What is going on inside the Sun?

We live in a complex universe, which we don’t really understand even. But one thing we know for sure is that the fundamental currency of our universe is energy. We need energy for everything; light energy to see around, electric energy to create heat and survive cold winters, energy we get from food to basically survive…

Now this energy can be taken from many different sources including fossil fuels, or splitting atoms (fission), or the sunlight. But usually, we will get some kind of byproduct which often harms the nature: burning fossil fuels release gases that create greenhouse effect, fission energy will result in tons of nuclear waste and the sunlight energy is unfortunately a seasonal source of energy which is not available throughout the year. But even though we are not able to receive the full potential of the Sun, it seems to be releasing virtually infinite amount of energy. How is that even possible?

The reaction that takes place in the center of the Sun, is a unique one. As we know big masses, like the Earth, have their own pull force which we call Gravity. This gravity is proportional to both the mass of the object and the distance between the object and the particles that are being pulled. In our specific case, the Sun, mass is HUGE! Mass of the Sun is around 300,000 times the Earth’s. Which will result in a gigantic amount of force pulling these small atoms together, and at the center this force will pull atoms from every direction resulting in atoms fusing into each other forming bigger atoms. This fuse force is so high that can only be sustained at the centers of the sun, but scientists are looking for ways to create a Fusion reactor on Earth. To understand how they may be able to do so, and also to see how does Einstein’s famous E=mc2 formula comes into the scene, we must dive a bit deeper into the concept…

First thing first, how do we get energy when two atoms fuse? This is a phenomenon caused by the loss of mass when particles are fused. One proton is approximately 1.0073u (atomic mass unit) and a neutron is 1.0087u. Here, “1u” is a unit used in atomic scales which is equal to 1.67x10-27 kilograms. So an average Helium nucleus with one proton and one neutron is expected to approximately have a mass of 2.015u. But turns out that is not the case; the Helium nucleus is lighter than the total mass of particles forming the nucleus! This unexpected result is caused by the conversion of mass to energy by the formula E=mc2. Here “c” is the speed of light and m is the amount of mass loss in the fusion reaction. Using these values, we get the amount of energy created and this is the process behind the energy creation by fusion!!!

Fusing two particles into each other is quite a tough process. When we say ‘fusing two particles’ we mean fusing two nuclei (plural of nucleus) into each other. As we know the nucleus of an atom is negatively charged. So, when we try to bring close two nuclei, they will start to repel each other. This repulsion force is unbelievably huge in atomic dimensions, meaning under normal circumstances it is impossible to fuse two nuclei. The large amount of gravitational force in the center of the Sun is the reason for fusion to take place. But how can we replicate such a large force on the Earth?

Well, if you have read this far great! Now we will get a bit scientific:) When we are in atomic scales, there isn’t much difference between different types of energy: they all make atoms vibrate at a higher rate. What makes the atoms vibrate at a higher rate in the center of the Sun is the gravitational potential energy. Because of this huge energy, atoms vibrate and move at greater speeds, eventually fast enough to pierce their way into the electrical repulsion force and fuse into each other. As collecting 300,000 Earth amount of mass together is not really practical, what scientist do is that they use varying magnetic field to heat up metals to enormously high temperatures. This may seem a bit unlike the gravitational potential energy, but as I said before at atomic scales the effect is similar: faster particles. If they were to heat the metal up to the needed temperature, we would have our own Fusion Reactor giving us as much energy as a barrel of oil using only a glass of water…