Ever since astronomers have determined that the age of Sun is measured in billions of years, we are faced with a mystery of solar energy origin.
The amount of energy emitted by the Sun in one second is so large that it could melt and turn into steam an ice block with the diameter of two thousand kilometers. And if the sun, in spite of this, today shines with great brightness, it means that some source of energy continuously made up flow of heat and light in the sun for all time of its existence.
First of all, there was a natural suggestion that the sun burns some material and in this case releases a lot of heat. But the calculations showed that even if the sun was composed of carbon, then it would burn as little as for three thousand years. The origin of the solar energy was explained by the fact that the gravitational force, which acts between the particles of solar matter, causes the sun to shrink, and compression of gases (the Sun is in fact a gas sphere) is always accompanied by heat.But if the sun would once even in 10,000 times greater than now and gradually shrank to its present size, even in this case, released heat would have been consumed in just 25 million years.
At the beginning of XX century, studying of radioactivity opened to scientists a new and very powerful source of energy. But spectral analysis showed that there are a small number of radioactive substances in the sun and the amount of energy released due to the decay of atoms of these substances should therefore be a comparatively negligible.
Thus, the problem of solar energy origin had been remaining unresolved for a long time. New theories have arisen only recently due to the development of nuclear physics, which studies the structure of atomic nuclei.
In the depths of Sun the temperature reaches millions of degrees. At this temperature all atoms are converted into the “bare” nuclei devoid of electrons, which in normal conditions revolve around a nucleus. Nuclei are in thousand times smaller in volume than atoms and when they lose electrons and become closer to each other we obtain the matter density never seen on Earth. At the same time a huge temperature causes these nuclei to move at the speeds of 100-200 kilometers per second. And rushing at full speed and having tremendous energy nuclei of atoms often collide with each other by an unusual density of solar material. Laboratory physical experiments have shown that collision of atomic nuclei can cause the substance, which generate huge amounts of energy. These considerations formed the basis of a new theory of solar energy origin that was recently proposed.
Calculations showed that only one percent the Sun mass, if this mass turns into energy, is enough to maintain the solar radiation for 100 billion years.
But our Sun is just one of countless stars. Therefore, if this hypothesis is confirmed, we may understand where the energy of universe is got.