 Our universe consists of about four fundamental forces, gravity, the weakest of all four, the electromagnetic force which we perceive in our everyday life as light, the strong nuclear force which is what holds the nucleus of your atoms together, and the weak force which is responsible for the radioactive decay that the nuclei of atoms undergo sometimes. In this video we're going to be taking a closer look at the electromagnetic force. After the Big Bang the universe was so hot that all the four forces were unified into a single force but soon gravity and the strong nuclear forces split and became independent forces on their own. Eventually the universe cooled down enough for the remaining electroweak force split into the electromagnetic and the weak nuclear force. So that's how the electromagnetic force came to be. So now the question is what makes up the electromagnetic force? According to the laws of quantum mechanics any force in the universe is made up of subatomic particles. In the case of the electromagnetic force we call these particles photons. Light as many of you know by now is proposed to be the fastest thing in the universe. This is due to the fact that photons aka the particles of light have zero mass and according to Einstein any massless objects can move at the speed of light. So now the next question is how exactly does the electromagnetic force even work? Well the answer to that can be quite messy so here's a short simplified answer. When two electrically positive or negative charged particles interact they exchange photons causing them to be attracted or repelled from each other. This phenomena is nothing but the electromagnetic force in action. Finally let's take a look at how the electromagnetic force functions as the light which we use to see objects around us. Electrons orbit the atom on different energy levels called electron shells. When an electron absorbs a photon it gets enough energy from the photon to jump to a higher energy level and when it wants to go to a lower energy level it emits a photon to lose energy and this emitted photon may end up going inside your eye allowing you to see whatever you're seeing. So there you have it the electromagnetic force. Please don't forget to like, share and subscribe and be sure to check out the new upcoming science book The Interesting Universe Journey into the Quantum Realm and stay tuned for more science videos.