[rebel_yell2]

From a scientific standpoint, you are correct. You simply cannot prove a "negative." You can only prove a "positive." Just because you have no evidence that Bush did not serve doesn't mean that he did not serve. It simply may mean that one has come forward that remembers him. However, now some witnesses have come forward, effectively refuting the "null" hypothesis that he did not show up in favor of the "alternative" hypothesis that he did show up.

[Southack]

"From a scientific standpoint, you are correct. You simply cannot prove a "negative."

That's actually a myth.

You *can* prove some negatives when you can exhaust all possibilities in a set.

For instance, how can I prove that the red ball isn't in my black box that holds 20 balls?

Well, if I take out every one of all 20 balls, and none of them are red, then I have just proven a negative.