• Question: how quickly can energy travel compared to the speed of light?

    Asked by serenalovesburgers to Yasmin, Natasha, Jemma, James, Davide, Craig, Charlie on 23 Jan 2017.
    • Photo: Yasmin Ali

      Yasmin Ali answered on 23 Jan 2017:

      Well… light travels in photons, and photons carry energy, so energy can actually travel as fast as light!

    • Photo: Craig Fisher

      Craig Fisher answered on 24 Jan 2017:

      Electromagnetic energy (of which light is one form, and thermal radiation another) travels at the speed of light. Lasers are thus a pretty good way of transferring energy over large distances (known as “power beaming”), as are microwaves. Depending on the electrical resistance of the conductor and its surrounding insulator, an electrical signal in a wire travels close to the speed of light, as it is also electromagnetic radiation, even though the individual electrons in the conductor travel at only a tiny fraction of the speed of light.
      Thermal energy transferred by convection and conduction in fluids, or just conduction inside solids, just like mechanical transfer of energy, is also much, much slower than the speed of light, more like the speed of sound or slower.

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