It's not uncommon for scientists to have their disagreements, but usually they do so in the pages of impenetrable periodicals and journals. Science Kombat, a free browser game you can play right now, imagines it otherwise: it's the only opportunity you'll ever get to witness Stephen Hawking bash Charles Darwin on a sandy 16-bit beach. So you'd better take it!
Playable characters include Albert Einstein, Nikola Tesla, Isaac Newton, Marie Curie, Alan Turing and Pitagoras, so there's lots of amusing what-if scenarios to play around with. I only played it for roughly 10 minutes, and while it's unlikely to give any other fighting game a run for its money, it's a fun little distraction. As Hawking, I pretty much spammed my attack button and took Darwin down without so much as a fist to the face, so don't expect Street Fighter levels of complexity.
The game is in Portuguese, but the user interface is pretty straightforward. Thanks to PC & Tech Authority for the heads up.