The
nearest star is the sun. It took the human race quite a few thousand
years to discover this fact, for no objects could seem more unlike than the
dazzling, burning sun and the coldly scintillating stars. It is the sun’s
extreme closeness that makes the difference, and makes the sun so
overwhelmingly important to us.
The amount of energy we receive from this
nearest star is enormous, and the earth itself intercepts only a minute
fraction of the sun’s rays; most of the energy goes rushing past into space. If the sun were made of coal, for
example, it would have burnt
itself out in a couple of thousand years. Astronomers racked their brains and decided that the sun obtained its energy from its slow contraction
under gravity.
But if the sun were contracting, it must once
have been bigger, and calculations showed that 50 million years earlier it
would have embraced the earth. This obviously set a limit to the age of
the earth. Geologists pointed out, however, that 50, 100, even 500 million years was not long enough for the
changes our planet has seen - mountains worn away, chalk beds kilometers thick
that had been laid down on the beds of vanished seas. They told the astronomers
to look for a few more noughts. Not until the discovery of radioactivity did
astronomers realize that gigantic stores of energy were locked up in the atoms
themselves, and that the sun was able to tap that energy, which was sufficient
to keep it shining for thousands of millions of years. But how does the sun tap
the energy of matter?
Many of the ordinary elements are present in
the sun. Some elements - radium, for example - are naturally unstable and
continuously give out energy until they have decayed into less spendthrift
substances such as lead. But radium could not account for such a vast
generation of power over so long a period; the sun must have learnt the secret
of releasing energy from “ordinary” matter. The first major clue to that secret
came in 1868, when the newly developed spectroscope revealed an element in the
sun not yet discovered on earth. The new element was named “helium,” and after
an intensive search it was found in our atmosphere in minute quantities.
We know now that helium is the ash left when atoms
of hydrogen are fused in the furnace of the sun. This type of “burning” is
infinitely fiercer than ordinary combustion; it is an atomic rather than a
chemical process, and takes place deep within the sun, under pressures and
temperatures beyond imagination. Helium and hydrogen are vastly more abundant
in the sun than all the other elements put together. Every second about four
million tons of matter are converted into energy; to equal this output, we
would have to explode 80,000 coal trucks full of TNT every second. The
released energy batters its way up to the surface of the sun, hundreds of
thousands of kilometers above. Then, in the form of light, heat and other
radiations, it spreads out into space.
No man has ever seen the sun, or ever will.
Only a small part of its radiation - narrow band of visible light - leaks down
through the earth’s atmosphere, which filters out the ultra-violet and X-rays
that would otherwise continually bombard us. At times the sun sends out sudden
spurts of ultra-violet light that cause such intense electrification of the
upper air that long-distance radio circuits are disrupted. In recent years it
has been possible to make computer-simulated movies of the surface of the sun,
and by speeding them up several hundred times to project on the screen the life
story of cataclysmic solar events which may occupy hours of time and multiple
millions of cubic kilometers of space. Some of these movies are awe-inspiring; they show immense fountains of glowing gases spurting to heights of a hundred thousand kilometers; bridges of incandescent
gases, which could span a dozen
earths, forming and crumbling; exact replicas of A-bomb bursts -
but a thousand times as large - shooting up into space.
Watching
these movies, you see the action
of forces completely beyond our
understanding. A slanting jet of incandescent gas, for example, will shoot out on a long, flat trajectory,
reach its apex, and then whip back along its original path -
as if a shell at the peak of
its flight decided to return to
the gun. And sometimes, thousands of kilometers above the sun’s surface,
cascades of glowing matter will pour down from no apparent source, as if
they were created high in the solar atmosphere.
Since
the sun is purely gaseous, it is
surprising that its surface is
so sharply defined. Seen through
the telescope, its edge is a perfect circle. One reason for the sharpness of the sun, edge
is its intense gravity, 28 times that of the earth. On the sun an average man would
weigh over two tons. Although many stars wax and wane in brilliance, the sun’s output of heat and light has changed little during the course of human history. But what of the future? What will
happen when the sun starts to
run out of fuel about the, year - A.D 10,000,000,000? The obvious assumption would be that the sun will gradually cool down to a
dull red and finally gutter out
into extinction. But the obvious
assumption is not the correct
one. The sun is not cooling
down; it is warming up!
As the sun
uses up its hydrogen fuel
and the helium “ash” accumulates round its core, the rate of reaction will increase. Like a gambler who bets more and more frantically as he approaches the end of his resources,
the sun will go out in a final
blaze of glory. Within a span of a mere five million years it will increase its brilliance a hundred-fold, melting down
the earth and the inner planets into balls of glowing lava. Then it
will collapse swiftly to a tiny
star only a few thousand kilometers
in diameter. It will still be bright,
but it will give out little more
heat than the full moon does today.
The minute star which finally gutters
to extinction will not be anything we would recognize as the
sun.
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| How Great Thou Art... |
So, at
least, runs the current theory,
but to claim that is an accurate description of what must happen would
be rash. Even when we have attained a complete understanding of the processes taking place inside the sun, we
cannot be sure that external factors - clouds of interstellar dust into which
it may run, for example
-may not write new and unexpected
chapters in its history. At any
rate, we need not worry about the sun blowing up, or going out by
‘natural causes’, for the next few thousand years – at least scientifically…
How can anyone still doubt the existence and power of GOD ~ SB
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