"Cosmic Jackpot - Why the Universe is Just Right For Life" by Paul Davies

Cosmic Jackpot: Why Our Universe Is Just Right for Life

Paul Davies

This is the latest book by Paul Davies who has always been one of my favorite popular physics authors. I was lucky to come across one of his earlier books in high school which kept me interested in physics despite the mundane physics class.

The greatest value of this book lies in its clear descriptions of the latest developments in physics as it affects cosmology such as dark matter, dark energy, anti-gravity, cosmic inflation. No other recent book does as good a job.

The great achievement of modern cosmology was the publication in 2003 of the WMAP satellite's high resolution microwave background radiation image that shows the state of our universe only 380,000 years after its creation in the Big Bang, a time when the universe had cooled just enough to allow electrons to be captured by hydrogen and helium atoms freeing light to run free for the first time.

Yet the attempt by Paul Davies to delve into metaphysics is weaker due to his scientisim worldview in which nothing can exist beyond of the material universe. But at least he is attempting to deal with these hard questions in print which is really something special for a professional physicist.

His reasoning that nothing can exist beyond our own material universe starts with his conclusion that time itself cannot exist outside of the universe (page 68). He bases this on Einstein's General Relativity equations which shows that the space-time continuum goes to zero when the matter term is set to 0. All this equation says is that time and space cannot exist within our own universe if matter goes to zero. Time is the dimension that allows matter to move (more generally it allows causal signals to go from place to place) while space is the dimension that allows matter to have form. One cannot apply General Relativity to higher dimensional spaces outside of our universe, especially if these spaces are not involved in the self-assembly of structure. One can reasonably say that if any causal movement exists within some higher dimensional space then some time dimension will exist.

The author goes on to say that this is the same solution the Christian Saint Augistine took when he claimed that God was outside of (transcended) space and time because he created space and time. Augustine was trying to reconcile a changeless God (a changeless nature being an expected property of eternity) with an act of change. Yet as previously mentioned without time no changes, no causal signal flows, are possible so the whole idea of some cause producing thing transcending time is false.

Then one comes to string or membrane theory which is the theory of everything while at the same time being a theory of nothing. By using vibrating strings or membranes that can vibrate in multiple spatial dimensions (with those spatial dimensions being compacted so small that matter can't enter them) having any shape and with the strings or membranes taking any shape string theory makes nearly anything possible. The author does not state how the idea of other dimensional spaces in string theory can be reconciled with the idea that no other space exists outside of our expanding universe. I assume cosmologists think they can just add as many compacted spaces as they want to the General Relativity equations without any good reason beyond making the equations so general that they can describe everything. This does not make a theory which are supposed to provide constraints on what is possible. This is why  string theory is also a theory of nothing.

One of these "everything is possible" with string theory is the idea of the multiverse in which the universe just keeps on creating new parts forever much like bubbles in a bubble bath with the water running keep expanding. In this way there is no creation just infinite growth! Well, metaphysically continued growth has never been thought of as a property of eternity. Another reason for multiverses is that the physical constants can be random with the result that we, intelligent conscious beings, only appear in those universes with the right physical constants (about 20 of them must have their values determined from experiement and are not derived from any deep theory). While multiple such universes may be plausible this multiverse idea is not the way to go about it.

[Edit: added April 30, 2007] The recent finding that the universe is not only expanding but accelerating is very significant because it gives an answer to how the universe will end (page 124). As space expands it carries all objects embedded within it along. Eventually all galaxies will move out of sight of each other as they move out beyond each others event horizon (light can no longer cover the distance in the time since creation). As the expansion continues the event horizon around each material object continues to shrink in diameter. From the point of view of our  of our then dead sun the stars will disappear one by one, then the  remaining planets will disappear, then the atoms making up the sun will begin disappearing from each other. So what happens when all matter is cut off from each other? No one knows. Perhaps matter and its space will then disolve back into the primoridial chaos (higher dimensional space) from which it came.

[Edit: added April 30, 2007] The cause of this spatial acceleration is dark energy. All the normal matter that makes up the self-assembled structure of the universe only makes up 4% of the total. Some unknown matter that seems to hover invisibly around the galaxies makes up another 22% while the dark energy uniformly distributed throughout the universe makes up the remaining 74%. (page 123).

[Edit: added April 30, 2007] Dark energy is negative energy. The standard reference point for negative energy is represented by the orbits of matter around each other. If a planet falls straight into a star from its orbit it releases positive energy. While in orbit this same amount of energy is called the planet's potential energy (energy cannot be destroyed or created but only transformed). So where is the extra energy when the planet fell into its orbit? This extra energy has to be represented as a component in the gravitational field and since falling into orbit releases positive energy it must have been absorbed by the gravitational field as negative energy so the total energy equals 0. Since energy is equivilent to matter via E = mc² this negative energy equals negative gravity. Recent estimates show that this total negative energy is equal to the total postive energy represented by all the matter in the universe so while gavity locally is attractive at the universal scale it is repulsive just enough to cancel out the attraction. From this data the universe should neither be expanding nor contracting. (page 43).

[Edit: added April 30, 2007] The remaining anti-gravity comes from dark energy measured to be mass equivelent to 10^-28 grams per cubic centimeter. The most likely candidate for this dark energy is the negative energy from other non-gravity force fields. In terms of quantum mechanics these force fields are represented by virtual particles which "borrow" positive energy (making the energy negative) for short amounts of time. How this works is that each particle sets up its set of potential paths and interaction options (the wave like quantum potential) which then interacts with those from other particles. This quantum potential field is continuosly updated. Eventually some interaction event between the two particles will be triggered resulting an exhange a virtual force carrying particle. This is somewhat analogous to the triggering of an action potential (an interaction event) in a neuron when its threshold is exceeded, but with the neuron having a randomly varying threshold.

[Edit: added April 30, 2007] Yet physics has a big problem in that their calculations for this dark energy are way off! (page 148) Calculations show that the dark energy equivelent should be 10⁹³ grams per cubic centimenter which is different from the measured value by a factor of 10¹²⁰. Physicist Stephen Hawking quipped that this must be the biggest failure of physical theory in history (page 147). Personally I tend to think this is a problem with their metaphysics in that they are treating fields classically instead of from an information processing point of view more in conformance with quantum mechanical interactions as described in the previous paragraph. Do non-gravity fields really exist continuously in the absence of two interacting particles? Classically a field is formed from only one particle but that does not seem to be consistent with quantum mechanics.
 
Still, despite my disagreements over the metaphysics this is one of those must read books for anyone interested in physics, cosmology, and metaphysics.