Stop the universe, it's leaving us behind (faster-than-light expansion)

Sydney Morning Herald ^ | 3/21/02 | Richard Macey

[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."

[HeadOn]

"Damn it Scottie, I said expound on the universe, not expand it."

Clearly a case of bad Cellular.

[Delbert]

BIG BANG? YOU'VE GOT TO BE KIDDING.

GOD

[Doctor Stochastic]

I need not expand into anything. It is just expanding.

[VadeRetro]

If you are in a space ship traveling at the speed of light and you turn on the headlights, what happens?

1) The photons, unable to escape, overheat the headlights and melt the cheap plastic mountings.
2) I get another @#$%^&! ticket.
3) I'd already have my lights on. If I get c out of my 6-cylinder Impala, I want people to notice.

[concerned about politics]

Ever wondered what happens if you disturb a black hole? Or when two black holes collide? Strange.

[VadeRetro]

So, if we're going to "boldly go where no man has gone before," we'd better go pretty fast?

[Frapster]

so - if we have some method of knowing that the universe is expanding then I would guess that we have some notion as to the general shape of the universe and it's center? can someone show me a pic of what it looks like? Does it look like a moose with cheeze in the center?

[Salgak]

Actually, it can. The mathematics, formally known as "calculus of infinities", allows it. But in a more practical sense, the Universe as we know it is but a bubble in a sea of "quantum foam". While infinite in span, the bubble STILL grows, stretching the underlying space-time fabric, and increasing the distance between two given point, even if those two points are stationary, relative to each other. Astrophysics is literally mind-blowing stuff. . .

[laotzu]

"admitted they did not have a clue...We don't understand...were debating...universe was to blame...It was a huge surprise...was "shaking his head"...you have to rearrange the mental furniture"

Tell me again about global warming... is the sky really falling?

[HeadOn]

Honest question: How does this relate to the apparent ages of stars, then? If light from 10 billion light years away has the added component of this "faster than light expansion", doesn't that skew the age to younger than 10 billion years?

[longshadow]

C would be the max speed you could travel over the surface of the balloon, but it does not have anything to do with the rate of expansion of the balloon, which is what actually causes the galaxies on its surface to move apart.

You've got it.

The reason for this is that the speed of light limit applies to the movement of matter and transmittal of information; it does NOT apply to spacetime itself (as spacetime, the "fabric" of the Universe, has no mass and isn't "information.")

[r9etb]

Thanks for the ping.

I'm reminded of the fellow who at the beginning of the last century claimed that all of the fundamental discoveries of science had been made and that the rest would be technical improvements and cataloguing the results.

[Theophilus]

"Start" is defined by time, therefore there is no "Start" to time.

[RadioAstronomer]

The problem is you cannot reach the speed of light (much less surpass it). As you approach the speed of light "C" time slows down and mass increases. All of the energy in the universe could not get one single proton to obtain the speed of light. The link will provide a graph of this phenomenon:

http://www.rsgc.on.ca/math/lorenz1.html

[Salgak]

That assumes:

1. That faster-than-light (FTL) implies time travel. The equations, in one interpretation, give a result of negative time. Whatever that means. It may mean time travel, it may not. We need experimental data, and since the rules prohibit going AT the speed of light, it makes it rather difficult to go FTL. . .

2. That the galaxies themselves are moving FTL. They aren't. The underlying space-time is moving at speeds which may be FTL. The relativity equations, and the Lorentz-Fitzgerald contraction, talk about motion IN space-time, not motion OF space-time itself. . .

I know, clear as mud. . . . (g)

[OldFriend]

No doubt Albore can explain this perfectly, since he invented the universe.

[RadioAstronomer]

So, if we're going to "boldly go where no man has gone before," we'd better go pretty fast?

ROFL!!!

[Musketeer]

Upon reading this article I had a sudden sense that we are just an element of God's fireworks display. Just after the initial detonating big bang (oooooohhh!) there is that beautiful spread of bright sparkling color (aaaaaaahhhhh!) which then expands, twinkles, and finally winks out.

Enjoy the view. :)

[concerned about politics]

While infinite in span, the bubble STILL grows, stretching the underlying space-time fabric, and increasing the distance between two given point,

Until it implodes?

[dead]

It's really gonna suck, billions of years from now, when our descendents look up in the night sky and all the stars have moved away.

On the bright side, they'll all be long dead by that time, after the Sun's death throes, so they won't notice.