[net.astro] StarDate: August 3 If the Sun Stopped Making Energy

dipper@utastro.UUCP (Debbie Byrd) (08/03/85)

What would happen if the sun suddenly stopped making energy in its
interior?  We talk about it -- after this.

August 3  If the Sun Stopped Making Energy

If you burned all of Earth's fossil fuels, that energy would equal only
about a ten-thousandth of the energy produced by the sun every second.
But what would happen if the sun suddenly stopped making energy?
Surprisingly, not much -- for quite some time.

Here's why.  The source of the sun's energy is thermonuclear fusion.
Our sun produces the energy equivalent of 100 million 10-megaton
hydrogen bombs every second.  In the sun's interior, thermonuclear
fusion converts hydrogen into helium -- with energy as a by-product.
The center of the sun, where all this energy is being created, is at
the incredible temperature of some thirty million degrees Fahrenheit.

The sun is so hot that the atoms composing it bombard each other with
enormous impact.  Electrons are negatively charged particles which are
normally locked up in atoms.  But in the sun many electrons are knocked
out of atoms and are free to move around.  These charged particles
greatly retard the outward movement of energy created in the sun's
interior -- so that the energy we receive from the sun today was
created in its interior some ten million years ago.

In other words, if the sun stopped making energy right now, it would
still shine as usual for millions more years.  There are ways to tell
whether the sun is still fusing hydrogen in its core.  But the energy
takes so long to go from the core to the surface of the sun, we
wouldn't SEE a difference for millions of years.


Script by Wayne Wyrick.

(c) Copyright 1984, 1985 McDonald Observatory, University of Texas at Austin