June Fritz, Brockville, Ontario, for her questions
Where does the sun get its heat?
An ordinary fire needs oxygen. It gets this gas from the air, and. a draft which supplies more oxygen makes this ordinary fire burn more brightly The sun, like the earth, has an atmosphere. But its atmosphere does not contain the vast supplies of oxygen necessary for its enormous bonfire.
The solar fire, then, must be a different kind from the ordinary fire in the*grate. And so it is. The sun is a vast atomic furnace. Its heat is atomic energy. Not only the sun, but all the other stars we see in the heavens are huge nuclear furnaces.
The word nuclear means that the energy comes from the nucleus of the atom, which is its very heart. Each atom is an orderly group of particles: Some particles form the nucleus. Other particles orbit the nucleus as the planets orbit the sun. Atoms are forever losing and regaining their outer particles. We are able to control this process to create electricity. But changing the particles in the nucleus of the atom is a far greater problem. This is what releases atomic energy.
And our glorious sun runs on atomic energy. There are several theories which suggest how the sun creates its atomic energy. No one theory has been proven. But one of them is widely accepted as the most likely process.
Most experts believe that the sun operates by turning the gas hydrogen into the gas helium. The change takes place in the nuclei of the atoms. Four atoms of hydrogen are fused to form one atom of helium. But there is a little more material in four hydrogen atoms than in one helium atom. This material is the waste from the atomic furnace. It is freed to become atomic energy.
The process of fusing a larger atom from several smaller atoms is called atomic fusion. The hydrogen bomb works by atomic fusion. In the sun countless trillions of hydrogen atoms are transformed into helium atoms every second. The waste material from this fusion is given off as thesun's radiant energy,
The fuel of the sun's atomic furnace is hydrogen. Billions of tons of it are used every second. The sun has been burning away for billions of years. Yet, we are told, it still has enough hydrogen fuel to feed the atomic furnace for billions of years to come.
The sun gives off its atomic energy day and night from its entire surface. If we could put a ,jacket of ice 100 feet thick around the sun, the ice would melt in less than a minute, Its radiant energy pours forth in all directions. From every square yard it sends out enough energy to drive 700 automobiles. Only about two parts in a billion parts of this energy reaches our earth. But that is enough to support life as we know it.