A Choice of Catastrophes Page 2

  Why the devil is to be put out of action for a thousand years or ‘millennium’ and then turned loose ‘a little season’ is not clear, but at least it lifted the pressure from those who believed that the day of judgement was at hand. One could always say that the Messiah had come and that the devil was in bonds, meaning that Christianity could give strength—but the true final battle and the true end would come a thousand years later.2

  It seemed natural to suppose that the thousand years had begun ticking away with the birth of Jesus and in the 1000 there was a flurry of nervous apprehension, but it passed—and the world did not pass.

  The words of Daniel and of Revelation were so elliptical and obscure, and the urge to believe was so great, however, that it always remained possible for people to reread those books, re weigh the vague predictions, and come up with new dates for the Day of Judgement. Even great scientists, such as Isaac Newton and John Napier played that game.

  Those who tried to calculate when that crucial thousand years would start and end are sometimes called ‘millennialists’ or ‘millennarians’. They can also be called ‘chiliasts’ from the Greek word for a thousand years. Oddly enough, Millennarianism, despite repeated disappointments, is stronger now than ever.

  The current movement began with William Miller (1782–1849), an army officer who fought in the War of 1812. He had been a sceptic but after the war he became what we would now call a born-again Christian. He began to study Daniel and Revelation and decided that the Second Coming would take place on 21 March 1844. He supported it by involved calculations and predicted that the world would end in fire after the fashion of the lurid descriptions of the Book of Revelation.

  He gained a following of as many as 100,000 people, and on the day appointed, many of them, having sold their worldly goods, gathered on hillsides to be swept upward to meet Christ. The day passed without incident, whereupon Miller recalculated the matter and set 22 October 1844, as the new day, and that passed without incident also. When Miller died in 1849, the universe was still in business.

  Many of his followers were not discouraged, however. They interpreted the apocalyptic books of the Bible in such a way as to have Miller’s calculations indicate the beginning of some heavenly process as yet invisible to the ordinary consciousness on Earth. It was still another ‘millennium’ of waiting, after a fashion, and the actual Second Coming, or ‘Advent’ of Jesus was postponed once again into the future—but, as always before, the not-too-distant future.

  Thus was founded the Adventist movement, which split up into a number of different sects, including the Seventh-Day Adventists who returned to such Old Testament observances as keeping the Sabbath on Saturday (the seventh day).

  One person who adopted Adventist views was Charles Taze Russell (1852–1916) who, in 1879, founded an organization that came to be called Jehovah’s Witnesses. Russell expected the Second Coming momentarily and predicted it on several different days after the fashion of Miller, each time being disappointed. He died during World War I, which must have seemed to him like the opening of the final, climactic battles described in Revelation—but still the Advent did not follow.

  The movement continued to flourish, however, under Joseph Franklin Rutherford (1869–1942). He awaited the Second Coming with the stirring slogan, ‘Millions now living shall never die’. He himself died during World War II, which again must have seemed like the opening of the final, climactic battles described in Revelation—and still the Advent did not follow.

  But the movement flourishes anyway and now claims a world membership of over a million.

  2

  The Increase of

  Entropy

  THE CONSERVATION LAWS

  So much for the ‘mythic universe’. Along with the mythical outlook, however, there has been a scientific view of the universe, one which deals with observation and experiment (and, occasionally, intuitive insights which must then, however, be backed by observation and experiment).

  Suppose we consider this scientific universe (as we shall in the remainder of the book). Is the scientific universe, like the mythic universe, fated to come to an end? If so, how, and why, and when?

  The ancient Greek philosophers felt that while Earth was the home of change, corruption and decay, the heavenly bodies followed different rules and were changeless, incorruptible, and eternal. The medieval Christians felt that the sun, moon, and stars would meet the common ruin of the Day of Judgement but till then they were, if not eternal, at least changeless and incorruptible.

  The view began to change when the Polish astronomer Nicolas Copernicus (1473–1543) published a carefully reasoned book in 1543, one in which Earth was removed from its unique position at the centre of the universe, and was viewed as a planet which, like other planets, circled the sun. It was the sun that now took over the unique central position.

  Naturally, the Copernican view was not adopted immediately and, in fact, was violently opposed for sixty years. It was the coming of the telescope, first used to view the sky in 1609 by the Italian scientist Galileo (1564–1642), that removed opposition from, any claim to scientific respectability and reduced it to mere stubborn obscurantism.

  Galileo discovered, for instance, that Jupiter had four satellites that circled it steadily thus disproving once and for all that Earth was the centre about which all things turned. He found that Venus showed a full cycle of moonlike phases, as Copernicus predicted it would have to, where earlier views had predicted otherwise.

  Through his telescope, Galileo also saw the moon to be covered by mountains, craters, and what he took to be seas, showing that it (and by extension the other planets) were worlds like the Earth and, therefore, presumably subject to the same laws of change, corruption, and decay. He detected dark spots on the surface of the sun itself, so that even this transcendent object, which, of all material things, seemed the closest approach to the perfection of God, was after all, imperfect.

  In the search for the eternal, then—or at least for those aspects of the eternal that could be observed and were therefore part of the scientific universe—people had to reach for a more abstract level of experience. If it was not things that were eternal, perhaps it was relationships among things.

  In 1668, for instance, the English mathematician John Wallis (1616–1703) investigated the behaviour of colliding bodies and came up with the notion that in the process of collision, some aspect of movement doesn’t change.

  Here’s the way it works. Every moving body has something called ‘momentum’ (which is the Latin word for ‘movement’). Its momentum is equal to its mass (which may be roughly defined as the amount of matter it contains) multiplied by its velocity. If the movement is in one particular direction, the momentum can be given a positive sign; in the opposite direction a negative sign.

  If two bodies approach each other head-on, there will be a total momentum which we can determine by subtracting the minus-momentum of one from the plus-momentum of the other. After they strike each other and recoil, the distribution of momentum between the two bodies will change, but the total momentum will be the same as before. If they collide and stick, the new combined body will have a different mass from either separately and a different velocity from either, but the total momentum will stay the same. The total momentum stays the same even if the bodies hit at an angle instead of head-on and bounce away in changed directions.

  From Wallis’s experiments and from many others made since, it turns out that in any ‘closed system’ (one in which no momentum enters from the outside and no momentum vanishes into the outside) the total momentum always remains the same. The distribution of the momentum among the moving bodies in the system may change in any of an infinite number of ways, but the total remains the same. Momentum is therefore ‘conserved’; that is, it is neither gained nor lost; and the principle is called ‘the law of conservation of momentum’.

  Since the only truly closed system is the whole universe, the most general way of stating the law of
conservation of momentum is to say ‘the total momentum of the universe is constant’. In essence, it never changes through all eternity. No matter what changes have taken place, or may yet take place, the total momentum does not change.

  How can we be sure? How can we tell from a few observations made by scientists under laboratory conditions over a few centuries that momentum will be conserved a million years from now, or was conserved a million years ago? How can we tell whether it is conserved right now a million light-years away in another galaxy, or right in our neighbourhood under conditions as alien as those in the centre of the sun?

  We can’t tell. All we can say is that at no time under any conditions have we observed the law violated; nor have we detected anything which indicates that it ever might be violated. Furthermore, all the consequences we deduce on the assumption that the law is true seem to make sense and to fit in with what is observed. Scientists therefore feel they have ample right to assume (always pending evidence to the contrary) that the conservation of momentum is a ‘law of nature’ that holds universally through all of space and time and under all conditions.

  The conservation of momentum was only the first of a series of conservation laws worked out by scientists. For instance, one can speak of ‘angular momentum’, which is property possessed by bodies that turn around an axis of rotation, or around a second body elsewhere. In either case, one calculates angular momentum from the mass of a body, its velocity of turning, and the average distance of its parts from the axis or centre about which the turning takes place. It turns out there is a law of conservation of angular momentum. The total angular momentum of the universe is always constant.

  What’s more, the two types of momentum are independent of each other and are not interchangeable. You can’t change angular momentum into ordinary momentum (sometimes called ‘linear momentum’ to differentiate it from the other) or vice versa.

  In 1774, a series of experiments by the French chemist Antoine-Laurent Lavoisier (1743–94) suggested that mass was conserved. Within a closed system, some bodies might lose mass and others might gain it, but the total mass of the system remained constant.

  Gradually, the scientific world developed the concept of ‘energy’, that property of a body which enables it to do work. (The very word, energy, is from a Greek expression meaning ‘containing work’.) The first to use the word in its modern sense was the English physicist Thomas Young (1773–1829), in 1807. A variety of different phenomena were all capable of doing work—heat, motion, light, sound, electricity, magnetism, chemical change, and so on—and all came to be considered different forms of energy.

  The notion grew that one form of energy could be converted into another, that some bodies might lose energy in one form or another and that other bodies might gain energy in one form or another, but that in any closed system, the total energy of all forms was constant. By no means the first to think so was the German physicist Hermann L. F. von Helmholtz (1821–94), but he managed, in 1847, to persuade the scientific world generally that this is so. He is usually considered, therefore, the discoverer of the law of conservation of energy.

  In 1905, the German-Swiss physicist Albert Einstein (1879–1955) was able to argue convincingly that mass was one more form of energy, that a given quantity of mass could be converted into a fixed quantity of energy, and vice versa.

  For that reason the law of conservation of mass disappeared as a separate conservation law, and one speaks only of the law of conservation of energy these days, it being understood that mass is included as a form of energy.

  Once the structure of the atom was determined by the British physicist Ernest Rutherford (1871–1937) in 1911, it was found that there existed subatomic particles, which not only followed the laws of conservation of momentum, angular momentum, and energy, but also the laws of conservation of electric charge, baryon number, isotopic spin, and a few other such rules.

  The various conservation laws are, indeed, the basic rules of the game played by all the bits and pieces of the universe; and all those Jaws are general and eternal as far as we know. If a conservation law turns out not to be valid after all, then this proves to be so because it is part of a more general law. Thus, the conservation of mass turned out to be invalid, but part of a more general conservation of energy that includes mass.

  Now we have one aspect of the universe that would seem to be eternal and with neither beginning nor end. The energy the universe now contains will always be there in precisely the same quantity as now and has always been therein precisely the same quantity as now. Ditto the momentum, the angular momentum, the electric charge, and so on. There will be all sorts of local changes as this part or that part of the universe loses or gains one of these conserved properties, or has one of the conserved properties change its form—but the total was, is, and will be, unchanged.

  ENERGY FLOW

  We can now draw a parallel between the mythic universe and the scientific universe.

  In the case of the mythic universe, there is an eternal and undecaying heavenly kingdom against which is the changing world of the flesh with which we are familiar. It is this changing world which we think of as coming to an end; it is only this changing world concerning which the word ‘end’—or ‘beginning’, for that matter—has meaning. It is not only changing, it is temporary.

  In the scientific universe, there are the eternal and undecaying conserved properties against which is a changing world that plays itself out against the background of and according to the rules of those conserved properties. It is only this changing world concerning which the word ‘end’—or ‘beginning’—has meaning. It is not only changing, but it is temporary.

  But why should there be a changing and temporary aspect of the scientific universe? Why don’t all the components of the universe get together into one super-massive object with some certain momentum, angular momentum, electric charge, energy content, and so on, and then never change?

  Why, instead, does the universe consist of a myriad of objects of all sizes that constantly transfer bits of the conserved properties from one to another?3

  The driving power behind all these changes is, apparently, energy, so that, in a way, energy is the most important property the universe possesses, and the law of conservation of energy is considered by some to be the most basic of all the laws of nature.

  Energy drives all the changes in the universe by itself participating in changes. Bits of energy flow from one place to another, from one body to another, changing in form at times as they do so. This means we have to ask what it is that drives the energy this way and that.

  The reason for this, apparently, is that energy is spread through the universe in uneven fashion; it is present in more concentrated form in some places and in less concentrated form in other places. All the flow of bits of energy from one place to another, from one body to another, from one form to another, takes place in such a way that the tendency is to even out the distribution.4 It is the energy flow, that converts an uneven distribution to an even one, that can be used to do work and to bring about all the changes we see taking place; all the changes we associate with the universe as we know it, with life and with intelligence.

  What’s more, the evening-out of energy is spontaneous. Nothing has to drive the energy flow necessary to bring it about. It takes place by itself. It is self-driving.

  Let me give you a simple example. Suppose you have two large containers of equal size connected near the bottoms by a horizontal tube which is blocked so that no actual communication exists between the two containers. You can fill one of the containers with water all the way up to the top, while in the other you can put only a little bit of water.

  The container that is full has its water higher, on the average, than the container that is nearly empty. To lift water higher against the pull of gravity requires an input of energy so that the water in the full container has a higher level of energy with respect to the gravitational field than the water in the nearly
empty container. For historical reasons, we say that the water in the full container has more ‘potential energy’ than the water in the nearly empty container.

  Imagine, now, that the tube connecting the two containers is opened. Promptly, water will flow from the place where it contains a higher potential energy to the place where it contains a lower one. Water will flow from the full container to the nearly empty one—spontaneously.

  There’s no question in anyone’s mind, I’m sure, provided that that mind has had the least experience with the world, that this is a spontaneous and unavoidable event. If the tube were open and the water failed to flow from the full container to the nearly empty one, we would decide at once that the connecting tube was not open after all but was still blocked. If what little water was in the nearly empty container were to flow into the full container, we would have to decide that the water was being pumped.

  If the tube were undeniably open and if it were clear that no pumping was involved and if the water did not flow from the full container to the nearly empty one, or if, worse still, the water flowed in the other direction, we would have to come to the worried conclusion that we were witnessing what could only be described as a miracle. (Needless to say, no such miracle has ever been witnessed and recorded in the annals of science.5)

  In fact, so certain is the spontaneous flow of water in this fashion that we use it, automatically, as a measure of the direction of time-flow.

  Suppose, for instance, that someone had taken a motion picture of events in the two containers, and we were watching the results. The connecting tube is opened and yet the water doesn’t flow. We would at once come to the conclusion that the film wasn’t running and that we were watching a ‘still’. In the movie universe, in other words, time had come to a halt.