Physicists uncover new solution for cosmic collisions

http://www.theanalystmagazine.com/pr/6782628.htm

It turns out that our math teachers were right: being able to solve
problems without a calculator does come in handy in the "real" world.
Two theoretical physicists at Rensselaer Polytechnic Institute have
used what they call "pen-and-paper math" to describe the motion of
interstellar shock waves -- violent events associated with the birth of
stars and planets.