How many fish are in the sea? What would it cost to wash all of the windows in New York City? How many ping-pong balls would it take to fill a 747? If you want to be able to answer these questions and others like them, then come and learn about Fermi estimation! We'll cover some tips and tricks for making "back-of-the-envelope" calculations like these in order to solve difficult problems involving really large numbers.

You have one minute and an index card to write down the biggest number you can think of. We'll talk about Busy Beaver Numbers, Turing Machines, the Ackermann function, different sizes of infinity and other strange and interesting things. Then we'll play again. Who can name the bigger number? Inspired by Scott Aaronson's essay of the same name.

What would you do if you suddenly came across a time machine? What if we told you that you could use it solve some of the most difficult problems known to humankind in the time it takes to read them? You may have heard of the P vs.NP problem, and the idea that some problems take longer to solve than the universe gives you. In this class, we'll cover basic algorithms and then work our way up to those NP-hard problems that take longer than the age of the universe to solve. And then we'll ask: but what if you had a time machine?