MUSINGS ABOUT THE UNIVERSE
I love talking about the universe as we don't see it. Look at the nighttime sky. Looks like a still photograph. But actually it's a peek into a vast time machine. With many things to marvel about.
First, the light that is coming to us from the stars -- actually any meteor, comet, planet, or any other celestial object -- is unique. The rays that hit the retina of our eyes have been traveling for vastly different times. Seconds for sunlight bouncing off the moon, eight minutes for light directly from the sun, Mars and Venus, millions upon millions of years from great galaxies, and even billions of years from galaxies at the edge of the universe. Scientists say that the universe has no edge, so let's say from galaxies we see that were formed within a few hundred million years after the big bang that set it all in motion. There is no other scene in all our existence where we can seen so far back in time -- from seconds to billions of years. It's really a snapshot of the closest thing we'll ever see to eternity.
That's really what we are seeing. Individual rays of light hitting our eyes at the same time, but of vastly, vastly different ages. But we know that most everything we touch or see on this earth ages. Trees grow and die, so do people, mountains are worn down and continents drift.
But as far as we know, those tiny dots of light coming to us from space are exactly the same as they were either seconds ago or billions and billions of years ago. No difference, WE THINK. Or at least no one has any evidence to the contrary. Talk about perpetual motion machines. Light is the closest thing we have to it. After billions of years, you get bored and stop counting. Of course, the intensity of the light rays can be diminished as they pass through clouds of dust and gases in the universe. But the light waves come to us unchanged in their ability to reveal the size, shape chemistry of the star or nebula or galaxy from which they left.
Well, what happens to those tiny rays of light that come to our planet? Some get absorbed into the retina of our eyes. They raise the energy level of the molecules and atoms on our retina, and that is what produces the signal that our bodies have learned to absorb and process to give us a picture of what we think is the outside world.
Other rays bounce off our hats, jackets, skiis or the beach on which we are sitting. And those bounced rays run off in a shower back out into the universe. Probably too weak for any UFO telescope to discern, but they are there, zooming away from us still at a speed of 186,000 miles a second. Remember, it doesn't matter if the rays were produced by an unbelieveably large stellar explosion or from the glint off someone's hair on a Bahama beach. Their speed is not different.
So what, exactly are we seeing? Of course, the pattern of night objects we see at night is just a snapshot of one tiny point in time. The light that started out from a distant galaxy began way before the age of dinosaurs. Some, way at the "edge" of the universe, before the earth itself was formed. But here they all are, arriving at our retinas at the same time. Of course, every star, galaxy, planet and comet out there is no longer where it was when each ray of light from each object started out. Even the moon has moved a little from the point when the reflected rays of the sun bounced off it a mere second ago.
So, if you really want to blow your mind, you need to think about two pictures of the night sky. The one that you can see with your naked eye, and the one that you could construct with the aid of a lot of mathematics and astronomical science. That would be a picture of where all those objects are now. They have all moved. Most of the changes would be imperceptible to earth-bound observers without Hubble telescopes, but move they have. Remember many of these objects can move with mind-blowing speed. We're talking about thousands of miles a second. Particularly shock waves from exploding stars.
(To be continued . . .)
I love talking about the universe as we don't see it. Look at the nighttime sky. Looks like a still photograph. But actually it's a peek into a vast time machine. With many things to marvel about.
First, the light that is coming to us from the stars -- actually any meteor, comet, planet, or any other celestial object -- is unique. The rays that hit the retina of our eyes have been traveling for vastly different times. Seconds for sunlight bouncing off the moon, eight minutes for light directly from the sun, Mars and Venus, millions upon millions of years from great galaxies, and even billions of years from galaxies at the edge of the universe. Scientists say that the universe has no edge, so let's say from galaxies we see that were formed within a few hundred million years after the big bang that set it all in motion. There is no other scene in all our existence where we can seen so far back in time -- from seconds to billions of years. It's really a snapshot of the closest thing we'll ever see to eternity.
That's really what we are seeing. Individual rays of light hitting our eyes at the same time, but of vastly, vastly different ages. But we know that most everything we touch or see on this earth ages. Trees grow and die, so do people, mountains are worn down and continents drift.
But as far as we know, those tiny dots of light coming to us from space are exactly the same as they were either seconds ago or billions and billions of years ago. No difference, WE THINK. Or at least no one has any evidence to the contrary. Talk about perpetual motion machines. Light is the closest thing we have to it. After billions of years, you get bored and stop counting. Of course, the intensity of the light rays can be diminished as they pass through clouds of dust and gases in the universe. But the light waves come to us unchanged in their ability to reveal the size, shape chemistry of the star or nebula or galaxy from which they left.
Well, what happens to those tiny rays of light that come to our planet? Some get absorbed into the retina of our eyes. They raise the energy level of the molecules and atoms on our retina, and that is what produces the signal that our bodies have learned to absorb and process to give us a picture of what we think is the outside world.
Other rays bounce off our hats, jackets, skiis or the beach on which we are sitting. And those bounced rays run off in a shower back out into the universe. Probably too weak for any UFO telescope to discern, but they are there, zooming away from us still at a speed of 186,000 miles a second. Remember, it doesn't matter if the rays were produced by an unbelieveably large stellar explosion or from the glint off someone's hair on a Bahama beach. Their speed is not different.
So what, exactly are we seeing? Of course, the pattern of night objects we see at night is just a snapshot of one tiny point in time. The light that started out from a distant galaxy began way before the age of dinosaurs. Some, way at the "edge" of the universe, before the earth itself was formed. But here they all are, arriving at our retinas at the same time. Of course, every star, galaxy, planet and comet out there is no longer where it was when each ray of light from each object started out. Even the moon has moved a little from the point when the reflected rays of the sun bounced off it a mere second ago.
So, if you really want to blow your mind, you need to think about two pictures of the night sky. The one that you can see with your naked eye, and the one that you could construct with the aid of a lot of mathematics and astronomical science. That would be a picture of where all those objects are now. They have all moved. Most of the changes would be imperceptible to earth-bound observers without Hubble telescopes, but move they have. Remember many of these objects can move with mind-blowing speed. We're talking about thousands of miles a second. Particularly shock waves from exploding stars.
(To be continued . . .)
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