An infinite number of mathematicians walk into a bar. The first one says, "I'll have 1 pint of beer." The second says, "I'll have 2 pints of beer." The third says, "I'll have 3 pints of beer." The fourth says, "I'll have 4 pints of beer." The bartender looks at them, says, "Aw, the heck with all of you!" and pours 1/12 of a pint back into the barrel. Get it? because 1+2+3+4+...=-1/12? We'll be exploring sums like these and how to apply them to find real forces on real objects with quantum field theory.