Valid criticism does you a favour.
Some people consider science arrogant – especially when it purports to contradict beliefs of long standing or when it introduces bizarre concepts that seem contradictory to common sense; like an earthquake that rattles our faith in the very ground we’re standing on, challenging our accustomed beliefs, shaking the doctrines we have grown to rely upon, can be profoundly disturbing. Nevertheless, I maintain that science is part and parcel humility. Scientists do not seek to impose their needs and wants on Nature, but instead humbly interrogate Nature and take seriously what they find. We are aware that revered scientists have been wrong. We understand human imperfection. We insist on independent and – to the extent possible – quantitative verification of proposed tenets of belief. We are constantly prodding, challenging, seeking contradictions or small, persistent residual errors, proposing alternative explanations, encouraging heresy. We give our highest rewards to those who convincingly disprove established beliefs.
Here’s one of many examples: the laws of motion and the inverse square law of gravitation associated with the name of Isaac
Newton are properly considered among the crowning achievements of the human species. Three hundred years later we use Newtonian dynamics to predict those eclipses. Years after launch, billions of miles from Earth (with only tiny corrections from Einstein), the spacecraft beautifully arrives at a predetermined point in the orbit of the target world, just as the world comes ambling by. The accuracy is astonishing. Plainly, Newton knew what he was doing.
But scientists have not been content to leave well enough alone. They have persistently sought chinks in the Newtonian armour. At high speeds and strong gravities, Newtonian physics breaks down. This is one of the great findings of Albert Einstein’s Special and General Relativity, and is one of the reasons his memory is so greatly honoured. Newtonian physics is valid over a wide range of conditions including those of everyday life. But in certain circumstances highly unusual for human beings – we are not, after all, in the habit of travelling near light speed – it simply doesn’t give the right answer; it does not conform to observations of Nature. Special and General Relativity are indistinguishable from Newtonian physics in its realm of validity, but make very different predictions – predictions in excellent accord with observation – in those other regimes (high speed, strong gravity). Newtonian physics turns out to be an approximation to the truth, good in circumstances with which we are routinely familiar, bad in others. It is a splendid and justly celebrated accomplishment of the human mind, but it has its limitations.
However, in accord with our understanding of human fallibility, heeding the counsel that we may asymptotically approach the truth but will never fully reach it, scientists are today investigating regimes in which General Relativity may break down. For example, General Relativity predicts a startling phenomenon called gravitational waves. They have never been detected directly. But if they do not exist, there is something fundamentally wrong with General Relativity. Pulsars are rapidly rotating neutron stars whose flicker rates can now be measured to fifteen decimal places. Two very dense pulsars in orbit around each other are predicted to radiate copious quantities of gravitational waves, which will in time slightly alter the orbits and rotation periods of the two stars.
Joseph Taylor and Russell Hulse of Princeton University have used this method to test the predictions of General Relativity in a wholly novel way. For all they knew, the results would be inconsistent with General Relativity and they would have overturned one of the chief pillars of modern physics. Not only were they willing to challenge General Relativity, they were widely encouraged to do so. As it turns out, the observations of binary pulsars give a precise verification of the predictions of General Relativity, and for this Taylor and Hulse were co-recipients of the 1993 Nobel Prize in Physics. In diverse ways, many other physicists are testing General Relativity, for example by attempting directly to detect the elusive gravitational waves. They hope to strain the theory to the breaking point and discover whether a regime of Nature exists in which Einstein’s great advance in understanding in turn begins to fray.
These efforts will continue as long as there are scientists. General Relativity is certainly an inadequate description of Nature at the quantum level, but even if that were not the case, even if General Relativity were everywhere and forever valid, what better way of convincing ourselves of its validity than a concerted effort to discover its failings and limitations?
This is one of the reasons that the organized religions do not inspire me with confidence. Which leaders of the major faiths acknowledge that their beliefs might be incomplete or erroneous and establish institutes to uncover possible doctrinal deficiencies? Beyond the test of everyday living, who is systematically testing the circumstances in which traditional religious teachings may no longer apply? (It is certainly conceivable that doctrines and ethics that may have worked fairly well in patriarchal or patristic or medieval times might be thoroughly invalid in the very different world we inhabit today.) What sermons even-handedly examine the God hypothesis? What rewards are religious sceptics given by the established religions – or, for that matter, social and economic sceptics by the society in which they swim?
Science, Ann Druyan notes, is forever whispering in our ears, ‘Remember, you’re very new at this. You might be mistaken. You’ve been wrong before.’ Despite all the talk of humility, show me something comparable in religion. Scripture is said to be divinely inspired – a phrase with many meanings. But what if it’s simply made up by fallible humans? Miracles are attested, but what if they’re instead some mix of charlatanry, unfamiliar states of consciousness, misapprehensions of natural phenomena and mental illness? No contemporary religion and no New Age belief seems to me to take sufficient account of the grandeur, magnificence, subtlety and intricacy of the Universe revealed by science. The fact that so little of the findings of modern science is prefigured in Scripture to my mind casts further doubt on its divine inspiration. But of course I might be wrong.
Read the following two paragraphs – not to understand the science described, but to get a feeling for the author’s style of thinking. He is facing anomalies, apparent paradoxes in physics; ‘asymmetries’ he calls them. What can we learn from them?
It is known that Maxwell’s electrodynamics – as usually understood at the present time – when applied to moving bodies, leads to asymmetries which do not appear to be inherent in the phenomena. Take, for example, the reciprocal electrodynamic action of a magnet and a conductor. The observable phenomenon here depends only on the relative motion of the conductor and the magnet, whereas the customary view draws a sharp distinction between the two cases in which either the one or the other of these bodies is in motion. For if the magnet is in motion and the conductor at rest, there arises in the neighbourhood of the magnet an electric field with a certain definite energy, producing a current at the places where parts of the conductor are situated. But if the magnet is stationary and the conductor in motion, no electric field arises in the neighbourhood of the magnet. In the conductor, however, we find an electromotive force, to which in itself there is no corresponding energy, but which gives rise – assuming equality of relative motion in the two cases discussed – to electric currents of the same path and intensity as those produced by the electric forces in the former case.
Examples of this sort, together with the unsuccessful attempts to discover any motion of the earth relative to the ‘ether’, suggest that the phenomena of electrodynamics as well as of mechanics possess no properties corresponding to the idea of absolute rest. They suggest rather that, as has already been shown to the first order of small quantities, the same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good.
What is the author trying to tell us here? I’ll try to explain the background later in this book. For now, we can perhaps recognize that the language is spare, technical, cautious, clear, and not a jot more complicated than it need be. You would not offhand guess from how it’s phrased (or from its unostentatious title, ‘On the Electrodynamics of Moving Bodies’) that this article represents the crucial arrival of the theory of Special Relativity into the world, the gateway to the triumphant announcement of the equivalence of mass and energy, the deflation of the conceit that our small world occupies some ‘privileged reference frame’ in the Universe, and in several different ways an epochal event in human history. The opening words of Albert Einstein’s 1905 paper are characteristic of the scientific report. It is refreshingly unselfserv-ing, circumspect, understated. Contrast its restrained tone with, say, the products of modern advertising, political speeches, authoritative theological pronouncements – or for that matter the blurb on the cover of this book.