Adrian Binkerd, age 12,, of Des Moines., Iowa, for the questions
How does the sun produce heat?
If the sign were a fire of blazing coal, it would burn to ashes in a thousand years. Yet fossil plants tell us that summer suns were smiling down on the earth millions of millions of years ago. All this time the sun has been blazing away with no sign of turning to ashes. The fact is that this glorious star is actually an atomic or nuclear furnace. ,
This kind of energy is vastly different from that given off by ordinary burning. Under certain conditions, mass is a form of energy and energy is a form of mass. The suns s mass is a great ball of seething gases and constantly some of that mass is turning into energy. The energy thus released is in the nucleus or heart of the atom and there is a tremendous amount of this energy in a small amount of mass. If we could use all of the nuclear energy from 1/28th of an ounce of fuel, it could lift seven million tons one mile above the ground. This is the kind of energy poured forth from the nuclear furnace of the sun.
It is believed that the fuel of the sun is protons of hydrogen gas. Such a proton is the nucleus of the hydrogen atom with the orbiting electron stripped away. In a series of stages, four of these protons join to form an atom of helium. This is called atomic fusion. A few nuclear particles do not fit into the reshuffle and are given off as energy. In the fusion of hydrogen into helium, about one per cent of the original mass becomes nuclear energy.
Protons of hydrogen atoms, under terrific heat and pressure, exist on the sun in great abundance. Conditions are such that countless groups of four protons are constantly fusing to form helium nuclei. In the process, each group releases 26.? million electron volts of energy.
If the sun were encased in a sheet of ice 39 Feet thick, the heat from its nuclear energy would melt it all in one minute. Most of this radiant energy pours forth into empty space to travel on and on. About one part in two million, million parts reaches the earth. This radiant energy travels in varying wave lengths. We are aware of some of the wave lengths as light and some as heat. Still others are radio waves and waves of ultra violet. Passing through space, the heat and various colors of light are hidden. The sun's energy becomes heat only when it strikes an opaque surface, such as the earth.
In five million, million years, the sun has converted perhaps one per cent of its mass into energy. At this rate, it is expected to remain more or less as it is for the next 20 million years. If it then begins to fail, the human race should certainly be smart enough to find a new home on a planet near a younger sun.