How do we know that fusion reaction takes place on the Sun?

We live in a world where nuclear reactions determine the outcome of everything. What most people do not know is that they are the basis of atomic bombs and other significantly dangerous objects. In fact, these reactions are sometimes natural as well. For centuries, all kinds of nuclear reactions have been occurring on the surface of the sun. It is us humans who have realized the importance of these reactions just yet.

To understand how they take place, we will have to understand a little background of nuclear reactions first. There are two types of reactions: fission and fusion. The latter is also called the hydrogen reaction that is seen on the surface of the sun commonly.

Both of them are chain reactions that, once initiated, cannot be stopped. That is why there is no control over atom bombs. If carried out in controlled settings under proper monitoring, they are relatively safe. Right now, we will only focus on the fusion reaction.

If you look at the periodic table, you will see that hydrogen is the first element, while helium is the second. These two are very crucial for this process. This explains why fusion reactions are also called hydrogen reactions. Luckily, both the required elements are commonly found in the universe. Therefore, it is available in abundant quantities on the surface of the sun.

This reaction occurs in several steps. The protons, also known as hydrogen ions, rarely react with each other. It does not happen commonly, but when it does, it accumulates a lot of energy. And in order to find stability, it reacts over and over to transform into a heavier element, helium. But when helium is generated, a lot of energy is released in the form of gamma rays. However, this does not end here. Along with the energy and helium, an unstable neutron is also released. This neutron again reacts with another hydrogen element starting the reaction all over again, and the chain continues.

But here’s the thing. Hydrogen ions require special conditions to react. They cannot fuse just out of anywhere. So there has to be some sort of special energy on the sun that facilitates this process.

Apparently, when nebulae condense to form stars, immense pressure and heat are generated as a consequence. This simulates the conditions that cause Hydrogen atoms to fuse in a series of steps to form helium. In a way, we can say that stars are the reason behind this whole scenario.

The proof of this hydrogen reaction lies in the by-products formed because of it. The neutrinos, positrons, and gamma rays produced as the result of fusion proves our theory. Scientists have detected them and their existence verifies the established equations for nuclear fusion.

We can also prove the occurrence of this phenomenon by the presence of helium. This is done by analyzing the electromagnetic spectrum of the radiation from the sun. Fun fact, helium was first discovered on the sun and is named after the Greek sun god, Helios.