Slashdot Mirror
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."
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.
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.