“The only way of discovering the limits of the possible is to venture a little way past them into the impossible.” – Sir Arthur C. Clarke
Time travel has likely been a dream of Mankind since our ancestors huddled together in caves. Who wouldn’t like to have mastery over time – and the godlike powers that would come with it?
Science fiction authors have often speculated about the consequences that may await a time traveler and the type of technology necessary to build a working time machine. The most famous of these stories is H.G. Wells’ “The Time Machine.”
For many years physicists dismissed the entire concept of time travel as nonsense. Indeed, even Stephen Hawking devoted some energy and brain power in a fruitless quest to prove that attempts to discover how to travel through time is a waste of time.
Yet there are physicists who believe the impossible just may be possible. A few, like Dr. Michio Kaku, Professor of Theoretical Physics at City College of New York [website] and Kip Thorne, the Feynman Professor of Theoretical Physics at California Institute of Technology [website], believe time travel is possible and violates no known laws of physics. Both extrapolate upon the work done by Albert Einstein.
In his “Special Theory of Relativity,” Einstein postulated that as an object approached the speed of light (186,000 miles per second) the rate of time would slow. Theoretically if an object could attain that speed time would grind to a halt. The key word is “theoretically.” In reality an object with mass cannot ever attain the speed of light because – as Einstein also showed – the mass would become infinite. Therefore, accelerating towards the speed of light can slow time, but never stop or reverse it.
Is there a way to achieve true time travel? There are several things that – hypothetically – can work. All of them achieve time travel by avoiding the speed of light entirely.
Wormholes that warp space and twist it upon itself drill a hole through the space time continuum like a worm eating through an apple. Other heavenly bodies, black holes, have a gravitational pull so intense that nothing can escape it not even light. Yet in theory, if you approached the curvature of a black hole fast enough, you could slingshot yourself around it and travel through time – but only in one direction: the future.
Those are both however, naturally occurring phenomenon in our universe. What of something engineered? Is it possible – at least in theory – to construct a real, working time machine?
As it so happens, it is possible. The physics of a time machine can be shown mathematically. Although constructing one is still beyond our technology and engineering skills it may not be someday.
The Tipler Time Cylinder
Back in 1974, Dr. Frank Tipler, a mathematical physicist and cosmologist at Tulane University, Louisiana, found a way to take advantage of space time continuum anomalies. In his breakthrough paper, “”Rotating Cylinders and the Possibility of Global Causality Violation,” Tipler created a mathematical model of a super dense mass in the shape of a cylinder rotating it longitudinally along the length of its axis at a velocity approaching half the speed of light. In the paper Tipler demonstrated the possibility of creating a stable, closed time-like curve. Stability is important; otherwise the gravitational waves could violate weak energy and collapse the field or worse, generate an extremely dangerous naked singularity.
The bottom line is the gravitational waves generated by the rotating mass warp space time and creates time ripples extending into the past. How far one travels into the past is determined by the vector, speed and the entry point along the cylinder where the time ripple has been penetrated.
The Tippler Cylinder is the only extrapolated technology to date that has the relativistic mathematics to support its possibility. All other hypotheses are merely speculation revolving around natural phenomena that theoretically can be utilized for time travel. Such theorized phenomenon includes the event horizons of rotating black holes and gravitational wormholes.
Tipler gave several lectures about the theory and the math supporting it. Despite the fact that articles have appeared on the Internet claiming the cylinder must be infinitely long and the rotation near the speed of light, Tipler pointed out that a cylinder approaching the density of a white dwarf spinning at one half the speed of light and one thousand kilometers long would be sufficient to create what he termed a “frame-dragging effect.” This effect bends space time into a curved loop causing the light cones of objects near the effect to warp. At that point some of the cone points backwards instead of forwards into time. Traveling along that backwards path achieves time travel.
Tipler’s Cylinder is limited to traveling in only one direction: backwards. Travel is also restricted in the sense that no time traveler could go backwards in time farther than the point at which the cylinder achieved operational mode.
Yet the very fact that Tipler was able to demonstrate a machine that could allow travel through time is sufficient to postulate that many other methods of time travel are waiting to be discovered.
Are Time Travelers amongst Us?
Some in the scientific community heap scorn on the idea of time travel. They point out that if time travel were ever to exist where are all the time travelers?
They have a valid question, but what makes them think that time travelers are not with us already? Clues exist that suggest they may well be with us and have been exploring the Earth all throughout history and pre-history: Ribbed boot prints found in a 70 million year old fossilized riverbed have extinct dinosaur prints overlapping them; machined aluminum alloy screws have been discovered embedded in coal beds over 100 million years old more than once, and many other such anomalies have cropped up over the past centuries..
Debunkers of such evidence don’t have much to say. What are the answers to such enigmas? Well, there are two possibilities: either this planet has had visitors from the stars as long ago as 100 million years B.C.E., or a time traveler on a field trip left an inadvertent record of his travels during the Jurassic period many millions of years ago.
Either possibility is quite astounding.
Links
Photo of Dr. Tippler
The Tipler Time Cylinder: Illustration #1, Illustration #2
“Rotating Cylinders and Global Causality Violation” by Frank Tipler, Physical Review D9, 2203-2206 (1974)
“Is Time Travel Possible?” Dr. Michio Kaku lecture on YouTube. [2 m, 44s]
