Sunday, December 18, 2011

Cosmic Reflections - Some Mind-Boggling Facts about Our Sun

When the weather turns cold and the holiday season approaches, the message that courses through our culture is mostly this - buy, buy, buy. Buy this mass produced jewelry; every kiss begins with Kay. Or buy this $50,000 Lexus and put a huge red bow on it to surprise your spouse Christmas morning. These messages are supposed to be charming and inspiring. But to me, they're outrageous.

I'm afraid I'm not with the program. This time of year, I'm more drawn to cosmic realities. Such as the fact that on the 21st of December, in the northern hemisphere the days begin to get longer, promising the approach of warmer weather.

Or on a cold night I'll look up at the stars and try to understand what I'm seeing. Before long, I'll be reminded of certain facts...

For example, the next time you're on a beach, pick up a handful of sand and imagine how many grains of sand you are holding. Now look up and down the beach. Imagine how many grains of sand you can see. Mind-boggling. Now try to imagine how many grains of sand cover the Earth.



FACT: There are more stars in the universe than there are grains of sand on Earth.

FACT: No two stars in the universe are the same. Their size, composition, internal chemistry and physics, and lifespan are determined by the nebula cloud from which they were formed.

You may have heard the saying, "We are made of stars." This happens to be true.

FACT: All the heavy elements, such as carbon and silicon, which are the basis for life, can only be created by the intense gravitational pressure caused by the end-of-life implosion and explosion (supernova) of a very large star.

FACT: Our own star, "The Sun," was formed by an aggregation of the stardust from such a supernova five billion years ago.

FACT: Our sun is a medium-sized star. 93 million miles away, millions of hydrogen bomb explosions happen every second. That's what I said...every second. So why doesn't it just blow itself up? The answer is that the immense gravity of this enormous object holds everything in. About 5 billion years from now, the fuel for all these explosions will be gone, and our star will die. But for now, it's radiating energy like crazy.

As you may know, our sun occasionally forms "sunspots" on its surface. They appear dark because they're relatively cooler than the rest of the sun's surface. Sunspots are associated with intense magnetic activity that erupts as solar flares. Some of these flares are so strong they escape the sun's gravity and blast into outer space. These flares can disrupt communication when they reach Earth. From time to time, these blasts are unusually powerful. Such a blast is called a "coronal mass ejection."

FACT: Coronal mass ejections rocket into space in random directions. It is unlikely - but possible - that one would hit the Earth head-on. But if it did, scientists estimate that the energy would knock out every man-made electronic and electrical device on the planet, including communication satellites. Power stations would be fried. Technologically, human civilization would be knocked back 200 years. It could take decades to restore everything to normal, assuming we survived the chaos and panic.

FACT: Most of the time, over 90% of the typical energy particles from the sun are deflected by Earth's electromagnetic field, which is generated by the movement of molten iron in Earth's hot core. Without this protection, our atmosphere would be stripped away by the constant radiation of this "solar wind."

An example of what can happen is Mars. Billions of years ago, the small iron core of Mars cooled, causing its electromagnetic field to disappear. Almost nothing is left of its atmosphere. The same thing happened to Venus.

Earth's electromagnetic field is what causes compasses to point north. But every 100,000 to 10 million years, the field switches poles. Scientists aren't sure when this will happen again, although the last known switch was nearly 800,000 years ago.

FACT: The poles will switch again someday. Scientists don't know when or how long the switch will take. If that transition isn't instantaneous, our atmosphere will be temporarily unprotected. The ozone layer could be stripped away, our atmosphere would be exposed to the solar wind, and life on Earth would be threatened. Earth could become a biologically dead planet, like Venus and Mars.

GOOD NEWS FOR YOU, DEAR READER...

The fact that you'll live to a maximum of only 100 years means that the chance that you'll be around to suffer any of these catastrophes is infinitesimally small. Woo-hoo! You have a better chance winning the lottery.

Whether you push against your credit limit buying stuff this season, be sure to lift a glass to toast your good fortune - that you are alive during the Golden Age of the cosmos, when stars were still burning brightly, and conditions were still just right for life to flourish on Earth.

Post by Dennis E. Coates, Ph.D., Copyright 2011. Building Personal Strength .

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