• Question: What happens at absolute zero?

    Asked by r3vilo to Andrew, Daniel, Hayley, Natalia, Peta on 18 Nov 2011.
    • Photo: Hayley Smith

      Hayley Smith answered on 18 Nov 2011:

      If it were possible to reach absolute zero things would be very strange indeed! Absolute zero is the point at which systems won’t absorb or release energy – this means everything is static, atoms won’t move, they’re all in their lowest energy state.

      I think it’s impossible to get a system to absolute zero though as the work needed to remove heat from the gas gets more and more the colder the gas gets – although people have got very close!

    • Photo: Daniel Scully

      Daniel Scully answered on 18 Nov 2011:

      At absolute zero nothing is moving, everything is absolutely stationary, and as Hayley says it’s impossible to reach this situation. You need everything in the entire universe to be at absolute zero as well, else the bit above will heat up the rest until it’s not at absolute zero any more.

      Quantum Mechanics starts to cause weird things to happen when you slow particles down a lot…
      When they are moving very slowly, you know very precisely how fast they are moving.
      But in Quantum Mechanics, constraining the speed a lot means the position becomes very un-constrained.
      What you see is the thing you’re trying to cool down can start to leak out of it’s container! Weird!

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