"Say, 'Hey, I'm in trouble, I'm beginning to look like a first order equation!'"

"And so the whole solution blows up."

"Nice doesn't mean nice, it means not as nasty as nasty."

"What are your chances of survival now?"

"You can't be a sculptor unless you know how to be a chisel."

2003

"They fixed the Millennium Bridge by fixing the sides to green dashpots"

"Supposing I'm the solution and my derivative's not right and I'm getting nervous and the second solution says 'trust me'!"
(on a differential equation)