Our Universe-51

There is an interesting philosophical question about the universe we live in. And that question is: Was the universe built just for us? Consider the following facts with which astronomers, astrophysicists, cosmologists, and physicists all seem to generally agree as based on an article in the December 2008 DISCOVER magazine among other sources:

If the force of gravity were just a bit weaker, then there would have been no clustering of matter after the Big Bang and as a consequence no galaxies or stars or planets would have formed and therefore no us.

On the other hand, a beefed-up gravity would have compressed stars more tightly, making them smaller, hotter, and denser. The results would have been that these stars would have burned through their fuel in millions of years instead of billions, thereby not allowing enough time for life to have formed. Again no us.

As we all know, atoms consist of electrons, neutrons, and protons. Now if these protons were just 0.2% more massive than there are, they would be unstable and would decay into more elementary particles. In that case, atoms would not exist and again neither would we.

Stars produce energy by converting two hydrogen atoms into one helium atom. During that reaction, 0.007% of the mass of the hydrogen atoms is converted into energy as illustrated by the famous e=mc² equation of Albert Einstein. If that energy conversion percentage were as little different as 0.006% or 0.008% then untoward (in respect to us) events would have occurred. The lower number would have resulted in the universe filled only with hydrogen; the higher number would have left the universe with no hydrogen, therefore no water, no stars like our sun, and hence no us.

The early universe was delicately balanced between runaway expansion and terminal collapse. Had the universe contained a great deal more matter, additional gravity would have made it implode. If it had contained considerably less matter, it would have expanded too quickly for galaxies to have formed. In both instances, no us.

If matter in the universe had been more evenly distributed after the Big Bang, it would not have clumped together to form galaxies. Had matter been clumpier, it would have condensed into black holes. Again in either case, no us.

Atomic nuclei are bound together by the so called Strong Nuclear Force. If that force were slightly more powerful then all of the protons would have paired off and there would be no hydrogen which fuels long-lived stars. Water would not exist either, nor would any known form of life, which arguably includes us.

In 1998 two teams of astronomy researchers, observing supernovae, found that the expanding of the university is accelerating. The discovery was baffling in that just about everyone else involved in astronomy expected that the cosmic expansion, which started with the Big Bang, must be gradually slowing down, braked by the collective gravitational pull of all of the galaxies and other matter in space. However, it seems that built into the very fabric of space is some unknown form of energy. Physicists call it simply dark energy that is pushing everything apart. Many cosmologists, astronomers, and astrophysicists were skeptical at first, but follow-up observations with the Hubble Space Telescope along with independent studies of radiation left over from the time of the Big Bang, have powerfully confirmed the reality of dark energy.

What to make of all this. One could claim that God made the universe just for us. That may be satisfactory for some, but then the discussion is closed as there is nothing more to contemplate. What I want to know is how this seemingly unique situation came to pass. Postulating that God created the universe and His method is unknowable by us, however true or not that might be, does not advance the explanation in any way so let us consider a non divine hypothesis.

One theory, quite controversial, called the Multiverse Theory, is that there are many universes, as many as 10 5ºº of which ours is the one suited for carbon based life. That is an extremely large number, larger in fact than the number of dollars the U.S. government is using in the current economic bailout. Let’s see how much larger. The one dollar bill is close to 6 1/8 inches long. If laid end to end it would take approximately 962 billion to reach between earth and the sun (the mean distance of the earth from the sun is about 93 million miles). One billion is 1 followed by nine zeros. To get to 10 5ºº we need 1 followed by 500 zeros.

How many one dollar bills would it take to span the diameter of our Milky Way galaxy? Our galaxy is approximately 100,000 light-years across (a light-year is the distance light travels in one year – circa 5.88 x 10¹² miles in the vacuum of space). So it would take on the order of 6 x 10²¹ one dollar bills laid end to end. Still a bit short of the 10 5ºº number.

What about the number of one dollar bills stretching across the diameter of the known universe? The universe is estimated to be 156 billion light-years across. Therefore it would take on the order of 9.5 x 10 27 one dollar bills to span the known universe. How much of a deficit do we still have from the 10 5ºº number? The answer is approximately 10 5ºº / 10 28 = 10 472. It seems we have not made much of a dent in the 10 5ººnumber. What is the evidence there are 10 5ºº different universes? It is part of the Multiverse Theory, but is not absolutely provable.

The specific term “Multiverse” was coined in 1895 by psychologist William James. In these contexts, parallel universes are also called “alternative universes”, “quantum universes”, “interpenetrating dimensions”, parallel worlds”, “alternate realities”, “alternate timelines”, etc.

As previously stated, different universes within the Multiverse (also called the Meta-Universe) are called Parallel Universes. According to this theory each universe starts with its own Big Bang and acquires its individual physical laws as it cools and traces its own cosmic cycle. Physicists do not like the idea of a Multiverse because it lacks testability and without hard physical evidence is non-falsifiable outside the methodology of scientific investigation to confirm or disprove. Yet there is no other current satisfactory explanation of why our universe is the way it is thereby allowing us to exist.

The concept of other universes has been proposed to explain why our universe seems to be fine-tuned for conscious life as we experience it. If there were a large number (possibly infinite) of different physical laws or fundamental constants in as many universes, some of these would have laws that were suitable for stars, planets, and life to exist. The anthropic (human) principle could then be applied to conclude that we would only consciously exist in those universes which were fine-tuned for our conscious existence. Thus, while the probability might be extremely small that there is life in most of those universes, this scarcity of life-supporting universes does not automatically implies intelligent design as the only explanation of our existence.

Strikingly the temperature of space is everywhere the same, just 2.7 ºC above absolute zero. How could different regions of the universe, separated by such enormous distances, all have the same temperature? In the standard version of the Big Bang theory they couldn’t. Cosmic inflation is the hypothesis that the nascent universe, just after the Big Bang, passed through a phase of exponential expansion in the very early universe. Cosmic inflation answers the classic conundrum of the Big Bang cosmology of why the universe appear flat, homogeneous, isothermal, and isotropic in accordance with the cosmological principle when one would expect, on the basis of the Big Bang, a highly curved, inhomogeneous, and non-isotropic universe.

A counter argument that life simply began and evolved to meet the physical conditions of our universe, galaxy, solar system, and planet is not persuasive in that it seems more than implausible that life could come about without stars and planets, to say nothing of atoms or water molecules.

This is heavy stuff and also involves string theory which is a physically and mathematically complex concept involving up to 11 dimensions. It was co-invented by world famous professor of theoretical physics at the Graduate Center of the City University of New York, Michio Kaku. Professor Kaku has appeared on various television programs about science and is a best selling author of such books as Hyperspace, Parallel Worlds, and Physics of the Impossible.

I do not pretend to comprehend these abstruse physics and mathematics principles, yet before one dismisses them as flights of fancy the nagging question of why our universe, perhaps uniquely, is seemingly inexplicably suited for us must be confronted.