• Question: Why is it not possible to go faster than the speed of light?

    Asked by ebygum to Adam, Geoff, Rob, Sheila, Suzie on 15 Mar 2011 in Categories: . This question was also asked by lwebb.
    • Photo: Sheila Kanani

      Sheila Kanani answered on 15 Mar 2011:

      Because of Einsteins amazing equation:

      E=MC^2

      So the faster you go the more energy you have so E increases, since C the speed of light is constant. This means that M (mass) increases proportionally.
      So as the speed increases the mass increases. And the more mass it has the more energy it needs to speed up.

      So eventually once you reach a speed (very near the speed of light) the mass of the objects is so large that it is practically infinite and therefore, the energy you put into it to speed it up is also infinite (by definition impossible) hence it can’t happen.

      Also you cannot travel at C because of the of the fact that the speed of light is the same in all reference frames. If you run to catch up with a light ray, you can never reach it because no matter how fast you run, the light ray recedes from you at C.

    • Photo: Adam Tuff

      Adam Tuff answered on 15 Mar 2011:

      Well, here’s an odd answer for you – because you don’t need to! Einstein’s theory of relativity says the faster you go towards the speed of light you go, you see two effects – one is called length contraction – which means everything you see as you travel becomes squashed – and becomes more and more squashed! The other is time dialation – so if you travel really fast, time slows for you!

      Complicated I know! If you could travel at 99% of the speed of light, it would take you 2 minutes to get to Mars…but to someone on Earth, it took you 14 minutes! This is because space became squashed, so it appeared as if you only had to move less distance!

      If you were to travel at the speed of light, and you were sat on top of the light beam (if you could do that), you would occupy everywhere in space, as the universe would have squashed down to nothing as seen by you, which means it doesn’t take you any time to get there! But, to someone on the earth, you’d still only be moving at the speed of light!

      Weird isn’t it? Maybe this is how we will travel to distant galaxies in the future…you just need to figure out a way to get to light speed now!

    • Photo: Suzie Sheehy

      Suzie Sheehy answered on 15 Mar 2011:

      Great question.
      It all has to do with Einstein’s theory of special relativity. As you get faster and faster until you’re getting close to the speed of light, it starts to take more and more energy to increase your speed. It turns out that if you want to get right up to exactly the speed of light, it would take an infinite amount of energy… which we don’t have!
      That’s why when we talk about the Large Hadron Collider, we tend to talk about particles in terms of their “energy” rather than saying that they are going at 99.999999% the speed of light (I think that’s the right number of 9s…) because pretty soon all the decimal points get boring…

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