The problem in Good Will Hunting

We now have a Tumblr: Tumblr: http://numberphile.tumblr.com
This paper on ebay: http://www.ebay.co.uk/itm/221197137799

Just how hard was the second problem cracked by Will in Good Will Hunting? Matt Damon!

And who doesn't love Homeomorphically Irreducible Trees?

This video features Dr James Grime - http://singingbanana.com/

Music by Alan Stewart - http://www.youtube.com/user/AlanKey86