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From: Michael Helland on 7 May 2010 16:14 On May 7, 9:39 am, Sam Wormley <sworml...(a)gmail.com> wrote: > On 5/7/10 7:46 AM, Michael Helland wrote: > > > On May 6, 9:10 pm, Sam Wormley<sworml...(a)gmail.com> wrote: > >>http://www.astro.ucla.edu/~wright/CosmoCalc.html > > > Sam, I will have to say, I am genuinely happy about your response. > > > But these days I'm leaning toward redshift being a function of the > > duration of light's journey from a distant galaxy to our telescopes. > > That has been shown to be wrong How could that possibly be when there is a 1 to 1 relationship between distance and duration light travel's in an expanding Universe? If light can't be redshifted as a function of how long in duration it is traveling, than the Big Bang would be falsified.
From: spudnik on 7 May 2010 16:32 there is no vacuum, a la Pascal's experimental dyscovery (he didn't know about "partial pressure" .-) --Light: A History! http://wlym.com --Stop Waxman's #2 capNtrade rip-off (unless, you like gasoline at a dime per drop)
From: Michael Helland on 7 May 2010 16:48 On May 7, 9:36 am, Sam Wormley <sworml...(a)gmail.com> wrote: > On 5/7/10 7:41 AM, Michael Helland wrote: > > > Tell me this, is the big bang an unquestionable fact, Alan? > > Look at the evidence! > > No Center > http://www.astro.ucla.edu/~wright/nocenter.html > http://www.astro.ucla.edu/~wright/infpoint.html > > Also see Ned Wright's Cosmology Tutorial > http://www.astro.ucla.edu/~wright/cosmolog.htm > http://www.astro.ucla.edu/~wright/cosmology_faq.html > http://www.astro.ucla.edu/~wright/CosmoCalc.html > > WMAP: Foundations of the Big Bang theory > http://map.gsfc.nasa.gov/m_uni.html > > WMAP: Tests of Big Bang Cosmology > http://map.gsfc.nasa.gov/m_uni/uni_101bbtest.html That makes it a good theory, not an unquestionable fact. But the way of science is sometimes a better theory comes along.
From: Sam Wormley on 7 May 2010 17:39 On 5/7/10 3:48 PM, Michael Helland wrote: > On May 7, 9:36 am, Sam Wormley<sworml...(a)gmail.com> wrote: >> On 5/7/10 7:41 AM, Michael Helland wrote: >> >>> Tell me this, is the big bang an unquestionable fact, Alan? >> >> Look at the evidence! >> >> No Center >> http://www.astro.ucla.edu/~wright/nocenter.html >> http://www.astro.ucla.edu/~wright/infpoint.html >> >> Also see Ned Wright's Cosmology Tutorial >> http://www.astro.ucla.edu/~wright/cosmolog.htm >> http://www.astro.ucla.edu/~wright/cosmology_faq.html >> http://www.astro.ucla.edu/~wright/CosmoCalc.html >> >> WMAP: Foundations of the Big Bang theory >> http://map.gsfc.nasa.gov/m_uni.html >> >> WMAP: Tests of Big Bang Cosmology >> http://map.gsfc.nasa.gov/m_uni/uni_101bbtest.html > > > That makes it a good theory, not an unquestionable fact. > > But the way of science is sometimes a better theory comes along. http://arxiv.org/abs/astro-ph/0504481v1 http://arxiv.org/pdf/astro-ph/0504481 > ABSTRACT > We have obtained high-quality Keck optical spectra at three epochs of the > Type Ia supernova 1997ex, whose redshift z is 0.361. The elapsed calendar time > between the first two spectra was 24.88 d, and that between the first and third > spectra was 30.95 d. In an expanding universe where 1 + z represents the factor > by which space has expanded between the emission and detection of light, the > amount of aging in the supernova rest frame should be a factor of 1/(1 + z) > smaller than the observed-frame aging; thus, we expect SN 1997ex to have aged > 18.28 d and 22.74 d between the first epoch and the second and third epochs, > respectively. The quantitative method for determining the spectral-feature age > of a SN Ia, developed by Riess et al. (1997), reveals that the corresponding > elapsed times in the supernova rest frame were 16.97�2.75 d and 18.01�3.14 d, > respectively. This result is inconsistent with no time dilation with a significance > level of 99.0%, providing evidence against �tired light� and other hypotheses in > which no time dilation is expected. Moreover, the observed timescale of spectral > evolution is inconsistent with that expected in the �variable mass theory.� The > result is within 1 of the aging expected from a universe in which redshift is > produced by cosmic expansion. http://www.astronomycast.com/astronomy/ep-79-how-big-is-the-universe/ http://arxiv.org/abs/astro-ph/0005229 http://arxiv.org/pdf/astro-ph/0005229 > In the spring of 1996, I switched from the SCP to the HZT. > Although I continued to work with the SCP on some aspects > of their project, such as the reduction and analysis of Keck > spectra of high-z supernova candidates, my primary allegiance > was with the HZT. The switch occurred largely because of > differences in style and culture: I preferred to work within the > somewhat amorphous structure of the HZT, where my voice > was more likely to be heard. Also, the HZT�s ways of resolving > issues of scientific procedures and credit were more to my > liking. As was previously the case with the SCP, on the HZT > I was still largely responsible for the Keck spectroscopy of SN > candidates. However, I was also more closely involved with > the cosmological interpretation�and indeed, a great opportunity > presented itself when Adam G. Riess, formerly Bob Kirshner�s > graduate student at the CfA, came to the University of California, > Berkeley in 1996 September as a Miller Postdoctoral > Fellow to work with me. > One of Adam�s first projects was to develop a quantitative > method for determining the age of a SN Ia from its spectrum. > His �spectral feature age� technique turned out to work remarkably > well, and we were able to demonstrate that the spectrum > of SN 1996bj (z p 0.57) evolved more slowly by a factor > of 1 z p 1.57 than that of a nearby, low-redshift SN Ia (Riess > et al. 1997). This effectively eliminated �tired light� and other > nonexpansion hypotheses for the redshifts of objects at cosmological > distances. (For nonstandard cosmological interpretations > of all the SN Ia data, see Narlikar & Arp 1997 and > Hoyle, Burbidge, & Narlikar 2000; a proper assessment of these > possible alternatives is beyond the scope of this essay.) Although > one might have been able to argue that something other > than universal expansion could be the cause of the apparent > stretching of SN Ia light curves at high redshifts, it was much > more difficult to attribute apparently slower evolution of spectral > details to an unknown effect. In a collaboration involving > me, Kirshner, and SCP members Perlmutter and Peter Nugent, > Adam used spectral feature ages to develop a method for determining > �snapshot distances� of SNe Ia from just a single > spectrum and a single night of multifilter photometry (Riess et > al. 1998a). Such distances are slightly less precise than those > obtained from well-sampled SN light curves, but they have the > advantage of requiring much less telescope time.
From: eric gisse on 7 May 2010 19:08
Michael Helland wrote: > On May 7, 9:36 am, Sam Wormley <sworml...(a)gmail.com> wrote: >> On 5/7/10 7:41 AM, Michael Helland wrote: >> >> > Tell me this, is the big bang an unquestionable fact, Alan? >> >> Look at the evidence! >> >> No Center >> http://www.astro.ucla.edu/~wright/nocenter.html >> http://www.astro.ucla.edu/~wright/infpoint.html >> >> Also see Ned Wright's Cosmology Tutorial >> http://www.astro.ucla.edu/~wright/cosmolog.htm >> http://www.astro.ucla.edu/~wright/cosmology_faq.html >> http://www.astro.ucla.edu/~wright/CosmoCalc.html >> >> WMAP: Foundations of the Big Bang theory >> http://map.gsfc.nasa.gov/m_uni.html >> >> WMAP: Tests of Big Bang Cosmology >> http://map.gsfc.nasa.gov/m_uni/uni_101bbtest.html > > > That makes it a good theory, not an unquestionable fact. > > But the way of science is sometimes a better theory comes along. Perhaps you should learn what science is before asking stupid questions. |