The Tipler cylinder is a cylinder of dense matter and infinite length. Historically, Dutch mathematician Willem Jacob van Stockum (1910–1944) found Tipler cylinder solutions to Einstein’s equations of general relativity in 1924. Hungarian mathematician/physicist Cornel Lanczos (1893–1974) found similar Tipler cylinder solutions in 1936. Unfortunately, neither Stockum nor Lanczos made any observations that their solutions implied closed timelike curves (i.e., time travel to the past).

In 1974, American mathematical physicist/cosmologist Frank Tipler’s analysis of the above solutions uncovered that a massive cylinder of infinite length spinning at high speed around its long axis could enable time travel. Essentially, if you walk around the cylinder in a spiral path in one direction, you can move back in time, and if you walk in the opposite direction, you can move forward in time. This solution to Einstein’s equations of general relativity is known as the Tipler cylinder. The Tipler cylinder is not a practical time machine, since it needs to be infinitely long. Tipler suggests that a finite cylinder may accomplish the same effect if its speed of rotation increases significantly. However, the practicality of building a Tipler cylinder was discredited by Stephen Hawking, who provided a mathematical proof that according to general relativity it is impossible to build a time machine in any finite region that contains no exotic matter with negative energy. The Tipler cylinder does not involve any negative energy. Tipler’s original solution involved a cylinder of infinite length, which is easier to analyze mathematically, and although Tipler suggested that a finite cylinder might produce closed timelike curves if the rotation rate were fast enough, Hawking’s proof appears to rule this out. According to Hawking, “it can’t be done with positive energy density everywhere! I can prove that to build a finite time machine, you need negative energy.”

One caveat, Hawking’s proof appears in his 1992 paper on the “chronology protection conjecture,” which has come under serious criticism by numerous physicists. Their main objection to the Hawking’s conjecture is that he did not employ quantum gravity to make his case. On the other hand, Hawking and others have not been able to develop a widely accepted theory of quantum gravity. Hawking did just about the only thing he could do under the circumstances. He used Einstein’s formulation of gravity as found in the general theory of relativity. Another fact, Hawking’s proof regarding the Tipler cylinder is somewhat divorced from the main aspects of his paper and could be viewed to stand on its own. However, in science we are always judged by the weakest link in our theory. Thus, with a broad brush, the chronology protection conjecture has been discredited, and even Hawking has acknowledged some of its short comings.

Where does that leave us with a finite Tipler cylinder time machine? In limbo! There is no widely accepted proof that a finite Tipler cylinder spinning at any rate would be capable of time travel. There is also another problem. We lack any experimental evidence of a spinning Tipler cylinder influencing time.

Source: *How to Time Trave*l (2013), Louis A. Del Monte

Relativity states that distance is shortened as you approach the speed-of-light, I believe that the distance is a function of the rate-of-time in a given frame of reference and that as you approach the speed of light, distance contracts not as a function of velocity but as a function of the change, reduction, in the rate-of-time in a relative frame of reference. From my Theory, for a Cylinder to have an Infinite length it must exist in a frame of reference where Delta Time = 0 or Time is stopped. Therefore the Cylinder could not rotate in dT = 0 and therefore you could not travel back in Time.

Additional thoughts, the scenario of a Cylinder of Infinite length assumes that the entire Cylinder exists in a single, consistent Relativistic frame-of-Reference, even if our own Universe is Infinite in length, our Universe has as a property that of Variations of rate of Time such as regions of space near a Black Hole, therefore a Cylinder of Infinite length would not be able to spin uniformly throughout its entire length and still remain a Cylinder.

Where can the equations be found? What is the the minimum length of the cylinder and lowest period of rotation to send a 2000lb device through time? Lets break out the math.

You want to “break out the math” for numbers and variables you pulled out of thin air. First off who said that the tipler cylinder is two thousand pounds? For all we know it could be much heavier or lighter depending on the materials used. Furthermore its not the tipler cylinder that is being sent through time, it’s a person. So adjust the variable from 2000 to roughly 200 for starters. First we would need to design a hypothetical finite tipler to proceed. Assuming the tipler is 2000 lbs like you randomly guessed, you would add that into the equation with the unknown length of the machine. Since it can’t be infinite and were using made up numbers I’ll say its about 1500 feet long. Then you need to factor in the speed, or acceleration. That brings up the question of how fast do we need to go. The speed of light or just fast enough to alter grscoty inside the cylinder? If its the latter then there’s a formula for that based on length and weight assuming the machine is tall enough to not create a distortion in the axis. I don’t think its the math that’s important, with the right variavles we can get the math, the question IS what variables to use. Where can we put the machine? On earth or in space. Does exotic energy effect the machine or can we build a machine thick enough? This is the reason its impractical. The machine would be too big And be too far to power using conventional methods. If were gonna use a machine that big we might as well power it with microsingularities in the near future, but if we’re using micro singularities anyway we can build a smaller machine, similar to the one talked about in the John Titor saga. Assuming you can successfully vent the xrays without killing the driver.

[…] Tipler cylinder time travel – Is It Possible? […]

[…] out some idea on exactly how a time machine could be built, referencing work by Frank J. Tipler (the Tipler cylinder), Roy Patrick Kerr (rotating black holes), and J Richard Cott (cosmic […]

[…] out some idea on exactly how a time machine could be built, referencing work by Frank J. Tipler (the Tipler cylinder), Roy Patrick Kerr (rotating black holes), and J Richard Cott (cosmic […]

[…] Tipler cylinder time travel – Is It Possible? […]

When a person traveled back to the past and visit object and people who lives in the present time too, it means that the mass of person he meet are in two times, so the principle of material survival is violated. So the question is, according to the theory of time travel and the return to the past (Tipler cylinder and other theories), does a person meet those who are also in the present time (as if they themselves are in two times?)