Posted on 03/20/2002 6:47:11 AM PST by dead
Wave goodbye to the universe. The expansion of the universe, which began about 15 billon years ago with the Big Bang, is mysteriously getting faster, Australian and British astronomers say.
However, they admitted yesterday they did not have a clue what "dark energy" was driving the galaxies to defy gravity and fly apart with ever increasing speed.
"We don't understand the physical process," said Matthew Colless, of the Australian National University.
But, "eventually the universe will accelerate so rapidly the more distant galaxies we can see today will move away faster than the speed of light and will disappear over the horizon."
Expansion faster than light is possible because, not only are galaxies flying apart at extraordinary speeds, but space itself is expanding, carrying the galaxies away with it.
Until 1998 astrophysicists were debating whether gravity was slowing the expansion enough to eventually cause the universe to collapse in a Big Crunch.
That year other astronomers, including Brian Schmidt, of the ANU's Mount Stromlo Observatory, near Canberra, produced the first solid evidence that the expansion was accelerating.
Studying exploding stars, they found that the more distant ones were fainter - and thus further - than seemed possible. They concluded an accelerating universe was to blame.
"It was a huge surprise," Dr Schmidt recalled yesterday. "I was rather scared to go out and tell people. I thought they'd laugh me off the planet."
Dr Colless, one of the first he told, was "shaking his head".
The new project, involving the ANU, the University of NSW, the Anglo-Australian Observatory near Coonabarabran, and British scientists, led by Cambridge Professor George Efstathiou, used a different method to reach the same finding.
They spent five years mapping the position and speed of 220,000 galaxies. They then compared the data with microwave radio charts of other scientists to "map" the universe as it was 150,000 years after the Big Bang - before the first galaxies even lit up. They found that only an accelerating universe would have allowed it to grow to today's size.
"Now we have two independent pieces of evidence that both give exactly the same answer," Dr Colless said. "I didn't believe Brian at first ... you have to rearrange the mental furniture."
While most galaxies would vanish from view, the Milky Way, and its nearest neighbours, glued together by gravity, would travel on alone. Dr Schmidt said the confirmation was "great news for me. I can sleep a little better. It's evidence we didn't screw up four years ago."
I don't think he said that the universe was expanding faster than light now -- just that it might do so.
But, still -- if the "distance" we observe is determined by an assumption that is not true (i.e. constant speed of light, no expanding universe) ... well, seems to me that any correction one would make on the basis of the new evidence would have the effect of making the universe younger than Sagan's "billions and billions of years."
Now, I wonder if anyone will attempt to determine what the rate of increase in the expansion is? Or, having done that, what the result will be when the age of the universe is reckoned on the basis of this data?
hmmm the More important question is how does Cow Flatulence fit into this equation? I think the Cow Flatulence Theory on Global Warming is the most exciting scientific discovery since the "Chia Pet"...
Another interesting question: Who says that expansion (or contraction) has not been occurring at differing speeds over the life of the universe? What was the rate a few hundred years ago before we even understood we could measure it? If this is so, then all of Sagan's bets are off.
Really throws a kink in everything, doesn't it?
IMHO, until we arrive at a better determination of space topology it is too early to attribute the observation to speed faster than light:
Cosmic crystallography looks at the 3-dimensional observed distribution of high redshift sources (e.g. galaxy clusters, quasars) in order to discover repeating patterns in their distribution, much like the repeating patterns of atoms observed in crystals. They showed that "pair separation histograms" are in most cases able to detect a multi- connected topology of space, in the form of spikes clearly standing out above the noise distribution as expected in the simply-connected case. The researchers have particularly studied small universe models, which explain the billions of visible galaxies are repeating images of a smaller number of actual galaxies.
Lay off the lesbian jokes, okay?
This is probably a bad explanation but here goes:
Time (due to due to relativistic time dilation) slows down as objects speed up. Thus even though the universe is expanding, light did indeed leave the object in question 10 billion years ago.
I know that after drinking multiple glasses of "Midwest Screwdrivers" the Universe seems to speed up and then procede to rotate to the right at an ever increasing rate of speed...
Then I wake up the next morning and it seems the Universe is going at a high rate of speed in reverse (which would explain why my eyeballs feel like they are gonna pop out of my head)
All the stars you see in the sky are in our own galaxy. I don't believe there are any naked eye objects outside our galactic cluster.
Ask Dr. Science! He knows! He has a master's degree in science!
I've actually seen Dr. Science perform this very experiment on a PBS special about ten years ago. Extremely funny stuff.
I knew this thread would get around to Nudity if I hung around long enough...
BTW is there any prgress on posting the Figure Skating Nipple picture yet?
Large and Small Magellanic Clouds, M31 (Andromeda Galaxy), and others are all extra-galactic naked-eye objects.
"Whoever pulls this sword from my head will be proclaimed king!"
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.