Did you ever run across any neat definitions for math/science concepts?

Question

I like "quantum mechanics is the dreams that stuff is made of"

And "time is something God invented to keep everything from happening all at once"

Answer 1

"If it bites and scratches, it's biology

if it smells and pops, it's chemistry

if it doesn't work, it's physics"

Answer 2

"And God said 'Let there be light' and there was the big bang"