The Fourth Dimension

Enigma of Time

Dayalanand Roy

• Publisher: BrownWalker Press
• Year: 2021
• ISBN:
  9781599426235
• Topic: Physical Sciences
• Subtopic: Physics
• Index: Physics

Einstein shocked the world by revealing that time can be different for different observers. This book offers a possible explanation of why it is so. It offers a never-attempted-before approach to understand the secret of time. As we all know, there is an

Chapter 1

We are All Time Travelers

“What is time? If no one asks me, I know. If I wish to explain it, I know not.”

—(St. Augustine in Confessions)

What is Time?

It’s unbranched and unclaimed,

Elusive and in vain.

It ebbs and it flows,

Wishing away as it goes…..

It heals the broken and bruised,

Has been abused and misused.

Infinite and untamed,

Only time will remain.

—Crystal Lewis, “Only Time Will Remain.”

These beautiful lines of the American poet and singer, Crystal Lewis beautifully describe the enigmatic time. Unbranched and unclaimed, yet infinite and untamed! But what is this unbranched and unclaimed time? What is that that only will remain infinite and untamed? Can our finite vision be ever able to peep into this infinite and untamed healer of the broken and bruised, the witness of our first breath and our ashes’ last cast?

None other quote than the one by St. Augustine in ‘Confessions’ that opens this chapter gives the answer to these questions in a better way. If no one asks me, I know. If I wish to explain it, I know not.

I am not a physicist. I study Biology. Like every lay person, I had never thought seriously about time before the year 2012. I, too, had the idea that time is something like a continually flowing entity, like an invisible river, that causes everything in this world, including us, to get old. It flows always in one direction, from past towards future. We were taught in our childhood that it is the most precious thing we have got and that we ought to respect it and never waste it. It was a common riddle being asked among children that what it is that never stops, and the wise ones would answer- “time”. This was the background about the concept of time with which I, like most of us, grew up.

About two and half decades ago, I heard about Stephen Hawking and his book A Brief History of Time. Somehow (it was not available in the city I reside, nor was it a time of online shopping for us), I purchased a copy of it and got to know the stake of this great physicist on the subject of time. However, though I learned something about the basics of physics from this book, the secret of time remained obscured to me. At about the same time, I read an article of the physicist Sir Martin Rees, and wrote a letter to him. With his reply, he was kind enough to send to me a copy of his book, Cosmic Coincidences which I read thoroughly. These books created an interest in me to know more about the physical world. But unfortunately, I could not pay much attention to it for some years. Time still remained an enigma for me.

Time is something with which almost every one of us- a scientist or a non-scientist, an educated or an uneducated- at every moment of our life is intimately associated; yet it is an enigma. It is a subject for the study of which some of the great workers of past and present, from philosophy to physics, have devoted a large part of their lives; yet it is an enigma. According to Lee Smolin, most of the problems of the modern physics and cosmology are related to the question of time.2

In order to see why the question- “What is time?”- remains the most important question facing science, let us have a bird’s eye view of the views of some prominent workers about it. For our convenience, we can divide the development of the concept of time into two phases- the Pre-Relativity phase and the Post-Relativity phase.

The Pre-Relativity Phase of Time

It appears to me that the pre-relativity phase of time was mostly dominated by the view that time is something like an independent entity that flows in one direction at a fixed, universal and absolute speed. In a sense, it was conceived as an essential tool in the design of the universe. A tool that makes new-born babies grow; makes our world lightened up with the rise of the sun in the east every morning; causes the sun to set in the west and gets our world engulfed by darkness every evening; causes periodic changes in weather and, finally, that is also the cause behind our aging and our last ritual too—the death.

It was this view of time that probably dominated Newton’s mind too, led him to think of an absolute and constantly flowing time, at a fixed rate, and even while doing his epoch-making work on gravity, he did his best to accommodate it unharmed and unaltered. Newton’s time flew at a uniform velocity in the big container called universe which contained everything. Thus, probably Newton’s time was, as far as I can understand, substantial and real.

However, it is not so that there was no alternative view about time during the pre-relativity era. As early as in the 4th century BCE, Aristotle explained time as a mere number used for measurement, particularly, measurement of movement. Greek metaphysicist, Heraclitus (530–475 BCE) gave the concept of flux- the constant change that everything in the world experiences at each moment. This flux was in a way equivalent to time. According to his concept, time and change were inextricable. Heraclitus defined time and events by each other, making each necessary for the other. But still, he always thought that time flows at the same rate for all observers.

However, the nineteenth century English philosopher, Mc. Taggart strongly believed in unreality of time and defined it in either of the two ways- as past, present and future (which he called the A series), or, as earlier and later (the B series, as he called it). Further, he characterized time as the dimension of change. Immanuel Kant, the great eighteenth century German philosopher too believed in transcendental nature of time. According to him, “time and space are characteristics not inherent in things themselves but only in their relation to our sensibility”. Similarly, Leibniz, a Newton’s contemporary, too believed in relational theory of time, which implies that time’s existence is related to some physical processes in the universe, such as a movement or a change in a field. He described time merely as a successive order of things in the famous Leibniz/Clark correspondence. According to this view, no change implies no time. Earnst Mach, the great nineteenth century physicist who is said to have made a great impact on the thoughts of Einstein, defined time merely as an abstraction- “It is utterly beyond our power to measure the changes of things by time……time is an abstraction at which we arrive by means of changes of things”. For a detailed history of the study of time and to have a glimpse of the views of different workers about time, I shall urge the interested reader to go through the ‘Encyclopedia of Time: Science, Philosophy, Theology & Culture; edited by H. James Birx.3

And not only physics and philosophy, literature too was not far behind in giving an alternative meaning to time. In what is held as probably the first science fiction, The Time Machine, written in 1895 by H. G. Wells, the author explains time to be the fourth dimension of objects-

“Any real body must have extension in four directions: it must have Length, Breadth, Thickness and- Duration. ……There are really four dimensions, three of which we call the three planes of space, and a fourth, Time.”4

However, these alternative views could not undermine the dominance of the absoluteness of time, flowing nature of time; until Einstein came into picture.

Probably this is why, The Time Machine of Wells, which starts with such a beautiful reality of time, runs into such a beautiful fiction- and why should it not, as it is a fiction itself- that it sends its Time Traveler to the year 802701, to witness the humanity split into two bizarre races- the ethereal Eloe and the subterranean Morlocks, and then to further thirty million years into the future to have a tryst with a slowly dying earth and a bloated sun. It is no doubt a beautiful fiction as is evident by the fact that hundred and twenty two years after its first publication, it is still in print.

It appears to me that this fiction of H. G. Wells is not only a fiction; it reflects the way most of us think about time and successive events of the universe. We usually think of the successive events as if they are successive railway stations we pass through during a train journey, and during our return journey, we shall be passing through the same stations, though in a reverse order. But, as we shall see, it is not like that.

The Post-Relativity Phase of Time

In 1905, Einstein shocked the world by presenting his special theory of relativity. However, before Einstein, Henry Poincare (1854–1912) too criticized the concept of absolute time. Hereafter started the second phase of the development of the concept of time. Einstein proposed in his special theory of relativity the ground breaking concept that time is relative. Challenging the Newton’s absolute time that was constant for every observer, he proposed that time is not constant for every observer. It is local. It is personal. It said that the clock of an observer in motion may not agree with the clock of a stationary observer. Time can be slowed.

This was stunning. It is true that we often feel time to flow differently in different circumstances- it creeps, it strolls, it runs and it flows. And not only it flows, it sometimes goes. Henry Twells beautifully articulates these different appearances of time with our different phases of life in his lyrical rhyme, ‘Time’s paces’-

When as a child I laughed and wept,

Time crept.

When as a Youth I waxed more bold,

Time strolled.

When I became a full grown man,

Time RAN.

When older still I daily grew,

Time FLEW.

Soon I shall find, in passing on,

Time gone.

O Christ! Wilt thou have saved me then?

Amen.

—Henry Twells, Hymns and Other Stray Verses

However, in spite of enjoying these different experiences of time at different phases of our life, we could never surmise, before Einstein’s special theory of relativity, that this could be a reality- time really flows at different speeds for different observers.

Even present, past and future lost their universal meaning and became personal. What we call ‘now’ became a mystery with the onset of relativity. However, this blurring of ‘now’ disturbed Einstein too. Dieter Zeh in his The Physical Basis of the Direction of Time quotes Carnap regarding the views of Einstein about ‘now’- “Einstein said that the problem of the Now worried him seriously.”5 Einstein knew that every man has a special meaning for the term now. All of us clearly distinguish our now from our past and future. But the physics he had developed had no special treatment for this ‘Now’. So, he concluded “that there is something essential about the Now which is just outside the realm of science.”5

Thus, while on one hand, the theory developed by Einstein himself wipes away the notion of ‘now’; on the other hand, this abolition of ‘now’ seems to be painful for him. But he is unable to locate the significance of this ‘now’ within the realm of science. How can it be that something so essential to man should be outside the realm of science? Can we make another attempt to seek this ‘now’ within the realm of science? I hope we can more clearly grasp the meaning of ‘now’ by considering an alternative concept of time itself.

Not only this much, the theory of relativity also fused time with space to create a new concept of space-time. And a decade later, when Einstein unveiled his general theory of relativity, the world came to learn that the space-time is not always flat but may be curved also.

Thus, time was present in a new getup before the world. It could be slowed; it- in association with space- could be curved. And the theory of relativity was not simply a theoretical model. Most of its predictions were confirmed, again and again, practically. It introduced the world with a completely virgin level of nature’s architecture hidden in quite awesome properties of space and time.

But what did it tell the world about the very nature of time?

Julian Barbour, who has devoted a significant part of his life to the study of time, writes in his book, The End of Time about the concept of time in Newton’s and Einstein’s theories-

“Without question, their theories contain wonderful truths, but they both take time as given. It is a building block on a par with space, a primary substance.”6

It is said that when asked- “What is time?” Einstein once replied, “Time is what our clocks read”. However, since the entire theory of relativity is pivoted on space and time, we can expect this theory to convey a deeper meaning of time. O...

Table of contents

• Cover Page
• Half Title
• Full Title
• Copyright
• Dedication
• Table of Contents
• Acknowledgements
• Preface
• 1. We are all Time Travelers
• 2. Ontogeny: The Starting Phase of Our Time Travel
• 3. Time: A Requirement for Age or an Acquirement by Age?
• 4. Measurement of Time
• 5. Time as the Fourth Dimension
• 6. The Relative Time
• 7. The Arrow of Time
• 8. Time Travel: In the Classical Sense
• 9. Conclusion
• Notes and References
• Bibliography
• Index