After the sheer amount of biological content which has been posted on this blog over the past 24 hours I figured it might be bring a little bit of physics into the situation, if only so that we don’t have to bend our brains around all those polyeuro-somethings and bacterial doodads.
Anyways, I always maintain that there’s nothing like a little thought experiment to clear the head on a thursday morning, and today I’ll explore one of my particular favourites:
Imagine two mirrors, facing exactly opposite, with a single photon* of light bouncing between them. This is what we will call a “Light Clock”. The photon travels at a constant speed, so the photon will regularly hit each mirror. Simple, right? But what if this light clock began to move? The photon still has to bounce off each mirror, in exactly the same place, but now the mirror has moved away slightly. This means that the photon has to take a slightly diagonal path in order to make the clock work. The photon does this, no problem, but the clock is no longer “ticking” as regularly as we would like! This is because the diagonal path is longer than the straight path, meaning that the photon takes slightly longer to get to the other mirror, stretching out the space in between the “ticks”. If we increase the speed, closer and closer to the speed of light (the speed limit for anything in the universe), we see that the ticks become further and further apart! When the clock is travelling at light speed the photon is effectively stuck to one of the mirrors, and our clock is broken.
“This is all very well!” I hear you say, “but what is the point of all this light clock business?”
It’s a fair point, but the answer is simple. We have effectively shown that with a little bit of lateral thinking, and a liberal spoonful of relativity, that the faster you go, the slower you move through time! Time and space must distort since the speed of light is constant**. This is thanks to the equation “Speed equals distance over time”. In this case, it is time that is distorting, slowing down to balance the equation. This means that as you move closer to the speed of light, everything around you would speed up, faster and faster, while you would still be living at a normal speed. Of course, to everyone else, you would look like a bullet-time CGI from the Matrix whizzing through the air faster than the speed of sound! You could travel into the future, simply by going mind-numbingly fast. Of course, speeds like this are pretty much impossible for anything bigger than a subatomic particle, so unless the shrink ray becomes a big thing in the next decade (send in the coupon at the bottom of this article with £9.99 and it could be yours today!), it’s doubtful we’ll ever be able to fling ourselves into the future! Here’s hoping though, mine’s a laser-lager on the rocks, Chin-Chin!
Harry Saban – The Octave Doctor (Phd Pending)
*A photon is a particle of light. I’ll probably do a blog post about the standard model explaining how the hell this actually works!
**Einstein discovered that no matter how fast you are travelling, you will always percieve the speed of light to be the same, which is incredibly useful for calculating all sorts of things, from doppler shifts to time dilation. Bonza!