Is there definitive evidence for an expanding universe?

Evolution out of the ‘Dark Ages’

Expansion of the universe is fundamental to the big bang cosmology. No expansion means no big bang. By projecting cosmological expansion backwards in time, they assert, one will, hypothetically, come to a time where all points are the same. Since these points are all there is, then it logically follows that there is no space or time ‘before’ this moment. It is the singularity, and we cannot use language couched in concepts of time when no time (or space) exists.

Yet there are Christians who use this presumed fact as evidence in support of the Genesis 1 account and even for the existence of God Himself. They argue that only God could have started the big bang. Though it is true the universe does need a first cause it is an enormous leap into the unknown to suppose that the big bang story is that which is described in the Genesis 1 narrative. The sequence of events is nothing like it. See The big bang is not a Reason to Believe!

Redshift

Redshifted The spectral lines for this element still show the same distinctive pattern, but all have been shifted towards the red end of the spectrum.

At the end of the 1920s, Edwin Hubble made a significant discovery. He found a proportionality between the amount by which the spectral lines in the light coming from relatively nearby galaxies are redshifted(z) and their distances (r) from Earth. That relationship is now called the Hubble law c z = H0 r, where c is the speed of light and H0 is Hubble’s famous constant of proportionality.

The Hubble law has since been extended to very great redshifts (therefore by inference, distances) in the cosmos, via the redshift-distance relationship. At small redshifts, and by interpretation at small distances, this becomes precisely the Hubble law.

Redshifts have been interpreted as a velocity of recession, i.e. that galaxies are moving through space. And that the recession implies expansion of the universe. But Hubble, up to the time of his death, was not so convinced of this interpretation.  He was open to the possibility that there could be another mechanism to explain redshifts.

In 1935 Hubble wrote:2

“… the possibility that red-shift may be due to some other cause, connected with the long time or distance involved in the passage of the light from the nebula to observer, should not be prematurely neglected.” [emphasis added]

Yet the ‘true’ cosmologists nowadays ‘know’ that redshifts mean that the galaxies are essentially stationary in space and they are dragged apart as the universe expands. This is called cosmological expansion. But whether or not motion of galaxies through space or expansion of space is the correct interpretation, is there any strong evidence for expansion of the universe, of any kind?

To test expansion

Once the distance to a target galaxy exceeds several million light years, methods of measuring distance in the universe, apart from the Hubble law, become extremely problematic. Generally at large redshifts the redshift-distance relationship, the large-scale extension of the Hubble law, is used, so that redshift then is a proxy for distance. However, it may well be true that the Hubble law applies, as a method of determining distance, but that the mechanism for generating the redshifts is, as yet, unknown.3 In other words it may not be the result of expansion of the universe, yet it may still give us a measure of cosmic distance back to the source galaxies.

It should be reiterated that the Hubble law itself, though derivable from General Relativity, is not sufficient grounds to conclude that redshifts are a reliable proxy for distance in the universe. One counter-example where an astronomical object with a very large redshift (z ~ 2) is seen ejected towards us out of the nucleus of a relatively low redshift spiral galaxy (z ~ 0.02) is sufficient to prove that the Hubble law as a method of determining distance is not so robust. High redshift should always mean great distance if the Hubble law is true, hence this counter-example calls into doubt the notion of cosmological expansion. See Big-bang-defying giant of astronomy passes away.4

The way to test the idea of the expanding universe is to look for a parameter that would be different as a function of distance, and hence a function of historically elapsed time, in an expanding universe as compared to a static one. One such parameter is the angular size of galaxies; another is the surface brightness of galaxies. Angular size is not easy to test because you would first need to establish a standard size galaxy that you observe at different redshifts, but surface brightness is somewhat easier to test for.

In these tests you assume redshift is a proxy for distance. You don’t need to know why. But if the test for expansion fails, it must then lead to the conclusion that either the universe is not expanding, i.e. it is static, or, redshifts cannot be used as a proxy for distance. These types of tests have been performed and I have published a summary of those results in Does observational evidence indicate the universe is expanding?—part 2: the case against expansion.  (See also the table at the end of the article).

Hubble Ultra-Deep Field

“Universe is Not Expanding After All, Scientists Say” was the headline of one online news site.5 This was in relation to a peer-reviewed paper6 published on a study of the surface brightness of about a thousand galaxies as a function of redshift. The method, first proposed by Tolman in 1935,2 is independent of any particular cosmological model of the structure or history of the universe. It only relies on the fact that if the universe is expanding, and therefore more distant galaxies are at greater redshifts, then their surface brightness would be expected to be much lower than in a static universe.  The assumption was made that redshift is a measure of distance in both the expanding and static universe, applying a simple Hubble law for that relationship in the static universe case, but without a mechanism why the Hubble law would hold.

(Update added 29/10/14)  Clarification on the method: All galaxies used to test this are chosen within a narrow range of absolute magnitude (brightness) by assuming a simple Hubble law relation for distance and redshift. (This requires this necessary assumption, hence it is not definitive.) Then one looks at the galaxies from the earth and their surface brightness is measured, which only depends on the radius of the galaxy and its apparent magnitude (brightness as observed). The apparent magnitude is a measure of light intensity per unit area and it is a constant, as a function of distance, in a static universe because the photons observed at earth decrease in number by the square of the distance to the galaxy (inverse square law of illumination) and also the surface area of the galaxy (radius squared) decreases by the same factor. Hence they cancel and you get no net dependence on distance, which we assume redshift (z) is a measure of. Using units of AB magnitudes: in a static universe the surface brightness is a constant as a function of redshift (assuming redshift is a distance measure) but in an expanding universe the surface brightness decreases by the factor (1+z)3, a function of redshift (z).

Strong agreement for a static universe was found from extremely high redshifted galaxies out to redshift z ~ 5 in the Hubble Ultra-Deep Field.  The Hubble Ultra-Deep Field (HUDF) is a survey where the Hubble Space Telescope and some earth-based telescopes looked at galaxies out to the limit of the visible universe, hence they have very high redshifts. Though by itself this study is not definitive it was found that the evidence is inconsistent with an expanding universe. It was found that surface brightness was independent of redshift and therefore a static universe was favoured.

But surely the best evidence for expansion of the universe is to just simply look at many galaxies at successive redshifts, i.e. at z = 10, 9, 8, 7, 6, etc? Since redshift is meant to represent different past epochs or time steps a change in the number density of galaxies should show evidence of expansion over time, which would be redshift in an expanding universe.

By counting the number of galaxies at each redshift one should observe the density of galaxies to decrease as the universe expands. This means one would expect to see a systematic trend of lower density or concentration of galaxies at lower redshifts. Going from higher to lower redshift in an expanding universe implies going from an earlier time period to a more recent time period.

Figure 1 illustrates the presumed cosmic history of the universe according to the standard big bang cosmology. Redshift is shown across the top and the corresponding time, counting backwards from the alleged big bang, supposedly 13.7 billion years ago, is shown across the bottom axis. ‘Recombination’ is the name given to the hypothetical period when atoms condensed out of the hot-yet-cooling plasma from the big-bang fireball. After that there supposedly ensued a period of cosmic ‘Dark Ages’ before the first stars and hence galaxies formed. Following that was the alleged period called ‘Reionization’ when neutral hydrogen atoms in the intergalactic medium were ionized, by starlight as stars and galaxies began to form, and hence the intergalactic medium became transparent to electromagnetic radiation (i.e. it was no longer in darkness). This means today we should be able to detect emissions from those ionized atoms.

Figure 1: Cosmic timeline illustrated showing redshift across the top, and ‘lookback’ time to the big bang along the bottom. Credit: m.caltech.edu/file/6861

Figure 1: Cosmic timeline illustrated showing redshift across the top, and ‘lookback’ time to the big bang along the bottom. Credit: m.caltech.edu/file/6861

It is now claimed from studies of HUDF galaxies that we observe galaxy formation at the beginning of the era of Reionization. The latter is supposed to have occurred in the period between z = 12 and z = 8 as indicated in Fig. 1 (between dotted lines labelled Hubble 2012 and Hubble 2009). Prior to this Reionization period all radiation at wavelengths consistent with the states of neutral hydrogen was absorbed and hence it is labelled the cosmic ‘Dark Ages’. These atoms, according to the theory, absorbed rather than emitted light, hence the label.

After the Dark Ages the ensuing galaxy formation process is described:

“Current models for galaxy formation follow the picture in which dark matter halos form by collisionless collapse, after which baryons fall into these potential wells, are heated to virial temperature, and then cool and condense at the centers of the halos to form galaxies as we know them. In short, baryons fall into the gravitational potentials of ‘halos’ of dark matter at the same time that those halos grow in size, hierarchically aggregating small clumps into larger ones.”7 [emphasis added]

The authors here, writing on the alleged early history of the big-bang universe, write as if they have definitive knowledge of dark matter providing the necessary gravitational energy to collapse the hydrogen gas into stars and galaxies. Understand please that dark matter here is essential to overcome the problem of naturalistic galaxy formation. No dark matter, no galaxy formation! More on that later but this is how the story goes.

Look at these epochs or redshifts and you will see a growth of structure so a progressive increase in density of galaxies from a redshift of z = 12 towards z = 8. Remember, decreasing redshift (z) implies the forward arrow of time from the alleged big bang towards the present.  Then after z = 8 you should see a decrease in density due to the expansion of the universe. All the while the universe was supposedly expanding but the growth of structure (i.e. size and numbers of galaxies per unit volume) in the period of redshift z = 12 to z = 8 outweighs the dissipating effect of the expansion.

This is illustrated in Fig. 2, assembled from 10 years of observational data from the Hubble Space Telescope, called the Hubble eXtreme Deep Field (XDF). There you see an increase in density from the more distant hence ‘more than 9 billion years’ frame to the middle frame labelled ‘5 billion to 9 billion years’ and then a decrease in density towards the closest or more recent frame labelled ‘less than 5 billion years’.

This is what one new study claims.8 In the XDF data they identified 7 galaxies at redshift z ~ 9, 1 galaxy at z ~ 10 and 1 galaxy at z ~ 11. They studied ultra-violet (UV) light emission, which is assumed to indicate star formation (hence growth of structure or ‘evolution’) and concluded,

“… an accelerated evolution beyond z ∼ 8, and signify a very rapid build-up of galaxies with MUV < −17.7 mag within only ∼200 Myr from z ∼ 10 to z ∼ 8, in the heart of cosmic reionization.”

XDF

Figure 2: Hubble eXtreme Deep Field. The eXtreme Deep Field, or XDF, the photo was assembled by combining ten years of NASA/ESA Hubble Space Telescope observations taken of a patch of sky within the original Hubble Ultra Deep Field.

With extremely scant evidence, this means that it was concluded that there was an accelerated evolution of the size of galaxies because of the few bright galaxies they observed between redshifts z ~ 8 and z ~ 10 and their UV light-emissions. But this is not even the real issue.

The real issue is that ‘evolution’ is the ‘catch all’ used to explain everything. By adjusting the evolution rate of accumulation of size and galaxy density one can adjust the model to fit the data—to fit any data. Put it this way: if the expansion rate of the universe appears to be too slow, and there is a faster build-up of galaxies with decreasing redshift than expected, one simply adjusts the evolution rate to compensate. Just turn the evolution ‘knob’ by the appropriate amount!

But if the dark matter, which does not interact with any normal matter, was not present in the first place no evolution could occur, since no galaxies would grow and the expanding universe model would be in serious trouble, because there would be no galaxies in their universe.

Conclusion

Is the evidence really consistent with an expanding universe or not? Well…, it is equivocal.9,10 What remains is a ‘good’ story based on observations that rely on unprovable assumptions, that are either consistent with an expanding universe or in conflict with the idea. But when in conflict with that story the ‘knobs are turned’ in the standard big-bang model such that it can be made to fit any evidence. Evolution of galaxy size is used to counter those apparently contradictory lines of evidence. This means that whatever observations are proffered, one way or another, an alternate explanation can always be found. Unfortunately this is the very nature of big-bang cosmology. No wonder a substantial and growing number of even secular physicists and cosmologists are frustrated by what they say is its totally unwarranted stranglehold on thinking—even extending to denial of publication/funding of alternative notions, regardless of quality. See Secular scientists blast the big bang.

References

  1. That is, shifted towards the red end of the spectrum.
  2. Hubble, E.P. and Tolman, R.C., Two methods of investigating the nature of the nebulae red-shift, Astrophys. J82:302–337, 1935.
  3. Marmet, L., On the Interpretation of Red-Shifts: A Quantitative Comparison of Red-Shift Mechanisms, marmet.org, December 4, 2014
  4. See also Hartnett, J.G., Universe: Expanding or static?
  5. www.sci-news.com/astronomy/science-universe-not-expanding-01940.html
  6. Lerner, E.J., Falomo, R., and Scarpa, R., UV surface brightness of galaxies from the local universe to z ~ 5, Int. J. Mod. Phys. D, DOI: 10.1142/S0218271814500588, 2014; available at http://arxiv.org/ftp/arxiv/papers/1405/1405.0275.pdf
  7. Ratra, B., and Vogeley, M.S., The Beginning and Evolution of the Universe, Pub. Astron. Soc. Pac., 120(865): 235-265, 2008.
  8. Oesch, P.A., et al., Probing the dawn of galaxies at z ∼ 9–12: New constraints from HUDF12/XDF and CANDELS data, Astrophys. J773:75, 2013.
  9. Hartnett, J.G., Does observational evidence indicate the universe is expanding?—part 1: the case for time dilation
  10. Hartnett, J.G., Does observational evidence indicate the universe is expanding?—part 2: the case against expansion

Radio interview on this: John Hartnett on Galaxy Brightness and the Expansion

On Bob Enyart Live   Date: 20/6/2014   Length: 28:19


Comment on this article (added 29/8/2014)

My friend Hilton Ratcliffe, a South African astronomer and author, posted the following on FaceBook sharing the link to this article “Is there definitive evidence for an expanding universe?” The following highlights the true nature of the battle. It’s not science but philosophy and ideology.HR comment cut

Related Articles

Further Reading