Monday, February 21, 2011

Special Relativity I

Before I talk any more in the science department I guess I should talk about relativity. I'm going to skip over Newtonian physics because it's pretty basic and obvious to grasp in most casses, but I will probably go back and talk about it during this post if it requires it. Relativity is a very strange and non obvious way to see the world, and i admit I still have trouble understanding everything about it (this post is also a test to see how my relativistic skills are, cuz the best way to learn something is to teach it(or blog it in this case)). I might not go into some aspects to deeply and completely explain relativity in this post but whatever, if I can perfectly explain relativity to people on the internet in one post i think i deserve a Nobel prize. Once again if someone here actually has a PHD or something in anything I'm talking about and notices i say something wrong PLZ comment saying something.

Any ways as probably anyone knows the person who came up with relativity was Albert Einstein. And as you know he came up with this stuff in a patent office, not that he was not educated though. He did go to college to learn about physics so he's not some guy who knew nothing. He started thinking about what a wave of light would look like if you were speeding along side it. He thought that that was such a silly thing to imagine, but soon he realized that it would be physically impossible to go at the speed of light, that no matter how fast you're moving light would always appear at the same speed.

Pretty much just with this assumption came all of his theories of Special Relativity. It's pretty trippy. One of the implications of this is the distortion of time. For this we shall set up the classic thought experiment, The Light Clock! Pictures would be helpful for this, TO GOOGLE IMAGES!
Excellent. So how the light clock will work is that it will send a photon from the source and it will hit the mirror and bounce back and hit the sensor, then the number of ticks will increase and then it will instantly send out another photon. Well say you're chillin in a train station with this light clock the size of a grandfather clock for no reason. Well you know the train is going to come in exactly 15 minutes and since you know the speed of light and the distance between the the the mirror and the sensor you know how long the photon will take to travel from the source back to the sensor. So you know exactly how many ticks it will take for the train to come. Every fifteen minutes the number of ticks will increase by the same amount.  So know you understand how the clock works right?

Well since that explanation took fifteen minutes the train's coming down the track now! But NO! The conductor is drunk at the wheel or whatever and the train barrels by without slowing down at all(yes this is how relativity is taught every where). But some passerby notices your clock and takes a gander at it. To him the clock is moving as the same speed the train looks like it is moving to you. So by the time the photon is shot out and hits the mirror the mirror has moved the by some amount and it appears that the light is moving at some diagonal angle as shown in the picture above (b).  So the distance the light has to travel is longer when you are moving than when it is still. However the photon to the passenger still looks like it is moving at the same speed. So it will take more time for it to travel this distance so that each tick will, to the passenger, take longer than the ticks for you. There fore time looks like it is going the slower outside of the train than inside for the passenger.

However if he perchanced to have his own light clock to you it would appear to move slower than your clock, so to you everything happening in the train would appear to move slower than outside even though the passenger is experiencing quite the opposite!

See relativiety is quite trippy indeed. Now Ima let that sink into your heads and also I'm tired of writing so I shall pick this up in my next post, good bye Nobel prize :'(