Thursday, May 23, 2024

The Goldilocks Enigma – Part Three

By Laura Knight-Jadczyk

In the previous post, it was noted that Darwin’s ‘Natural Selection’ was early seized upon as the one and only underlying law of our reality: random processes of matter, no consciousness needed, and it has been the steady application of this perspective that underlies that chaos and disorder we now experience in a world declared to be devoid of information and organization.

The materialist solution to the appearance of design is to postulate Laws of Nature. Davies then asks the obvious question: “Where do the laws of nature come from?... How can they be explained?”

I briefly recounted the development of the idea that there were/are Laws of Nature and then recounted an exchange between Ark and Robin Amis about the differences between Science and Religion which concluded that perhaps, a marriage between the strengths of science and mysticism might be the way to go.

I concluded with Davies noting that the Universe certainly reveals that there is a cohesive scheme of things but most scientists do not consider that evidence for meaning or purpose. Davies wrote:

Of course, scientists might be deluded in their belief that they’re finding systematic and coherent truth in the workings of nature. Ultimately there may be no reason at all for why things are the way they are. But that would make the universe a fiendishly clever bit of trickery. Can a truly absurd universe so convincingly mimic a meaningful one?

And then I concluded with Davies setting himself the task of Explaining the Universe. The question is: will his explanations result in any change of perspective? Will he conclude that there is no meaning or purpose or will he find that the evidence is overwhelming for meaning and purpose?

Davies says that the science of cosmology really only came into its own on 11 February 2003 when the Wilkinson Microwave Anisotrophy Probe map was created and published.

A full-sky map produced by the Wilkinson Microwave Anisotropy Probe (WMAP) showing cosmic background radiation, a very uniform glow of microwaves emitted by the infant universe more than 13 billion years ago. Colour differences indicate tiny fluctuations in the intensity of the radiation, a result of tiny variations in the density of matter in the early universe. According to inflation theory, these irregularities were the “seeds” that became the galaxies. WMAP's data support the big bang and inflation models, and cosmic microwave background is at the farthest limits of the observable universe. ~ NASA/WMAP Science Team

Apparently, the importance of this map consisted in the fact that it showed that, on the largest scale of size, there is order and uniformity in the Universe. This suggests that the laws of physics are identical far out in the universe.

Only in the past few decades have astronomers been able to measure the scale of the thing. Our sun is one of hundreds of billions of stars in our galaxy: the Milky Way. The Milky Way galaxy is just one of hundreds of billions of galaxies. The gaps between stars are so large they are measured in light years: the distance light travels in a year at 186K miles per second. One light year is about 6 trillion miles or 10 trillion kilometers. The furthest galaxies imaged by the Hubble telescope are over 10 billion light years away.

Eighty years before the WMAP map was achieved, astronomers Edwin Hubble and Vesto Slipher studied light from many galaxies and found that the further away they were, the redder the light was. It was already known that light from receding sources is stretched and shifted to the red end of the spectrum while light from an approaching source is shifted the other way, toward the blue end of the spectrum. Apparently, the red shift got bigger the further away from us a galaxy was. Moreover, it appeared that the effect – the red shift – was the same in all directions. So, Hubble announced that obviously, the galaxies are all rushing away from us in an orderly pattern of expansion. The conclusion drawn from this observation and analysis was that: if the universe is expanding now, it must have been compressed in the past. And so, using the measured rate of expansion, they ran the movie backwards and decided that all the galaxies had been squeezed into one place at some point, and the universe must have begun with a big explosion; enter The Big Bang. The date of this event was estimated to be 13.7 billion years ago.

Here Davies notes that the term ‘Big Bang’ was derogatory, having been coined by Fred Hoyle who never accepted the theory laid out above. But, never mind since the next conclusion was that, if the pre-Big Bang universe was all compressed into one spot, then it was certainly very hot. Like REALLY hot, since matter heats up when it is compressed and cools when expanded and we are talking about serious compression here. That being the case, we should expect the heat from the birth of the universe to have left a faint glow of radiation after 13.7 billion years. Apparently, that is what was found by radio engineers from Bell Labs, Arno Penzias and Robert Wilson. In 1967 they came across radiation coming from space that they soon identified as the expected relic of the big bang. This radiation is evenly distributed across the sky at a temperature of 2.725 K which works out to be minus 270 degrees C. Since radiation at this very cold temperature is in the microwave region of the EM spectrum, this has been named ‘cosmic microwave background’ or CMB.

Temperature fluctuations in the cosmic microwave background radiation after the dipole pattern (due to the Solar System's motion relative to the rest of the Universe) and the strong emission from the Milky Way galaxy have been removed. Based on 4 years of data from COBE.

Astronomers were able to measure the precise spectrum of the cosmic background radiation and this resulted in the following graphic representation that Davies calls ‘the smoking gun’:

The above graph is based on the measurements made by the WMAP satellite and shows how the heat energy left over from the Big Bang is distributed across a range of wavelengths. Davies tells us that the shape of the curve is distinctive, corresponding precisely to the spectrum of radiation from a system at a uniform temperature. This, then, suggests that the CMB originated from a state of thermodynamic equilibrium in the distant past. Conclusively, the observations fit the Big Bang theory precisely. And the implication is that the material of the early universe must have been smoothly and evenly distributed through space at the same density and temperature everywhere. That is, it was mightily compressed and astonishingly hot through and through! The graph above appears to confirm that the universe began in a hot, dense, uniform state, and from which is expanded and cooled to become what it is today.

Well, the early form of the universe apparently wasn’t totally and completely uniform because there is ‘clumping’ such as aggregations of galaxies. If the pre-bang universe had been completely and perfectly uniform, there would be no structure, but at the same time, even small initial irregularities would have been amplified by gravity and that would have resulted in an early catastrophic collapse if it were not also expanding which counters the tendency for aggregation. Davies writes:

Calculations of these competing effects indicate that to grow galaxies distributed in the observed manner, the universe must have started out with density variations of about one part in 1000,000. Because denser gas is more compressed it is hotter, so irregularities in density translate into irregularities in temperature. So the early universe should have possessed tiny temperature variations, if the big bang theory is to hang together consistently. And that is precisely what WMAP found.

So the story goes something like this. The universe began 13.7 billion years ago with a big bang. The state of the early universe was one of extremely hot and dense, ionized, opaque, expanding gas suffused with heat radiation. The gas was distributed through space with almost but not quite perfect uniformity. By about 380,000 years after the big bang, the universe had cooled to a few thousand degrees, and at this point the gas de-ionized (i.e. the nuclei and electrons combined into atoms) as a result of which it became transparent. The heat radiation thereafter was largely unaffected by its passage through matter, and it has travelled almost freely ever since. Therefore, when astronomers detect the CMB they are glimpsing the universe as it was about 380,000 years after the big band. In effect, the CMB is a snapshot of what the universe was like when it was less than 0.003 per cent of its present age. The tiny variations in temperature detected by WMAP represent the seeds of cosmic structure without which there would have been no galaxies, stars, planets – or astronomers. So this is another one of those ‘convenient’ facts that makes the universe bio-friendly, and which needs explaining.

There are, however, some additional things that must be taken into account. First of all, if the Big Bang was the explosion of a compact ball of matter floating in some kind of void, there would be a center. If there were a center, then some galaxies would be in the middle and others would be on the outside edge and then, empty space. But that is not what is seen through our telescopes. What is seen is something like 100 billion galaxies distributed uniformly with none of them clustering up around a ‘center’ and no apparent thinning of the arrangements at any outer edges. That means that there is no systematic flow of galaxies out from any particular location. All of the galaxies move away from all others at the same rate and everywhere you look the space between the galaxies gets bigger and bigger as time goes on. The observer’s impression of being located at the center is an illusion because everything is all moving away from everything else and no part of the sky has any big glow of primordial radiation which it would have if the Big Bang had happened at a given point in space.

How to explain this? Cosmologists have made some attempts including the following cited by Davies:

·       Space is in the universe rather than the universe being in space.
·       The big bang happened everywhere, not at one point in space.
·       The big bang was the explosion of space, not an explosion in space.

Davies uses the analogy of a string of elastic with beads attached. As you stretch the elastic, the beads are farther and farther apart. There is a somewhat better image on the net here: called the Expanding Balloon Analogy by Prof. Ned Wright :

The trick is to think of space as being elastic and capable of being stretched. This capacity of space to stretch, to curve or warp is the basis of Einstein’s general theory of relativity. And so, the apparent movement of galaxies away from each other appears to be the expanding of the space between them.

There are questions about this, too. Maybe we can’t see a center or an edge because our telescopes are not powerful enough to see that far? Or, maybe the universe is infinite in all directions. Davies notes that the simplest default assumption is that what you see is what you get everywhere: there is an infinite number of galaxies extending through infinite space forever and ever.

The uniformity of space that is seen no matter which way you look is referred to as the cosmological principle which is an application of a more general principle: the principle of mediocrity, or there is nothing special or privileged about our location in the universe.

Also notice that the balloon universe depicted above demonstrates that the universe can be finite in volume without having a center or an edge. Of course, thinking about a balloon configured universe makes some of us wonder who is blowing up the balloon???