Did you know that a knot is 15% faster than a mile per hour? That means that if you have one of those handy tip-calculator pocket cards, you can instantly convert a speed in knots to the more familiar mph. Just pretend your speed is your bill, calculate the tip and add it to your total.

(Obviously, you can do this in your head too, but that’s not as glamorous.)

Today’s episode has been brought to you by science!