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> So the pyramids are visible out to 3000 light years away if the aliens have extremely powerful optical telescopes. Is such a telescope (resolving power etc.)

> So the pyramids are visible out to 3000 light years away if the aliens have extremely powerful optical telescopes. Is such a telescope (resolving power etc.) actually possible? At the level of basic physics, could anyone build it, hypothetically? I don't know, because I am an idiot who has spent 30 years building websites of various complexity and pretending that is advanced knowledge.

boomboomsubban 3y ago
It seems to involve building a telescope with a diameter of several million kilometers. As a reminder, the circumference of the earth is about 40,000km. So several hundred times bigger than the earth. It's hard to imagine, but the baseline mentioned is being able to utilize all the energy of their star.
- jandrese 3y ago
  Anybody who starts off their paper with mentions of the Kardashev scale is already pretty far out there. It has never been clear to me if even a Level 1 civilization is practical, there could well be physical (as in physics based, like thermodynamics) limits that prevent you from reaching that point. And the scale goes dramatically up from there. Level 2 is building Dyson Spheres. It always felt like the whole thing was made by someone who didn't really have a good grasp of scale. Maybe it's a failure of imagination on my part, but I tend to think that projects on scales like that are just too impractical for real life. It's like if you decided to make up a scale for land speed records, and made type 1 100,000 kph, level 2 100,000,000 kph, and level 3 100,000,000,000 kph.
- Kye 3y ago
  I like to think a sufficiently advanced civilization can stack gravity lenses to get a better view the way camera lenses stack multiple bits of glass and plastic to clear up different kinds of problem.
- kshacker 3y ago
  Not only they need that powerful a telescope, they need to be focused on exactly where the pyramids are/were because that that zoom, they could be scanning a whole lot of nothingness.
- intotheabyss 3y ago
  More likely they'd use their star for magnification by placing telescopes at the right focal point.
- ufmace 3y ago
  So it might be possible for a sufficiently advanced species to build such a thing. But would they choose to? The real question for these things is, if you are capable of building such a thing, what other things are you capable of building much simpler and cheaper that can do the job better?
- whoopsie 3y ago
  The only industry capitalized to support that is porn. So if it does happen, this is very bad news for us.
intelVISA 3y ago
> an idiot who has spent 30 years building websites of various complexity and pretending that is advanced knowledge Tbf web has an unmatched pay to work ratio for the avg. developer, I wouldn't call that idiotic by any stretch.
- bemusedthrow75 3y ago
  Oh I didn't say I was well-paid doing it :-/
tzs 3y ago
Yes, it is possible. Briefly, you use your solar system's star as a gravitational lens. There are currently a couple proposals working their way through the system to do that here in our solar system. It doesn't require technology much beyond what we already have, nor is it much more expensive than other unmanned deep space missions. We wouldn't be able to see pyramid sized objects on alien planets that way because the Sun is only about 1.4 million km diameter, and from other comments it would take a few million km. But for aliens with a bigger star? No problem. Here's a PBS Space Time episode that talks about the proposals for building a Sun based gravity lens telescope [1]. [1] https://www.youtube.com/watch?v=4d0EGIt1SPc https://www.youtube.com/watch?v=4d0EGIt1SPc
- sph 3y ago
  It is possible in theory. Until we build one, I wouldn't be so sure it's as effective as claimed to be.

boomboomsubban 3y ago

It seems to involve building a telescope with a diameter of several million kilometers. As a reminder, the circumference of the earth is about 40,000km. So several hundred times bigger than the earth. It's hard to imagine, but the baseline mentioned is being able to utilize all the energy of their star.

jandrese 3y ago
Anybody who starts off their paper with mentions of the Kardashev scale is already pretty far out there. It has never been clear to me if even a Level 1 civilization is practical, there could well be physical (as in physics based, like thermodynamics) limits that prevent you from reaching that point. And the scale goes dramatically up from there. Level 2 is building Dyson Spheres. It always felt like the whole thing was made by someone who didn't really have a good grasp of scale. Maybe it's a failure of imagination on my part, but I tend to think that projects on scales like that are just too impractical for real life. It's like if you decided to make up a scale for land speed records, and made type 1 100,000 kph, level 2 100,000,000 kph, and level 3 100,000,000,000 kph.
Kye 3y ago
I like to think a sufficiently advanced civilization can stack gravity lenses to get a better view the way camera lenses stack multiple bits of glass and plastic to clear up different kinds of problem.
kshacker 3y ago
Not only they need that powerful a telescope, they need to be focused on exactly where the pyramids are/were because that that zoom, they could be scanning a whole lot of nothingness.
intotheabyss 3y ago
More likely they'd use their star for magnification by placing telescopes at the right focal point.
ufmace 3y ago
So it might be possible for a sufficiently advanced species to build such a thing. But would they choose to? The real question for these things is, if you are capable of building such a thing, what other things are you capable of building much simpler and cheaper that can do the job better?
whoopsie 3y ago
The only industry capitalized to support that is porn. So if it does happen, this is very bad news for us.

intelVISA 3y ago

> an idiot who has spent 30 years building websites of various complexity and pretending that is advanced knowledge Tbf web has an unmatched pay to work ratio for the avg. developer, I wouldn't call that idiotic by any stretch.

bemusedthrow75 3y ago
Oh I didn't say I was well-paid doing it :-/

tzs 3y ago

Yes, it is possible. Briefly, you use your solar system's star as a gravitational lens. There are currently a couple proposals working their way through the system to do that here in our solar system. It doesn't require technology much beyond what we already have, nor is it much more expensive than other unmanned deep space missions. We wouldn't be able to see pyramid sized objects on alien planets that way because the Sun is only about 1.4 million km diameter, and from other comments it would take a few million km. But for aliens with a bigger star? No problem. Here's a PBS Space Time episode that talks about the proposals for building a Sun based gravity lens telescope [1]. [1] https://www.youtube.com/watch?v=4d0EGIt1SPc https://www.youtube.com/watch?v=4d0EGIt1SPc

sph 3y ago
It is possible in theory. Until we build one, I wouldn't be so sure it's as effective as claimed to be.