Not That Kind Of Vacuum

Last night we played the Game of Knowledge with the kids. (It's sort of like Trivial Pursuit, but made for kids to play with adults). The question to William:

What is the measure of the distance that light travels in a single year in a vacuum?

Oh, the looks on their faces. There's light in a vacuum??

Melissa: "Light in a vacuum? I don't even know how fast dirt travels in a vacuum!"

Ah....not that kind of vacuum.

Then William said as the light bulb goes off in his head, "Oh, a vacuum like a black hole?"

HEY! Maybe he is learning something at this school!! YES!!