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Fraser
2009-Sep-16, 02:30 PM
Rats! Another perplexing space mystery solved by science. New analysis of the famous "cold spot" in the cosmic microwave background reveals, and confirms, actually, that the spot is just an artifact of the statistical methods used to find it. That means there is no supervoid lurking in the CMB, and no parallel [...]

More... (http://www.universetoday.com/2009/09/16/what-no-parallel-universe-cosmic-cold-spot-just-data-artifact/)

trinitree88
2009-Sep-16, 06:10 PM
Rats! Another perplexing space mystery solved by science. New analysis of the famous "cold spot" in the cosmic microwave background reveals, and confirms, actually, that the spot is just an artifact of the statistical methods used to find it. That means there is no supervoid lurking in the CMB, and no parallel [...]

More... (http://www.universetoday.com/2009/09/16/what-no-parallel-universe-cosmic-cold-spot-just-data-artifact/)

Fraser. That one goes on the polywater/Nessie/Ogopogo list. pete


polywater see:http://en.wikipedia.org/wiki/Polywater
Nessie see:http://en.wikipedia.org/wiki/Loch_Ness_Monster
Ogopogo see:http://en.wikipedia.org/wiki/Ogopogo

Jerry
2009-Sep-20, 03:13 PM
Curious. The original 'cold spot' was confirmed in the 5 year analysis:

http://www.ingentaconnect.com/content/bsc/mnr/2009/00000396/00000003/art00006

See also:

http://arxiv.org/abs/0704.0908v2


The investigations reported here were conducted independently and originally without knowledge of the McEwen et al. (2007) analysis. However, our work is a posteriori in nature, because we were specifically looking for the properties in the direction of the cold spot.

...These results thus support and quantify the NVSS properties in the specific direction of the cold spot, but should be considered along with the McEwen et al.Similar results are found when using totally independent methods to model and subtract out the foreground emission (Cruz et al. 2006), namely the combined and foreground cleaned Q-V-W map (Bennett et al. 2003) and the weighted internal linear combination analysis (Tegmark et al. 2003).
Completely independent, but also producing the same artifact?

If the coldest spot is a fluke, how now are the other unexpected anisotrophies, warm and cold, found first by COBE and confirmed by WMAP?

I think we better wait for PLANCK to weigh-in...hopefully with results not cross-contaminated with data from the earlier surveys.

01101001
2009-Sep-20, 03:55 PM
News back in May, 2008:

Huge hole in the cosmos disappears (http://www.eurekalert.org/pub_releases/2008-05/ns-hhi051408.php)


But a new analysis casts doubt on Rudnick’s conclusion. The existence of voids is really a matter of interpretation, says Kendrick Smith, an astronomer at the University of Cambridge, whose work with Dragan Huterer of the University of Michigan, Ann Arbor, suggests that Rudnick got it wrong. They plan to submit their paper to the Monthly Notices of the Royal Astronomical Society.

trinitree88
2009-Sep-20, 04:20 PM
That's interesting. An ~one billion light-year wide hole just disappeared in a computer glitch, in a universe a little bigger than an order of magnitude from that....possibly two orders. Yet, the rest of the data measures accurately the temperature of the CMB to a part in a million, we trust. Interesting times these are.

Gigabyte
2009-Sep-20, 04:21 PM
Oh yes, oh yes.

clint
2009-Sep-21, 06:28 AM
Makes you wonder what other discoveries might be just 'statistical errors', too.
A good reminder that one shouldn't take anything for 100% granted before it has been confirmed by at least one different method of analysis.

01101001
2009-Sep-21, 06:44 AM
But give Rudnick, the discoverer, some credit, for suggesting that what he found needed a closer look.

L. Rudnick - Void - FAQ (http://webusers.astro.umn.edu/~larry/void/):


Are there more voids like this?
Probably. Our current surveys of the universe have not yet been of large enough volumes to find voids of this size. First though, it is important that we and other astronomers confirm that the new void is not simply a statistical fluke, and that there are no attractive alternatives to explain the data.

From the published paper, Extragalactic Radio Sources and the WMAP Cold spot (http://homepages.spa.umn.edu/~larry/coldspot.pdf):


A fuller examination of the statistical uncertainties associated with our combination of the
McEwen et al. (2007) wavelet results and our own a posteriori analysis should be performed.
With this caveat, we conclude that the cold spot arises from effects along the line of sight,
and not at the last scattering surface itself.

Jerry
2009-Sep-22, 04:40 AM
http://lanl.arxiv.org/abs/0909.3515v1

19 Sep 2009
The Impact of Secondary non-Gaussianities in the CMB on
Cosmological Parameter Estimation


We consider corrections to the cosmological parameters due to secondary contributions from
weak gravitational lensing, the integrated Sachs-Wolfe effect, and the Sunyaev-Zel’dovich effect contained in the trispectrum. We incorporate these additional contributions to the covariance of a binned angular power spectrum of temperature anisotropy data in the analysis of current and prospective data sets...

For the case of CMBPol, secondary non-Gaussianities lead to parameter biases on the order of 1, as well as parameter degradations up to 30%. We find the weak lensing scaling parameter to be consistent with unity at 1.5. Non-Gaussian effects in the trispectrum push the best fit value even closer to unity. However, given that there is a discrepancy with the expected value, perhaps there is still new physics to be found.

Well, that about clears up everything:{

Gigabyte
2009-Sep-22, 02:19 PM
It's confusing. Which is the ATM today? That there is a huge void, or that there isn't a huge void?

trinitree88
2009-Sep-23, 04:03 PM
The latest mainstream view is that the void is gone as an artifact of processing algorithms. Kind of like the grin from the Chesire cat in Alice in Wonderland, but not quite as funny.:shifty::lol: pete

SEE:http://disney-stationary.com/coloring-book/Alice-Wonderland/Cheshire-Cat-color.jpg

SEE:http://www.cartoonstock.com/directory/c/chesire_cat.asp

Gigabyte
2009-Sep-23, 04:26 PM
I'm still waiting for an answer. If they say there is a void, then saying "I don't believe it" is ATM. If now they say, "There is no giant void", then my saying "I don't believe you" is ATM.

So which is it?

trinitree88
2009-Sep-23, 05:35 PM
Robinson. There is no giant void. Being a non-believer makes you ATM. Me, I'm a big believer, but not in giant voids....pete

01101001
2009-Sep-23, 07:30 PM
The latest mainstream view is that the void is gone as an artifact of processing algorithms.

During what period was the mainstream view that the void certainly existed?

trinitree88
2009-Sep-24, 03:57 PM
During what period was the mainstream view that the void certainly existed?

01. I think post #14 by William, in this thread...SEE:http://www.bautforum.com/astronomy/63827-huge-hole-found-universe.html.followed by your comment there, gave little argument against, and a lot of support to the original supposition. williams references are pretty mainstream, No? pete

Jerry
2009-Sep-25, 05:26 AM
It must be pick on WMAP week:

http://lanl.arxiv.org/abs/0909.4294v1

Revisiting the WMAP – NVSS angular cross correlation. A skeptic view.



When restricting our analyses to multipoles l < 60, we fail to find any evidence for cross correlation in the range l ∈ [2, 10], where according to the model predictions and our simulations ∼ 50% of the S/N is supposed to arise. Also, the accumulated S/N for l < 60 is below 1, far from the theoretical expectation of S/N∼ 5. Part of this disagreement may be caused by an inaccurate modeling of the NVSS source population: as in previous works, we find a level of large scale (l < 70) clustering in the NVSS catalog that seems incompatible with a high redshift population. This large scale clustering excess is unlikely to be caused by contaminants or systematics, since it is independent of flux threshold, and hence present for the brightest, most clearly detected (> 30σ) NVSS sources. Either our NVSS catalogs are not probing the high redshift, large scale gravitational potential wells, or there is a clear mismatch between the ISW component present in WMAP data and theoretical expectations.

Gigabyte
2009-Sep-25, 02:51 PM
You want to explain what that actually means?

01101001
2009-Sep-25, 03:05 PM
01. I think post #14 by William, in this thread...SEE:http://www.bautforum.com/astronomy/6....html.followed by your comment there, gave little argument against, and a lot of support to the original supposition. williams references are pretty mainstream, No? pete

My own feelings, labeled as feelings, should not be confused with sound conclusions. For crying out loud, may I add?


The webpage cannot be found

Probably: BAUT Forum topic: Huge Hole Found in the Universe (http://www.bautforum.com/astronomy/63827-huge-hole-found-universe.html)

"William's mainstream reference" #1:
http://arxiv.org/pdf/0704.0908.pdf

OK. The original:

Extragalactic Radio Sources and the WMAP Cold spot
Lawrence Rudnick, Shea Brown, Liliya R. Williams

From the concluding remarks:

"A fuller examination of the statistical uncertainties associated with our combination of the
McEwen et al. (2007) wavelet results and our own a posteriori analysis should be performed."

The original team wanted more analysis.

"William's mainstream reference" #2:
http://en.wikipedia.org/wiki/Sachs-Wolfe_effect

Wikipedia. Please.

And as quoted in the topic: "A fuller examination of the statistical uncertainties associated with our combination of the McEwen et al. (2007) wavelet results and our own a posteriori analysis should be performed." That sounds familiar.

Don't make me go chasing the support for your belief. Maybe you could directly quote some original mainstream sources that indicated the void certainly existed?


The latest mainstream view is that the void is gone as an artifact of processing algorithms.

Try again. When was the mainstream conclusion that the void certainly existed? What were you trying to establish by your brief history of your perception of mainstream views?

trinitree88
2009-Sep-25, 03:56 PM
My own feelings, labeled as feelings, should not be confused with sound conclusions. For crying out loud, may I add?



Probably: BAUT Forum topic: Huge Hole Found in the Universe (http://www.bautforum.com/astronomy/63827-huge-hole-found-universe.html)

"William's mainstream reference" #1:

OK. The original:

Extragalactic Radio Sources and the WMAP Cold spot
Lawrence Rudnick, Shea Brown, Liliya R. Williams

From the concluding remarks:

"A fuller examination of the statistical uncertainties associated with our combination of the
McEwen et al. (2007) wavelet results and our own a posteriori analysis should be performed."

The original team wanted more analysis.

"William's mainstream reference" #2:

Wikipedia. Please.

And as quoted in the topic: "A fuller examination of the statistical uncertainties associated with our combination of the McEwen et al. (2007) wavelet results and our own a posteriori analysis should be performed." That sounds familiar.

Don't make me go chasing the support for your belief. Maybe you could directly quote some original mainstream sources that indicated the void certainly existed?



Try again. When was the mainstream conclusion that the void certainly existed? What were you trying to establish by your brief history of your perception of mainstream views?

01101001. I'm not trumpeting views from international conferences here....merely pointing out that the paper accepted for Arxiv is an indication that it passes pretty much mainstream peer review for technical competence and exposition. Nothing more. True nitwit science doesn't get that far (as a rule), and getting that far never guarantees that it's true. There remain thousands of old physics articles that are archived, and nobody goes back and highlights the best ones in green, the questionable ones in yellow and the wrong ones in red. Science Citation Index is helpful in recent decades, but it is becoming incresing evident that operating at the statistical limit of certainty of signal to noise ratios is somewhat risky. On the other hand, sometimes that's where the truly interesting stuff lies. Been there: done that. I respect the nerve it takes for a pro to go out on a limb and broker a new view of the universe. It can cost a career.
If you feel I have overstepped my boundaries here, that is not my intent. My intent is to make people think twice before incorporating things into their cosmologies that have no experimental basis in fact in a lab, where we have extraordinary control over variables....something that doesn't happen in the cosmos. Fair enough? pete

matt.o
2009-Sep-25, 10:26 PM
01101001. I'm not trumpeting views from international conferences here....merely pointing out that the paper accepted for Arxiv is an indication that it passes pretty much mainstream peer review for technical competence and exposition. Nothing more. True nitwit science doesn't get that far (as a rule), and getting that far never guarantees that it's true.


Not true at all. ArXiv is a preprint server which has no peer review process. Papers need not be accepted for publication in a journal to be placed on the server. I see many "nitwit science" papers appear on the ArXiv, most of them appear on BAUT at some stage in posts by the usual suspects.



There remain thousands of old physics articles that are archived, and nobody goes back and highlights the best ones in green, the questionable ones in yellow and the wrong ones in red. Science Citation Index is helpful in recent decades, but it is becoming incresing evident that operating at the statistical limit of certainty of signal to noise ratios is somewhat risky.


Citation index does not necessarily verify a papers content. A paper which is wrong can receive many citations.



On the other hand, sometimes that's where the truly interesting stuff lies. Been there: done that. I respect the nerve it takes for a pro to go out on a limb and broker a new view of the universe. It can cost a career.


It will only cost you your career if you doggedly refuse to accept contrary evidence to your ATM hypothesis. In fact, the opposite can be true. Most astronomers/cosmologists would love to make that discovery which goes against GR or lambdaCDM as this can be a truly career enhancing prospect.



If you feel I have overstepped my boundaries here, that is not my intent. My intent is to make people think twice before incorporating things into their cosmologies that have no experimental basis in fact in a lab, where we have extraordinary control over variables....something that doesn't happen in the cosmos. Fair enough? pete

The Universe is a much more diverse laboratory on which we can conduct many experiments designed to test theories outside the laboratory. Besides that, some things just aren't testable here on Earth (try experimenting on the accretion disk around a supermassive black hole in the lab). Why do you think people don't think about things before developing cosmologies?

trinitree88
2009-Sep-27, 10:12 PM
Not true at all. ArXiv is a preprint server which has no peer review process. Papers need not be accepted for publication in a journal to be placed on the server. I see many "nitwit science" papers appear on the ArXiv, most of them appear on BAUT at some stage in posts by the usual suspects.

1. True, they can be seen there, but most of the ones I see in BAUT are in the press stages, or accepted for publication.


Citation index does not necessarily verify a papers content. A paper which is wrong can receive many citations.

2. True, just as a paper which is right can be ignored. Weinberg's best fell like a feather.


It will only cost you your career if you doggedly refuse to accept contrary evidence to your ATM hypothesis. In fact, the opposite can be true. Most astronomers/cosmologists would love to make that discovery which goes against GR or lambdaCDM as this can be a truly career enhancing prospect.

3. Here I disagree. Most of them take the safest route to the next step in funding, rarely stepping out of bounds. Witness the debaucle of money spent on string theory in 20+ years.


The Universe is a much more diverse laboratory on which we can conduct many experiments designed to test theories outside the laboratory. Besides that, some things just aren't testable here on Earth (try experimenting on the accretion disk around a supermassive black hole in the lab). Why do you think people don't think about things before developing cosmologies?

4. Also here I disagree. In the lab you conduct experiments. You control the variables. In the universe you perform observations. It controls the variables, and you try to match up what you think was happening with what happened. ....else I have an experiment for you. Try putting our moon in orbit around Mars and see what effect it has on Deimos and Phobos. No fair using Newtonian mechanics, galactic rotation curves say that ain't true.

pete

matt.o
2009-Sep-27, 10:56 PM
You've screwed up the quotes, but I'll try to decipher your post as best as possible.



1. True, they can be seen there, but most of the ones I see in BAUT are in the press stages, or accepted for publication.


Right, but it must be emphasised that the ArXiv is not peer reviewed.



2. True, just as a paper which is right can be ignored. Weinberg's best fell like a feather.


Yep.



3. Here I disagree. Most of them take the safest route to the next step in funding, rarely stepping out of bounds.

Really? What quantitative evidence do you have for this? Have you sat on funding allocation committees or telescope time allocation committees? What is "the safest route"? From experience, the "safest route" to a career at all is leaving the profession of Astronomy!


Witness the debaucle of money spent on string theory in 20+ years.


What is debaucle? Why shouldn't alternatives like string theory be funded? How else are they to be tested?



4. Also here I disagree. In the lab you conduct experiments. You control the variables. In the universe you perform observations. It controls the variables, and you try to match up what you think was happening with what happened. ....else I have an experiment for you. Try putting our moon in orbit around Mars and see what effect it has on Deimos and Phobos. No fair using Newtonian mechanics, galactic rotation curves say that ain't true.

pete

Why put the Moon into orbit around Mars? We already have a different experiment with different variables (set by the Universe) there to test our theories of gravity.

trinitree88
2009-Sep-28, 10:44 AM
You've screwed up the quotes, but I'll try to decipher your post as best as possible.



Right, but it must be emphasised that the ArXiv is not peer reviewed.



Yep.



Really? What quantitative evidence do you have for this? Have you sat on funding allocation committees or telescope time allocation committees? What is "the safest route"? From experience, the "safest route" to a career at all is leaving the profession of Astronomy!



What is debaucle? Why shouldn't alternatives like string theory be funded? How else are they to be tested?



Why put the Moon into orbit around Mars? We already have a different experiment with different variables (set by the Universe) there to test our theories of gravity.

matto. To the best of my recollection, there is no test of string theory....after 20+ years.

matt.o
2009-Sep-28, 09:20 PM
matto. To the best of my recollection, there is no test of string theory....after 20+ years.

Sure, but the hypothesis needs to be explored and developed. It seems this is a bit of a closed minded view on what should/shouldn't be funded. How is science to progress if alternatives like string theory never get funding?

trinitree88
2009-Sep-30, 11:43 AM
Sure, but the hypothesis needs to be explored and developed. It seems this is a bit of a closed minded view on what should/shouldn't be funded. How is science to progress if alternatives like string theory never get funding?

matt.o Agreed. As an alternative it should be explored. The issue is which fertile venue should be the new money path. String theory has dominated the field for decades with some good mathematical developments but no viable predictions, the true essence of science. It begins to feel like sailors on the ocean looking for the edge of the world with a big roaring waterfall a thousand years ago. pete