Thursday, June 18, 2009

How the Sun Shines

What makes the sun shine? how does the sun produce the vast amount of energy necessary to support life on earth?
The Sun shines because it sends out energy in all directions as radiation. This radiation takes the form of light and heat. Almost the same amount of radiation leaves the Sun in all directions. It takes about eight minutes for the light from the Sun to travel to the Earth.
the Sun is an enormous ball of hydrogen and helium, with a few trace elements thrown in. At the surface, the Sun is only about 6,000 Kelvin, but as you drop down within the Sun, the temperatures and pressures rise. By the time you reach the core, the temperatures are more than 15 million Kelvin. And the normally lightweight hydrogen has been crushed together with a density of more than 150 times the density of water.

At these pressures and temperatures, fusion can happen. Inside the core of the sun, two atoms of hydrogen are combined to create helium-4 atoms. This process happens countless times every second. In fact, more than 600 million tons of hydrogen are converted into helium every second. The Sun converts the equivalent of the mass of the earth every 70,000 years.

This releases an incredible amount of energy as photons. These photons are released and then absorbed by gas molecules. And this process happens millions of times during the lifetime of a photon. Amazingly, it takes time for this energy to get out of the Sun. A photon of energy generated at the core of the Sun can take 200,000 years to reach the surface. The light takes hundreds of thousands of years to get from the core to the surface, and then a mere 8 minutes to travel from the Sun to the Earth.

So, the question is change right now, when it will be stop to shine?

just imagine by know, what will be happen.