120 years later, we're still learning about Special Relativity!

 In class, we get into length contraction when it comes to Einstein's special theory of relativity. When objects move, their lengths shorten up by some amount in the direction of motion. This is a well-known conclusion from relativity. It is also really challenging to try and measure this at everyday speeds, because the length contraction is so tiny; not until a substantial fraction of the speed of light will it become more measurable. 

However, it turns out that what we would actually see is surprising and different from just a meter stick being a little shorter. We would see the stick, as a stationary observer with the stick flying past us really fast, rotate by some amount! This has to do with the behavior and tiny time differences of photons coming from the stick and reaching our sensors; it was calculated by two scientists about 20 years ago, and is called the Terrell-Penrose Effect. 

Now, with crazy-fast electronics and video technologies, this has actually been observed, and the real relativistic prediction confirmed, in the lab! This is a good Scientific American article, with some visuals, as to what it looks like for real! Very cool!