WELL, I GUESS IT WOULD BE NICE IF I COULD TOUCH YOUR BODY

Science Fashions and Scientific Fact (Michael Riordan, Physics Today)

One of the great strengths of scientific practice is what can be called the "withering skepticism" that is usually applied to theoretical ideas, especially in physics. We subject hypotheses to observational tests and reject those that fail. It is a complicated process, with many ambiguities that arise because theory is almost always used to interpret measurements. Philosophers of science say that measurements are "theory laden," and they are. But good experimenters are irredeemable skeptics who thoroughly enjoy refuting the more speculative ideas of their theoretical colleagues. Through experience, they know how to exclude bias and make valid judgments that withstand the tests of time. Hypotheses that run this harrowing gauntlet and survive acquire a certain hardness--or reality--that mere fashions never achieve. This quality is what distinguishes science from the arts.

But many of today's practicing theorists seem to be unconcerned that their hypotheses should eventually confront objective, real-world observations. In a recent colloquium I attended, one young theorist presented a talk on his ideas about what had transpired before the Big Bang. When asked what observable consequences might obtain, he answered that there weren't any, for inflation washes away almost all preexisting features. Young theorists are encouraged in such reasoning by their senior colleagues, some of whom have recently become enamored of the possibility of operating time machines near cosmic strings or wormholes. Even granting the existence of cosmic strings, which is dubious, I have a difficult time imagining how anyone could ever mount an expedition to test those ideas.

I like to call this way of theorizing "Platonic physics," because implicit within it is Plato's famous admonition that the mathematical forms of experience are somehow more real than the fuzzy shadows they cast on the walls of our dingy material caves. And, in reaction to the seemingly insuperable problems of making measurements to test the increasingly abstract theories of today, some people have even begun to suggest that we relax our criteria for establishing scientific fact. Perhaps mathematical beauty, naturalness, or rigidity--that Nature couldn't possibly choose any other alternative--should suffice. Or maybe "computer experiments," as Stephen Wolfram intimated last year in A New Kind of Science, can replace measurements. According to a leading science historian, such a subtle but ultimately sweeping philosophical shift in theory justification may already be underway.

If so, I think it would be a terrible mistake. There would then be little to distinguish the practice of physics from, say, that of painting or printmaking--in which the criteria that distinguish the good from the bad are based largely on opinions of art critics and historians. There is something unique about scientific fact, and that uniqueness has much to do with the often tedious practice of making telling empirical observations. The primary criterion of good science must remain that it has been repeatedly tested by measurements--no matter how difficult they may prove to be--and found to be in excellent accord with them.

Without such a rigorous standard of truth, science will have little defense against the onslaughts of the creationists and postmodernists, for whom it is just one of many ways to grasp the world.

It is, of course, only a lack of genuine skepticism that makes Mr. Riordan believe that "good science" can lay any greater claim to truth than metaphysics. And the shift in theory he's worried about happened when scientists accepted Darwinism based wholly on the circularity of the theory and the challenge it represented to metaphysics. Note that here too, the specific examples he uses come where scientists are trying to extend science beyond its capacities in order to challenge faith--as in speculations about what precedes the Big Bang. No one with any aesthetic sensibility will have ever believed that something as ugly as string theory was going to hold up, only the scientific mind could give such nonsense any credence. When we do finally--if we do--arrive at a final cosmological theory, it will turn out to be not only beautiful but simple and inevitable; we'll look at it and ask how we could ever have believed it to be otherwise. As Stephen Hawking says at the end of his book, A Brief History of Time:

[I]f we discover a complete theory, it should in time be understandable by everyone, not just by a few scientists. Then we shall all, philosophers, scientists and just ordinary people, be able to take part in the discussion of the question of why it is that we and the universe exist. If we find the answer to that, it would be the ultimate triumph of human reason -- for then we should know the mind of God.

Such is the purpose and ultimate end of science, to enable us to finally hear the harmony of the Universe which we only intuit now.

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ON THE MUSIC OF THE SPHERES (John Milton)

For what sane man would suppose that Pythagoras, that god of philosophers, at whose name all the men of his times rose up to do solemn reverence -- who, I say, would have supposed that he would have brought forward so well grounded a theory? Certainly, if he taught a harmony of the spheres, and a revolution of the heavens to that sweet music, he wished to symbolize in a wise way the intimate relations of the spheres and their even revolution forever in accordance with the law of destiny. In this he seems to have followed the example of the poets -- or, what is almost the same thing, of the divine oracles -- by which no sacred and arcane mystery is ever revealed to vulgar ears without being somehow wrapped up and veiled. The greatest of Mother Nature's interpreters, Plato, has followed him, for he has told us that certain sirens have their respective seats on every one of the heavenly spheres and hold both gods and men fast bound by the wonder of their utterly harmonious song. And that universal interaction of all things, that lovely concord among them, which Pythagoras poetically symbolized as harmony, was splendidly and aptly represented by Homer's figure of the golden chain which Jove suspended from heaven? Hence Aristotle, the rival and perpetual detractor of Pythagoras and Plato, hoping to pave his way to glory over the ruins of the theories of such great men, imputed this symphony of the heavens, which has never been heard, and this music of the spheres to Pythagoras. But, O Father Pythagoras, if only destiny or chance had brought it about that your spirit had transmigrated into me, you would not now be lacking a ready advocate, however great the load of infamy you might bear.

And indeed why should not the heavenly bodies produce musical vibrations? Does it not seem probable to you, Aristotle? Certainly I find it hard to believe that your intelligences could have endured the sedentary task of revolving the heavens for so many aeons, unless the ineffable chanting of the stars had detained them when they would have departed, and persuaded them by its harmonies to delay. If you take that music out of heaven, you hand over those lovely intelligences of yours and their subsidiary gods to slavery, and you condemn them to the treadmill. Why, Atlas himself would have long ago dropped the sky off his shoulders to its destruction if, while he panted and sweated under such a weight, he had not been soothed by the sweet ecstasy of that song. And the Dolphin, tired of the stars, if he had not been consumed by the thought of how far the vocal orbs of heaven surpass the sweetness of Arion's lyre, would long ago have preferred his native ocean to the skies. Why, it is quite credible that the lark herself soars up into the clouds at dawn and that the nightingale passes the night in solitary trilling in order to harmonize their songs with that heavenly music to which they studiously listen.

Hence arose also that primeval story that the Muses dance day and night before Jove's altar; and hence comes that ancient attribution of skill with the lyre to Apollo. Hence reverend antiquity believed Harmonia to be the daughter of Jove and Electra, and at her marriage with Cadmus it was said that all heaven's chorus sang. What though no one on earth has ever heard that symphony of the stars? Is that ground for believing that everything beyond the moon's sphere is absolutely mute and numb with torpid silence? On the contrary, let us blame our own impotent ears, which cannot catch the songs or are unworthy to hear such sweet strains. But this celestial melody is not absolutely unheard; for who, O Aristotle, would think those 'goats? of yours would skip in the mid region of the air unless they cannot resist the impulse to dance when they so plainly hear the music of the neighboring heavens?

But Pythagoras alone of mortals is said to have heard this harmony -- unless he was a good genius or a denizen of the sky who perhaps was sent down by some ordinance of the gods to imbue the minds of men with divine knowledge and to recall them to righteousness. At least, he surely was a man who possessed every kind of virtue, who was worthy to consort with the gods themselves, whom he resembled, and to enjoy celestial society. And so I do not wonder that the gods, who loved him very much, permitted him to enter into the most mysterious secrets of nature.

Our impotence to hear this harmony seems to be a consequence of the insolence of the robber, Prometheus, which brought so many evils upon men, and at the same time deprived us of that felicity which we shall never be permitted to enjoy as long as we wallow in sin and are brutalized by our animal desires. For how can we, whose spirits, as Persius says, are warped earthward, and are defective in every, heavenly element, be sensitive to that celestial sound? If our hearts were as pure, as chaste, as snowy as Pythagoras' was, our ears would resound and be filled with that supremely lovely music of the wheeling stars. Then indeed all things would seem to return to the age of gold. Then we should be immune to pain, and we should enjoy the blessing of a peace that the gods themselves might envy.

Posted by Orrin Judd at August 13, 2003 7:10 PM