Chapter 8: Cyclic Universe

Many people in China and the former Soviet Union, and other places say: Matter can be changed into energy, and energy into matter. But energy cannot be destroyed. This is proved by the first Law of Thermodynamics. Thus, matter, energy, and the universe must be eternal: without beginning and without an end. Since matter and energy are eternal, God cannot have made them. - That are serious arguments. Are they valid?

Is energy eternal, because it cannot be destroyed? Has the universe once begun? Or has it always been there? And will the universe finally have an end? Or will it expand, collapse, and then expand again in an endless cycle of death and rebirth? What have some of the world’s leading scientists found out about this?

The British physicist Sir James Jeans says in his book The Universe Around Us (1931:314): "The first law of thermodynamics, which embodies the principle of ‘conservation of energy,’ teaches that energy is indestructible; it may change about from one form to another, but its total amount remains unaltered through all these changes, so that the total energy of the universe remains always the same. As the energy which is the cause of all that life of the universe is indestructible, it might be thought that this life could go on for ever undiminished in amount."

Is that true?

Sir James Jeans: "The second law of thermodynamics rules out any such possibility. Energy is indestructible as regards its amount, but it continually changes its form, and generally speaking there are upward and downward directions of change. It is the usual story - the downward journey is easy, while the upward is either hard or impossible. As a consequence, more energy passes in one direction than in the other. For instance, both light and heat are forms of energy, and a million ergs of light-energy can be transformed into a million ergs of heat with the utmost ease; let the light fall on any cool, black surface, and the thing is done.

"But the reverse transformation is impossible; a million ergs which have once assumed the form of heat, can never again assume the form of a million ergs of light. This is a special example of the general principle that radioactive energy tends always to change into a form of longer, not shorter, wavelength. In general, for instance, fluorescence increases the wave-length of light; it changes blue light into green, yellow or red, but not red light into yellow, green or blue. Exceptions to the general principle are known, but they are of special type, admitting of special explanations, and do not affect the general principle." (1931:314, 315).

"It may be objected that the everyday act of lighting a fire disproves all this. Has not the sun’s heat been stored up in the coal we burn, and cannot we produce light by burning coal? The answer is that the sun’s radiation is a mixture of light and heat, and indeed of radiation of all wavelengths. What is stored up in the coal is primarily the sun’s light and other radiation of still shorter wave-length. When we burn coal we get some light, but not as much as the sun originally put into the coal; we also get some heat, and this is more than the amount of heat which was originally put in. On balance, the net result of the whole transaction is that a certain amount of light has been transformed into a certain amount of heat." Jeans, J. (1931:315).

What does this show us?

Sir James Jeans: "All this shews that we must learn to think of energy, not only in terms of quantity, but also in terms of quality. Its total quantity remains always the same; this is the first law of thermodynamics. But its quality changes, and tends to change always in the same direction. Turnstiles are set up between the different qualities of energies; the passage is easy in one direction, impossible in the other. A human crowd may contrive to find a way round without jumping over turnstiles, but in nature there is no way round; this is the second law of thermodynamics. Energy always flows in the same direction, assuredly as water flows downhill.

"Part of the downward path consists, as we have seen, of the transition from radiation of short wave-length into radiation of longer wave-length. In terms of quanta, the transition is from a few quanta of high energy to a large number of quanta of low energy, the total amount of energy of course remained unaltered. The downfall of the energy accordingly consists in the breaking of its quanta into smaller units. And when once the fall and breakage have taken place, it is impossible to reconstitute the original large quanta as it was put Humpty-Dumpty back on his wall. Although this is the main part of the downward path, it is not the whole of it. Thermodynamics teaches that all the different forms of energy have different degrees of ‘availability’ and that the downward path is always from higher to lower availability." - Jeans, J. (1931:316).

"And now we may return to the question with which we started the present chapter: ‘What is it that keeps the varied life of the universe going?’ Our original answer ‘energy’ is seen to be incomplete. Energy is no doubt essential but the really complete answer is that it is the transformation of energy from a more available to a less available form; it is the running downhill of energy. To argue that the total energy of the universe cannot diminish, and therefore the universe must go on for ever, is like arguing that as a clockweight cannot diminish, the clock-hand must go round and round for ever." Jeans, J. (1931:316).

Will the Universe finally end?

Will the universe always be there, since its energy cannot be destroyed? Or will it finally end?

Sir James Jeans: "Energy cannot run downhill for ever, and, like the clockweight, it must touch bottom at last. And so the universe cannot go on for ever; sooner or later the time must come when the last erg of energy has reached its lowest rung on the ladder of descending availability, and at this moment the active life of the universe must cease. The energy is still there, but it has lost all capacity for changes; it is as little able to work the universe as the water in a flat pond is able to turn a water-wheel.

"Such is the teaching of modern thermodynamics. There is no reason for doubting or challenging it, and indeed it is so fully confirmed by the whole of our terrestrial experience, that it is difficult to see at what point it could be open to attack. It disposes at once of any possibility of a cyclic universe in which the events we see are as the pouring of river water into the sea, while events we do not see restore this water back to the river. The water in the river can go round and round in this way, just because it is not the whole of the universe; something extraneous to the river-cycle keeps it continuously in motion - namely, the heat of the sun.

"But the universe as a whole cannot so go round and round. Short of postulating continuous action from outside the universe, whatever this may mean, the energy of the universe must continually lose availability; a universe in which the energy had no further availability to lose would be dead already." Jeans, J. (1931:317).

Where else can one apply these general principles?

Sir James Jeans: "The same general principles maybe applied to the astronomical universe. There is no question as to the way in which energy runs down here. It is first liberated in the hot interior of the star in the form of quanta of extremely short wave-length and excessively high energy. As this radiant energy struggles out to the star’s surface, it continually adjusts itself, through repeated absorption and re-emission, to the temperature of that part of the star through which it is passing. As longer wave-lengths are associated with lower temperature, the wave-length of the radiation is continually lengthened; a few energetic quanta are being transformed into numerous feeble quanta. Once these are free in space, they travel onward unchanged until they meet dust particles, stray atoms, free electrons, or some other form of interstellar matter.

"Except in the highly improbable event of this matter being at a higher temperature than the surfaces of the stars, these encounters still further increase the wave-length of the radiation, and the final result of innumerable encounters still further increase the wave-length of the radiation, and the final result of innumerable encounters is radiation of very great wave-length. The quanta have increased enormously in numbers, but have paid for their increase by a corresponding decrease in individual strength. In all probability, the original very energetic quanta had their source in the annihilation of protons and electrons, so that the main process of the universe consists in the energy of exceedingly high availability which is bottled up in electrons and protons being transformed into heat energy at the lowest level of availability.

"The final state of the universe will, then, be attained when every atom which is capable of annihilation has been annihilated, and its energy transformed into heat-energy wandering for ever round space, and when all the weight of any kind whatever which is capable of being transformed into radiation has been so transformed." - Jeans, J. (1931:318, 319).

The Creation of Matter

The waves of radiation are getting longer with time, are getting weaker. High-quality energy changes into low-quality energy. - What does that prove?

Sir James Jeans: "All this makes it clear that the present matter of the universe cannot have existed forever. ... In some way matter which had not previously existed, came, or was brought, into being. If we want a naturalistic interpretation of this creation of matter, we may imagine radiant energy of any wave-length less than 1.3 x 10^-13 cms. Being poured into empty space; this is energy of higher ‘availability’ than any known in the present universe, and the running down of such energy might well create a universe similar to our own. ... radiation of the wave-length just mentioned might conceivably crystallise into electrons and protons, and finally form atoms." (1931:324).

The Cyclic Universe, since all Eternity?

Has the universe always been there, as some claim, since all eternity? - If not: What clear scientific proof is there? What have scientists found out about this in the meantime?

The British physicist John Gribbin writes in his book The Omega Point (1988:5): "The most important feature of our world is that night follows day. The dark night sky shows us that the Universe at large is a cold and empty place, in which are scattered a few bright, hot objects, the stars. ... If the Universe had existed for an eternity, and had always contained the same number of stars and galaxies as it does today, distributed in more or less the same way throughout space, it could not possibly present the appearance that we observe. Stars pouring out their energy, in the form of light, for eternity, would have filled up the space between themselves with light, and the whole sky would blaze with the brightness of the Sun.

"The fact that the sky is dark at night is evidence that the Universe we live in is changing, and has not always been as it is today. Stars and galaxies have not existed for an eternity, but have come into existence relatively recently; there has not been time for them to fill the gaps in between with light. Astrophysicists, who study the way in which the stars produce their energy, by nuclear reactions deep in their hearts, can also calculate how much light a typical star can pour out into space during its lifetime. The supply of nuclear fuel is limited, and the amount of energy a star can produce by the conversion of hydrogen into helium, is also limited.

"Even when all the stars in all the galaxies in the known Universe have run through their life cycles and become not more than cooling embers, space, and the night sky, will still be dark. There is not enough energy available to make enough light to brighten the night sky. The oddity, the strangeness of the observation that night follows day, is not that the sky is dark, but that it should contain any bright stars at all. How did the Universe come to contain these short-lived (by cosmological standards) beacons in the dark? That puzzle is brought home with full force by the light of the Sun in the daytime. This represents an imbalance in the Universe, a situation in which there is a local deviation from equilibrium. It is a fundamental feature of the world that things tend towards equilibrium.

"If an ice-cube is placed in a cup of hot coffee, the liquid cools and the ice melts as it warms up. Eventually, we are left with a cup of lukewarm liquid, all at the same temperature, in equilibrium. The Sun, born in a state which stores a large amount of energy in a small volume of material, is busily doing much the same thing, giving up its store of energy to warm the Universe (by a minute amount) and, eventually, cooling into a cinder in equilibrium with the cold of space. ...

"Because night follows day, we know that there are pockets of non-equilibrium conditions in the Universe. Life depends on the existence of those pockets. We know that the Universe is changing, because it cannot always have existed in the state we observe today and still have a dark sky. The Universe as we know it was born, and will die." - Gribbin, J. (1988:5-7).

The Supreme Law

What is the "supreme law" in physics? And what does it have to do with our question: Has the universe been there already since all eternity? And will it finally have an end?

John Gribbin: "All these features of the Universe are bound up with what Arthur Eddington, a great British astronomer of the 1920s and 1930s, called the supreme law of Nature. It is named the second law of thermodynamics, and was discovered, during the nineteenth century, not by astronomical studies of the Universe but from very practical investigations of the efficiency of the machines that were so important during the Industrial Revolution - steam engines.

"It may seem odd that such an exalted rule of nature should be the ‘second’ law of anything; but the first law of thermodynamics is simply a kind of throat-clearing statement to the effect that heat is a form of energy, that work and heat are interchangeable, but that the total amount of energy in a closed system is always conserved - for example, if our coffee cup is a perfect insulator, once the ice-cube has been dropped into the hot coffee, although the ice warms and the coffee cools, the total energy inside the cup stays the same. This in itself was an important realization to the pioneers of the Industrial Revolution, but the second law goes much further." (1988:7, 8).

"There are many different ways of stating the second law, but they have to do with the features of the Universe that I have already mentioned. A star like the Sun pours out heat into the coldness of space; an ice-cube placed in hot liquid melts. We never see a cup of lukewarm coffee in which an ice-cube forms spontaneously while the rest of the liquid gets hotter, even though the two states (ice-cube + hot coffee) and (lukewarm coffee) contain exactly the same amount of energy.

"Heat always flows from the hotter to the cooler. Although the amount of energy is conserved, the distribution of energy can only change in certain ways, irreversibly. Photons (particles of light) do not emerge from the depth of space to converge on the Sun in just the right way to heat it up and drive the nuclear reactions in its core in reverse."

"Another definition of the second law involves the idea of information - when things change, there is a natural tendency for them to become more disordered, less structured. There is a structure in the system (ice-cube + hot coffee) that is lost in the system (lukewarm coffee). In everyday terms, things wear out. Wind and weather crumble stone and reduce abandoned houses to piles of rubble; they never conspire to create a neat brick wall out of debris.

"Physicists can describe this feature of nature mathematically, using a concept called entropy, which we can best think of as a negative measure of information, or of complexity. Decreasing order in a system corresponds to increasing entropy. The second law says that in any closed system, entropy always increases (or, at best, stays the same) while complexity decreases."

"The concept of entropy helps to provide the neatest, and best, version of the second law, but one which is only really useful to mathematical physicists. Rudolf Clausius, a German physicist who was one of the pioneers of thermodynamics, summed up the first and second laws in 1865: the energy of the world is constant; the entropy of the world is increasing. Equally succinctly, some unknown modern wit has put it in every day language: You can’t get something from nothing; you can’t even break even. This is apposite because entropy, and the second law, can also be thought of as telling us something about the availability of useful energy.

"Peter Atkins, in his excellent book The Second Law, points out that since energy is conserved, there can hardly be any energy ‘crisis’ in the sense that we are using up energy. When we burn oil or coal we simply turn one (useful) form of energy into another (less useful, less concentrated) form. Along the way, we increase the entropy of the Universe, and diminish the quality of the energy. What we are really faced with is not an energy crises, but an entropy crises." - Gribbin, J. (1988:8-10).

What do you conclude now from your research?

John Gribbin: "The whole Universe - which must, by definition, be a closed system in the sense of the term - is in the same boat. Concentrated, ‘useful’ energy inside stars is being poured out and spread thin throughout space, where it can do no good."

"Energy at high temperature is low in entropy, and can easily be made to do useful work. Energy at low temperature is high in entropy and cannot easily be made to do work. This is straightforward to understand, since energy flows from a hotter object to a cooler one, and it is easy to find a cooler object, than, say, the surface of the Sun, into which energy from the Sun can be made to flow and do work along the way.

"It is hard to find an object colder than - say - an ice cube, so that we can extract heat from the ice cube and use it to do work. On Earth, it is much more likely that heat will flow in to the ice-cube. Things would be a little different in space, where it is much colder than the surface of the Earth. An ice-cube at 0°C would still contain some useful energy which could be extracted and made to do work under those conditions. But still, there is a limit, an absolute zero of temperature. 0 K on the Kelvin scale named after another of the thermodynamic pioneers. An object at 0 K contains no heat energy at all." - Gribbin, J. (1988:10, 11).

Result

The idea about the "cyclic universe" is disproved by the second law of thermodynamics. The universe has once begun. Also its energy, of very high quality, has arisen then. The Creator has made it from nothing. - All material things - also the universe - in a closed system will wear down in time and pass away, according to the second law of thermodynamics. But the Creator exists outside the time and space of the universe. He can (and will) renew the universe, so that it will last forever. So it will have then a beginning, but no end.