• Question: why is everything made of particles?

    Asked by THEMONST3RPG to David, Eva, Kate, Nicholas, Rachel on 17 Nov 2015.
    • Photo: David Nunan

      David Nunan answered on 17 Nov 2015:

      Hey,

      So we normally think along the lines of dividing cells and molecules into tinier and tinier bits until you can’t divide them any more.

      But some scientists think we need to think not in terms of particles but in terms of “fields”. You’re already familiar with some fields. When you hold two magnets close together, you can feel their attraction or repulsion before they even touch—an interaction between two magnetic fields. Likewise, you know that when you jump in the air, you’re going to come back down. That’s because you live in Earth’s gravitational field.

      Every particle is actually a field. The universe is full of fields, and what we think of as particles are just excitations of those fields, like waves in an ocean. An electron, for example, is just an excitation of an electron field.

    • Photo: Nicholas Pearce

      Nicholas Pearce answered on 17 Nov 2015:

      Hi,

      Everything has to be made of something right?
      The ancient Greeks though everything was made of earth, air, fire or water.
      But then people started thinking that idea was too basic and that perhaps if you kept cutting something in half, eventually you wouldn’t be able to cut it in half any more and you would be left with a single tiny object, a particle. This was all just an idea, but people thought it was a good idea and so it stuck around for a while. Nobody could make a microscope good enough to check, so it remained an idea – but then one day, science had improved enough to test this particle idea and it seemed to work.

      These days there are some scientists who think that even particles are made up of something else. Have you heard of string theory? In string theory particles are thought just to be vibrations on a string, where different vibrations make different particles, just like how on a guitar string you can make different notes.

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