Lee Turner, Age 11, of Okemos, Mich., for his question:
How can the sun burn in a vacuum?
Our starry sun stands in the center of our Solar System, and far away out in space are its nine orbiting planets. Until recently, most experts assumed that this space was an empty void. Now We know that space is thing populated with energetic particles. However, these fine fragments do nothing to stoke the furious furnace of the sun.
Earthlings are used to flaming fires of crackling logs and glowing coals. Like the raging forest fire and the flickering flame of a candle., these burning processes need Oxygen. When a candle is sealed in a bottle, its little flame will use up all the Oxygen in the air and then go out. We tend to think of the sun as a similar fire on a super doper scale, and it is natural to wonder how it gets oxygen in empty space.
But the sun does not need oxygen to shed its radiant heat. Its mighty powerhouse is a nuclear furnace of atomic energy. This process needs no Oxygen. The dazzling light and the seething heat of the sun come from nuclear fusion. The word nuclear refers to the dense wad of particles which form the core of the tiny atom. And fusion, of course., Means joining.
On a small scale, the devastating explosion of the hydrogen bomb is caused by nuclear fusion. Hydrogen atoms fuse to form atoms of helium, and in a split second the furious damage is done. A team of four hydrogen atoms joins to make each atom of helium, and seething is left over from each tiny fusion. This surplus blasts forth as blinding light and scorching heat and searing radioactivity.
Experts suspect that the furnace of the sun is somewhat like a continuous explosion. Hydrogen bomb its fuel is hydrogen, and every second it converts tons of hydrogen gas into helium gab. The seething star provides the heat, pressure and other conditions necessary to stoke its mighty furnace. It needs no oxygen in order to burn. Its nuclear activity adds fields of energy and streaming particles to the wide reaches of space around it. But these are wastes from the nuclear furnace, and the sun does not need them to keep going.
Every second, the sun converts millions of tons of hydrogen into helium to keep its nuclear activity going. Scientists estimate that it has been using its hydrogen fuel at this lavish rate for some five billion years. In all that time, only half of its original supply of hydrogen has been used which means that we can expect the sun to continue beaming upon the earth for the next five billion years.