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NASA: Evidence Favors Infinitely Expanding Universe
Chris Gondek writes "The Sydney Morning Herald has a story here about how NASA is expected to announce this week that it has proved the existence of "dark energy," a cosmic force that counteracts gravity and will keep the universe expanding forever. The announcement will effectively demolish the theory that life will be wiped out in a "big crunch" when the universe collapses, and should end decades of academic dispute. Scientists ranging from Stephen Hawking, the Cambridge University physicist, to Albert Einstein, have argued that the universe eventually will stop expanding and then implode under the force of gravity, destroying all life. The Chicago Sun Times has also got some info."
Pretty much what I was going to say. There's only x amount of energy, and if the universe is constanly expanding... OOPS! From one of the articles:
"Although NASA's discovery means the universe will go on forever, the same is not true for human life. As the universe expands, all of its energy will be used up."
You crazy man? You piss off supahfly!
This announcement has been informally known for a few weeks in the physics community. A famous cosmologist (Edward "Rocky" Kolb, FNAL) told us that it was delayed the official announcement after the Columbia tragedy.
"There is no teacher but the enemy."-Mazer Rackham
Check out the Omega Point Theory... in this book. It suggests a way to use the expansion of space to generate energy to run a computer that would contain everyone's' information. Seems plausible, until he mixes its up with religion and it turns metaphysical. This theory has been promoted by Tipler, the same guy who has written many physics text books. I don't but the theory, but it answers your question about an alternate theory...
"There is no teacher but the enemy."-Mazer Rackham
The current Big Bang theory doesn't depend on any oscillatory process in the universe. It explains the universe since 10^-43s after the Bang. before that the String Theorists specullate about the universe, and that is it.
"There is no teacher but the enemy."-Mazer Rackham
My guess is that they are talking about the results from MAP. This is a satellite that was looking at the CMB. Unfortunately, this won't tell us one bit about dark energy. What it tells us about is the total matter-energy budget of the universe. But we've known that the universe is "flat" since COBE (the last satellite to look at the CMB).
The basic way at looking at cosmological parameters is this: CMB tells us about the geometry of the universe (Omega_total = Omega_matter + Omega_energy), clustering tells us about the matter content (Omega_matter), and supernovae tell us about the acceleration of the universe (Omega_matter - Omega_energy).
Only supernovae have given us direct evidence that the universe is accelerating.
If NASA in fact were able to make an accurate measurement of a source of dark energy (seems improbable with today's technology), then the new data could impossibly show anything that isn't already known.
It is already known that the maximum amount of dark energy that *could* exist in the universe stands at an approximate 1 to 10^7 ratio against regular matter (observed universal radio emission compared to gravity, normal distribution). It is also known that energy in space decrements exponentially (law of ripple distribution (eph = md/(e^(1/r)). Therefore, it is possible to calculate a pretty good estimate for how much influence the dark energy has on spacetime. This calculation has been done already! (presented by Brockmeyer in 1999 or 2000)
The thing we *don't know* is whether dark energy is gravitationally reflective, but that's really no more than a minor parameter, and we only need to know it in other contexts (particularly when studying quasars).
Alas, this is (on the time scale of the advancement of astrophysics research) old news. In fact last spring, the ever-expanding Universe and the exsitence of dark energy was the cover story for Time Magazine.
The evidence for an eternally expanding universe and dark energy has been around for a couple of years from:
-Type 1a supernovea of the acceleration of the expansion of the Universe (science magazine story of the year a couple years back)
-Large Scale structure measurements of the mass density of the Universe
-Other CMB experiments of the geometry and mass density of the Universe.
Other CMB measurements to note, which have previously 'announced' this result are:
Archeops: http://arXiv.org/abs/astro-ph/0210306
BOOMERANG: http://arXiv.org/abs/astro-ph/0104460 (Astrophys.J. 571 (2002) 604-614)
CBI: http://arXiv.org/abs/astro-ph/0205387
DASI: http://arXiv.org/abs/astro-ph/0104490 Astrophys.J. 568 (2002) 46-51
MAXIMA: http://arXiv.org/abs/astro-ph/0104459 Astrophys.J. 561 (2001) L1-L6
VSA: http://arXiv.org/abs/astro-ph/0212495
Of course MAP *may* also be announcing other new things tomorrow, which will make it exciting, but the results listed in the posting are not new.
This is the way the world ends
This is the way the world ends
This is the way the world ends
Not with a bang but a whimper.
from "The Hollow Men", TS Eliot.
Attribute your sources!
--Jim
Just picking a nit, but I think you mean "googol", not "google". One is a number, the other is a search engine.
The rate of expansion IS decreasing, the question is will that be enough to cause the crunsh or not because the rate of decrease (second derivitie of velocity) is decreasing as well.
That's the old (early 90's) model. Before the supernova data, we thought that the universe would be decelerating. However, now we're pretty sure that the universe is accelerating, not decelerating.
However, that doesn't mean that the universe won't decelerate later (or didn't decelerate earlier). There are still a lot of questions as to what the dark energy is and all of the accelerating/decelerating depends on what it is.
Google for quintessence. It's beyond my area of expertise.
Regardless of what the dark energy actually is, the universe is accelerating right now.
The human race will cease to exist in the year 2095 AD.
Sorry guys, but just don't waste your time with all this "universe big bang collapse" theory stuff, because in the end no one will be around to give a flying crap.
Hm, I'd say that's more Insightful than Funny - I mean, it is a rather serious metaphysical question if we really are facing a gloomy, dark, cold, lonely end to things, is there some way we can reverse entropy, maybe going beyond pure science and empiricism?
Anybody remember the Asimov short story, name escapes me, with the central computer that answered questions, and from time to time different generations would ask it "How can entropy be reversed?"; every time the answer was "There is as yet insignificant data to compute an answer." Eventually, mankind dies off and leaves this multidimensional hyperspatial uber-computer, which is left with one unanswered question, and it churns away, until the Universe reaches the end, heat death...and this computer finally gets the data, and the answer, and it booms out..."Let There Be Light".
Facts do not cease to exist because they are ignored. - Aldous Huxley