So, my friend Huaizhi Chen is a huge nerd and one of the smartest guys I know. Because he is simultaneously lame and cool, he spent his Friday night solving Problem #2 in the following XKCD comic:

I saw this solution: http://www.mbeckler.org/velociraptors/velociraptors.html but it relies on genetic programming/evolutionary algorithms, which is slower and doesn’t necessarily guarantee an optimal solution. Huaizhi uses a numeric differential equation solver to get approximately the same solution, which I find to be a much more elegant and we know it’s optimal.

He kindly wrote up his solution and posted it here: http://sites.google.com/site/chnhzh/Home/velociraptor.pdf which you should check out. The final solution turns out to be 32.6 and 147.4 degrees north of the horizon. Pretty cool!