• Question: Why do you think it's useful/important to give cosmic ray detectors on schools?

    Asked by javanlangar to Kate on 20 Jun 2013. This question was also asked by withington, lfcdansk.
    • Photo: Kate Husband

      Kate Husband answered on 20 Jun 2013:

      I think its a great way to enthuse students on science and we need more people working in science, technology, engineering and maths (STEM subjects) in this country. It also helps build links between scientists and schools and teaches students about experimenting, analysis, logical thinking etc., all great skills for later in life. It lets students see what science could be like as a job rather than just learning facts out of textbooks. And finally you are doing real science so we might learn something brand new!

Comments

  • Photo: Claire

    Claire commented on :

    Cosmic rays are actually really really cool because they prove a really strange part of Einstein’s theory of relativity.

    One of the things the theory says is that, as you go faster and faster, time actually slows down and lengths get shorter. Weird huh? But it’s true – cosmic rays are proof.

    Cosmic rays are high energy particles from space (like protons) that hit our upper atmosphere and cause a shower of particles like muons to fall towards earth. Muons are like electrons, but heavier, and they don’t live very long (about 2.2 microseconds) before decaying (to an electron and a neutrino)

    The problem is that even with the muons travelling really fast, they shouldn’t ever reach Earth’s surface – the time it would take them to travel that distance is longer than their lifetime so we shouldn’t see really fast-moving neutrons down here.

    Except, we do! How is this possible?

    Well, what actually happens is that, from our point of view, relativity makes the muon time slows down, so it seems as if they’re actually living longer than they should be. This gives them enough time to get to Earth’s surface 🙂

    Now the crazy part – from the muon’s point of view, it lives for exactly it’s allocated 2.2 microseconds. But from it’s point of view, the distance it has to travel has gotten shorter, so again, it is able to make the trip in its lifetime!

    Now I ask you – which one of these is correct? Does the distance between the Earth’s atmosphere and surface actually get shorter? Does the muon actually live longer?

    So why are cosmic ray detectors cool? They teach us about really fast particles coming from outer space, and how time slows down and lengths get shorter as you go closer to the speed of light 🙂