres)
- TeMPOraL 7y ago
  http://www.projectrho.com/public_html/rocket/spacewardetect.php http://www.projectrho.com/public_html/rocket/spacewardetect.... - Stealth in space: much more than you wanted to know. (TL;DR: next to impossible)
dexen 7y ago
Any sufficiently advanced technology is indistinguishable from magic. -- Arthur Clarke An advanced civilization (Type II on Kardashev scale, i.e, able to harvest their sun's energy output), having built a Dyson sphere[1] or similar, would appear to outsiders to be a red dwarf or a brown dwarf: a mildly hot star or sub-stellar object. It would be a sphere that emits more-or-less typical black-body radiation of a slightly warm (in stellar sense) object, with some spectral lines related to the surface material. Granted, the apparent "red/brown dwarf" of a Dyson sphere would have much larger size than usual, but on cosmic distances, individual object sizes aren't measured directly - instead we infer them from indirect measures such as light emission and gravitational effects, & comparing to known references & theoretical models. We can assume some advanced civilizations would want to keep private for safety reasons - as to not invite hostile attention - and thus would do their best to closely approximate spectrum of actual red or brown dwarf through engineering. Meaning we couldn't tell them apart from actual red or brown dwarf without getting close enough to observe the size directly, or somehow recognizing minute deviation from expected spectra. Right now we may be looking at several advanced (Type II) civilizations, mistakenly dismissing them as mere red dwarfs. dexen's dictum #2: presume all apparently planet-less cold stars to be potential Dyson spheres until positively proven otherwise. [1] I've just realized a full Dyson sphere would be a good Faraday cage, preventing radio emissions leaking outside.
- taneq 7y ago
  "Any technology distinguishable from magic is insufficiently advanced." - Corollary to Clarke's Law Also, on the topic of advanced civilizations being coy: > "Once there were three tribes. The Optimists, whose patron saints were Drake and Sagan, believed in a universe crawling with gentle intelligence—spiritual brethren vaster and more enlightened than we, a great galactic siblinghood into whose ranks we would someday ascend. Surely, said the Optimists, space travel implies enlightenment, for it requires the control of great destructive energies. Any race which can't rise above its own brutal instincts will wipe itself out long before it learns to bridge the interstellar gulf. > Across from the Optimists sat the Pessimists, who genuflected before graven images of Saint Fermi and a host of lesser lightweights. The Pessimists envisioned a lonely universe full of dead rocks and prokaryotic slime. The odds are just too low, they insisted. Too many rogues, too much radiation, too much eccentricity in too many orbits. It is a surpassing miracle that even one Earth exists; to hope for many is to abandon reason and embrace religious mania. After all, the universe is fourteen billion years old: if the galaxy were alive with intelligence, wouldn't it be here by now? > Equidistant to the other two tribes sat the Historians. They didn't have too many thoughts on the probable prevalence of intelligent, spacefaring extraterrestrials— but if there are any, they said, they're not just going to be smart. They're going to be mean. - Peter Watts, Blindsight And the corollary to Watts' Law (if he doesn't already have one I call dibs on this being called that) is, of course, that if there are any intelligent, spacefaring extraterrestrials, they're going to be sneaky.
HNLurker2 7y ago
And sci fi idea is that black matter is just that. And in reality civilizations are more peaceful but many

Maybe one reason we can't detect advanced civilizations is because they're capturing and recycling all their waste heat & waste EM. We could start looking for cold spots that should be warm.

raverbashing 7y ago

Could be. I never bought the whole Dyson spheres idea. A truly advanced civilization wouldn't need that much energy (they would be very efficient), and certainly wouldn't need to "kidnap" a start for that. A single digit percent of the Earth would need to be covered with solar panels with today's technology for our energetic consumption, I don't see why advanced civilizations would need let's say 10% of the energy of a star (let alone need to capture it)

newsbinator 7y ago
One reason to harness a star might be replicator or transporter technology. It takes a lot of energy to make an omelette. Or a lot more energy to make a person-sized person.
ajuc 7y ago
> they would be very efficient https://en.wikipedia.org/wiki/Jevons_paradox https://en.wikipedia.org/wiki/Jevons_paradox > In economics, the Jevons paradox (/ˈdʒɛvənz/; sometimes Jevons effect) occurs when technological progress or government policy increases the efficiency with which a resource is used (reducing the amount necessary for any one use), but the rate of consumption of that resource rises due to increasing demand.[1] > In 1865, the English economist William Stanley Jevons observed that technological improvements that increased the efficiency of coal-use led to the increased consumption of coal in a wide range of industries. He argued that, contrary to common intuition, technological progress could not be relied upon to reduce fuel consumption.[4][5] With enough energy crazy things are possible. Terraforming planets, human-lifespan interstellar travel, swarms of space habitats allowing everybody to have their own ecosystem changing to their will. Assuming people won't do it because they don't do it now (when energy is limited) is unwise. Don't you think some rich people would like to have their own space habitat where they can change gravity, day-night cycle, and the whole ecosystem at will? It's possible with current technology, just very expansive. It creates new real estate from scratch. With enough energy everybody could have one. I don't see any point at which people decide "this is enough". Always there will be some people that want more. BTW I agree it won't be a Dyson sphere, it will probably be a Dyson swarm. Much easier to start, cheaper, and has all the benefits of a sphere.
- raverbashing 7y ago
  That's a good comeback The counterproblem is: capturing energy from a star is one thing, transporting it to where it can be used a different problem (as we even see today with electric cars) Or maybe they will just mine bitcoin with it, who knows
  - TeMPOraL 7y ago
    Transporting energy from a star is simple: concentrating the light. The most basic incremental design for a Dyson sphere would be a swarm of mirror satellites. How do we see energy transport problem with electric cars? That's only a matter of the right sockets not being available. The power grid is there.
    - raverbashing 7y ago
      Can the grid handle 10% of cars moving from gas to electricity? 50%? 90%? Not to mention battery issues (range, charge time, safety, etc) which are getting better, no doubt about it It's not only a matter of having the right socket
      - ajuc 7y ago
        It's complicated, for sure, and will need changes in the infrastructure. But it has some advantages as well. Imagine 10 000 000 cars with 50 kWh battry capacity each connected to the grid and letting 10% of their capacity to be used for balancing of the network. If the grid has excess power - charge to 100%. If the grid lacks power - discharge to 90%. That's 50 GWh of balancing capacity. It basically solves the problems with unpredictability of most of the renewable power sources.
BuckRogers 7y ago
Glad to hear I'm not the only Dyson doubter. Seems too primitive to me. Any advanced civilization will have advanced knowledge on the truth to our reality, and will find ways to manipulate the laws of nature in this or other universes. We're already getting an initial grasp on that with our own developments and we're way behind. Mega structures around a star is just too basic to make sense at the stage where you could build one.
- TeMPOraL 7y ago
  Why? Basic things usually work well. Chemical rockets, firearms, water wheels, wind generators, pumping water for energy storage - these are just few random examples of the extremely basic, brute-force approaches that work really well for us, and see no sign of being replaced. Complexity beyond the point of what's needed is usually sign of bad design.
  - BuckRogers 7y ago
    Your question forces me to restate the original post again in other words, but you're correct, if understanding and manipulating the substrate of our reality is a sign of "bad design". Nothing you mentioned is basic from the viewpoint of a mere single planet species. But it's all basic enough to ensure we've remained a single planet species. Thus, if you can build a Dyson sphere, you probably won't need one because at that point your fundamental knowledge will be much greater than "bigger gun". In fact, we stopped building bigger firearms long ago due to greater understanding.
TeMPOraL 7y ago
> I don't see why advanced civilizations would need let's say 10% of the energy of a star (let alone need to capture it) Because you're thinking about maintaining status quo of early XXI century Earth (and not that, solar panels won't be enough for that), not about future possibilities. Space travel, for one, is a huge energy sink if you want to do it in reasonable timeframes. A probe to Mars in a year? Sure, usual chemical rockets will do. A passenger ship in 2 weeks? Now we're talking absurd amounts of energy. If human history teaches us anything, it's that there's always use for more energy. Hell, recently we've been inventing some potentially infinite energy sinks - like the idea of running the economy on cryptocurrencies. I'm still not sure whether Bitcoin is a conspiracy to have humanity cook itself on Earth, or to force humans to start building a Dyson sphere in the next 100 years...
- raverbashing 7y ago
  But you see, the problem with space travel is not the lack of energy, it's how to transport it efficiently (rocket equation) and how to use it efficiently to increase speed (specific velocity, etc) You can throw all the fuel you want at a chemical rocket and it won't take you to Mars in less than a year (more or less).
  - TeMPOraL 7y ago
    > it's how to transport it efficiently (rocket equation) This applies only if you have to carry chemical fuel with you; you can cheat a lot if you have lots of raw energy available. Chemical rockets won't open up the outer Solar System to us, but beamed power just might. Hell, at the Dyson sphere technology level, you could just push things around the system with giant lasers. (Yes, that same technology could also be used as a powerful weapon, but it's the unfortunate feature of distances in space - anything interesting you'd like to do in timescales we're used to from daily lives requires handling energy in levels and forms that could be used as weapons of mass destruction.)
xondono 7y ago
You do realize that covering 10% of the planet in solar panels is the start of a Dyson sphere right? Just push it up to 100% and start adding "fake" planets until a sphere is formed. :) Jokes aside, "A truly advanced civilization wouldn't need that much energy" reminds me of "640K ought to be enough for anybody", energy is in some sense like RAM, the more you have, the more you can do with it.

dTal 7y ago

It's impossible to capture and recycle all waste heat. It's an inevitable consequence of the second law of thermodynamics. Life, an anomalously low-entropy state, must survive by dumping its entropy somewhere else. Relatedly: stealth as shown in The Expanse is impossible. https://www.forbes.com/sites/chadorzel/2015/12/22/the-expanse-and-the-physics-of-stealth-in-space/ https://www.forbes.com/sites/chadorzel/2015/12/22/the-expans... (the article also tackles Dyson spheres)

TeMPOraL 7y ago
http://www.projectrho.com/public_html/rocket/spacewardetect.php http://www.projectrho.com/public_html/rocket/spacewardetect.... - Stealth in space: much more than you wanted to know. (TL;DR: next to impossible)

dexen 7y ago

Any sufficiently advanced technology is indistinguishable from magic. -- Arthur Clarke An advanced civilization (Type II on Kardashev scale, i.e, able to harvest their sun's energy output), having built a Dyson sphere[1] or similar, would appear to outsiders to be a red dwarf or a brown dwarf: a mildly hot star or sub-stellar object. It would be a sphere that emits more-or-less typical black-body radiation of a slightly warm (in stellar sense) object, with some spectral lines related to the surface material. Granted, the apparent "red/brown dwarf" of a Dyson sphere would have much larger size than usual, but on cosmic distances, individual object sizes aren't measured directly - instead we infer them from indirect measures such as light emission and gravitational effects, & comparing to known references & theoretical models. We can assume some advanced civilizations would want to keep private for safety reasons - as to not invite hostile attention - and thus would do their best to closely approximate spectrum of actual red or brown dwarf through engineering. Meaning we couldn't tell them apart from actual red or brown dwarf without getting close enough to observe the size directly, or somehow recognizing minute deviation from expected spectra. Right now we may be looking at several advanced (Type II) civilizations, mistakenly dismissing them as mere red dwarfs. dexen's dictum #2: presume all apparently planet-less cold stars to be potential Dyson spheres until positively proven otherwise. [1] I've just realized a full Dyson sphere would be a good Faraday cage, preventing radio emissions leaking outside.

taneq 7y ago
"Any technology distinguishable from magic is insufficiently advanced." - Corollary to Clarke's Law Also, on the topic of advanced civilizations being coy: > "Once there were three tribes. The Optimists, whose patron saints were Drake and Sagan, believed in a universe crawling with gentle intelligence—spiritual brethren vaster and more enlightened than we, a great galactic siblinghood into whose ranks we would someday ascend. Surely, said the Optimists, space travel implies enlightenment, for it requires the control of great destructive energies. Any race which can't rise above its own brutal instincts will wipe itself out long before it learns to bridge the interstellar gulf. > Across from the Optimists sat the Pessimists, who genuflected before graven images of Saint Fermi and a host of lesser lightweights. The Pessimists envisioned a lonely universe full of dead rocks and prokaryotic slime. The odds are just too low, they insisted. Too many rogues, too much radiation, too much eccentricity in too many orbits. It is a surpassing miracle that even one Earth exists; to hope for many is to abandon reason and embrace religious mania. After all, the universe is fourteen billion years old: if the galaxy were alive with intelligence, wouldn't it be here by now? > Equidistant to the other two tribes sat the Historians. They didn't have too many thoughts on the probable prevalence of intelligent, spacefaring extraterrestrials— but if there are any, they said, they're not just going to be smart. They're going to be mean. - Peter Watts, Blindsight And the corollary to Watts' Law (if he doesn't already have one I call dibs on this being called that) is, of course, that if there are any intelligent, spacefaring extraterrestrials, they're going to be sneaky.

HNLurker2 7y ago

And sci fi idea is that black matter is just that. And in reality civilizations are more peaceful but many