/sci/ - Science & Math

if there's a Nazi base on the moon what would be the best way for communication between us and them? do we have to pin point them exactly on the surface or can we scatter a signal for them to get and bounce back? how expensive would the set up be for simple text messages in German?

Why have we not heard aliens?

http://en.wikipedia.org/wiki/Voyager_program#Communications

When Voyager 2 flew by Neptune, they used the VLA to receive photographs from it. So we're talking about a huge difference in how directional the receiving antennas are versus your car radio.

And it's not like the photographs are being downloaded particularly fast.

So from what I've learnt refracting telescopes basically are just concav mirrors that "colect light" (or waves in general) and focus it into the focuspoint where a camera or secondary mirror is located.

But how do they compensate for the "hole" in the image caused by the camera?