If you look at classical physics, it turns out that the sun is not actually hot enough to make itself burn. By classical physics, I basically mean the stuff that everyone experiences all day, everyday. The sun is fuelled by loads of hydrogen atoms combining with other hydrogen atoms to form helium atoms. It’s a pretty common reaction up in space. However, it takes a lot of energy to make this reaction happen, and the energy that is given out by the sun is insufficient, i.e. the sun shouldn’t be self-sustaining.
But the sun does exist. Weird.
So we must welcome in quantum physics. One of my best friends. Most people know that weird stuff is about to happen when someone mentions quantum physics, and I am about to reinforce to this preconception. There’s this amazing thing called quantum tunnelling that particles can do. And it kinda does what it says on the tin; it allows particles to ‘tunnel’ through a barrier.
So if we look at the sun, there is an energy barrier. Classical physics says that we can’t get over it. Quantum physics says that we don’t need to go over it, we can just go through it instead. So that’s what these particles of hydrogen do. They just pass through the barrier and appear on top of each other. Birds and bees and out pops a helium atom (and a load of energy/light) in their place! And so via this delightful quantum tunnelling mechanism, the sun keeps burning and the Earth keeps spinning, despite all the political and humanitarian turmoil that may be going on.
So if anyone ever says to you that physics isn’t important or who cares about quantum physics, just refer them to the large ball of fire floating in the sky (and then smack them in the chops cos obviously physics is important).
P.S. apologies for the chest pains that I may have induced in any physicists reading this.