PDA

View Full Version : Durham astronomers' doubts about the 'dark side'



EricFD
2010-Jul-23, 09:08 PM
After a year of surveying the CMB, there appears to be a discrepancy in the data provided by the more accurate Plank Space Observatory and WMAP. It is a rather disturbing revelation concerning the distribution of dark matter and dark energy in the universe. It has a professor of astronomy at Durham University in the UK and his graduate student very concerned.

To read more about their concerns here's an article from the Royal Astronomical Society about it: Durham astronomers’ doubts about the 'dark side' (http://www.ras.org.uk/news-and-press/157-news2010/1836-doubts-on-the-dark-side)

Nereid
2010-Jul-24, 03:12 PM
After a year of surveying the CMB, there appears to be a discrepancy in the data provided by the more accurate Plank Space Observatory and WMAP. It is a rather disturbing revelation concerning the distribution of dark matter and dark energy in the universe. It has a professor of astronomy at Durham University in the UK and his graduate student very concerned.

To read more about their concerns here's an article from the Royal Astronomical Society about it: Durham astronomers’ doubts about the 'dark side' (http://www.ras.org.uk/news-and-press/157-news2010/1836-doubts-on-the-dark-side)
arXiv preprint is here (http://arxiv.org/abs/0912.0524).

There have been quite a lot of papers, over the past few years, on the WMAP beam profiles, and how misestimation of them may have influenced the estimates of the cosmological parameters.

One VERY GOOD THING about Planck is that it will, independently, provide estimates of the angular power spectrum. So far as I can see, the single greatest weakness of WMAP is that there are no independent observations of the angular power spectrum, at comparable levels of sensitivity, for l ~< 500.

EricFD
2010-Jul-24, 03:56 PM
arXiv preprint is here (http://arxiv.org/abs/0912.0524).

There have been quite a lot of papers, over the past few years, on the WMAP beam profiles, and how misestimation of them may have influenced the estimates of the cosmological parameters.

One VERY GOOD THING about Planck is that it will, independently, provide estimates of the angular power spectrum. So far as I can see, the single greatest weakness of WMAP is that there are no independent observations of the angular power spectrum, at comparable levels of sensitivity, for l ~< 500.

Thanks for the link to the preprint, Nereid.

The controversy surrounding the WMAP results, from what I've read so far, seems to be centered around the calibration of WMAP's instruments.

I agree that it is a good thing that Planck will provide independent estimates of the angular power spectrum.

Roger E. Moore
2010-Jul-25, 03:45 PM
The controversy surrounding the WMAP results, from what I've read so far, seems to be centered around the calibration of WMAP's instruments.
Isn't this similar (in a broad way) to the issue of Peter van de Kamp thinking he had found planets around Barnard's Star, when in actuality someone had readjusted the telescope slightly when it was cleaned? Bad instrumentation is bad.

Nereid
2010-Jul-25, 05:29 PM
Isn't this similar (in a broad way) to the issue of Peter van de Kamp thinking he had found planets around Barnard's Star, when in actuality someone had readjusted the telescope slightly when it was cleaned? Bad instrumentation is bad.
In reverse.

AFAIK, none of the many, many papers on the WMAP beam profile have been shown to have legs, when more detailed investigations were subsequently done.

That's not to say that the WMAP team hasn't fine-tuned and tweaked their analyses (they have, several times); however, there has been no significant change in the overall conclusions ...

Strange
2010-Jul-25, 05:46 PM
There was another thread (or two) on this recently: http://www.bautforum.com/showthread.php/105005-New-study-quot-Dark-energy-may-not-exist-in-space-quot

EricFD
2010-Jul-27, 05:55 AM
There was another thread (or two) on this recently: http://www.bautforum.com/showthread.php/105005-New-study-quot-Dark-energy-may-not-exist-in-space-quot

Yes, you are correct, Strange. I just checked out the link that you provided to the other thread, and they are indeed talking about the same thing as we are here. Thanks for pointing that out. I was unaware of the other thread until now.