WASHINGTON (Reuters) - Five teams of astronomers training
their sights on the very nature of the universe reported on
Thursday that it is ``lightweight'' -- not terribly dense -- and
is likely to expand and endure forever.
``With 95 percent confidence, we can say the universe is
going to expand forever,'' researcher Ruth Daly of Princeton
University said at a news briefing where all the teams presented
their findings. The denser the universe, the more likely it is to
reach a limit to expansion and to collapse in on itself. But the
researchers found that the universe has only one-fifth the mass
needed to generate the gravity to cause such an end.
What will happen as the lightweight universe infinitely expands?
``Anything that is gravitationally bound will remain
gravitationally bound,'' Daly said.
But because no new structures will form, ``the stars will
just age and die and everything will turn into a burned and
dirty ember. Finally there will be just a bunch of rocks left
... It will be a rather uninteresting and cold place.''
For now, though, there was a bit of rejoicing among the
astronomers that such cosmological questions could be addressed
based on empirical data rather than on theory.
``For the first time ever, we're going to actually have
data, that you will go to an experimentalist to find out what
the cosmology of the universe is, not to a philosopher,'' said
Saul Perlmutter of the Lawrence Berkeley National Laboratory.
Perlmutter's team collected data on the light from exploded
stars, known as supernovae, to calculate how fast the universe
is expanding.
By knowing the speed of light and the relative dimness or
brightness of each supernova, they could determine how old and
how far away the supernovae were, and hence could estimate the
expansion rate of the universe.
Much of the data on supernovae were collected from
Earth-based telescopes. But the orbiting Hubble Space Telescope
also observed a specific type of supernova that is considered a
reliable indicator of distance because there is a direct link
between their intrinsic brightness and how fast they fade after
they explode.
Other teams used different methods for dealing with the data
from supernovae, and still others tracked the development and
decay of galactic clusters -- the largest known formations in
the universe -- and the energy from radio galaxies, which emit
huge plumes of radio waves that can be picked up by instruments
on Earth.
The five teams also agreed that the universe is probably
about 15 billion years old, a difference from earlier reports
that put the age at as little as 11 billion years. The higher
age estimate would also retire a modern astronomical conundrum
in which the oldest stars were believed to be older than the
universe itself.
^REUTERS@
This interesting article over infobeat imho seems to give the
Tipler scenario of life expanding to the omega point a boost
( life continuing indefinitely into the whole! universe ? )
I've got some extensions to put in ...
I don't know how the scientist came up with the 1/5 mass thing
can anyone out there enlighten us on the link between supernovae
and the possible open/expanding forever universe .... seems
pretty thin ....
I would think it's going to be an accurate mass census of the
universe .... all the dark stuff etc etc ...
Anyhow, if the universe seems to be forever running away ....
one could envisaged 'creating' more mass to slow down the expansion
so that 'we'(posthumans) and our tech can 'catch' up with the
expansion and ultimately populate the entire universe and resulting
in a stable and hyper-intelligent universe ....
Anyone care to comment
Alex Tseng
===
Nothing worth doing is completed in our lifetime;
therefore we must be saved by hope.
Nothing true or beautiful or good makes sense in any immediate
historical context; therefore we must be saved by faith.
Nothing we do, however virtuous, can be accomplished alone;
therefore we are saved by love.
§:-)= galaxy brain * Ø:-) = saturn brain
The value of a man should be seen in what he gives
and not in what he is able to receive.
--Albert Einstein
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