Prologue
June 25, 2002
Washington D.C.
It had the feel of yet another hot and humid summer day in the nation’s capital as I entered a large lecture hall on the sprawling urban campus of Howard University. Inside the air-conditioned hall, rows of seats rose upward from the podium, creating a theater-like setting that seemed apropos as I was about to deliver the most important presentation of my life.
Since the age of eleven, I had told only a few confidants about my secret dream. Long fearing professional suicide, I had until recently held off revealing to colleagues at the University of Connecticut, where I am a professor of physics, my hope of turning one of man’s favorite science-fiction fantasies into a scientific reality. Had I done so earlier, I would not have received tenure.
The time had arrived. Before fifty or so of the world’s leading physicists assembled here for the International Association for Relativistic Dynamics 3rd Biennial Conference, I was about to reveal in detail my plan for finally realizing my lifelong goal. It would not be enough for me to tell them my belief that this century will be the century of time travel just as the 20th century was the century of air and space travel. No, this audience would want the nuts and bolts.
My work had been outed in the past year, no doubt the reason I had been invited to deliver a paper before this prestigious body whose mission was “to facilitate the acquisition and dissemination of knowledge about research programs in classical and quantum relativistic dynamics of particles and fields.” Yet, that my research had been featured in publications as varied as New Scientist, The Village Voice, Boston Globe, The Wall Street Journal, Rolling Stone Magazine and even Pravda (Moscow), would mean little at this august scientific gathering, and might even raise an eyebrow or two.
Sitting in the seats and peering down at me would be some of the heaviest hitters in my field of relativity physics: Bryce DeWitt, Director of the Center for Relativity at the University of Texas at Austin and one of the founders of an early form of a quantum theory of gravity; Georgia Institute of Technology’s David Finkelstein, who had made several important contributions, including a novel way of looking at black holes, and L. P. Horwitz, an influential Tel Aviv University professor who had hosted the last conference and had made a number of significant contributions to relativistic quantum mechanics.
Although my work is based squarely on Einstein’s general theory of relativity – a solid foundation for any physicist to stand upon – I would be presenting some controversial results. This audience would expect to see the equations and solutions that led me to believe I had made a theoretical breakthrough that could lead to the design of the first working time machine.
For a few weeks, I had spent 12 to 15 hours a day working on my calculations to be ready. I had transferred data to transparencies which I intended to project during my talk. If I didn’t get my math right, these experts would let me know, and be none too tactful about it in the process. Should I make a mistake in a calculation and veer off course, I would be interrupted mid-speech and subjected to in-your-face critiques – “Professor, your equations are wrong” – rather than any gentle, instructive words of advice. That is the world of physics – we are, after all, scientists not psychotherapists.
I was scheduled to deliver my talk at 10 a.m. that morning. Much to my chagrin, I saw on the schedule that Bryce DeWitt would be going right before me presenting his paper on “The Everett Interpretation of Quantum Mechanics,” about the many-worlds or parallel-worlds theory of the universe. That I would be following such a well-known star to the podium made me appreciate how the guy who came up to bat after Babe Ruth must have felt.
I knew I was in trouble right away when DeWitt started off by saying that a speaker needed only six transparencies to discuss his ideas, which, of course, was the exact number he had brought along. I looked down with dismay at my bulging folder, crammed with 26 transparencies. DeWitt went on to say that he always told his graduate students that they need not tell their audience everything they knew about a subject. I told myself to keep breathing.
DeWitt, a legendary and pioneering theoretical physicist, received his Ph.D. from Harvard in 1950. Tall, lean and energetic, DeWitt had hiked in the Himalayas and Africa. During World War II, he served as an aviator, and after the war conducted research at the famed Institute for Advanced Study at Princeton, which was at that time also Einstein’s academic home.
Elegant is an adjective often used by DeWitt’s colleagues to describe his use of mathematics in physics, and it is certainly a compliment. The elegance in his work showed in the natural flow of his physical arguments, and the beauty was to be found in the pleasing symmetry of his equations. As a graduate student, I had learned that elegance and beauty in physics were nearly as important as whether an idea was correct.
DeWitt’s presentation about one of the strangest consequences of quantum mechanics — the possible existence of parallel universes – could play an important role in the possibility of time travel, so he had my rapt attention.
Quantum mechanics is the mechanics of sudden energy change. In quantum mechanics, energy cannot be gained or lost continuously, but only in fits and starts. In 1913, the Danish physicist Niels Bohr, often called “the father of quantum mechanics,” showed that the electron orbiting the proton in the hydrogen atom can only change it’s orbit either by gaining or losing a certain definite amount of energy – no more and no less. These definite or discrete amounts of energy are called quanta of energy.
In 1957, physicist Hugh Everett III, a recent graduate of Princeton, first applied quantum mechanics to the entire universe, which resulted in his many-worlds or parallel-worlds interpretation of quantum mechanics.
Quantum mechanics, in short, is a world of probability. In the ordinary, everyday world, when a pitcher throws a baseball, it is possible to describe exactly where the ball is and how it’s moving. In the world of quantum mechanics, we can only say what will probably happen next, as we can’t know exactly what an object is going to do.
In applying quantum mechanics to the whole universe, Everett found that whenever there is the possibility of more than one outcome for an event, there is a potential split in the universe. For example, suppose that at lunch you are trying to decide between a cheeseburger or a tuna sandwich. At the moment you make the decision, according to Everett, the universe splits into two parts. There is a universe in which you have chosen the cheeseburger, and there is also an equally real universe in which you have chosen the tuna sandwich. These new universes are parallel and separate. The you in the universe with the cheeseburger is not aware of the you in the separate universe with the tuna sandwich. Although this idea of a parallel universe seems incredible, it is completely consistent with the proven theory of quantum mechanics.
Like everyone in the audience, I was familiar with Everett’s parallel universe theory, and yet I was enthralled by DeWitt’s masterful explanation.
When DeWitt finished, I went to the podium. Having not forgotten DeWitt’s pronouncement that a speaker needed no more than six transparencies and did not have to tell the audience everything the speaker knew about a subject, I decided to face the situation straight up. “Just to let you know – I have no more than sixty transparencies. When I found out that Professor DeWitt was in the audience, I felt as if I was back in graduate school, and that I’d want to show him everything I know about the subject.”
DeWitt and the audience laughed, and I caught my first deep breath.
I began by reviewing the tenets of Einstein’s general relativity theory, which in this crowd of relativistic physicists was akin to preaching to the choir. Forthwith, I began to outline my own theories based on Einstein’s work, projecting on a screen my transparencies with illustrations, equations and final solutions, which I said showed that space and time could be manipulated in a whole new way that would lead to the possibility of time travel into the past.
A satisfying thought hit me – my dream and I had come a long way.
Then, I realized that pencils and pens had been put to paper in those rows of seats above me, and were busy scribbling away as my esteemed peers began working through my calculations.