What does the phrase “you can’t prove a negative” actually mean?

Question

What does the phrase “you can’t prove a negative” actually mean?

In: 1149

Answer 1

Let’s say we’re sitting in a restaurant and you get up to go to the bathroom. You’re gone for one minute, and then you return.

When you sit down, I ask you to prove to me that you *didn’t* drop down and do pushups in there before coming back out.

That would be proving a negative. There is no evidence you can provide to me that *proves* you did **not** do pushups in the bathroom.