Stringing Out Einstein
a Novice's Review of NOVA's "The Elegant Univverse"
by Ted Robinson
2005 being the hundredth anniversary of Einstein's "miracleyear", during which he published the first five of his mostsignificant papers, including special relativity, it seems onlyright to talk now about the possible answer to his final, mostfrustrating goal. Unreached by him, unfortunately, this drive for a Theory of Everything, but his earlier studies at least started others toward what might end up meeting the criteria for such a theory, according to the first part of a 3-hour series onNOVA, titled "The Elegant Universe". I missed the program when first shown in 2003, so, on hearing it would be repeated in one 3-hour clump this year, I flagged thecalendar, stationed myself before our plasmatized wall, yellow tablet and multi-pens poised, and awaited. The product of my scribblings follows, together with a couple of my dilettante musings on the subject (usually hiding within parentheses), although it loses something without the quite imaginative visuals used in NOVA. This is not intended as any kind of scientific dissertation, of course, certainly not from any shopping center developer, but it might lure some responses and clarifications from the real physicists among us.
NOVA begins the journey toward a Theory of Everything by first exploring Einstein's attempts at tying together the only two forces known at the time -- gravity and electromagnetism -- with some common element. He previously solved the macro-workings of gravity in 1915 with his theory of general relativity, a warping of space-time "like a trampoline", wherein the indentation (my word, Ithink, although an obvious one) in the trampoline by a large mass causes smaller masses either to fall into it or, angled at the right speed, to circle around the curvature of the indentation. (My grasp of this is that mass just gets in the way of an otherwise ongoing space-time, which would seem to give the mental picture more dimensionality than a trampoline, but I'm not sure whether this would be either adequate or correct.)
The main problem with finding a common element, however, was the enormous difference in strength between the two forces, since the electromagnetic force is "some thousand billion, billion, billion,billion times stronger than gravity." (Direct quote.) His efforts along these macro-world lines fell apart when young upstarts like Neils Bohr found that atoms were not the smallest particles in nature, but instead were themselves made up of a proton-neutron nucleus, orbited by electrons. Einstein's macrotheories were useless, as I understand it, at explaining how these tiny bits interact with each other. Then it got worse, and a lot more weird, with the development of quantum mechanics, which made a further shambles out of Einstein's "orderly universe". At the scale of atoms and particles the world appeared to be a game of chance, with only a "probability" of one outcome over another, and now two new forces needed to come into play -- the "strong nuclear force" to hold protons and neutrons together in the nucleus, and the "weak nuclear force" that accounts for radioactive decay (although I didn't catch what necessary function this plays), which creates radioactivity. The strong force is so powerful that if it could be broken, splitting the atom in a specific way, a chain reaction would follow and the energy released could become, among other things, an atomic bomb, with the weak force releasing the radioactive residue. Ergo, again, there seemed no way to relate relatively weak gravity with the power of either the strong force or electromagnetism.
The refinement of quantum mechanics eventually did tie together and explain three of the above -- the strong and weak forces and electromagnetism -- but at the possible cost of our sanity. The physical rules in our macro-world do not exist at the quantum level, which also spookily infers the existence of parallel universes within all the other combinations of probabilities. (I once attempted to start a discussion of these multi-world possibilities with the real physicists in the TNS e-discussions, which caused them to huff themselves off the list, hurling the epithet "pop science!" as they went. However, this NOVA program has given me a whole list of physicists from MIT, Columbia, Harvard, Cambridge and the like to hide behind as we progress into the even stranger "string"phase of this discussion. Although, as Prof Edward Farhi of MIT asks and answers himself during the program, "Do I feel likeI have a deep intuitive understanding quantum mechanics? No." So if he doesn't, me neither.)
Ah, strings. Each one a hundred billion billion (yes, a hundred billion billion) times smaller than an atom, each having their own vibration, or "song", which, in turn form together into the components of force, mass, and all things universal. (On seeing this, I could not help wondering if this was akin to reduction to such a tiny number that it becomes a common denominator for any numerator of force or mass, which would make it more of a mathematical trick. Or not. Don't ask me anything more onthat.)
Apparently the boiling down of the calculations of string theory culminated one summer night in 1984 when two scientists, Michael Greenand John Schwarz, were trying to apply the mathematics at a depth that would encompass all four basic forces. This apparently required both of two calculations (quantum and general relativity? I missed that part) to be totally free of anomalies, and, for this, both needed to come out with the same number. "On one side of the black board they got 496," said the NOVA narrator. "And if they got the matching number on the other side it would prove string theory to be free ofanomalies". They did, and therefore it was. (I have double-checked these calculations and also did not find any anomalies. . . . Just kidding.) But again (the horror, the horror), their calculations predicted a universe of more than the three-plus-one dimensions in our space-timeworld. The first calculations called for six extra dimensions, and from there it went downhill as others began jumping on the string bandwagon, creating four other string theories. Each required different numbers of dimensions, each performing without mathematical anomalies, one using 26 dimensions. Now what?
Then comes Professor Edward Witten, whom all the other scientists describe as the genius above them all, who determined that what they thought were five theories were actually just five different ways of looking at the same thing. He was able to combine them into one, his "M" theory, that recognizes that "strings need to move in more than three dimensions", but the M theory calculated that the real number of dimensions required was 11, and that number apparently has now stood unchallenged to date, more or less.
So here they've arrived at the Theory of Everything sought byEinstein, at least they've done so on paper, albeit being virtually untestable. They have, that is, if one can grasp the concept of the universe being composed of unbelievably tiny, squiggly strings. (My first thought on this, for what it's worth, was that although these calculations mathematically describe string-like elements, that might be all they do, only because strings are understandable objects in our macro-world. But these elements, having the characteristics of strings, vibrating squiggles of energy, or fields, or points of non-existence, might not be as graspable as simply picturing strings. What they really are might not be graspable at all by the current mortal ways of thinking.)
One other interesting extrapolation of this theory, a step beyond the multi-worlds of quantum mechanics or the multi-dimensions needed by strings, is that our universe is only a membrane of one dimension among many membranes that form into a larger reality. (I recall reading in an issue of Scientific American last year that, rather than the Big Bang, the origin of the universe might well be the collision of two of these so-named "branes". This further theory, apparently by applying string theory math, does calculate out without the need of supra-natural physics, such as that required by the believability-challenged expansion following the Bang.)
But, these other dimensions might indeed be provable, someday, maybe. The string theory has determined that most strings are open-ended and attached to the membrane of our dimension. Gravitons, on the other hand, are unattached closed loops and therefore are free to travel between dimensions, this slippage being a possible explanation why the force of gravity is thus so weak in our dimension. Fermilab, located near Chicago, is busily shooting hydrogen protons toward each other within a 4-mile tunnel at nearly the speed of light, hoping that the shower of particles from the collision will show a graviton in the process of disappearing into another dimension. Thus farthey haven't, but hope remains that they will before the giant CERNlab, seven times more powerful than Fermilab, comes on line in Switzerland.
Anyway, as the narrator of NOVA concluded, a hundred years from now this Theory of Everything and its inferences might be looked upon as quaint, or not, but for now at least we have one that fits, so for now the only difference between you and me appears to be the way our strings wiggle. -- T.R. __ __ __