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Has Relativity Theory
put paid to Absolute Time?


Isaac Newton

The concept of absolute time was, from the publication of Newton's Principia in the 17th Century, the accepted theory regarding the nature of time until 1905 when Einstein published his theory of relativity. This new theory based time on observers and relative positions and motions, and as a resultno longer required an absolute framework in which to exist (although some would disagree). Since then, relativity has become the accepted theory of the nature of time (at least instrumentally) and in this sense has "put paid" to absolute time.

Newton's Principia states that "absolute, true and mathematical time flows equably and without respect to anything external"², whereas "relative time" is just our sensible means of defining time as we perceive it. That is, "real and proper" time is explicitly defined as flowing evenly, constantly and in one direction. It was publications such as the Principia which shifted the way of thinking about time. During antiquity, it had been considered the product of events and motion, without which it simply would not exist. Plato for instance considered time to be created by the motion of the firmament, and Aristotle referred to time as "the number of motion". With Newton however, time became an absolute reference body in which events took place. The logical extension of this idea is of course that even if no motion or events occur, time will continue to exist, and indeed has always existed, "forever" (whatever that may mean!).

This concept of time dominated thinking for centuries, probably because it seems a fairly natural idea, and is the way in which we seem to experience time. However, at the opening of the 20th Century a scientist named Albert Einstein took a concept called the principle of relativity and turned it into a new and unusual theory³ that regarded time as completely relative to an observer. This of course created something of an upset among a few scientists who refused to disbelieve in an absolute time, such as Herbert Ives and Dean Turner, but all in all, the concept became integrated into our notion of time and is today used and taught routinely.

Newton's Absolute Time and Space seem fairly logical at a glance. It is reasonable to assume that any point in space can be defined with reference to some absolute coordinate system, and that time has a definite past, present and future. After all, this is precisely how we experience time in everyday life - I know that things I saw on the news last night occurred BEFORE now, and that I will die at some point AFTER now. As for the present, it seems to be moving towards the events that will occur after now, and away from those which occurred before now. This inherent sense of direction is known as the arrow of time, and according to Newton, the rate at which I move along this arrow is constant. Ie. the basic unit of time is always the same regardless of where I am or what I'm doing. Although sometimes time might seem to us to be somewhat elastic (as in the old adage "time flies when you're having fun"), this is put down to being our perception of events, and not anything actually to do with time itself. Newton's absolute time also implies simultaneity, the occurrence of two events at the same point in time regardless of velocities or distance. This would seem to be obvious, but Einstein would have us believe otherwise.

Einstein's Theory of Relativity sets out to say that there is no absolute time or space. We can only talk about time and space with respect to some particular reference coordinate system. For instance, relative to me, the computer at which I type this essay is directly in front of me, and the printer is to my left. In a Newtonian system, these objects could also be defined as having another position, defined by the absolute coordinate system of space. By Einstein's theory, we could also make our reference system centered about the computer. In this case, it would be I who was in front of the computer. This relativity between reference systems is what lies at the heart of the theory. Relativity begins to get very interesting when we consider time to be relative as well as space.

Due to the limiting speed of light (the ultimate velocity in the universe), one can observe events occurring at a distance only some time after they have actually occurred. This is obviously the case if one thinks, for a moment, of sound instead of light. When we see a lightning flash in the sky, it is not for a few seconds that we hear the accompanying thunder and this is because sound takes longer to travel than does light. If we were only to hear the event and not see it, we might assume that the event occurred when we heard the thunder, when in reality, it was several moments prior. To extend this principle to light one only has to observe the stars in the night sky, the light from which is thousands or millions of years old. The light from the nearest star (excluding the Sun) takes four years to arrive at Earth, so we are in fact seeing four years into that star's past. For another star, the light may take twenty years to reach us, so we see that star as it was twenty years ago. If another observer sees the two stars in question from a different point in space relative to our own, then obviously their perception of the stars' ages would be quite different. With these examples in mind, it is easy to see that time can certainly be considered relative to any particular observer we care to specify. By this argument, Einstein states that it is meaningless to talk of simultaneity except inside one reference system. So, if there is no simultaneity, the distinctions between past, present and future become decidedly blurred. What is my past could be your present, or even your future, depending on our relative distances.

Up until now, these concepts have not been too difficult to grasp, but when we introduce the idea of relative velocities into the theory, time becomes very strange indeed. As an object (say, a spaceship) approaches the speed of light, time on the ship will begin to slow down relative to some external observer. This can be proven not only through the Lorentz transformations manipulated by Einstein⁴, but also by actual experimental evidence which demonstrates irrefutably that when a clock, for example, is flown around the Earth in a plane, it actually slows down relative to a reference clock stationary on the Earth's surface⁵. With this bizarre effect proven, absolute time would appear to be disproved, but as we shall see in a moment, it was not to be that easy thanks to the efforts of various non-relativists.

At any rate, it is quite clear that Relativity Theory is completely at odds with Newton's concepts of Absolute Time and Space, and it was only a matter of "time" before one replaced the other.

Soon after Einstein's entrance, most scientists converted to his new theory because it provided more accurate results (with respect to anomalies in the path of Mercury, for instance) and simplified electrodynamics⁶ and other theories. Not all scientists were convinced by the theory however. Two notable such examples were Herbert Ives and his "disciple", Dean Turner. Turner refers to Ives' substantial body of papers rejecting relativity, as "Ives' Absolute Space and Time Theory"⁷, and attempts to defend it with extreme vigour and persistence against the tide of relativistic scientists.

Ives and Turner attempt to provide a theory that explains any and all phenomena associated with relativity, such as time dilation, and Fitzgerald contraction⁸, but with an absolute basis for time and space instead of an abstract relative version. According to Turner, to accept relativity is to "believe that nature is perversely illogical"⁹. It is statements such as this that seem to diminish somewhat his propositions, since he seems to be dismissing much of relativity on the grounds that it doesn't make logical, tangible sense. Another apparent drawback with Ives' theory is that it relies on some concept of a God¹⁰. This God acts in much the same way as does Newton's God. Ie. as a domain within which absoluteness exists. This metaphysical philosophy is an unnecessary component, since relativity theory provides the same functionality without resorting to a God.

In his attack on relativity, Turner uses the analogy of a merry-go-round or carousel to demonstrate relative motion¹¹. He states that we can observe the rotation of a carousel with reference to the "fixed" Earth, or alternatively, we can ride the "fixed" carousel and see the universe rotate around it. An interesting problem arises out of this. It is clearly sensible to anyone who has ridden a carousel that a force is exerted upon one's body towards the edge of the wheel. This is called Centrifugal Force. How do we explain this force if we assume the carousel to be fixed at the centre of a rotating universe? According to Einstein, the force is generated by the movement of all the mass of the rotating universe attracting one¹s body through a gravitational field, upon which Turner comments:

To presume the starting and stopping of all the fixed stars and galaxies just for one's little old merry-go-round introduces an embarrassing jungle of complexities. To be explained away are the unheard-of accelerations and velocities projected to all the stars insofar as they tend to lie in the plane of the merry-go-round.¹²

It would appear that Turner has completely missed the point of relativity. His comment "unheard-of accelerations" implies he believes the stars are accelerating with regard to some sort of absolute framework. Turner (and indeed Ives, upon whose work is based much of Turner's) seems to be viewing the whole theory from some sort of preconceived platform of an absolute space and time. The theory of relativity makes no claim that the stars are really spinning around the carousel at fantastic velocities, nor indeed that the carousel is turning inside a fixed universe - these are just modes of thinking of the relationship that is in place. We imagine that our reference system (for instance the carousel) is absolutely at rest, only so we may imagine the motion that is derived relative to it by the stars. To say that the carousel is actually absolutely at rest (as Turner seems to think) is both ridiculous and unintended.

Another common attack against Einstein's Special Theory of Relativity is the Twins Paradox championed by such non-relativists as Herbert Dingle It involves a pair of twins, Betty and Ann¹³, one of whom (Betty) has always wanted to be an interstellar trekker, and the other (Ann) who prefers a simple pastoral existence on Earth. If we say that Betty leaves Earth in a spaceship travelling at 80% of the speed of light, leaving Ann stationary on the ground, and returns some time later, then according to the special theory, Ann will be older than Betty by some substantially appreciable amount. This is seen by the fact that as an object approaches the speed of light, it slows down relative to an observer (recall the clocks experiment mentioned above). So, relative to her twin, Betty will move through time at a slower rate. A paradox, however, arises thus - if we accept the principle of relativity, we can view such a relative system with respect to the coordinate system of a fixed Earth (as we have just seen), or a fixed spaceship. So, let us now assume that we have a fixed spaceship, with the Earth rushing away from it at 80% of the speed of light. In this case, it would be Ann (on Earth) who would age less quickly with respect to Betty (on the "fixed" spaceship). Thus, on the Earth's return to the spaceship, we would find Ann to be younger than Betty! How can both of these results be maintained? Either, the dichotomy can be explained by some other phenomena, or the principle of relativity must be wrong. As it happens, Einstein provided some sort of solution to this paradox in his 1905 paper. He states that this relative system cannot be regarded as symmetrical, since Betty is accelerating and decelerating whilst Ann is not. The special theory of relativity deals only with objects moving at a uniform velocity, so in fact, the changes in velocity, will create an asymmetrical slant to the system, and this will in turn, skew the way in which time dilates. In other words, Einstein is arguing that whilst velocity is relative, acceleration is absolute - equal for two objects regardless of their relative velocities or distance. This is clear through a simple thought experiment which Einstein presents to us. If we were standing in a room in space, somewhere sufficiently removed from the influence of most of the matter in the universe, then we would be unable to detect the difference between a gravitational field pulling us to the floor and some being accelerating us upward¹⁴ This can be easily demonstrated by standing in a lift. If the lift is moving at uniform velocity, it is impossible to detect if one is moving or not. It is only when the lift accelerates or decelerates that some sort of motion is discernible. To Einstein, this demonstrates that acceleration is absolute whilst velocity is relative.

It is virtually universally accepted that Einstein's Theory of Relativity is simpler to use, more well defined, and more useful than that of an absolute time theory (including Ives' revision). Modern physics is based on relativity rather than classical Newtonian mechanics simply because it better explains the reality - it "saves the appearance" more readily than does any other current theory. It is not really important to decide which is REALLY correct. An instrumental approach is probably the best course to take when it comes to science, since if history has shown us anything, it is that everything we believe will eventually be refined and incorporated into a new, more general theory. In fact Newton's classical mechanics is merely a specific case of relativity - that where velocities are very small when compared to the velocity of light.

Since Einstein's Theory of Relativity has been more generally accepted than an Absolute Time concept, it is true to say that it has "put paid" to absolute time.

Notes

¹P. Davies, About Time : Einstein's Unfinished Revolution, Viking, USA, 1995, p.40.
²I. Newton, Principia Book I.
³This General Theory of Relativity was based on the mathematical equations of Lorentz and coordinate systems of Gauss, as opposed to Newton's more rigid coordinate systems of Euclid and Galileo.
⁴A. Einstein, Relativity, The Special and General Theory, A Popular Exposition, Methuen & Co. Ltd, London, 1920, pp. 35-37.
⁵D. Turner, The Einstein Myth and the Ives Papers, The Devin-Adair Company, USA, 1979, p. 46.
⁶Einstein, op cit. (note 4), p. 41.
⁷Turner, op cit. (note 5), p. 59.
⁸The tenet that states an object will contract in length in the direction of its motion as it approaches the speed of light.
⁹Turner, op. cit. (note 5), p. 3.
¹⁰Ibid., p. 65.
¹¹Ibid., p. 40.
¹²Ibid., p. 40.
¹³Paraphrased from Davies, op. cit. (note 1), p. 59.
¹⁴Einstein, op. cit. (note 4), p. 66.

Works Consulted

Borel, E., Space and Time, Dover Publications, New York USA, 1960.
Davies, P., About Time, Viking, Great Britain, 1995.
Davies, P. and Gribbin, J., The Matter Myth, Viking, Great Britain, 1991.
Einstein, A., Relativity, The Special and the General Theory, A Popular Exposition, Methuen & Co., London GB, 1920.
Grünbaum, A., Philosophical Problems of Space and Time, D. Reidel Publishing Company, Boston USA, 1973.
Newton, I., Principia, (published on the Internet).
Turner, D., The Einstein Myth and the Ives Papers, The Devin-Adair Company, USA, 1979.

Isaac Newton image published on the Internet.