Big Bang Disproven?

[SLD]

http://www.sciencedaily.com/releases/2006/09/060905104549.htm

This isn't a crack pot science site or a creationist site, but i've seen the creationist already taking off on this finding. Apparently there is no shadow in the cosmic microwave background, even though galactic clusters ought to create them. I'm not sure I understand why such clusters would specifically cut through the microwave background. I'd rather imagine they'd be rather transparent to it.

This article first came out last September - has anything new come out to refute it?

SLD

[Jesse]

This article (http://www.space.com/scienceastronomy/060911_mystery_monday.html) says: But Spergel says he seriously doubts the conclusions reached by Lieu's team are correct for a number of reasons. First, WMAP, one of the instruments used by Lieu's team, is not the best instrument for detecting the shadow effect, Spergel said. The shadow effect "occurs on small angular scales predominately, while WMAP is designed to look at large scales across the sky," he said.

Secondly, other astronomers have confirmed the shadow effect in other galaxy clusters using not only WMAP, but also with ground-based radio telescopes, which have higher resolution and are thus better able to spot the effect.

Lieu counters that WMAP's resolution might be a problem for far away galaxy clusters, but points out that the clusters he examined were relatively close by, and certainly close enough for WMAP to see a shadow effect if it existed.

"The WMAP's resolution is not an excuse here," Lieu said.

Afshordi, the Harvard astrophysicist, suggested that a more likely explanation for Lieu's findings is that there is something about galaxy clusters scientists don't yet understand.

"I think that even if Lieu were correct, it would teach us about clusters rather than the Big Bang theory," Afshordi said in a telephone interview. "Clusters are complicated things and there's still a lot to learn about them."

Lieu concedes this is a possibility. "That I do buy," he said. "I myself am not at this point prepared to accept that the CMB is noncosmological and that there was no Big Bang. That would be doomsday."

Lieu said that one unlikely, but possible explanation is that the galaxy clusters he examined are unusually strong emitters of radio waves, which could have prevented the shadows from being seen.

[Caine]

I seem to recall that WMAP was very limited in sensitivity regarding the Sunyaev-Zel'dovich effect. There are at least two new arrays that will study the CMB in more detail using the SZ effect to find new galactic clusters. Certainly the title of this thread is nonsense anyway.

Incidentally sciencedaily may not be a crackpot site, but many of the articles are pretty poor.

[Jay GW]

can anyone here address these points:

# It is now known that, while almost all observed galaxies are redshifted, the Doppler interpretation of this shift does not provide a reliable measure of velocity or (indirectly) of distance.

# Quasars, whose high redshift would place them at the outer edges of the visible universe, are in fact physically and energetically linked to nearby low-redshift active galaxies.

# The most distant galaxies in the Hubble Deep Field show insufficient evidence of evolution, with some of them apparently having higher redshifts (z = 6-7) than the faintest quasars.

# The ages of globular clusters appear older than the universe.

# The average luminosity of quasars must decrease with time in just the right way so that their mean apparent brightness is the same at all redshifts, which is exceedingly unlikely.

-

[premjan]

Maybe different parts of the universe are expanding at different rates. And the quasars could be red-shifted due to gravity (black holes).

[Canard DuJour]

I feel confident to make a falsifiable prediction : This will later be called "compelling evidence" of super-dooper-fastasfuck expansion ("even faster than anyone imagined !") dark energy repulsive gravity or similar completely theoretical phenomenon.

[robto]

can anyone here address these points:

# It is now known that, while almost all observed galaxies are redshifted, the Doppler interpretation of this shift does not provide a reliable measure of velocity or (indirectly) of distance.
False. Redshift is the main method of finding distance for distant galaxies and quasars.

# Quasars, whose high redshift would place them at the outer edges of the visible universe, are in fact physically and energetically linked to nearby low-redshift active galaxies.

False. This claim has been pretty much disproven. Only a few astrophysicists doubt that redishift provides a reliable indicator of distance for quasars.

# The most distant galaxies in the Hubble Deep Field show insufficient evidence of evolution, with some of them apparently having higher redshifts (z = 6-7) than the faintest quasars.

Galaxy evolution is still poorly understood. The existence of fully formed galaxies at high redshift was surprising. It is is one of those surprises that helps drive better understanding of early universe processes by constraining the theoretical models.

# The ages of globular clusters appear older than the universe.

Don't know anything about this one. Can you cite a reference?

# The average luminosity of quasars must decrease with time in just the right way so that their mean apparent brightness is the same at all redshifts, which is exceedingly unlikely.

-
Don't know anything about this one either, but I don't see why said property is "exceedingly unlikely." Maybe the physical process that causes a quasar has an intrinsic brightness? We know this is true for other astrophysical phenomena: supernovas and certain types of stars.

[Jesse]

# The average luminosity of quasars must decrease with time in just the right way so that their mean apparent brightness is the same at all redshifts, which is exceedingly unlikely. Don't know anything about this one either, but I don't see why said property is "exceedingly unlikely." Maybe the physical process that causes a quasar has an intrinsic brightness? We know this is true for other astrophysical phenomena: supernovas and certain types of stars. Jay was saying they all have the same apparent brightness, not the same intrinsic brightness--if his claim was true, their intrinsic brightness would have to increase at greater redshifts, by just the right amount to keep apparent brightness constant. I'm very skeptical of this claim, though--can you provide a reference, Jay?

[Jesse]

# The most distant galaxies in the Hubble Deep Field show insufficient evidence of evolution, with some of them apparently having higher redshifts (z = 6-7) than the faintest quasars.Galaxy evolution is still poorly understood. The existence of fully formed galaxies at high redshift was surprising. It is is one of those surprises that helps drive better understanding of early universe processes by constraining the theoretical models. From what I've read, supercomputer simulations of structure formation in the early universe (which use the same ratio of matter/dark matter/dark energy that scientists inferred from WMAP measurements of the cosmic microwave background radiation (http://map.gsfc.nasa.gov/m_mm/mr_limits.html)) now show pretty good agreement with observation. For example, the simulation described in this article (http://physicsweb.org/articles/news/10/3/22) did show galaxies forming quite early: Using the "Earth Simulator" supercomputer in Japan, which is also used for climate modelling and simulating seismic activity, Masao Mori of the University of California at Los Angeles and Masayuki Umemura at the University of Tsukuba have calculated how galaxies evolved from just 300 million years after the Big bang to the present day. The results show that galaxies may have evolved much faster than currently believed (Nature 440 644).

...

Mori and Masayuki set up the initial conditions in their simulation based on a cold dark matter universe, the parameters of which are determined by measurements of the cosmic microwave background. These observations, first made in 2003, show that we are living in a flat universe comprising just 4% ordinary matter, 22% dark matter and 74% dark energy -- in agreement with the standard model of cosmology. The researchers then directly compared their numerical results with observations of primitive galaxies called Lyman-alpha emitters and "Lyman break" galaxies, which astronomers find in the most distant and therefore oldest parts of the universe.

The results show that the primordial bubbles of gas that formed in the early universe just 300 millions years after the Big Bang do indeed look like Lyman-alpha emitters. After about 1 billion years, the simulations show that these galaxies mutate into Lyman break galaxies. Finally, after 10 billion years of evolution, the structures resemble present-day elliptical galaxies.

The simulation also predicts the mixture of chemical elements in the galaxy at each stage of its evolution, and suggests that our Milky Way has roughly the same composition today as it did when it was just 1 billion years old. Until now, galaxies were thought to have evolved gradually and become enriched in heavier elements beyond hydrogen and helium over a period of 10 billion years by repeated star formation and supernova explosions.

"Our finding shows that galaxy formation proceeded much faster and that a large amount of heavy elements were produced in galaxies in just 1 billion years," says Mori. Also see the Millennium simulation (http://www.sciencenews.org/articles/20050813/bob9.asp) done in 2005, which had very good agreement with astronomical observations. # The ages of globular clusters appear older than the universe. Don't know anything about this one. Can you cite a reference? This is an outdated claim, based on estimates of the age of the universe which have been superceded by more recent estimates such as the one based on the WMAP results (http://www.space.com/scienceastronomy/map_discovery_030211.html) (this estimate says the Big Bang happened about 13.7 billion years ago). This article (http://www.space.com/scienceastronomy/060418_star_clusters.html) says: Globular clusters were also an early tip-off to astronomers that their estimates of the age of the universe were off.

Calculations based on early estimates of the Hubble Constant suggested the universe was only about 10 billion years old, but some globular clusters appeared to be between 12 to 15 billion years old.

"Globular clusters are old and give us a limit on the age of the universe," Pryor said. "The universe couldn't be younger than the oldest star cluster."