MIRA 1998 Bonestell Lecture: The Multiverse

EINSTEIN'S UNIVERSE
About the Big Bang and Black Holes
THE DEEP STRUCTURE OF MATTER AND FORCES
About Elementary Particles and Forces
SYMMETRIES - PRINCIPLES OF DESIGN
About the Search for the Holy Grail--The Theory of Everything
STRINGS AND STRINGY SPACE
About Hidden Dimensions
OUR UNIVERSE--A VERY SPECIAL PLACE
About Worlds Hospitable to Life
THE MULTIVERSE
About the Origin by Natural Selection
CONCLUSION

Now we are ready to look at that final step that might help to explain how, out of millions of possible types of universes ours came to be. This part is due to Lee Smolin and it is described in his recent book "The Life of the Cosmos", (1997) . Smolin is a prolific contributor to the development of string theory and is one of the principal architects in the attempts to develop QUANTUM STRING THEORY OF SPACE.

In his book he presents a theory of MULTI UNIVERSES that occur and evolve by process that is analog to NATURAL SELECTION in Biology. His theory is based on two principal theses.

THESIS I
Based on what is known so far about a possible Quantum Theory of Space and Gravitation he postulates that in a proper Quantum Theory of Space and Gravitation the formation of Singularities in Nature will not occur. The collapse of a star to a Black Hole will not end in a Singularity but instead will lead to a "BOUNCE". There is a path beyond a state of highest mass concentration, by processes that are not included in Einstein's theory because it does not include quantum physics. Smolin conjectures that the Black Hole continues by REEXPANDING INTO A NEW UNIVERSE. In a multidimensional space there is room for another universe to expand, connected to our universe by some sort of bridge, " WORMHOLE" which however is not visible to us in our universe, because of that EVENT HORIZON that surrounds the Black Hole. This kind of connection between two different universes had been noticed already by Einstein and a coworker, ROSEN in exploring the Schwarzschild solutions and such connection became known as Einstein-Rosen-Bridges. But this was not taken seriously then. That bounce of a Black Hole contraction out to a new universe is a Quantu Effect that would only occur at extreme matter concentrations where space is curved up to extreme curvature, of the order of the Planck Length when quantum effects of space become important. This kind of mass concentration can only occur when there are stars of large masses that at the end of their nuclear burning life contract to Black Holes. Only when a universe contains Black Holes are new universes being formed.

worm.jpg (13786 bytes)

If this is true then there must be many other universe now, at least as many as there are Black Holes in our universe. It is now believed, based on observations that many galaxies have Black Hole objects in their dense centers. There are also Black Holes scattered throughout the galaxy, and presumably similarly through other galaxies.

These other universe in turn may have Black Holes in them giving rise to Baby Universes. Similarly, our universe could the be the outcome of a Black Hole in a "Parent Universe".

It was said earlier that from our perspective TIME inside a Black Hole looses its meaning. Time in the Black Hole and in the universe emerging from the Black Hole is not related to our time. Each evolving new universe has its own time-scale. Each evolving universe is its own clock. Time itself has only meaning in connection with a evolving universe. If one insists on piecing the time of the Parent- universe and its Baby-universes together, one has the notion of a tree of times with many branches.

THESIS II
The second principal thesis is that at the bounce the basic laws of physics remain unaltered. The Baby-Universes are governed by the same unique String theory, perhaps our "MOTHER OF ALL THEORIES" which was mentioned earlier.

However in the bounce, the pattern structure of space that we talked about gets scrambled. The space and matter gets ground through the grinder of the quantum foam state before it reemerges. And it reemerges with a different fundamental pattern, one of the perhaps millions of possibilities. That new universe then will have a structure that gives different forces and different particles, a different world. The choice the Baby-universe adopts is in principle random among the millions of possibilities. Smolin however postulates that the changes in each event are small changes. The Baby-Universe has string patterns that have preserved something of the Parent-Universe. The changes in the force strengths and particle types in the new universe are small. The Baby-Universe has some similar features to the Parent-Universe. It is similar to the small genetic variation that we expect to occur naturally between parent and offsprings in biology.

Here is where our story about the special features ouf our universe comes in. It was mentioned that normal stars like those in our universe exist only when the particle types and forces acting are not too different from those we have in our universe. So, for most of the millions of possible space patterns out of our M-THEORY, stars would not work, could not exist. Then Black Holes would not exist. But the there could be no Baby-Universes without Black Holes. So, Black Holes and thus production of Baby-Universes can only exist in a small range of the possibilities. This then leads to a PRINCIPLE OF NATURAL SELECTION OF UNIVERSES. Only universes with parameters in a narrow range will have large numbers of offsprings. A universe with the right range of parameters gets produces many Black Holes and thus many chances to generate similar off-springs. It has many more chances to try out slight variations which might have more Black Holes and more off-springs. Species with parameters too far from the optimum values will the have fewer progeny and eventually die out as species.

One can plot a "FITNESS LAND SCAPE FOR UNIVERSES", see below, a landscape of hills and valleys over the plane of parameter values, the strength of the strong and electromagnetic force that universes can possibly have. Hills represent regions of these values for which a universe would have many Black Holes and thus Baby-universes. Valleys represent unfavorable values of these parameters. Once a universe occurs with values close to the peaks of the landscape it will multiply rapidly. After enough generations the peaks of the Fitness-Landscape will be highly populated. Our universe may well be near one of those peaks.

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The goal of a complete Theory of everything then is to extract from the theory's basic principles a model of the expected number of Black Holes in a universe with a given structure and pattern of particles and forces and condense this into such a fitness-landscape. Of course, in a real theory there are not only two significant parameters that characterize each possible world but many and the full consequences of such fitness landscape may be difficult to assess. There are fitness landscapes of this sort for biological species where the parameters are the various species- and environmental characteristics on which survival fitness is based. We are far from having a complete picture in the study of biological species evolution.