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Photons: They Ain't Just for Torpedoes

Science >

We all know that being out in the sun can make you hot. But did you ever wonder why? Summer is a good time to shed some light on the question. Let's follow the life of a packet of energy from the time it is created in our star to the time it crash lands on you as you relax at the beach.

Of course, our journey begins deep in the core of the sun. There is a lot of hydrogen there, with some helium mixed in. As you know, hydrogen is the smallest of the elements with a nucleus made up of only one tiny proton.

Now these little guys are under intense pressure, what with the whole weight of the sun over them. Consequently, they are crammed together real well. But they are also at extreme temperatures, in the tens of millions of degrees. In science that means they are moving really, really, really fast.

Through a set of events more detailed than we can cover here, the tiny, close, quick, positively charged hydrogen nuclei are actually so close and so quick that they can stick together! They form helium, next in line on the Periodic Table. This is the fusion process.

Fusion puts things together --- that's important. But along the way some of the mass gets lost. That's very important. Where did it go? It became energy!

In the sun, 600 million tons of hydrogen are fused each second! But only 596 million tons of helium get produced. The four million "missing" tons are converted into innumerable packets of energy called photons: photons on a mission, photons that need to get out.

A newly formed photon races about in a random way inside the sun, bashing into elements, being absorbed and re-emitted over and over again, and losing some of its energy along the way.

Eventually, after several million years (yes, million!) of high-energy pinball, our photon makes it to what is often called the "surface" of the sun, but which is known to astronomers as the photosphere.

This is the layer of the sun that is finally thin enough that the tiny photon actually has a chance of hitting nothing and --- kaboom zaloom --- it's gone!

Our tiny quantum of energy now speeds at over 186,000 miles a second completely by chance in the direction of that third rock from the sun, Earth.

After only two-and-a-half minutes our photon speeds by the orbit of Mercury. In just another three-and-a-half minutes, Venus' orbit whizzes by.

Finally, after millions of years of bouncing around inside the sun, and only 8 minutes and 20 seconds of spaceflight, our photon zips through Earth's atmosphere on a collision course for that beach and --- ka-blam! --- it's annihilated on your skin, transferring its energy into your body, causing you to say, "Sheesh, it's hot out here!"

Now this one little photon doesn't add up to much, to be sure, but multiply that by hundreds of billions and things can get toasty warm.

In fact you can get an idea of how much energy is flowing down on us by doing the classic magnifying glass procedure. Taking the photons that flow through just that couple of inches of glass and focusing them to a point, one can start a fire! And those are just the photons traveling through that tiny opening. Your body collects considerably more energy than that each second, which is why you have been designed with a great, if sometimes embarrassing cooling system, perspiration.

Until next time, clear skies and stay cool!

Questions or comments? Mark Ritter can be reached here.

Posted by Administrator at 2002.07.20 02:44 PM | Comments (0)

New Mysteries of the Milky Way

The Galaxy >

Your assignment this week, should you decide to accept it, is to go out and take a look at the Milky Way. This is no impossible mission, especially during the summertime. And it will be a rewarding one.

But before you go out, read below. There's some news coming out about The Way that will make you more appreciate the splendor of the whole experience.

The Milky Way, as you know, is the common name we give to our home galaxy, a spiral beauty consisting of more than 100 billion stars and great collections of gas and dust.

During the summer our orbit takes us to the side of the sun where Earth's "night" side opens toward the center of the galaxy where stars reside in great and incomprehensible number. It is then that the Great White Way is easily discernible in the night sky.

By looking towards the south --- in Sagittarius, to be exact --- you may even have noticed that the Milky Way is at its bulkiest. There, about 28,000 light years away, lies the hyperactive center of our galaxy. And within that lies, probably, a supermassive black hole.

Wouldn't it be nice if our solar system were further out on the disk so we could catch a richer, fuller view of the whole shebang? Or, conversely, what if we were closer to the center and had a sky filled with tens of thousands of bright gemlike stars in a monstrous band of light bleeding across the sky?

Astronomers tell us we should be thankful for the view we have now --- that we have the best, and safest, seat in the whole House. How's that?

Well, of course we'd never want to be at the core of the galaxy. The supermassive black hole residing there can ruin an otherwise perfect day.

And just a little further out from center puts us in a place that is crammed with stars. These stars can tug our tiny planet out of its perfect orbit in a heartbeat. Moreover, supernovae and other great stars flood the place with intense, deadly radiation.

But even far from the center is no place to be, either, apparently. A group of astronomers from the University of Washington, headed by Guillermo Gonzalez, says looking for a life-support planet all the way out to about 15,000 light years would be a fruitless quest!

Gonzalez says that here there is so much dust and debris from previously exploded stars --- planet building material, in other words --- that rocky planets forming around single stars would be enormous. This means flattened surfaces covered with water, probably surrounded by a lethal atmosphere. No vacation spot, that.
Further out from the center than about 40,000 light years is no place to settle down, either. There just isn't enough stuff out there to make planets like ours, perfect rocky bodies fit for life.

It's turning out that if one wants to find a life-support planet in our galaxy, one should look between 15,000 and 40,000 light years away from the core where there is just enough material around to build nice little planets. This is called by some the Galactic Habitable Zone (GHZ).

And right smack in the middle of the GHZ --- you'll never guess! --- revolves an ordinary, single yellow star with a tiny rocky planet that hosts the only known life in the universe.

Go out and have a look at the Milky Way tonight and be thankful for the perfect and awesome view we all share.

Questions or comments? Mark Ritter can be reached here.

Posted by Administrator at 2002.07. 6 02:45 PM | Comments (0)



Looking for something?	« June 2002 \| Main \| August 2002 » Photons: They Ain't Just for Torpedoes Science > We all know that being out in the sun can make you hot. But did you ever wonder why? Summer is a good time to shed some light on the question. Let's follow the life of a packet of energy from the time it is created in our star to the time it crash lands on you as you relax at the beach. Of course, our journey begins deep in the core of the sun. There is a lot of hydrogen there, with some helium mixed in. As you know, hydrogen is the smallest of the elements with a nucleus made up of only one tiny proton. Now these little guys are under intense pressure, what with the whole weight of the sun over them. Consequently, they are crammed together real well. But they are also at extreme temperatures, in the tens of millions of degrees. In science that means they are moving really, really, really fast. Through a set of events more detailed than we can cover here, the tiny, close, quick, positively charged hydrogen nuclei are actually so close and so quick that they can stick together! They form helium, next in line on the Periodic Table. This is the fusion process. Fusion puts things together --- that's important. But along the way some of the mass gets lost. That's very important. Where did it go? It became energy! In the sun, 600 million tons of hydrogen are fused each second! But only 596 million tons of helium get produced. The four million "missing" tons are converted into innumerable packets of energy called photons: photons on a mission, photons that need to get out. A newly formed photon races about in a random way inside the sun, bashing into elements, being absorbed and re-emitted over and over again, and losing some of its energy along the way. Eventually, after several million years (yes, million!) of high-energy pinball, our photon makes it to what is often called the "surface" of the sun, but which is known to astronomers as the photosphere. This is the layer of the sun that is finally thin enough that the tiny photon actually has a chance of hitting nothing and --- kaboom zaloom --- it's gone! Our tiny quantum of energy now speeds at over 186,000 miles a second completely by chance in the direction of that third rock from the sun, Earth. After only two-and-a-half minutes our photon speeds by the orbit of Mercury. In just another three-and-a-half minutes, Venus' orbit whizzes by. Finally, after millions of years of bouncing around inside the sun, and only 8 minutes and 20 seconds of spaceflight, our photon zips through Earth's atmosphere on a collision course for that beach and --- ka-blam! --- it's annihilated on your skin, transferring its energy into your body, causing you to say, "Sheesh, it's hot out here!" Now this one little photon doesn't add up to much, to be sure, but multiply that by hundreds of billions and things can get toasty warm. In fact you can get an idea of how much energy is flowing down on us by doing the classic magnifying glass procedure. Taking the photons that flow through just that couple of inches of glass and focusing them to a point, one can start a fire! And those are just the photons traveling through that tiny opening. Your body collects considerably more energy than that each second, which is why you have been designed with a great, if sometimes embarrassing cooling system, perspiration. Until next time, clear skies and stay cool! Questions or comments? Mark Ritter can be reached here. Posted by Administrator at 2002.07.20 02:44 PM \| Comments (0) New Mysteries of the Milky Way The Galaxy > Your assignment this week, should you decide to accept it, is to go out and take a look at the Milky Way. This is no impossible mission, especially during the summertime. And it will be a rewarding one. But before you go out, read below. There's some news coming out about The Way that will make you more appreciate the splendor of the whole experience. The Milky Way, as you know, is the common name we give to our home galaxy, a spiral beauty consisting of more than 100 billion stars and great collections of gas and dust. During the summer our orbit takes us to the side of the sun where Earth's "night" side opens toward the center of the galaxy where stars reside in great and incomprehensible number. It is then that the Great White Way is easily discernible in the night sky. By looking towards the south --- in Sagittarius, to be exact --- you may even have noticed that the Milky Way is at its bulkiest. There, about 28,000 light years away, lies the hyperactive center of our galaxy. And within that lies, probably, a supermassive black hole. Wouldn't it be nice if our solar system were further out on the disk so we could catch a richer, fuller view of the whole shebang? Or, conversely, what if we were closer to the center and had a sky filled with tens of thousands of bright gemlike stars in a monstrous band of light bleeding across the sky? Astronomers tell us we should be thankful for the view we have now --- that we have the best, and safest, seat in the whole House. How's that? Well, of course we'd never want to be at the core of the galaxy. The supermassive black hole residing there can ruin an otherwise perfect day. And just a little further out from center puts us in a place that is crammed with stars. These stars can tug our tiny planet out of its perfect orbit in a heartbeat. Moreover, supernovae and other great stars flood the place with intense, deadly radiation. But even far from the center is no place to be, either, apparently. A group of astronomers from the University of Washington, headed by Guillermo Gonzalez, says looking for a life-support planet all the way out to about 15,000 light years would be a fruitless quest! Gonzalez says that here there is so much dust and debris from previously exploded stars --- planet building material, in other words --- that rocky planets forming around single stars would be enormous. This means flattened surfaces covered with water, probably surrounded by a lethal atmosphere. No vacation spot, that. Further out from the center than about 40,000 light years is no place to settle down, either. There just isn't enough stuff out there to make planets like ours, perfect rocky bodies fit for life. It's turning out that if one wants to find a life-support planet in our galaxy, one should look between 15,000 and 40,000 light years away from the core where there is just enough material around to build nice little planets. This is called by some the Galactic Habitable Zone (GHZ). And right smack in the middle of the GHZ --- you'll never guess! --- revolves an ordinary, single yellow star with a tiny rocky planet that hosts the only known life in the universe. Go out and have a look at the Milky Way tonight and be thankful for the perfect and awesome view we all share. Questions or comments? Mark Ritter can be reached here. Posted by Administrator at 2002.07. 6 02:45 PM \| Comments (0)
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