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roland1996@googlemail.com
2006-Jan-18, 05:18 PM
After the discovery of galaxy HUDF-JD2, Sept.2005, is the big bang theory about to be revised?

Fortunate
2006-Jan-18, 05:40 PM
No.

01101001
2006-Jan-18, 05:45 PM
For those, like me, who didn't immediately recognize the galaxy in question:

NASA press release: NASA Finds 'Big Baby' Galaxies in Newborn Universe (http://www.jpl.nasa.gov/news/news.cfm?release=2005-156)


While astronomers generally believe most galaxies were built piecewise by mergers of smaller galaxies, the discovery of this object suggests at least a few galaxies formed quickly long ago. For such a large galaxy, this would have been a tremendously explosive event of star birth.

roland1996@googlemail.com
2006-Jan-18, 05:56 PM
This galaxy was formed in eight hundred million years we are told. Is this really possible

Cougar
2006-Jan-18, 06:08 PM
This galaxy was formed in eight hundred million years we are told. Is this really possiblePersonally, I could get a few things done in 800 million years. Can you conceive how long that is?

01101001
2006-Jan-18, 06:14 PM
The forum Search (http://www.bautforum.com/search.php) function will lead you to some previous discussions of HUDF-JD2, for instance:

Distant Galaxy is Too Massive For Current Theories (http://www.bautforum.com/showthread.php?t=32995)
Big Bang Busted? (http://www.bautforum.com/showthread.php?t=13803)
A BB Puzzle (http://www.bautforum.com/showthread.php?t=18013)

There are plenty more.

pasha582
2006-Jan-18, 10:22 PM
Not likely. There is a 25% probability this galaxy is a billion light years closer than originally measured. In addition, such anomalies are expected--the big surprise is that it was discovered in such a small sample size (IF the distance measurement is correct).

We will learn more as time goes on. The big bang has undergone significant change since it was first introduced--dark energy, hyperinflation, reintroduction of the cosmological constant. It is likely to undergo much more revision in the decades ahead. But some conclusions are on pretty solid ground. 13.7 billion years in age. Expanding. These things are extremely unlikely to be overturned.

Fortunate
2006-Jan-18, 11:03 PM
According to my understanding, the big bang theory is very minimal , simply stating that at one point the universe was extremely dense and that it has been expanding since then. If the new telescopes find objects at increasingly large distances - 14 billion light years, 15 billion light years, etc. - the BBT will eventually become untenable. If, on the other hand, we observe that there are no objects past a certain point (when our telescopes become clearly capable of seeing objects farther away than that), then the BBT will become even more difficult to deny.

Nereid
2006-Jan-19, 12:36 AM
BAUT members, let's keep this in perspective shall we?

First, it's just a single object.

Second, as this paper makes clear (http://arxiv.org/PS_cache/astro-ph/pdf/0509/0509768.pdf), the redshift (and hence distance) is estimated photometrically, from its colours (and esp the dropouts) ... despite using lots of time of the biggest telescopes we have, here on Earth, none of these folk could get a spectrum!

Of course it's tremendously exciting, but the path from the detection of a handful of photons (and the non-detection of a great many more) to a secure characterisation of the object is steep indeed.

roland1996@googlemail.com
2006-Jan-19, 10:56 AM
Thank you Fortunate. I await the launch of JWST inJune 2013. After more than fifty years of reflection on this perhaps JWST will show us some objects at 15 billion light years plus. If as you say we observe that there are no objects past a certain point the BBT will be more difficult to deny. This latter result I believe is improbable. We must patiently wait.

Nereid
2006-Jan-19, 02:16 PM
Thank you Fortunate. I await the launch of JWST inJune 2013. After more than fifty years of reflection on this perhaps JWST will show us some objects at 15 billion light years plus. If as you say we observe that there are no objects past a certain point the BBT will be more difficult to deny. This latter result I believe is improbable. We must patiently wait.Personally, I'd rather roll up my sleeves and see what good research can be done to test the theories (there is no one 'big bang theory'), with today's telescopes (etc), and especially try to find independent ways of testing concordance cosmology.

For starters, there are TB (terabytes) of high quality astronomical data, available for free, that anyone can do research on, much of which likely has cosmological model implications - SDSS, 2dF, HUDF, GOODS, WMAP, ...

Further, you can see, by reading the literature, that that's exactly what folk have been doing (look for example at the authors of papers analysing the CMB, esp the recent ones about low l anomalies - few are from the WMAP team, or even in the same institutions).

Fortunate
2006-Jan-19, 11:32 PM
For starters, there are TB (terabytes) of high quality astronomical data, available for free, that anyone can do research on, much of which likely has cosmological model implications - SDSS, 2dF, HUDF, GOODS, WMAP, ...

Further, you can see, by reading the literature, that that's exactly what folk have been doing (look for example at the authors of papers analysing the CMB, esp the recent ones about low l anomalies - few are from the WMAP team, or even in the same institutions).

Very good point. Probably lots of major findings accessible to anyone clever or lucky enough to look in the right place.

Nereid
2006-Jan-20, 08:15 AM
I'm in the slow class this week ... roland1996, you don't even have to take an active role in order to make a contribution to modern cosmology ... why not join the BAUT Einstein@home team (http://www.bautforum.com/showthread.php?t=33847), and contribute the unused cycles of your PC to testing GR, which is the foundation of modern cosmology! :)