Age of universe vs. age of stars

There was some dispute not too many years ago about the age of the universe
based on observations about expansion rate of the universe vs. the age of
the oldest stars known within our own galaxy (or possibly within other
galaxies too). Specifically based on expansion rates, the universe should be
around 15 billion yo, whereas based on the oldest stars the universe should
be at least 20 billions yo. Has that dispute been resolved? I presume one
party or the other has been proven wrong, or backed down on their assertion?

Also if this debate hasn't been settled, it is possible that they are both
right in a sense? What I mean is, is it possible that the oldest starts can
be over 20bn yo, but the edge of the _observable_ universe only goes back
15bn years? That is to say that there is a larger universe out there that is
expanding away from the rest of us at speeds greater than the speed of
light, therefore light from there would never get a chance to catch up to
us? The reason I say faster than the speed of light is because General
Relativity prevents matter or energy from travelling faster than light
within space, but it puts no speed limit on the rate of expansion of space
and time itself.

Yousuf Khan

There were two groups studying Supernova to refine the Hubble
(in)Constant and how far away galaxies are and their rate of change.
Everyone was expecting the universe to be expanding at a slower rate as
time passed by. But both groups kept studying and studying and
studying, long after other groups expected them to publish. Finally one
group published, and the other group quickly confirmed, the results of
their studys.

Exactly the opposite of everyones expectations. After the initial big
bang, the furthermost galaxies slowed their expansion, then started
increasing their expansion rate, which is still increasing. So, instead
of just looking for dark matter to hold galaxies together, people are
looking for dark energy that pushes the galaxies apart. And these
revised ages make the universe barely older than the oldest stars.

Einstein first proposed a cosmological constant to keept the galaxies
from collapsing fullfill the expectation of a steady state universe. He
withdrew that part when Hubble published that the galaxies were
expanding. Now it is back and at a stronger level than before, enough
to force the galaxies apart faster and faster.

Yousuf Khan wrote:

There was some dispute not too many years ago about the age of the universe
based on observations about expansion rate of the universe vs. the age of
the oldest stars known within our own galaxy (or possibly within other
galaxies too). Specifically based on expansion rates, the universe should be
around 15 billion yo, whereas based on the oldest stars the universe should
be at least 20 billions yo. Has that dispute been resolved? I presume one
party or the other has been proven wrong, or backed down on their assertion?

Also if this debate hasn't been settled, it is possible that they are both
right in a sense? What I mean is, is it possible that the oldest starts can
be over 20bn yo, but the edge of the _observable_ universe only goes back
15bn years? That is to say that there is a larger universe out there that is
expanding away from the rest of us at speeds greater than the speed of
light, therefore light from there would never get a chance to catch up to
us? The reason I say faster than the speed of light is because General
Relativity prevents matter or energy from travelling faster than light
within space, but it puts no speed limit on the rate of expansion of space
and time itself.

Yousuf Khan

Yousuf Khan wrote:
There was some dispute not too many years ago about the age of the universe
based on observations about expansion rate of the universe vs. the age of
the oldest stars known within our own galaxy (or possibly within other
galaxies too). Specifically based on expansion rates, the universe should be
around 15 billion yo, whereas based on the oldest stars the universe should
be at least 20 billions yo. Has that dispute been resolved? I presume one
party or the other has been proven wrong, or backed down on their assertion?

Most of this apparent discrepancy was clarified as a result of the Hipparcos
satellite recalibrations of the Cepheids and redetermination of the distances to
globular clusters. The clusters are now not as old as they once were thought to
be and the results of WMAP seem to point to an age of about 13.7 billion years
with error bars on the order of 10%, if memory serves.

For those interested in this finding that didn't make as much headlines as the
apparent discrepancy did - media feed on controversy/sensationalism, not on fact
finding - you might check out the Hipparcos web site:
http://astro.estec.esa.nl/Hipparcos/hipparcos.html

"Mike Schwab" wrote in message
...
There were two groups studying Supernova to refine the Hubble
(in)Constant and how far away galaxies are and their rate of change.
Everyone was expecting the universe to be expanding at a slower rate as
time passed by. But both groups kept studying and studying and
studying, long after other groups expected them to publish. Finally one
group published, and the other group quickly confirmed, the results of
their studys.

Exactly the opposite of everyones expectations. After the initial big
bang, the furthermost galaxies slowed their expansion, then started
increasing their expansion rate, which is still increasing. So, instead
of just looking for dark matter to hold galaxies together, people are
looking for dark energy that pushes the galaxies apart. And these
revised ages make the universe barely older than the oldest stars.

But weren't the oldest stars supposed to be in the 20 billion year range,
while the universe was supposed to be in the 12-15 billion year range? Has
the date of the oldest stars been revised downwards to make them younger?

Yousuf Khan

"J. Scott Miller" wrote in message
...
For those interested in this finding that didn't make as much headlines as
the
apparent discrepancy did - media feed on controversy/sensationalism, not
on fact
finding - you might check out the Hipparcos web site:
http://astro.estec.esa.nl/Hipparcos/hipparcos.html

Ah, good, that's what I wanted to know. Specifically this article:

http://sci.esa.int/science-e/www/obj...odylongid=1033

Yousuf Khan