Saturday, September 18, 2010

Baryon Acoustic Oscillations are NOT 'Redshift Quantization'

I recently received this in my email, apparently in response to the redshift quantization article on my main site (William Tifft's Quantized Redshifts).
Re: Tifft's Quantized Redshifts article

How does one deal with the fact that more recent observations have confirmed and extended Tifft's original findings, even some studies by his initial detractors? Recent reports from Daniel J. Eisenstein and his collaborators have shown evidence of the baryon acoustic oscillations in the distribution of galaxies, in data from the SDSS and 2dF surveys. And they, as well as others, are planning even more extensive studies of this phenomenon with the next generation of telescopes and spectrographs.
Some Young Earth Creationists, as well as Electric Universe supporters argue that the alleged  redshift quantizations are real.

Here's the original story link from the Sloan Digital Sky Survey (SDSS) from 2005.  The lead author of the paper, Daniel Eisenstein, also has a web page concerning the discovery.

The main error the email author makes is the assumption that the 'baryon acoustic oscillations' mentioned in the article correspond to 'redshift quantization'.  A simple search can help clarify (wikipedia: Baryon Acoustic Oscillations).

All oscillations are not equivalent.  Baryon acoustic oscillations are seen in the cosmic microwave background radiation and are part of the evidence of the correctness of Big Bang cosmology.  There is a pretty good description of this on Eisenstein's site which graphically plots the evolution of this enhancement by plotting the power spectrum as the universe expands.

The bottom line is that the deviations from a uniform blackbody spectrum observed in the cosmic microwave background (CMB), represent density enhancements in the plasma at the time electrons and protons are binding to form hydrogen atoms.  We expect these density enhancements to provide the 'seeds' of enhanced gravity from which larger cosmological structures will collapse and eventually form clusters of galaxies, galaxies, and stars.  Therefore, we expect this enhancement visible in the CMB to leave an 'imprint' in the distribution of galaxies which we can observe today.

Note that the baryon acoustic peak is a broad peak in the power spectrum, corresponding to a wide range of frequencies, therefore a broad range of time, and therefore distance.  Eisenstein reports this scale of distance in on the order of 500 million light-years (the distance between here and the Andromeda galaxy is about 2.2 million light-years).  Clearly the oscillation does not represent that galaxies are only spaced every 500 million light-years, but there distribution of galaxies which is enhanced at those separation scales.  Not a very effective 'quantization', which requires a very narrow frequency peak.

In regards to William Tifft's work, Tifft claimed a very narrow frequency for his quantization, originally 220 km/sec, though later papers reported significantly different values.  The claim was galaxies only existed on 'shell's with this spacing.  Using the latest determined value of the Hubble constant of 72 km/s per million parsecs (about 22 km/s per million light-years), this corresponds to a galaxy 'shell' spacing of about 220 km/s / (22 km/s/mly) = 10 million light-years.  This is smaller than the spacing of the acoustic peak by a factor of 50!  Clearly the acoustic oscillation does not correspond to Tifft's 'quantization'.

I've added more information about redshift quantization on my blog, incorporating newer results, as well as discussing some of the errors that researchers make in using the power spectral density:


Anonymous said...

I have never seen someone with such a bad case of denial. Now it's just sad.

W.T."Tom" Bridgman said...

To Anonymous,

Considering that you have provided nothing to refute the FACTS I have presented on power spectra used to identify redshift 'quantization' or BAOs, I can't really regard this as a credible criticism.

For more info on power spectra, see my series of posts on redshift quantization.