Wednesday, 11 March 2009

Relativity

Wow, MSPaintAdventures' Problem Sleuth adventure is finally over. It's been quite a ride.

What is the point in this post? Purely to mention something brilliant in the FAQs.

Einstein came up with the equations of relativity, which have been demonstrated to work again and again. The equations show that the faster you move (up until the speed of light*) weird shit starts to happen. Relative to an observer moving at a slower speed, time for you passes slower (i.e. you actually age less) you weigh more (increase in mass) and you shorten in length.

The last one was always very counter-intuitive to me, but in the MSPA FAQs there is a fantastic explanation that I wish my Physics teachers had used:

"This is because the speed of light is always constant, no matter where you are, or how fast you or anyone else is going. So if it takes a beam of light 1 second to travel from the back of a box to the front of a box, then if that box is moving, then that box has to be a little narrower for that same beam of light to reach the front of the box in one second!"

GENIUS! It makes so much more sense now!

*nothing can move faster than light apart from the purely theoretical species of particles called "Tachyons" which cannot go slower than the speed of light. However, the existence of such particles relies on the existence of numbers such as the square root of -2.
When I followed EvE, I mentioned this in a forum, and was responded to with what root-2 was: 1.41421356 i
The person who told me this neglected to realise that the "i" means "imaginary" - we have a hard enough time trying to convince ourselves Real numbers exist, so trying to claim that imaginary numbers exist just takes the cake. Away from a starving baby. With diabetes.

[edit] Also, the Schwarzschild radius is fascinating to know. Mine is (using Newtonian physics) 1.48×10-27 m/kg * 75ish... 1.11*(10^-25)m... 0.111 yocto metres.

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