Introduction

Religion does not take kindly to time. For many people the impulse to religion is generated by a desire to escape from the tyranny of time: we seek a refuge from the changes and chances of this fleeting world, and hope to evade the inevitable mortality of our temporal existence, by moving to a higher plane of reality, where the limitations of temporality are transcended by the eternal verities of absolute existence. And, independently of our motives for seeking God, it would seem to derogate from His perfection to subject the Almighty to the corrosion of time. So the Greeks, once they began to emancipate themselves from the all-too-human gods of Olympus, started to posit a timeless Absolute, an impassible, unmoved mover, the ground of our being, and perhaps the worthy recipient of our worship, but not an active intervener in our affairs or a person with whom we could communicate

The God of the philosophers was clearly very different not only from the Olympian deities but equally from the Yaweh of the Jews. The God of Abraham, Isaac and Jacob was thought to have intervened on many occasions in the course of the history of Israel, giving them a helping hand in their escape from Egypt, and a chastening one when they went after false gods. The word of the Lord came to the prophets, often unwelcomely as it did also to David and Ahab when they strayed from the straight and narrow path of righteousness.

Prediction and timing in motor skills

An impressive skill is that of the waiter who brings a tray of glasses full to the brim to your table and sets the glasses down, one by one, without spilling a drop – either from the one that he is lifting or from the ones that remain on the tray. Since one hand is placing each glass, he has only one hand free to balance the tray. Though it starts evenly loaded, as he takes each glass it necessarily upsets the balance, which requires corrective action if the tray is not to tilt and cause spillage. But note the problem: correction on the basis of sensory feedback takes time due to perceptual and motor delays – say one to two hundred milliseconds to process visual input and a similar further amount of time to select and implement appropriate corrective action – and requires attention. Yet the waiter's attention is probably fixed on determining who is to receive the glass and he does not have time (nor would it look so impressive) to check and correct the disturbance to equilibrium caused by removing the glass. The solution to this problem lies in prediction. If the waiter can anticipate the effect of removing the glass he can implement simultaneous correction.

Predictive adjustment of arm position was demonstrated in an experiment in which each volunteer participant (‘subject’) was blindfolded, while using one hand to support a weight.

Introduction

I expect that, for most readers, the title of this chapter would at first glance seem a little curious. Perhaps it is a misprint, and ‘physics’ should replace ‘genetics’? Most people would correctly consider the scientific study of time to lie more in the domains of theoretical physics and mathematics. These aspects will be covered in other chapters, but here the biology of time, and particularly the question of how time is encoded within the genome of an organism, will take centre stage.

Biological time, be it for a bacterium, a plant, a fruitfly or a human, is represented by any temporally defined activity. For example, circadian time (Latin: circa = about, dies = day), the major subject of this discussion, is the 24 hour cycle of behaviour and physiology that percolates through the very essence of almost every higher organism that lives on this planet. However, there are many other time scales, both longer and shorter than 24 hours, that have biological significance. Moving up the scale, the ovulation cycles in human females show a monthly rhythm. Our larger domesticated mammals show annual cycles of reproduction that are closely tied to the number of daylight hours, or photoperiod. There are also well-known examples of rhythms that span several years, for example some insect pests show six to seven year swarming cycles.

The subject of time

The subject of ‘time’ exercises a universal fascination. In no small part this is due to the genuinely interdisciplinary nature of the issues that arise. Thus questions about the nature of time occur in areas as disparate as physics, biology, psychology, philosophy, poetry (think of the work of T. S. Elliot), visual art, theology, music (for example, in the chanting of plainsong) and many more.

Some of these topics are covered in other chapters in this book, but in all cases – or, at least, in the more academic disciplines – a basic question is how the concept of time fits into the underlying metaphysical structure of the subject concerned. Thus, for us, a key issue is the role played by time in the foundations of modern physics. And, as theoretical physicists, we are particularly concerned with how the answer to this question relates to the various mathematical structures that are involved in the physicist's account of time.

Let us begin by remarking that there are two quite different ways in which time has been viewed by physical scientists: these are known as the absolute and relational ideas of time. In essence, the difference comes down to whether or not we grant time (and space) an existence independent of material objects and processes.

My title calls up childhood: ‘Storytime’ – a time set aside at home or in the school to listen to tales told, tales that are separated off from the busy routine of the day. That nursery setting is no accident. Listening to stories goes very deep down into personal history: it is there at the start of our learning where actuality and fantasy touch each other, and where they separate. It reinforces lines of descent. It tells us about the world before we were, and gives us a foothold in that world. Sylvia Townsend Warner, for example, dedicates her novel The True Heart (1929), with its submerged allusions to the tale of Cupid and Psyche:

In stories and their telling, time is endlessly renewable. Those early storytimes when tales are told or read aloud give us warnings and promises about the future too, though the figures are at first sight improbable: grandmothers who turn into wolves, wolves who turn into mothers, glass slippers that do not cripple you.

But there is something concessive in the word storytime, something a little condescending, even drab. The time reserved for stories is both privileged and defensive: stories are (it is implied) different in nature from the ordinary and, if they seep into daily life, they do so with a warning. They are fugitives from the reservation: from that encircled place that is also a particular time.

The accident at the Chernobyl nuclear power plant in the Soviet Union on 26 April 1986 is one of the defining moments of the nuclear age. It is the worst nuclear accident ever: a melt-down of the core of a reactor, followed by an explosion and fire releasing tons of radioactive debris into the atmosphere. The accident not only killed nuclear workers and firemen who fought to save the doomed reactor, but also condemned many others who lived under the path of the fallout to illness and premature death or a life of waiting for a hidden enemy. The weather, no respecter of nation states, carried its deadly passenger far and wide.

Fallout over Britain

At first, Britain seemed likely to escape as its predominant weather pattern comes from the west. Traditional British scepticism about weather forecasts was confirmed, however, when six days after the accident, torrential rain and thunderstorms over mountains and uplands deposited a charge of radioactive material. The Chernobyl cloud had undergone a 4,000 kilometre journey with virtually no precipitation until it reached Britain.

Every schoolchild sooner or later learns the standard story of the origins of oil; it runs something like this. Once upon a time, hundreds of millions of years ago, the earth was covered by vast oceans. Animals, plants and micro-organisms in the seas lived and died by the billion, their remains sinking to the bottom and mixing with sand and mud to form marine sediment. As the ages passed, the mud turned to rock and eventually the organic mass became buried deep under layers of rock. The oceans receded and the earth's crust heaved and buckled. Compressed under this vast weight of rock, decomposition occurred and the layers of biomass underwent a chemical change to form hydrocarbons (compounds composed only of hydrogen and carbon atoms) – coal, oil, and natural gas.

Special geological conditions are needed to keep the oil trapped underground. The organic material has to be covered by porous rocks and these, in turn, have to be covered by an impermeable layer which acts as a cap to prevent the oil and gas escaping. Oil is consequently found only in places where these geological conditions are met.

Although this crude, even mythical, account has become greatly more refined in modern petroleum geology, the underlying tenet that oil is formed by biological decay is the starting point for any exploration of the subject.

With the exception of most of Chapter 1 and the whole of Chapter 3, the substantive parts of this book are largely expositions of others' work; in this we follow the pattern of the first volume in the Golem series. The full bibliographic references to the works discussed both in this Preface and the other chapters, as well as additional reading, will be found in the Bibliography at the end of the volume.

As for the substantive chapters, Chapter 1 is Collins's redescription of the argument over the success of the Patriot missile. It is heavily based on the record of a Congressional hearing that took place in April 1992, and on two papers written by principal disputants, Theodore Postol and Robert Stein; it also draws on wider reading. Though this chapter is not a direct exposition of anyone else's argument, and though it uses a new analytic framework turning on different definitions of success, it must be made clear that the account was made possible only because of Postol's prior work. Also, Postol was extremely generous in supplying Collins with much of the relevant material and drawing his attention to more. Collins has tried to make sure that the account is not unduly influenced by Postol's views and that the material on which it draws represents the field in a fair way.

PROMISES DELIVERED

The conclusion of The Golem, the first volume in this series, argued that the book had wide significance where science touched on matters of public concern. Here we deliver on that promise.

The chapter on the Challenger explosion shows the way that human error is taken to account for technological failure and shows how unfair it is to assign blame to individuals when the uncertainties are endemic to the system as a whole.

The Challenger enquiry is one case among many that reveals that when the public views the fruits of science from a distance the picture is not just simplified but significantly distorted. Nobel laureate Richard Feynman demonstrated on TV that when a piece of rubber O-ring was placed in a glass of iced water it lost resilience. This was at best trivial – the effect of low temperature on rubber was already well understood by the engineers. At worst it was a dangerously misleading charade – an acting-out of the most naive model of scientific analysis. The crucial question was not whether low temperature affected the O-rings but whether NASA had reason to believe this would cause them to fail. Feynman gives the impression that doubts can always be simply resolved by a scientist who is smart enough.

On 24 April 1984, Margaret Heckler, US Secretary of Health and Human Services, announced with great gusto at a Washington press conference that the cause of AIDS had been found. A special sort of virus – a retrovirus – later labelled as HIV, was the culprit. Vaccinations would be available within two years. Modern medical science had triumphed.

Next summer, movie star Rock Hudson died of AIDS. The gay community had lived and died with the disease for the previous four years. Now that the cause of AIDS had been found and scientists were starting to talk about cures, the afflicted became increasingly anxious as to when such cures would become available. Added urgency arose from the very course of the disease. The HIV blood test meant lots of seemingly healthy people were facing an uncertain future. Was it more beneficial to start long-term therapy immediately or wait until symptoms appeared? Given the rapid advance in medical knowledge about AIDS and the remaining uncertainties (even the cause of AIDS was a matter of scientific debate), was it better to act now with crude therapies or wait for the more refined treatments promised later?

AIDS: THE ‘GAY PLAGUE’

AIDS is not confined to homosexuals, but in the US it was first described in the media as the ‘gay plague’ and gays as a community were quick to respond to its consequences. The gay community in the US is no ordinary group.

THE GULF WAR

In August 1990 Iraqi forces invaded Kuwait. The United States presented Iraq with an ultimatum – ‘withdraw or face a military confrontation’. The Iraqi president, Saddam Hussein, responded by threatening to stage ‘The Mother of All Battles’. Over the next four months the United States set about building up military strength in neighbouring Saudi Arabia with the intention of driving Saddam's army from Kuwait. Given Iraq's confrontational stance, this meant building a force capable of destroying all of Iraq's military resources.

Considering the scale of the imminent confrontation, and its distance from the American continent, the United States needed the backing of the United Nations and the military and political co-operation of many nations, notably Iraq's neighbours. A critical feature of this alliance was that a set of Arab states would side with the Western powers' attack on a fellow Arab state. As the old saying goes, ‘my enemy's enemy is my friend’, and at that time all the Arab states except Egypt had an enemy in common – Israel. On the other hand, America was Israel's staunchest ally, while Iraq was viewed as an important player in the confrontation with Israel. Thus the political alignment that the US needed to hold in place was continually in danger of collapse. It was crucial for American policy in respect of the forthcoming Gulf War that Israel did not take part in the conflict.

‘Science seems to be either all good or all bad. For some, science is a crusading knight beset by simple-minded mystics while more sinister figures wait to found a new fascism on the victory of ignorance. For others it is science which is the enemy; our gentle planet, our slowly and painfully nurtured sense of right and wrong, our feel for the poetic and the beautiful, are assailed by a technological bureaucracy – the antithesis of culture – controlled by capitalists with no concern but profit. For some, science gives us agricultural self-sufficiency, cures for the crippled, a global network of friends and acquaintances; for others it gives us weapons of war, a school teacher's fiery death as the space shuttle falls from grace, and the silent, deceiving, bone-poisoning, Chernobyl.

Both of these ideas of science are wrong and dangerous. The personality of science is neither that of a chivalrous knight nor pitiless juggernaut. What, then, is science? Science is a golem.

A golem is a creature of Jewish mythology. It is a humanoid made by man from clay and water, with incantations and spells. It is powerful. It grows a little more powerful every day. It will follow orders, do your work, and protect you from the ever threatening enemy. But it is clumsy and dangerous. Without control a golem may destroy its masters with its flailing vigour; it is a lumbering fool who knows neither his own strength nor the extent of his clumsiness and ignorance.

We always remember where we were when we first heard about a momentous event. Those over forty-five years old know what they were doing when they heard that John F. Kennedy had been assassinated. Similarly, anyone who was watching television remembers where they were at 11:38 a.m. Eastern Standard Time on 28 January, 1986 when the Space Shuttle Challenger exploded. The billowing cloud of white smoke laced with twirling loops made by the careering Solid Rocket Boosters proclaimed the death of seven astronauts and the end of the space programmme's ‘can do’ infallibility.

Unlike the inconclusive Warren Commission that inquired into Kennedy's death, the Presidential Commission chaired by William Rogers soon distributed blame. There was no ambivalence in their report. The cause of the accident was a circular seal made of rubber known as an O-ring. The Challenger's Solid Rocket Boosters were made in segments, and the O-rings sealed the gap between them. A seal failed and the escaping exhaust gas became a blow torch which burned through a strut and started a sequence of events which led to the disaster.

The Commission also revealed that the shuttle had been launched at unprecedentedly low temperatures at the Cape. Richard Feynman the brilliant, homespun American physicist is often credited with the proof. At a press conference he used a piece of rubber O-ring and a glass of iced water to show the effect of cold on rubber.

Shortly after the Second World War, an engineer from New Zealand, ‘Bill’ Phillips, working at the London School of Economics, built a model of the economy. The marvellous thing about this model was that it ran on water. Phillips's model was a set of tanks, valves, pumps, pipes, baffles and cisterns. If, say, the flow into some cistern increased while the cross section of the output remained the same, the water in the cistern would rise. The new level might increase the flow of water into another cistern, raising its level, or it might be enough to trigger a valve and restrict the flow somewhere else. The whole thing, which stood about seven feet high, weighed a good part of a ton, and was prone to leakage and corrosion, was meant to represent the flows of income around a national economy. Changes of levels were linked by indicators to scales which represented measures of economic performance such as price indices, stocks of money, or Gross National Product. It was even possible to link one of these gurgling monsters to another, thus representing the interaction of two national economies, or the interaction of one economy with the rest of the world. Phillips's hydraulic model of the economy has been restored recently and can be seen at the Science Museum in London.

Nowadays no one would dream of building a model of the economy that ran on water.