Get Up and Go Somewhen

By J. Richard Jacobs

TIME TRAVEL HAS BEEN A staple of science fiction bordering on forever. It is looked upon with disdain by some, cherished by others. However, there is a commonly held belief that, although it’s a nice idea and provides fodder for some great story lines, it is beyond the realm of possibility. It is thought that it treads an unsupportable and unscientific path that leads the story into the realm of fantasy. That we travel in time every moment of our lives is considered to be nothing more than the way things are; it’s merely ordinary, everyday physics at work. Not so. Well, the physics, yes; the ordinary, no.

Let’s lay in a small amount of foundation for what follows. Just one little bit of support for the wild things to come. In 1949, when I was but nine years old, Kurt Gödel constructed the first mathematical models of the universe in which travel into the past is possible. Within the framework of Einstein’s general theory of relativity, Gödel produced cosmological solutions to Einstein’s field equations which contain closed time-like curves. Curves in spacetime which folded in upon themselves. They were closed but still allowed for the passage of physical bodies. Any object thus traveling such a path would go backward in time. Back into its own past. More generally, Gödel demonstrated that, in his universe, for any two points P and Q on a body’s trajectory through spacetime (known as the body’s world line), arranged such that P temporally precedes Q, there is a time-like curve linking P and Q on which Q temporally precedes P. Reverse, you see. This means that you could enter your time machine and travel to any point in history.

In 1951, Gödel demonstrated the existence of paradoxical solutions to Albert Einstein's field equations in general relativity. He gave this elaboration to Einstein as a present for his 70th birthday. Something of a smart-ass move. These “rotating universes” would allow time travel and caused Einstein to have doubts about his own theory. His solutions are known as the Gödel metric.

This article focuses on but two of the many who are laboring to provide us with real, workable concepts for bouncing around in time. Their theories are mind boggling but not so esoteric that they reach beyond comprehension.

We were in 1951 with Gödel and old Al. Now, let’s leap forward in time to what’s going on in the present that will allow us to choose either the past or the future to avoid the present. Did that make sense? Well, no matter. Fast forward to the Year of Our Lord, 2005 and, please, fasten your seatbelt.

Dr. Amos Ori of the Technion in Haifa has given traveling back in time a boost. A boost that is simple, possible and quite realistic. Further, it remains within the realm of real physics. It is so straightforward that it set my teeth chattering back in 2006 (that’s when I first heard of his work and still had teeth) and it does not require exotic matter or the use of unobtanium to manifest itself. It is as exciting as if cold fusion, room temperature superconductors, and my dreamed about visit (no details) with the most beautiful woman in the world were to suddenly become reality. The only drawback, according to current theory, is that the travelers would be on a one-way street heading into a dimensional cul de sac; they couldn’t return to their own time. That is, unless they brought a ship with them that they could use. One that would give them an inertial frame producing the time dilation effect. That is not out of the question, either. Anything, without reservation, can be carried along in the loop.

Here is the abstract from Amos Ori’s paper presented on 17 March 2005, “A new time-machine model with compact vacuum core General Relativity and Quantum Cosmology”:

“We present a class of curved space-time vacuum solutions which develop closed timelike curves at some particular moment. We then use these vacuum solutions to construct a time machine model. The causality violation occurs inside an empty torus, which constitutes the time machine core. The matter field surrounding this empty torus satisfies the weak, dominant, and strong energy conditions. The model is regular, asymptotically-flat, and topologically-trivial. Stability remains the main open question.”

Since the presentation of that paper, great strides have been made in simplifying and quantifying the theory. He and other physicists working in this area have brought the theory to a level where the only thing remaining (aside from physical construction) is to jump into your local Ori Loop and go to when you want. There is a caveat here. According to Dr. Ori, you could not travel back in time any farther than the moment the “device” was activated. That is, you would not be able to sniff dinosaur poop. But there is an obverse to that coin. It would be possible that loops could be intertwined and moved about in time as well, thus permitting a first hand glimpse of the primordial ooze after making several transfers on the bus line. Tricky and weird idea, but possible. Whatever you do, don’t let Ori throw you for a Loop.

Then we have Dr. Ronald Lawrence Mallett. He is an American theoretical physicist, academic, and author. He has been teaching physics at the University of Connecticut since 1975 and is best known for his scientific position on the possibility of time travel. His active program, now known as The Space-time Twisting by Light (STL) project, is in full progress.

Here is a quote from Dr. Mallett:

“According to Einstein’s general theory of relativity, clocks run different rates in a gravitational field. This has real practical implications that affected the initial set up of the global positioning system. It turns out that clocks in the GPS unit of your car, which is at the surface of the earth where gravity is stronger, run at a slower rate than clocks at high altitude, such as those aboard satellites orbiting the Earth. The effects of gravity on time at different altitudes had to be taken into account in order for the GPS system to work. In Einstein’s theory it turns out that not only matter, such as the Earth, can create gravity but also light. It is the energy of light that creates gravity. Consequently, because time is affected by gravity and light can create gravity due to its energy, then light can also affect time. That is the core of my research.”

With Mallett’s theory, time travel could be realized in both directions. You could go forward in time, or you could go backward. Backward beyond the origination of the mechanism. It is currently unknown if this would also be a one-way trip as it is in the original Ori Loop. If it is, the machinery required for a return to your when could be carried along just as it could in the Ori proposition, so all is not lost. It could be said that Mallet’s concept, in its own twisted way, is lighting the way to the future and the past.

As I said, time travel stories have been with us a very long time. To illustrate this, take a look at the Mahabharata of Hindu mythological origin. It is a gigantic tome that, according to the oldest preserved texts, dates back to around 400 BCE. It is believed that the original text began about 800 to 900 BCE. In this story of more than epic proportion, some 1,800,000 words (roughly 10 times the length of the Odyssey and Iliad put together), time travel is unquestionably presented.

Then there is the story of Honi HaM’agel that appears in the Talmud. He fell asleep and stayed that way for 70 years. He awoke to a different world.

“Urashima Taro” comes to us from Japan. The tale considers Urashima Taro, a fisherman traveling far into the future. When he goes home, he finds himself some 300 years into the future of his village where all knowledge of his existence has evaporated in time. This story first appears in the Nihongi (720 CE).

Walter Map’s “De Nugis Curialium” throws King Herla and his hunting party more than 200 years from home in an odd future. (Scribbled sometime in 1100 CE.)

Then there’s Samuel Madden’s “Memoirs of the Twentieth Century” (1733) where conjecture, albeit fantasy, of travel through time in reverse is presented with artifacts (notes of future conditions) are carried back to 1728 from 1997-1998.

How about Johan Herman Wessel’s play, “Anno 7603” (1781 CE)? Here Wessel’s protagonists are shoved up to the year 7603. Some jump!

Ebeneezer Scrooge does quite a bit of temporal hopping in Charles Dickens’ “A Christmas Carol” (1843).

And the list trudges on. The interesting thing about this is that the people writing before the 1950s didn’t have much to hang their hat on in terms of supportable science. Now, in the Second Millennium, we have viable tools with which to write some incredibly exotic stuff, so put your pencil to paper (fingers to keyboard) and let’s see what can be done.

Oh, I see you’re worried about those paradoxes. Don’t let that bother you. I have it on good authority that they probably don’t—or can’t—exist. Don’t believe me? Okay, let’s take a look. We need to sort of glance at this problem out of the corner of the eye because it can get really gooey if we look too long and too directly.

Have you ever heard of a fellow named Dmitriyevich Novikov? And, no, he did not invent the AK-47, but he did come up with something special and of interest to writers of science fiction. We know of his creation today as the Novikov Self-consistency Principle. Then, as if on cue, along came Kip S. Thorne and added more bite to Novikov’s Self-consistency Principle. What they showed is that a traveler in a closed time-like curve (a time traveler) could never create any kind of paradox. Their works indicate that for any given action there are an infinite number of solutions or results possible. Basically that means that whatever the traveler does, the outcomes will lead away from producing a paradox.

Now let’s visit the MWI. The what? The Many Worlds Interpretation. Hugh Everett III introduced the idea that all quantum events may occur simultaneously in mutually exclusive histories. Um, parallel worlds (universes) where everything is the same but with differing events along the time line. One big, happy quantum-mechanical. The results of an action in one line of history would simply dovetail into the time line of a different world. Remember “Sliders”? Confusing, but fun. Okay, so “Sliders” wasn’t really the same idea—but it was close. Stephen Hawking said that even if the MWI were correct, the traveler should remain in his own world but with a different history to deal with. Oh, my. There were many who chimed in on this one, but the basic idea is that in no case in the MWI will there be impossible paradoxes because we have produced a quantum decoherence. Well, there shouldn’t be, anyway.

Karl Svozil and Daniel Greenberger suggested that quantum theory does the job of getting rid of parodoxes for us without all those weird machinations. In quantum theory if you observe something it can cause possible states to “collapse” into a single, measured state. Say what? Well, that’s a little weird, isn’t it? How about Schrödinger’s Cat? From the present looking over our shoulder at the past we recognize it as deterministic. That is to say, it has only one possible state. It is, after all, the past and no one from now has been then ... yet. On the other hand, for an observer standing on a street corner in 1900 San Francisco, the future has many, many possible states. The future has not yet been made and is clay in the hands of the traveler. Then he/she does something (deliberately or accidentally) that affects the time line and his/her whole view crumbles into one pile—a single state. Anything we have done will have to be thought of as having been inevitable. A Rube Goldberg device with no purpose other than to change the line of time.

So, let’s take a gander at some of those possible paradoxes and physical “impossibilities” to get a feel for what may or may not be plausible. I suppose the first one we ought to delve into is that classic Grandfather Paradox. Most are probably familiar with the general meaning of this one, but we have found that it may not be true. So, what are the parameters? Well, in the “nice” version, a time traveler goes back in time and does something to prevent his grandfather from marrying his grandmother. It doesn’t matter what he does to prevent the wedding and it also doesn’t matter whether we’re talking paternal or maternal but, if he were successful, there would be things to consider.

If he were successful, either his mother or his father would not have been born. That would result in the traveler not having been born—maybe. Temporal suicide for the traveler—maybe. Why the maybe? Well, according to the Novikov Self-consistency Principle, something in nature would prevent him from being successful in his quest. Like, maybe he’s on his way to his grandfather’s house, trips over a garden hose, suffers a broken hip and is taken to the hospital. He is not released until four days after the wedding and the “damage” has already been done. You can imagine an almost infinite number of possibilities that would naturally prevent the paradox from being manifested in the time line.

That was the “nice” one. How about the nasty one? Our traveler goes back with the intention of killing his grandfather/mother. He takes careful aim and is squeezing the trigger when a dog runs between his legs and his shot tears harmlessly through the garage wall. Apply the Novikov Self-consistency Principle however you wish. The paradox isn’t going to happen. I’m not going to succumb to the temptation to elaborate because that could go on forever and I think you have the picture clear in your mind. So, that’s life in the time lane according to Novikov, Thorne, and a few others.

In the MWI things get even more interesting and convoluted. Possibilities ricochet from all corners and things can really, really get messy. In the MWI you may feel free to do whatever you like because you’ll only be affecting a world different than the one you were in when you started. That’s right. At the instant you started your trip the action triggered events in the time line and you wound up going back to one of those many worlds.

Let’s say you went back to 1 April 1889 (you thought it was a fitting date) to kill a very pregnant Frau Klara Plölzl-Hitler and rid the world of one mean little Schnitzel. Under the MWI you could do that, but it would be in a parallel world and not the one from which you started. See, your movement in time generated a quantum decoherence. (You’ve affected the time line and popped into another world.) Of course, I’m on uncertain ground here as it relates to coming back to the time from which you started your journey. I am not sure, under the MWI, whether you would return to your own world wherein Hitler lived and raised havoc, or your time in the parallel world wherein he and his mother didn’t make it due to your visit. See, moving forward in time would produce the same quantum decoherence and who the hell knows where you would end up? Let’s hope Stephen Hawking was right, but, if he were, what does that mean? Never mind.

So, you see, you can’t do much of anything under the Novikov Self-consistency Principle and you are free to do whatever you want under the MWI. So get to it. Go write something. If writing isn’t your thing, you can at least read with a broader perspective. Have at it. 

J. Richard Jacobs has studied physics and astronomy. After formal schooling in these areas, he became a naval architect and worked at designing the largest moving machines on the planet (and some of the smallest). He has been privileged to know Richard Feynman, Kip S. Thorne, Carl Sagan and Clyde Tombaugh.