Posted on 03/12/2002 12:01:15 PM PST by RightWhale
Universe Frozen in Time
by Liesbeth de Bakker of our Science Unit, 12 March 2002
You'd better take a good look while you can, because the Universe is going to disappear! As space ages and expands, fewer and fewer galaxies will be visible to us. Even weirder, as we watch these galaxies fade, their appearance will freeze in time. No matter how long we watch , like celluloid heroes in the cinema they will never grow older or change. They will only grow dimmer as they recede from us.
For decades the fate of the Universe was a favourite topic of study for many a distinguished astronomer. There were two main lines of thought. Either the universe would keep on expanding, as it had done for 14 billion years since its ‘Big Bang' birth, or one day gravity would pull all stars and galaxies back together again in a life-ending crunch. It's only recently that consensus was reached thanks to new technology and data: Universal expansion will go on with ever increasing speed.
Bathroom Brilliance
Inspired by these revelations, Avi Loeb - a professor of astronomy at Harvard University in the USA - was thinking about the consequences one morning in his bathroom. "What will people see, looking at the sky billions of years from now?", he wondered. "So I went into my office and did some calculations. They took a day or two but I came up with some very interesting results."
Arrested Development
"50 to 100 billion years from now the universe will be a dark and lonely place," surmises Avi Loeb. We can only see a star if its light can reach us here on Earth. But if the universe is expanding at an ever increasing speed, then one day distant galaxies will be travelling away from us faster than the speed of light - a rare exception to the rule that nothing can go faster than light. When this happens, the light emitted by such galaxies will no longer be able to reach the Earth. "We will see how a star or galaxy develops up to that point," explains Professor Loeb, "and afterwards the source of light will be frozen in time."
Outlook for Astronomy
This has implications for our study of the distant Universe because the amount of information available to us is finite. So not only will the number of visible galaxies gradually shrink, we will also be unable to watch their evolution later in their history. Therefore Prof. Loeb thinks that astronomers should concentrate on the outer reaches of the universe now, rather than focus on what's relatively nearby . "The further away the source, the quicker it'll be gone," he says. "As a matter of fact, if we sent out a signal now, it would not be able to reach some sources that are already outside our reach. So if there are extraterrestrial communities out there, some of them will already be out of contact with us."
Promising Future
Isn't it silly though, to worry about a Universe that will be ‘frozen' in 50 billion years' time, when our own Sun will die much sooner, possibly taking the human race with it? Avi Loeb isn't fazed by such facts. "By that time", he muses, "newer stars will dominate our galaxy. We could venture out and find a new world. Our science is still young. Look at what we have achieved in just 100 years. If we can protect ourselves against destructive forces within our society, I can imagine us doing lots of very unusual things."
This is important because . . .
The Professor is teaching at Harvard and is being reported in Europe. Give serious thought to sending your children to Princeton.
Since, with the naked eye, we can't see much beyond our galaxy, this scenario is untrue. The
local group and our galaxy itself are gravitationally bound and are not flying apart. Except for
heading into the Great Attractor, which may gobble us up by then anyway.
...distant galaxies will
be travelling away from us faster than the speed of light -
a rare exception to the rule that nothing can go faster than light.
They aren't travelling at the speed of light. They are sitting there.
What is happening is that space is expanding between us. And
space expansion is not limited to the speed of light.
I don't think I know more than a professor of astronomy,
so put this down to dumb reportage. :)
The FOOLS!! They LAUGHED at my theories!!! They CALLED ME MAD!!!! But when I DESTROY THE UNIVERSE, THEY WON'T BE LAUGHING THEN!!!!
When it all dies out, laughter will be the sole source of energy.
"The universe is going to collapse in a billion years!"
"What? Omigod, omigod."
"What are you moaning about. You won't be here in a billion years, anyway?"
"A billion? Whew. Never mind. I thought you said a MILLION!"
Definitely worthy repeating. ;-0
He must have thought this one up after flushing. No wonder he's a professor....
Az
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