Categories
astronomy Cosmology Physics Science

No CMB shadows: an argument against the big bang that can no longer be sustained

I have previously made the argument that the cosmic microwave background (CMB) radiation, ‘light’ allegedly from the big bang fireball, casts no shadows in the foreground of galaxy clusters.1 If the big bang were true, the light from the fireball should cast a shadow in the foreground of all galaxy clusters. This is because the source of the CMB radiation, in standard big bang cosmology, is what is known as the “last scattering surface“.

The last scattering surface is the stage of the big bang fireball that describes the situation when big bang photons cooled to about 1100 K. At that stage of the story those photons separated from the plasma that had previously kept them bound. Then expansion of the universe is alleged to have further cooled those photons to about 3 K, which brings them into the microwave band. Thus if these CMB photons cast no shadows in front of all galaxy clusters it spells bad news for the big bang hypothesis.

Fig 1: Schematic of the Sunyaev-Zel’dovich effect that results in an increase in higher energy (or blue shifted) photons of the CMB when seen through the hot gas present in cluster of galaxies. Credit: astro.uchicago.edu/sza/primer.html

The CMB radiation shadowing effect, or more precisely the cooling effect, by galaxy clusters is understood in terms of the Sunyaev–Zel’dovich Effect (SZE). This is where microwave photons are isotropically scattered by electrons in the hot inter-cluster medium (ICM) (see Fig. 1) via an inverse Compton process leaving a net decrement (or cooling) in the foreground towards the observer in the solar system. Of those CMB photons coming from behind the galaxy cluster less emerge with the same trajectory due to the scattering. Even though the scattered photons pick up energy from the ICM the number of more energetic CMB photons is reduced. After modelling what this new CMB photon energy (hence temperature) should be, a decrement can, in principle, be detected.

Starting around 2003 some published investigations, using this SZE, looked for the expected shadowing/cooling effect in galaxy clusters. No significant cooling effect was found, by multiple studies, including the WMAP satellite data.2 This was considered to be very anomalous, significantly different from what was expected if the CMB radiation was from the big bang fireball. The anomaly was even confirmed by the early Planck satellite survey data in 2011.3

Categories
astronomy Cosmology Physics

‘Light from the big bang’ casts no shadows

If the big bang were true, the light from the fireball should cast shadows in the foreground of all galaxy clusters.

Published in Creation magazine 37(1):50-51, 2015.

Update (1/3/2018) I first have made this argument in 2006 based on the work of Prof. Lieu and others. If the big bang were true, the light from the fireball should cast a shadow in the foreground of all galaxy clusters as illustrated below. However new research (Xiao, W., Chen, C., Zhang, B., Wu, Y., and Dai, M., Sunyaev–Zel’dovich effect or not? Detecting the main foreground effect of most galaxy clusters, MNRASL 432, L41–L45, 2013) has thrown this conclusion into doubt. Prof. Lieu at the time wrote “Either it [the microwave background] isn’t coming from behind the clusters, which means the Big Bang is blown away, or … there is something else going on.” As it turns out that “something else” is contamination of the expected shadowing by radio emissions from the galaxy clusters themselves.

Without anything to contradict this new result, and the analysis seems strong, one must entertain the possibility that the anomaly first found by Lieu et al in 2006 has been adequately explained. The problem of course is that astrophysics is not exactly operational science. At best this no-shadow argument is now equivocal and hence I suggest that it may no longer be used as an argument against the big bang hypothesis.


One of the alleged ‘proofs’ of the big bang model of origins is said to be the Cosmic Microwave Background (CMB). The radiation was discovered in 1964 by Penzias and Wilson for which they won the Nobel prize in physics. Soon after their discovery, it was claimed that this radiation is the ‘afterglow’ of the original ‘explosion’ or fireball of the big bang. Since the time at which the radiation, which started as heat, was emitted from the fireball, the universe has allegedly expanded by a factor of 1,100. Thus, that ‘afterglow’ radiation has ‘cooled down’ to much longer wavelengths (‘stretched’ from the infrared to the microwave portion of the spectrum).These are detected by microwave telescopes today.

Figure 1: Temperature fluctuations of the all-sky projection of the CMB radiation, after a constant background equal to 2.725 K was subtracted. Darker spots represent cooler regions and brighter spots represent warmer regions. The central red region is radiation from the Galaxy, which needs to be removed before the supposed background radiation can be seen without foreground contamination.
Figure 1: Temperature fluctuations of the all-sky projection of the CMB radiation, after a constant background equal to 2.725 K was subtracted. Darker spots represent cooler regions and brighter spots represent warmer regions. The central red region is radiation from the Galaxy, which needs to be removed before the supposed background radiation can be seen without foreground contamination.

According to theory, the big bang fireball should be the most distant light source of all. Thus all galaxy clusters would be in the foreground of this source. Therefore all CMB radiation must pass the intervening galaxy clusters between the source and the observer, here on earth. This radiation passes through the inter-galactic medium, between the galaxies in the clusters, and is scattered by electrons, through inverse Compton scattering,now known as the Sunyaev–Zel’dovich effect (SZE).3  When this happens, the path of the CMB radiation is interrupted and distorted.