Sometimes, it’s not just math. It’s personal.

### The Situation

A plate of stale brownies, wrapped limply in plastic, sat in the office of the Yale Entrepreneurial Institute, growing staler by the day. And yet, each day, there were fewer brownies on the plate.

### The Problem

Each day, brownies were eaten — but a steadily decreasing number of brownies, as my co-workers reached their personal limits for brownie staleness.

Clearly, we had an **exponential decay function** on our hands. Each day, the number of people willing to eat brownies decreased. But since someone who will eat a very stale brownie doesn’t mind an extra day of staleness as much as someone who only eats fresh brownies, the rate of decrease in the rate of brownie-eating was itself decreasing.

Confused? Here’s a graph:

Fewer brownies are eaten with each passing day. Which of course invites the question: Does this graph have an asymptote? Will the last brownie ever be eaten?

### The Solution

To find an answer, I asked David Cruz, a computer scientist working on a secretive telecommunications startup in the Institute’s accelerator program. He was the sharpest mathematician in the room, so I thought he’d have some insight.

**A: **So, David, do you think the brownie graph has an asymptote?

**D: **Of course not!

**A: **What do you mean, of course? How can you prove that the last brownie will be eaten?

**D: **I could just eat all of the brownies on that plate right now. There! Proven!

**A: **…

**D: **Don’t think I won’t do it.

I considered challenging him, but I suddenly saw, in my mind’s eye, what would happen if I did:

David Cruz, shoveling brownies into his mouth with reckless abandon. And shouting, through a mouthful of crumbs: **“I dishprove it thush!”** And I wasn’t about to become the George Berkeley of that situation.

So instead, I named a theory after David. The brownies did, in fact, get eaten, though it took another week.

### The Moral of the Story

Never give a scientist the chance to prove you wrong by eating a huge number of brownies.

Too specific? Invent your own moral.