They would look like infrared point sources. Sadly none detected yet:
https://medium.com/starts-with-a-bang/dyson-spheres-the-ulti...
He pretty much handwaves away one of the biggest problems: material. Saying "we'll harvest Mercury" is such a "world hunger solution"* that I can't take anything further seriously.
*World hunger solution: A solution presented in such a way to seem simple but instead hides many more problems just under the surface. e.g. The best solution to world hunger is to simply give everyone enough food. True, that would solve the problem, but we don't know how to do that.
And saying that "advanced civilizations" will be able to do it is pretty much going into the Giorgio Tsoukalos camp. "Aliens" is not an answer. It still ignores the how. What are the costs of harvesting an entire planet? What are the energy requirements to send mining equipment there, mine the planet, and ship the materials back here to be processed into something useful?
Why do you assume that that level of technology will be cheap and readily available in the future?
Also, what options do you have if you're out of real estate? There is no faster than light travel. Slower than light interstellar travel is certainly not going to be cheap or easy. Of course the other option is for your civilization to stop growing, but who knows if all aliens would go for that.
It doesn't tell us why there are no Dyson spheres.
> Of course the other option is for your civilization to stop growing, but who knows if all aliens would go for that.
You act like this is a choice. What if it's not a choice? What if the initial cost to build a Dyson sphere is too great to overcome? Whether in time, material, energy, or another thing. What if it's just not feasible?
Where does that leave you?
You've basically reframed your statement. You find it convincing because you think it seems physically possible. But how? We're just getting to Mars and you think a significant mining operation on an alien planet to be something we're technologically capable of.
We've skipped straight to 3) Profit and forgot to flesh out step 2).
There's no reason to think we won't reach that level of technology - assuming we have a demand for space industry for some reason, like running low of key materials on Earth, or a population that keeps growing.
You're basically just doing that same thing as the OP, claiming "nuh uh" without backing that up either. To which I say "uh uh".
You claim there's no reason to think we won't reach that level of technology. What's the basis for that claim?
> just some solar panels floating in space an attached to something useful (e.g. our communications satellites)
You realize that a lot of our communications satellites already have solar panels attached to them, right?
And you do realize that a Dyson anything is an engineering project that far exceeds anything we have yet attempted. If your plan begins with strip mining a planet 48 million miles away with an army of self-replicating robots, you've obviously skipped a few steps of the process.
Using "science-y" words to describe your pipe dream doesn't make it any less of a fantasy.
I mean, we're still wondering if we can make a car drive itself reliably. That we may not be able to overcome some very basic limitations. And all of a sudden we get to assume we can build a probe that can travel to Mercury, mine it, process the raw material into something useful, assemble those materials into more probes, panels and habitats, then place those bits into orbit around the Sun in a way that it won't get smashed by other satellites, fly off, or get pulled in.
Reducing those concerns to "nuh uh" isn't doing you any favors. You're simply refusing to engage. You're asking skeptics to prove that we will never reach that level of technology rather than answer the question of why do you think we will. You're the one with the actual claim here, back it up.
Hence why I said (e.g. our communications satellites), which in English means communications satellites are examples of useful things with solar panels attached "floating" in space...
> And you do realize that a Dyson anything is an engineering project that far exceeds anything we have yet attempted. If your plan begins with strip mining a planet 48 million miles away with an army of self-replicating robots, you've obviously skipped a few steps of the process.
I already mentioned that's a strawman. A Dyson swarm is an orbiting collection of artificial satellites, orbiting the sun. It captures all or a good deal of the energy radiating away from the sun - but it's built incrementally and a single satellite can be the start of a Dyson swarm - so we have the tech now.
> You're asking skeptics to prove that we will never reach that level of technology rather than answer the question of why do you think we will. You're the one with the actual claim here, back it up.
You're deluded if you think you can get random people on HN to defend their statements to a level you'd be happy with. Honestly I don't have the time, and even if I did I don't care.
But since you've got me to engage this far, here goes: we have the tech to build solar powered satellites and launch them into orbit around the sun. So we could start building a Dyson swarm today.
The reason we don't is because it's very expensive, and we suffer a chicken-and-egg problem. There's not much demand for industry in space because we don't build anything in space. The inputs and outputs would have to come from and return to Earth. There's no demand for habitations in space because there's no supporting infrastructure, food, water, jobs, etc. Not to mention the long term health effects of living in space seem problematic to say the least. But it's not unforeseeable that something could change that situation, be it overcrowding on earth, demand for space mining, demand for zero-g manufacturing, space war, government programs, etc.
What you actually said was:
> You don't need to build the entire thing, just some solar panels floating in space an attached to something useful (e.g. our communications satellites) fit the bill.
Where the implication is that we'd attach these solar panels to something useful and that an example of something useful is the communication satellite. Whereas you wanted to infer that communications satellites were the entire enchilada, a solar panel attached to something useful. Which is also a bit disingenuous as the panel is a part of the satellite, the power source, not an add-on. Which pretty much led to the confusion.
> A Dyson swarm is an orbiting collection of artificial satellites, orbiting the sun.
That's a reduction as to what it actually is. A big part of the Dyson architecture is to capture and use the energy provided by a star. Simply having a satellite orbiting the Sun would not fit the bill.
And a space based solar power satellite does not exist. Because it's more expensive to launch and implement than it would return. All current solar power on satellites provide enough power to power themselves. That's it. What you are asking for is something different.
NASA themselves says that a SBSP satellite is decades away at the earliest. And any proposition to be speculative at best.
And yes, necessity is technically the mother of invention but it can't change the laws of physics. It can't change the cost of what's necessary.
> You're deluded if you think you can get random people on HN to defend their statements to a level you'd be happy with.
This is just a dodge. You've done nothing but say "It's not unforeseeable" and "It's inevitable". You haven't actually provided a reason as to why you think that. I'd be happy with anything more than a handwave in the general direction of the actual issues facing building a Dyson swarm.
> Honestly I don't have the time, and even if I did I don't care.
You do care, you just don't really have any answers besides the blind faith of "technology". Which is no better than blind faith in anything. Believing technology will get better doesn't actually make it better.
Why? I know it's a staple of SF that, on a long enough timespan, we will surely eventually build stuff like Dyson swarms and interstellar ships, but the more I observe actual humans, the less convincing I find this argument. Even assuming great advances in technology, Dyson swarms will be ridiculously expensive to build, especially relative to the benefits they provide, and human grumbling about costs and taxes will probably kill the project instead.
More generally, given the conflict between "fund and build this highly exotic and expensive thing now" vs. "don't bother, thus keeping taxes low", humans will always choose the latter in the absence of some kind of external motivation beyond "for science!", or even our own survival. Americans only agreed to spend the zillion dollars to go to the moon because we were in a dick-waving contest with the Soviets, and a lot of the necessary technology was already in existence thanks to money spent on ICBMs.
I think it's more likely than not that we will keep kicking the can down the road vis-a-vis the current problems of our population growth, and then just go extinct when they finally catch up to us. Or, even if you're not that pessimistic, that we just stay on Earth because no one wants to bother with the difficulties of going elsewhere. It's totally possible that the same thing happens to most other intelligent species and so there are no Dyson swarms.
Just think, a military entity with the population and resources of NATO or the Warsaw Pact would have been totally inconceivable just a few hundred years ago.
Worse, in such a civilization, it's pretty likely that even small organizations would have the kind of tech you'd need to induce a nuclear winter on a given planet. After all, you just have to crash an asteroid on the right spot, then you have a mass extinction that human civilization would definitely not survive.
[0] http://www.astrosurf.com/luxorion/qsl-mars-communication3.ht...