• Question: what happens when big particles are collided

    Asked by grew354bat to Lucy on 18 Jun 2019.
    • Photo: Lucy Budge

      Lucy Budge answered on 18 Jun 2019:

      That depends how you define ‘big’! You could think of the earth as a big particle, and when it collides with another planet you’d expect a very messy collision! In fact this is one of the theories for how the moon formed.

      You could also think of a snooker ball as a particle – and when these collide they simply bounce off each other.

      Particle physics though looks at the things that are smaller than atoms – electrons, protons and neutrons (and the quarks that are inside these last two).

      There’s a particle physics experiment in Europe called the Large Hadron Collider (based at CERN). Generally protons are collided together, however occasionally lead ions (lead atoms with the electrons removed) are collided as this gives us different information compared to protons. Since lead ions are composed of 82 protons and around 126 neutrons the collisions are very complicated and have huge amounts of debris! If you’re interested check out CERN’s website 🙂