Mr. C. was telling his students about a recent moon landing by Russian cosmonauts. He proceeded to ask the class:

"Why do they float while they are in space?"

His student, Mike, raised his hand like a lightning bolt, and, like the unruly immature student that he is, screamed out:

"You'd have to be retarded to not get this one!"

Mr. C. then asked him (after reprimanding him for such an offensive comment about mentally challenged people) what the answer was, if it was so easy.

Mike responded:

"They float because there is ABSOLUTELY NO GRAVITY in space."

Mike was absolutely shocked when Mr. C said:

"WRONG! Oy, I thought this was supposed to be the Talented and Gifted class!"

Why was Mike wrong?