• Question: Where does energy come from?

    Asked by jammydodger72x to Alexander, Josh, Serena, Simone, Stuart on 17 Jun 2013.
    • Photo: Stuart Archer

      Stuart Archer answered on 17 Jun 2013:

      It depends on what you mean by energy – there are loads of different kinds of energy e.g. light, heat, sound, chemical.

      Pretty much all of the energy that we use here on Earth originally came from the Sun. It’s basically a giant nuclear reactor that converts the simplest chemical element hydrogen into other elements by smashing them together in a process called ‘nuclear fusion’ – for example, helium (the same stuff that’s in balloons that float) comes from ‘fusing’ two hydrogen atoms together. All of the chemical elements that we commonly use such as oxygen, hydrogen, iron, copper, nitrogen – you name it – have come from this process. When the atoms fuse together, a large amount of energy is released as light – that’s where sunlight comes from!

      Sunlight it what is ultimately responsible for giving all living things energy to live. Plants and trees use sunlight to power the chemical reactions that let them make food from carbon dioxide in the air and water in the ground. Animals (and humans) eat these plants, and digest the plants to get the energy from the food that the plants made using sunlight. If you eat beef for example, then the energy you get from eating a tasty burger came from the grass that the cow ate, and the grass got it’s energy from the sun.

      When you burn petrol in a car, it releases energy which allows the car to move. Petrol (and other fossil fuels) come from dead plants and animals that have been buried in the ground for millions of years. The extreme conditions under the surface of the earth have caused the chemical reactions which have turned them into the fuels we know today. But where did these plants and animals get their energy from originally? That’s right – the sun!

    • Photo: Alexander Munnoch

      Alexander Munnoch answered on 17 Jun 2013:

      Hi jammydodger72x, good tough one!

      It really depends on how in-depth an answer you’d like.
      Generally speaking energy cannot be destroyed – it can only be transformed into other types of energy:
      e.g. chemically stored energy in say a battery can be turned into electricity which can then produce light and sounds through a mobile phone – as well as heat from resistances.
      This is commonly known as conversation of energy.

      I believe (please follow this up if in doubt) that the origin of energy is a consequence of our universe comprising mostly ‘matter’ and not equal quantities of ‘matter’ and ‘anti-matter’.

      Both ‘Matter’ or ‘anti-matter’ try to minimise their energy kind of like bubbles (generally why are they spheres and not squares?). This you would imagine would result in everything have little/no energy but…

      The lower energy forms of ‘matter’ can take the form of protons, neutrons and electrons (and larger atomic structures) which although low energy themselves, they can act very strongly on each other but…

      Again, this will only provide so much energy. Other factors play a significant role in energy generation such as gravity. Part of the reason our Sun is so hot is because of gravity trying to pull matter and atoms (mostly hydrogen) together when they are already pretty stable. 2 Hydrogen atoms though are still higher in energy than 1helium atom and by a process called fusion two hydrogens make a helium giving off a massive amount of energy (then helium can go on to make heavier atoms like carbon, oxygen and iron) and there is this continuous cycle throughout the universe.

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