October 5, 2012

Albert Einstein said his biggest mistake was in not predicting the expanding universe. He developed an equation in 1915 that described gravitational effects in terms of general relativity. Since everything in the Universe gravitationally attracts everything else, one would theoretically expect the Universe to collapse; however, we all observe that the Universe has not collapsed, so Einstein put an ad hoc repulsive force into his equation to make a steady-state universe possible. In 1929 Edwin Hubble suggested an expanding universe as another possibility. He observed an increasing red shift in light coming from more distant galaxies suggesting that everything in the Universe is moving away from everything else, and the further away it is the faster it’s moving apart. This seemed to point to some original explosion of matter from which we are still seeing the effects.

The revolution in scientific thinking from a steady-state to an expanding universe took awhile to accept for philosophical reasons. An expanding universe pointed to a beginning for the Universe, a point in time before which science couldn’t explore, an effect without a cause, a Beginner to start things off at the beginning. Fred Hoyle and others preferred an alternative theory of continuous matter creation and ridiculed the expanding universe theory by calling it the Big Bang – a name that stuck. Eventually, however a predicted cosmic background radiation from the Big Bang was discovered in 1964 by Penzias and Wilson and the scientific community came to accept an expanding universe. Now, the three classic pieces of evidence for the standard Big Bang cosmology model are the red shift, the background radiation, and the observed relative abundances of the light elements assumed to have been created immediately after the Big Bang occurred.

In the standard Big Bang model leptons (e.g., electrons) and quarks (constituents of protons) formed first. During the first three minutes, quarks grouped into protons and neutrons and the atomic nuclei of hydrogen and helium. After about 300,000 years the temperature of the Universe had decreased enough for electrons to attach to nuclei forming atoms. Then radiation was decoupled from matter and light was able to traverse large distances in the Universe. Finally, the atoms coalesced into stars and galaxies. Once a hydrogen star became massive and its interior became hot, the atoms were able to get close enough together to fuse into the heavier element helium. This fusion (that also occurs in hydrogen bombs) gives off tremendous amounts of energy that we see as starlight or sunlight and the process is governed by Einstein’s equation E=mc². After all the hydrogen is burned to yield helium then carbon and the heavier elements up to iron, the star no longer has fuel to burn and it collapses. In the process of collapsing to a very dense neutron star, part of it also explodes as a supernova and the additional energy rapidly generates the heavier elements beyond iron up to uranium. The elements we find in our solar system and on the Earth are explained as the result of burning stars and supernova explosions and the atomic abundances seem to match well what would be expected from such processes.

So how old is the Universe and the stars it contains? In the standard model, the Universe is about 14 billion years old and our Sun and Earth are about 5 billion years old. Some creationists are willing to accept this age for the matter of the Universe and solar system because they believe a gap may exist between Genesis 1:1 and 1:2 where God recently begins to create life on the Earth. Other creationists believe that the entire Universe is only a few thousand years old based on such verses as Exodus 20:11 that say, “For in six days the Lord made the heavens and the earth.” They explain the apparent age of the Universe as coming from God needing to create a working universe, or creating light in transit, or creating a universe where time behaves strangely due to general relativity. Both perspectives are held within the Seventh-day Adventist community.

Although the standard model is widely accepted in the scientific community, it has its difficulties: (a) Science cannot yet explain why the Universe has more matter than antimatter. The standard model assumes that the early universe contained equal abundances of both, but now the Universe appears to consist almost entirely of matter. Perhaps some conservation laws were broken in the early Universe, but this doesn’t seem sufficient to explain the discrepancy. (b) The Universe needs to have a certain mass for it to exist as it does. The observed amount of mass is much less than theoretically needed, so unobserved “dark matter” has been postulated and a number of possible candidates for this dark matter have been suggested. (c) Evidence from “the edge” of the Universe suggests that the expansion of the Universe is accelerating, rather than slowing down. This seems to require some kind of repulsive force or “dark energy” similar to Einstein’s cosmological constant that he stated was his biggest mistake. (d) Perhaps the biggest difficulty is that cosmology is not standard science. Cosmology extrapolates further back in time and much farther away in distance than any of the other sciences. The Big Bang is a singularity where the laws of physics break down. Objectivity is lost because we are part of what we are observing. Non-intuitive theories are required to explain how the Universe works – general relativity for very strong gravitational fields where light bends and quantum mechanics at the atomic scale.

A significant remaining question is: why does the Universe appear to be fine-tuned for its own continued existence and for the existence of life? For example, the mass of the Universe can’t be too great or it would collapse on itself, nor too small or it would expand forever without coalescing into stars and galaxies. Some have suggested that the mass must be exactly right to one part in ten to the fortieth power. As another example, the strong and electromagnetic forces must be finely balanced for the existence of both the light and heavy elements necessary for life. The fine-tuning is recognized in the scientific community and is accounted for by the anthropic principle or by multiverses. The anthropic principle states that the Universe must allow life to develop or else we wouldn’t be here to observe it. The multiverse idea suggests that many universes exist with different laws, and we happen to live in a universe where the laws make life possible. The creationist community would explain the fine-tuning as the result of God creating it to make life possible.

Finally, if intelligent life exists on the Earth, does it exist elsewhere? The last few years have seen an extensive search for earth-like planets orbiting other suns besides our own, where the conditions would be right for other intelligent beings to exist. Hundreds of such planets have been discovered and possibly some have the right conditions to be inhabited. The Seventh-day Adventist community does in fact believe that other intelligent beings exist besides humans, and perhaps they could live on such planets.

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Ben Clausen, PhD

Geoscience Research Institute