Question: How does fusion work

Jake Langham answered on 14 Nov 2017:

Great question! Fusion normally happens in stars – it’s what makes them so bright. Ok so first of all, let’s say you have two atoms. Normally if they get too close together they start to push each other away because of electric forces between the centres of the atoms. (It’s just like if you have two of those magnets that are red at one end and blue on the other. There’s a force that makes it difficult to push two of the same colour ends together.) However, inside a star, gravity is very strong and pulls all the atoms towards each other. In fact, it is so strong that it can ‘fuse’ two atoms together to create a new, bigger atom. In the Sun, the most common type of fusion is two Hydrogen atoms get squished together to create Helium. The fused atom needs less energy to hold it together than the two separate atoms and all the left over energy (which is a lot) turns into heat and light which keep the star glowing.

******

One day we might be able to use fusion ourselves as a source of electricity. This would be great because it gives of so much energy. Unfortunately it’s much easier to use it to make nuclear weapons (hydrogen bombs) than it is to use it to safely generate electricity. At the moment fusion power stations need to use more electricity than we get back out of them, which isn’t very useful at all!