• Question: what exactly is energy made of and why does it move things? has it been discovered? it must be made of something so is it made of particles something else or do we just not know?

    Asked by Alex to David, Gemma, Juhi, Matt, Stéphane, Yinka on 9 Mar 2018. This question was also asked by mac w.
    • Photo: Matt Bawn

      Matt Bawn answered on 9 Mar 2018:

      Great question I had to do some reading though to try and get an answer for you. The best discussion about this that I found was here: https://physics.stackexchange.com/questions/14444/what-is-energy-made-of
      stack-exchanges are good places to get answers from experts about (I use one when I need help with coding).
      To paraphrase a little energy isn’t made of anything but is a result of matters interaction with something else. So in their example when matter has velocity it is said to have kinetic energy. If you raise an object in a gravitational field it will then have potential energy etc. Imagine an object interacting with a beam of light: it will cast a shadow, but what is the shadow made of?
      Now thats all very good but how can energy move things? That comes down to the principle of conservation of energy: http://www.bbc.co.uk/schools/gcsebitesize/science/add_ocr_pre_2011/explaining_motion/energychangesrev5.shtml

      I hop this helps a little? Please ask more if you want.

    • Photo: Gemma Chandratillake

      Gemma Chandratillake answered on 10 Mar 2018:

      Your feeling that energy must be made of something is because when energy is explained as “the capacity to do work”, and then you’re told that “energy is never created or destroyed”, it feels a bit like you’re missing something, right? I think that’s a common feeling, that either you don’t “get it” or that whoever is explaining it is skimming over the surface or missing something out. That feeling of dissatisfaction with the explanation of energy is common, and it is because energy is an abstract concept; there is no physical “essence” of energy, and it is always related to something else, rather than being “pure” in its own right, so it is hard to pin down a clear way of saying what it is.
      Mostly, energy is related to movement, or the potential for something to move. Even heat is really about atoms moving. So for energy, the best we can do is say “it’s the capacity to cause movement”, and reassure you that energy really isn’t made of anything!
      Btw: I’ve shortened and paraphrased the explanation given here, which I found helpful: https://cosmosmagazine.com/physics/what-is-energy

    • Photo: Stéphane Berneau

      Stéphane Berneau answered on 11 Mar 2018:

      You already had two brilliant answers.
      I just add “Energy is precious, use your energy to build not to destroy.”

      I have decided to show you a video about ATP, the body energy!

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