The opening line of John Gribbin’s review of Brian Greene’s The Hidden Reality in today’s Wall Street Journal reveals all that one need know about the state of theoretical physics and the physicists that practice its dark arts:

The multiverse is an idea whose time has come.

Objective reality has no time when its time has come.  It just is.  That ideas attempting to explain objective reality can be considered to have a time that can come speaks to our bias and hubris, not to any attribute of objective reality. 

Gribbin explains that everybody (i.e., theoretical physicists, not just science fiction writers) now seems to be coming around to the idea that there’s no necessary limitation upon the number of universes, i.e., there can be many universes, i.e., a multiverse. 

My American Heritage Dictionary, Fourth Edition, carries no listing for the term “multiverse”, apparently uncomfortable with the illogical notion that a universe, which is defined as all matter and energy, including the earth, the galaxies and intergalactic space, regarded as a whole might not actually be as it is defined.  If the universe is defined as everything, how is it possible that there be multiple everythings, such as is contemplated by the notion of a multiverse?  The Oxford English Dictionary (online) offers a definition of multiverse as an infinite realm of being or potential being of which the universe is regarded as part or instance; but defines universe in much the same manner as American Heritage, stating it is all existing matter and space considered as a whole.  Apparently the English mind doesn’t abhor logical conundrums so much as its American offspring.   A universe can hardly be all existing matter and space, while at the same time being only a part of an infinite realm of being.  The universe either is everything, or it is simply a part of everything, thereby making it something less than a universe

It may be objected that this is just word play.  Fair enough.  But words are all we have at our disposal for describing reality.  Math is a particular type of language that uses terms and symbols as words, but still, it is language, and if the reality it describes is founded on rationality, i.e., on the idea that causes have effects, then the language used to describe it must also be founded on rationality, which means it must also avoid logical inconsistency.  The idea of multiple universes contorts logic.  It limits this universe to only those things about which we know and have deduced relationships (e.g., gravity, matter, energy, etc.).   It then conjures other worlds where our rules and relationships don’t apply, but makes the logical misstep of also calling them universes.  There can be only one universe.  Perhaps it comprises many different worlds, where, e.g., the gravitational force varies according to a bell curve distribution.  Perhaps it doesn’t.  But the universe is all those worlds and any more that we could imagine.  Else it isn’t a universe at all. 

Gribbon justifies the multiverse (i.e., the idea that universe in which we live is only one of a potential infinity of them) by using what’s commonly known as the anthropic principle to explain how it is that the universe which we inhabit has all the attributes (the right gravitational force, the proper speed of light, etc.) necessary for human habitation, whereas other universes might not.  Which explains nothing.  Of course the world we inhabit has the attributes necessary for human habitation, else we wouldn’t be here to ponder it.  The anthropic principle is a tautology.  How, exactly, it has anything to do with the idea that other universes (suspend disbelief for the moment that a word like “universe” could be used in the plural) exist is beyond me. 

Unless the aim is to set about proving man’s puniness.   Which ought not be difficult, considering that what we know of this universe makes man nothing more than a speck in its eye.  No need to add a bunch more universes to the mix that aren’t habitable to prove the point.  Yet proving man’s puniness seems to at least partially be the point of the eleven dimensions of M-theory and other versions of string theory that postulate multiple universes.  Or at least, Gribbon thinks so:

The good news, considering that “The Hidden Reality” is sure to be a best seller regardless, is that the book serves well as an introduction to the multiverse and will open up many people’s eyes. This idea, after all, is among the most profound in science, taking the Copernican Principle that there is nothing special about our own place in the universe to its logical extreme, to suggest that there is nothing special about the place of our universe in the multiverse.

How ironic, to claim that a multiverse idea takes things to their logical extreme.  It does nothing of the sort.  It takes things to an illogical extreme.  It is nothing more than an impossible-to-prove abstraction that physicist math wizards have formulated to resolve the central conundrum of this universe—that understanding behavior at its sub-microscopic level is no use in predicting behavior at the macro level and vice versa.  The two reigning ideas, relativity and quantum theory, (whose time lately came, though objective reality, as always, patiently awaited their arrival) are hopelessly incompatible.   Though each theory proved that mathematical abstraction can be capably employed to explain and predict attributes of reality, or at least slices of it, the premise does not follow that mathematical abstractions creating multiple universes explain much of anything, or at least, much of anything worth speculating about.    

And speculation, though employing a trove of complicated calculations, is all a theory positing multiple dimensions and universes will ever be.  It is as incapable of proof as is the idea of God.  It is mysticism, through and through.  Relativity theory made predictions about this universe—the one with flowers and trees and planets and stars and galaxies and other such realities—that were later proved true (with quite a bit of tinkering in the breach, but that’s another matter).  Quantum theory predicted a particle zoo that eventually proved to resemble a Noah’s Ark of the very tiny.  Each theory is, on some level, relevant to gaining an understanding of objective reality.  M-theory and string theory aren’t and never can be.  The only way we’d ever be able to worm-hole into another universe with triple the dimensions of ours would be to take something like an acid trip in our minds. 

I think the idea of having multiple universes is tempting because it helps our finite minds grasp the idea of infinity, which is essentially also the idea of one universe, comprising all of everything.  It is very difficult to grasp infinity when stuck smack dab in the middle of it, with nothing but a finite mind with which to grasp it.  By conjuring other realities, we limit the infinity of this one, rendering it more understandable.   It is as if we wish to play God, set apart by some gaggle of universes that define this one by exclusion.

For an example of how difficult it is to imagine infinity when immersed in it, consider how it is that the speed is measured.  Speed is always a relative measure (forget for the moment the premise of special relativity that light travels at the same speed, no matter the perspective of its observer).  It seems fairly straightforward what speed is when watching the 100 meter dash at the Olympics.  But the time each runner clocks is simply a measure against the apparently unmovable earth over which they race.   No consideration is given to the movement of the earth itself during the ten or so seconds that it takes the runners to complete the dash.  Nor, for that matter, to the movement of the solar system, or the galaxy, or the whole soup of reality that is the universe.  All speed is relative.  So how exactly is it that we are able to measure speed?  By motion relative to other objects that are more or less fixed in relation to it.  Now, consider that the whole of infinity; the whole of the universe, were graspable all at once, such as the Judeo-Christian god is supposed to see it.  Would there be anything against which to measure speed?  No.  Space-time dimensions would be meaningless.  But grasping the whole of infinity is the task we set for ourselves when we deign to understand the universe, this universe, in aggregate.  Never mind imagining a multitude of others.   We set ourselves the task of understanding infinity when trying to master the whole of the universe, but we only understand reality in the ordinary dimensions of space and time, which are necessarily always relative and finite matters. 

M-theory and string theory are perhaps intriguing intellectual exercises.  To believe that they will ever reveal anything of the truth of reality, either from our perspective or from the perspective of some entity understanding reality in a way that transcends dimension, is nothing more than a conceit of our frail, finite minds.