I forget when I learned about special relativity, sometime in Junior or Senior High School, I think. I always had the most basic of understanding. At some point, I read Stephen Hawking’s A Brief History of Time and I understood a bit more.
For some reason, my web meanderings today took me to a Wikipedia article on the Twin Paradox. What always confused me was to think what images each would see if the twin on earth had a telescope trained on the spaceship and vice versa for the twin on the spaceship. Well this Minkowski diagram explains the whole thing. Wow.
Read the whole article if you were still unclear on the whole Twin Paradox thing.
In terms of implementation effort, Mercurial has a clear advantage due to its efficient HTTP transport protocol.
In terms of features, Git is more powerful, but this tends to be offset by it being more complicated to use.
I’ve adopted Git for my own personal use, though have recently learned that there is a whole family of distributed version control systems. After reading this article, it made a lot of sense for Google to adopt Mercurial, but left me satisfied that Git is a better tool for my personal use. Still, it probably makes sense to spend a little time with Mercurial and a few of the other systems because you never know when a little bit of knowledge can help you out of a bind.