When Technology And The Future Of The Sun Collide

This question originally appeared on Quora. Answer by Xiangwei Tang.

Do you know what kinds of energy we are using?

Coal, petroleum, natural gas, these are the most important energy resources today.

Where do they come from?

The ancient trees, plants, animals died and buried in the earth, and after millions of years, their body turned to those fuels.

Then why can they be fuels?

Because their bodies contains carbon.

How do the carbon come into their bodies?

Animal get carbon from animals, animals get carbon from plants, plants get carbon from the air by using photosynthesis.

Photosynthesis is a complex chemical reaction. This reaction is driven by SOLAR ENERGY. In the view of energy, it transfers the solar energy into chemical energy.

So, the petroleum, coal and natural gas are 100% SOLAR ENERGY.

Oh, you may say, we can use hydropower station.

Yes, we can use them. Let’s see how the hydropower come from.

Water flow from the higher place to lower place and drive the generator to out put the electric power.

But what happen if all the water in the higher place all flow to lower place?

Don’t worry, the water in low will vaporize to the air, and some of them will fall to higher place to form a perfect cycle.

Then who vaporize the water?

Sadly, sun heat again.

So hydropower somehow comes from SOLAR ENERGY.

Then what about wind power?

When the part of the air was heated, its size will grow bigger and density become lower and then form a low pressure area. Then the air from a high pressure area will rush to the lower part. This rush is called wind.

OK, you should have noticed that, it is the SOLAR ENERGY which heated the air, so wind power comes from SOLAR ENERGY.

Then our last hope, nuclear energy.

Luckily, nuclear energy is not from the sun. Some radiation materials formed part of the earth at the very beginning time of our planet, and they are not solar energy.

However, the sun itself is a extraordinary big thermo-nuclear reactor. You can image that millions of millions of hydrogen bombs explodes on the sun everyday. While we have only less than 10 thousands of nuclear weapons.

So basically, almost all the energy we are using is from the sun, directly or indirectly. But compare to the whole energy of the sun, it is only a drop of water compare to the ocean. Because only extremely tiny part of solar energy finally reaches the earth, and preserved by the earth in billions of years.

Let’s do a roughly calculation. The sun-earth distance is about 150 million kms. Assume the solar energy spread equally in this distance, that’s about 3*10^17 km2. And the earth has surface area of 5*10^8 km2. So only 1/(6 billion) energy was received by the earth. Since there are about 7 billion people in this world, it means if every single item in the earth(not only human being) try to kill the sun, it is roughly equals to a single person try to kill everyone else in the world.

So can we kill the sun? Well, impossible for now and at least predictable future.