# What is the source of the Sun’s energy output?

Researchers say that the Sun emits more energy in one second than any person who has emitted it in his or her whole life! The inherent source of solar output is a complicated process called fusion. In the core of the Sun, millions of nuclear reactions take place, and those reactions then convert the matter into energy. Within the core, the density is about 12 times the density of solid lead or even 160 times the density of water. The temperature on the core reaches a peak of 15 million degrees Celsius. Under such extreme conditions, the nucleus of one hydrogen atom fuses with that of another. The result of the fusion is the conversion of four hydrogen protons into one helium-4 nucleus; however, some mass is lost during the entire process, as it is transformed into energy.

With many fusion reactions in the Sun taking place simultaneously, the heavenly body loses 4.3 million tons of mass every second, and it achieves this feat by converting 600 million tons of hydrogen into 596 million tons of helium or lower. Thus, only a small fraction (approximately 0.7%) of the mass of hydrogen going into a nuclear fusion reaction does not appear as the mass of helium. However, this lost mass is converted complexly into a huge amount of energy, and this could be identified by using Einstein’s equation E=mc2. The E denotes energy, while the m is mass lost, and the c is the speed of light squared. To take a specific example from this scenario, consider the conversion of one kilogram of hydrogen into helium. Despite the fact that the kilogram of hydrogen goes into a nuclear reaction, only 0.993 kilograms of helium is often produced. Using Einstein’s formula, it is relatively easy to determine the energy output:

E=mc2 = (0.007 kilogram) (3,00,000)2 = 6.3 x 1014 joules

The determined energy output is mainly equivalent to the energy released by burning 20,000 tons of coal in a stove or a burner. You should also keep in mind that we are talking about only 0.007 kilograms of the Sun’s mass that was lost, whereas the total mass it loses every second is about 40 million tons. Even though the Sun has been releasing high amounts of energy since the last 4.5 billion years, it has so far lost only a few hundred or speculatively 1% of its original mass of hydrogen.

## Transfer of Energy from Sun to Earth

Besides fueling itself to survive for millions of years, the Sun also provides energy for the plants in the solar system, and of course, the Earth also receives power from it. The primary type of energy brought by the Sun to the Earth is heat energy, which is converted naturally or artificially by the use of radiation, convection, and conduction.

For radiation, imagine they you are sitting in front of a fireplace, and you will immediately notice how warm it feels to stay there. The warmth you are feeling is caused by radiation. The process involves the transfer of heat energy in the air via electromagnetic radiation. This type of radiation is invisible to the naked eye, as it doesn’t have the frequency to produce light, unlike the sunshine.

Conduction is transferred by one heated item to another. For example, you are boiling water in a pot and accidentally left half of a metal spoon in the water. Once you get the spoon using the unsubmerged part after a few minutes, you will notice that even though that specific portion of the spoon isn’t in the water, it still feels warm to the touch. That is how conduction works, and the process is usually more effective in metals, which are highly conductible.

In convection, the radiation coming from the Sun would heat up a liquid and turn into a gas. You would commonly see convection happening when you are boiling water, as the steam the rises above the pot is a small amount of water turning into gas.

All in all, the Sun’s energy is not only needed by the heavenly body itself but also the planets that surround it in the solar system. Without the Sun, it is not possible for almost all living beings on Earth to survive, as most of us needed warmth and sunlight to provide us with enough energy to move.