Phil PlaitFeb 20

In other news…

This was fun: a reader asked if aliens were in a galaxy 66 million light-years away, how big a telescope would they need to see dinosaurs on Earth?

Guess!

No; bigger. Try again. Nope, still bigger. Third try? Nope. Way, WAY bigger.

https://www.scientificamerican.com/article/could-aliens-in-another-galaxy-see-dinosaurs-on-earth/

Could aliens in another galaxy see dinosaurs on Earth?

How big would a telescope need to be to see Earth’s dinosaurs from 66 million light-years away? Think big—and then think bigger

Scientific American
Show threadRobin BartonFeb 20
@badastro wild ass guess here but about the size of our solar system???
Show threadMichael Busch

@Robo105

Considerably larger than that.

There is also an additional complication that @badastro did not have the space to get into:

The interstellar and intergalactic medium will eventually blur the wavefronts, making imaging impossible.

Feb 20 at 5:03pmWeb
Show threadRobin BartonFeb 20
@michael_w_busch @badastro Well there goes my business idea of selling videos of other planets as reality TV
Show threadMichael BuschFeb 20

@Robo105 @badastro

There are other tricks one could play, such as using a star as a gravitational lens to magnify the image of the Sun and Earth.

But we cannot change the laws of physics.