The Sun - A Turbulent Ball Of Fire

 The Sun - A Turbulent Ball Of Fire

From the Earth the Sun looks like a white disc. It appears to be calm, serene and unchanging. But the astronomers hold a different view. According to them, the flat , bright disc has another face - ever turbulent, active, ever changing with violent eruptions that blaze forth in all directions. a few reach the Earth too.

 The Sun is essentially a huge mass of gas, about 330,000 times heavier than Earth. Its volume is 1.3 million times more than that of the Earth an radius about 700,000 kilometres. It contains mostly 74% of hydrogen, lightest element in the universe, 25% of helium, the second lightest element and the remaining one percent other chemical elements. So the Sun has no solid surface, unlike earth or moon.

What keeps the gases from escaping ?

The huge mass of Sun has tremendous gravity that keeps the gas from escaping. The outer layers of gas are constantly pulled towards the center of the Sun by this gravitational force. As a result of it, the pressure inside the sun increases with depth and the temperature soars. At the center of the Sun, known as Core , the pressure is more than 200 billion times the Earth's atmospheric pressure at the sea level and the density of gas goes up to 151,300 kg per metre cube - about 150 times the density of water. And then the temperature pf the gas reaches 5 million degree Kelvin.

The Changes that take Place :

When the pressure increases tremendously hydrogen and helium lose their electrons and the material consists of fast moving electrons, hydrogen nuclei (protons) and helium nuclei, all together known as Plasma. The protons undergo nuclear fusion reaction and four of them fuse to form a helium nucleus, thereby releasing a tremendous amount of energy. The same basic reaction produces the explosion in a hydrogen bomb, the most powerful destructive weapons ever invented man.

The Source of Radiation : 

The energy thus released in one second is more than what mankind has used since the dawn of civilization. Astronomers claim that this has been going on for the past 4.5 billion years and will go on for four to five billion years. This is the source of all the radiation we receive from the Sun.

What else does the solar radiation consist of ?

The solar radiation is not confirmed to only the light and heat. It also consists of radio waves, ultraviolet lights and x-rays too.All the light and heat and other forms of radiation we receive from the Sun come from the top of the Convective Zone, about 500 km thick, known as Photosphere. What we see from the earth as the Sun is this layer, which appears as a smooth white disc.

Why does the Sun appear like this ?

There are many reason for this. One reason is the large distance between the sun and us - 150 million kilometres, a distance at which one cannot discern features smaller than 43,500 km across - almost four times the diameter of the Earth. Another reason is that our eyes are sensitive to only a small band of the radiant energy, the visible radiation, emitted by the Sun. Were our eyes sensitive to any of the other wavelengths in the solar radiation, the Sun would have appeared entirely different.

How to view the unseen Sun : 

Astronomers have developed various types of instruments to view the unseen Sun with details not discernible to the naked eye and also in the other wavelengths for which our eyes are not sensitive.

 

                       pictures source : Google image ; “no copyright infringement is intended”