## The Relativistic Train

Really cool post I found on one of my favorite physicist’s blog.  It’s just a derivation for the relativistic addition of two velocities.

Typically you would think that to add two velocities you just add them together.  Ex. if someone is walking at a velocity $u$ on top of a train moving at velocity $v$, then to find out the velocity the person is moving relative to the ground you would normally just add the velocity of the train and the velocity of the person walking. $w = u+v$.

This gives a fairly accurate answer in most cases, but when you start approaching the speed of light this isn’t the case according to Einstein’s theory of relativity.  Instead the real equation for adding velocities looks like this:

$w = \frac{(u+v)}{1+\frac{uv}{c^2}}$

Take a look at the reason why

## The First Post

I was going to make a brand new full fledged blog on it’s own domain in addition to the one I already have at http://www.nicklarson.com, but I just decided that it would be more practical to come over to http://www.wordpress.com and make one here!

My purpose for creating this blog is so that I can post anything interesting I come across that has to do with physics, mathematics, or the like.  I would have done this on my other blog, but it seems too irrelevant to the topics that I already post there.

I therfore thought it would be a great idea and another excuse to make a new blog!

I’ll be posting interesting stuff on mainly physics and math, so if you like those things hopefully you’ll like this blog!

Later,
Nick