[SlowBoat407]

When you’re in space looking at the earth and moon, you only see “dark space” since, there is nothing there. Are we simply looking at the space between objects and getting the wrong inference?

The space between earth and moon doesn't distort their images or obscure them. Dark matter is detected by the fact that it distorts objects or bends the light from them in some way.

[edcoil]

How do we know what we look like from 5 billion light years away?

[Buckhead]

Unless it was something else that bent the light.