• Question: Why is a proton positive and an electron negative? (Rather than the other way round.)

    Asked by freddie to Adam, Geoff, Rob, Sheila, Suzie on 21 Mar 2011 in Categories: .
    • Photo: Adam Tuff

      Adam Tuff answered on 17 Mar 2011:

      I think it’s just the way the universe is…that is a good question! Don’t you find it a bit weird too that the big proton has the opposite charge of a tiny electron?

    • Photo: Sheila Kanani

      Sheila Kanani answered on 17 Mar 2011:

      Great question! Is it to do with ‘spin’? Maybe Suzie can answer this better.
      I’ve heard that everything in the universe has a ‘handedness’ like left or right handed. Maybe it is like electrons are right handed and protons are left handed. Not sure 😀

    • Photo: Suzie Sheehy

      Suzie Sheehy answered on 18 Mar 2011:

      I’d always wondered this as well when I was learning physics… But it was a completely arbitrary decision, physics would work exactly the same way if we called ‘positive’ things ‘negative’ and vice versa!

    • Photo: Robert Simpson

      Robert Simpson answered on 21 Mar 2011:

      For the same reason that the North Pole and the South Pole aren’t the other way around or that up isn’t down. They’re just the names we give things to help us understand them.

Comments

  • Photo: freddie

    freddie commented on :

    It is weird that an electron has such a high charge! But what actually is positive and negative charge? I’ve learnt about Coulomb’s law and atomic structure but still don’t exactly know what it is.

  • Photo: kraknor

    kraknor commented on :

    +ve and -ve charge are just names we have given to the corresponding properties of electrons and protons. There is no real reason ‘why’ electrons are -ve ly charged, they are just defined that way by convention.

    In terms of what charge is, I believe string theory states that charge comes from oscillations in the theoretical strings that make up all matter, but we don’t know this to be true yet!

  • Photo: Suzie

    Suzie commented on :

    Wow kraknor keeps beating me to answering comments – maybe you should be over on the scientist side!!
    Charge is a quantum number that particles have – it’s one of those age old fundamental questions but we know that we can only have 2 charges. Not positive, negative and say, blue (if you can imagine a third charge!!). We know that wouldn’t work (I think) because of the way the Standard Model of Particle Physics is set up.
    That said, we know that there is physics beyond the Standard Model already, so maybe we’re wrong about all of it!?!?