Did
you know that the sun rotates? The core of the sun rotates at about
the same rate of speed, but the exterior portions of the sun rotate
at different rates. For example, the equator rotates slower than
the polar regions of the sun. It can do that because it is a ball
of gas and not a solid.
THE SUN
There's an old joke
that goes:
An International gathering of world
leaders in science met in Geneva to discuss their latest findings.
Each nation took a turn sharing its latest developments. The leader
of one nation stood before the group and declared that they
had devised a spacecraft which would allow their astronauts to fly
directly to the sun. He was met with boisterous laughter from the
audience, to which he boldly replied, "I know what you're thinking,
but we have a plan. We're going to fly the ship at night!"
Just about everybody knows that
you can't fly directly to the sun, for several reasons, not the least
of which is that you can't even land there because there is no there
to land on. The sun is a star, which is an enormous ball of burning
gases. If you remember from your science lessons in school about the
three states of matter (solid, liquid, gas) you remember that gases
are not
solids. In order to land and stand
on any celestial body, it would need to be solid because we are solid.
Oh yeah, for us to fly anywhere near the sun we would have to build
a spacecraft that could withstand over 1,000,000 degrees Kelvin AND
keep the people inside protected from not only the extreme heat, but
the intense light and solar radiation. Human beings were built to withstand
the intensity of the sun from the distance of earth, not any closer.
Even at this distance, too much exposure to the sun can be dangerous.
Besides, we don't really need to fly to the sun to study it, we can
make observations from afar (it's much safer).
The Source of the Sun's
Tremendous Energy
You would probably think of the
sun as very old, as it is estimated that the "birth" of the sun happened
4.5 billion years ago. Things that grow old usually die, but 4.5 billion
years is young for our sun. It is estimated that there is enough fuel
in the interior of the sun to keep that lamp burning for about another
five billion years, growing twice as bright as it is now. The source
of the sun's fuel is hydrogen and helium gases. Through a special chemical
reaction, called nuclear
fusion, the hydrogen gas is "burned" releasing an enormous amount
of energy in the form of light and heat.
Two isotopes
of the element Hydrogen (tritium and deuterium) collide with each
other under extreme heat in the interior of the sun. The two atoms
smash into each other so hard that several things happen:
1. Like cars smashing into
each other in a high speed crash, the atoms lose pieces of themselves,
atomic particles
2. Unlike anything else
we know of in the universe, however, an ENORMOUS amount of energy
is released into the surrounding area, on the order of 450 times
the amount of energy required for a fusion reaction to initiate
(talk about a big return on your investment!)
3. The atomic particles
from the Hydrogen atoms that were released during the collision
are fused together, forming an entirely new molecule called Helium
Of course, there's a LOT more than just two atoms smashing into each
other in the center of the sun. There's so many nuclear fusion reactions
happening inside the sun at any given time that we don't have a number
big enough to count them! The light and heat energy travels from
the core of the sun to its exterior (the photosphere)
where we see it from earth (during the day). It takes a million
years for the energy from a single nuclear fusion reaction in the
center of the sun to reach the surface.
The sun is so powerful we can harness
the energy from it to make our lives easier - ever heard of solar
energy (using the heat from the sun
to heat the water for your house)? Now that you know a little
more about the sun, solar energy has a different meaning. True solar
energy comes from the nuclear fusion reactions of the sun's interior.
From the knowledge we have gained about about nuclear science we have
developed of the Hydrogen bomb and nuclear energy.
Solar Activity
The sun is a dynamic star exhibiting
changes in its intensity over time in cycles of warming and "cooling".
From knowledge scientists have gained about the sun this century we
know about a phenomena called sun
spots. Scientists are trying to understand what causes
these large spots on the sun; why they happen and what effect they
have on the sun's activity. They appear to be large regions of the
sun's surface that are significantly cooler
than the rest of the sun (about 3800 degrees Kelvin, as opposed to
the average 11,000 K). By examining temperature data that has been
gathered all over the world for the last three hundred years it appears
that sun spots effect the kind of weather we have here on earth.
One of the hottest things about
solar activity is the phenomenon of solar
flares. A solar flare happens when there's a sudden change
in the magnetic properties of the sun and GIGANTIC flares of burning
gas leap out from the sun's surface. These flares extend for hundreds
of thousands of kilometers into space and their intensity is such
that it effects life here on earth. Communications devices that rely
on transmission of radio waves (television, radios, cellular phones)
can be affected by increased interference, or noise and power lines
can experience major power surges.
See theWorld
Record Index to see all the records featured
on Extreme Science.
Facts: The sun is not actually
a planet it is a star. Even though it looks solid, it's actually
a sphere of burning gases. The center of the sun is an incredible
15,000,000 degrees Kelvin! This giant glowing orb is 1.4 million
kilometers, or 868,000 miles, across.
The Scientists Who Study this Cool
Stuff?
Astronomers, Astrophysicists.
Here
are some images of solar flares, taken from different angles. The photo
above is a magnified view of the surface of the sun, looking directly
down on a flare. The photo below shows a view of a solar flare from the
side, projecting out into space.
