Hellsheep

That's not only some interesting thought, it can cause serious problems. Fighter-pilots (USAF, RAF....) "fly in the past", as they say, that's when they fly at low attitude and high speed, because they're already behind a hill before they even recognize that they see it. Must be a scary job...

Maryjane

I thought I had this one posted last night? Maybe I did go in a time loop or something.

Vestiges of Big Bang Waves Are Reported

January 12, 2005
By KENNETH CHANG





SAN DIEGO, Jan. 11 - Astronomers reported on Tuesday that they had convincingly seen, in the patterns of galaxies scattered across the night sky, the vestiges of sound waves that rumbled through the universe after the Big Bang.

Stars and galaxies tended to form along the ripples of the sound waves where matter was slightly denser, and the pull of gravity was slightly stronger. The ripples preserve a picture of the universe when it was only about one million years old and fit well with astronomers' ideas of how the universe, which started smooth and uniform, became lumpy with stars, gas clouds and other celestial objects. Two teams of researchers analyzing the locations of
thousands of galaxies from two sections of the sky reported similar findings on the sound waves at a meeting of the American Astronomical Society here.

Earlier research had found signs of the ripples, but "we regard this as smoking-gun evidence," said Dr. Daniel Eisenstein of the University of Arizona, lead investigator of one of the teams.

"The important picture we have of the universe is hanging together amazingly well," said Dr. Martin Rees, a professor of cosmology and astrophysics at Cambridge University, who was not involved with either team. "The standard picture is firming up."

According to that picture, matter was evenly distributed in all directions for the first instant after the Big Bang. But then burbling caused by the physics of quantum mechanics created slight imperfections, clumps that were
slightly denser with ordinary matter, as well as dark matter, the unknown material that accounts for most of the mass in the universe.

Just as ripples spread out from a pebble dropped in a pond, sound waves spread out from the dense clumps, traveling about half the speed of light through the hot gas made of matter, which is composed of electrons and protons, and of photons, or particles of light.

About 400,000 years after the Big Bang, the universe cooled enough that the charged electrons and protons combined to form hydrogen atoms, which allowed most of the photons to escape the hot gas. Several years ago, astronomers detected the sound waves etched by the photons.

The sound waves continued to spread for an additional 600,000 years, and when the last remaining photons escaped,
the waves stopped, roughly 500,000 light-years from the dense clumps that produced them. When stars began to form, they tended to form around either the pebble-like clumps of dark matter or along the ripples.

As the universe has expanded in the 13.7 billion years since then, the typical distance between ripple and clump has stretched to 500 million light-years.

The new research shows the matter component of the early sound waves. Galaxies in the present universe are more likely to be 500 million light-years apart than other distances, Dr. Eisenstein said. One light-year is the
distance light travels in one year, or 6 trillion miles. The pictures do not show sharply delineated ripples, because the ripples were small and many overlapping ripples emanated from many different clumps.

"It's a much more subtle effect than that," Dr. Eisenstein said. "It's like you've taken a handful of gravel and thrown them in a pond."

Dr. Eisenstein and his colleagues used information from the Sloan Digital Sky Survey, which is mapping galaxies with a telescope in New Mexico.

The other team used data from a project called the 2dF Galaxy Redshift Survey that is scanning the sky with a
telescope in Australia.

The research has also refined estimates on the amount of matter - 18 percent of matter is ordinary matter that makes up stars and planets, and the remaining 82 percent is dark matter. And it offers further evidence that the geometry of the universe is perfectly flat, where the angles of all triangles always add up to 180 degrees.

"It's more than confirmation of what we already knew from the microwave background," said Dr. Richard S. Ellis, a professor of astronomy at the California Institute of Technology and a member of the 2dF team.

As the astronomers look farther away and further back in time, the size of the ripples will decrease in size. The ripples could serve as a convenient yardstick to track the history of the universe's expansion. That could shed light on dark energy, a mysterious force discovered in the past few years that, at cosmological distances, is stronger than gravity and is causing the expansion of the universe to accelerate.

http://www.nytimes.com/2005/01/12/science/space/12cosmos.html?ex=1106554830&ei=1&en=9e197f71a0dd07 8f

Neil040

Interesting stuff MaryJane..... shall absorb that and see if it makes any sense to me...

The thing that still gets me about the big bang.. (well amongst the other things I have mentioned already)... is that unless you combine it with a cycle of big bang... expansion... contraction... big bang... etc and for ever... you still end up with an almost supernatural event not that much different from the logic of those who believe in a god creator..

Which leaves you with the simple question.. so who made god then? Or in the big bang theory.. so what the hell was there before? And if there was nothing why in fooks name would it suddenly do the bang thing? And anyway... how CAN there be nothing? Makes no sense whatsover.. nothing in itself would have to BE somewhere! lol

Maryjane

Maryjane

Sumatra earthquake update

Science: Quake's Echo Raised Surface Around Globe

January 13, 2005
By WILLIAM J. BROAD





New studies of the giant earthquake that produced devastating tsunamis in the Indian Ocean show that its shock waves ricocheted around the globe for hours and lifted the earth's surface nearly an inch even half a world
away.

"They're like ripples in a pond," Dr. Richard C. Aster, a geophysicist at the New Mexico Institute of Mining and Technology, said yesterday. "But the pond is a sphere, so they keep going around and around."

Dr. Aster, who compiled seismograms to measure the shock waves at increasing distances from the quake's epicenter, said the waves were 1,000 times the size of those that seismologists customarily measure.

The colossal jolt struck Dec. 26 off the west coast of northern Sumatra, and the shock waves radiated out through the earth's rocky interior, traveling faster than waves do in air or water. Dr. Aster used data gathered by a global network of seismometers run by the Incorporated Research Institutions for Seismology, or IRIS, a consortium based in Washington that is financed mainly by the National Science Foundation. IRIS has nearly 150 member institutions at universities in the United States and abroad.

The closest readings came from the Australian Cocos Islands, south of Sumatra, and Sri Lanka, and the farthest from Ecuador. The seismic data show the waves traveling around the earth for six hours.

Dr. Aster said that even in Ecuador, the shock wave displaced the earth's surface more than two centimeters, or nearly an inch, but the movement was too slow to be perceptible to humans. The jolt was much sharper in
Pallekele, Sri Lanka, and shook the ground over a range of nearly four inches, he said.

Waves from the quake weakened as they bounced around the globe but were still discernible after making a complete loop. The seismogram from Tristan da Cunha, a group of British islands in the South Atlantic, shows the main wave arriving after a little more than an hour, then two smaller ones that circled the earth in two directions arriving after about 120 minutes and 230 minutes.

Sirathiel

So there are still people around not using the metric system. Beats me.

To get back to a topic discussed here a short while ago:
I just wanted to say that I know Earth is believed to be very lucky in being full of life. But I instantly thought: Who says that there aren't other forms of life possible? But I'm too late with that idea since it has already been mentioned. *shrugs* But I support it wholeheartedly!

Neil040

There are indeed Sirathiel! I for one use both! Feet and inches are still handy measurements.. metric better for precision but feet and inches for rough work.. having done a lot of building work I tend to use both.. so do many builders.. for example plasterboard here is sold in eight foot by 1600mm sizes.. lol

And a pint is a better size for beer! A litre too big.. half a litre too small..

And there is more! The french dont use metric for wine cases do they? nope.. ten per case does not work out.. has to be twelve... and we dont yet have anyone suggesting a 20 hour day either! Still have quarters and halves..

There.. my work is done...

Leto

We do what we want. we invented it. And for wine it's usually 6 bottles in a case. 12 is for oysters.

ommigosh

Someone once told me that the French once tried a 10 day week but it didn't catch on - don't know if they were pulling my leg or not. Any one else heard of it?

Maryjane