Frank Tipler's Rotating Cylinder

The rotating cylinder in general relativity poses an interesting mechanical system. It is a system that the researchers in the field considered seriously a time machine may be possible in the strong relativistic regime. Without going into a detailed mathematics, we can visualize what is going to happen in the rotating cylinder within the scope of dipole gravity and tachyonic mechanics. Due to the special relativistic dynamic mass increase effect, the effective gravitational field outside of the rotating cylinder will increase. So, the second order effect from general relativity will be the additional attractive force toward the center of the rotating cylinder.

If the Lense-Thirring force had the right sign, we would have to come to the conclusion that this second order effect of general relativity for a rotating cylinder would have to be outgoing, which isn't. Of course, this is another confirmation that the conventional signs of the Lense-Thirring force can not be correct. Also, there will not be any axial component of the force because the rotating infinite cylinder does not create the shift of the center of mass along the axial direction.

In the tachyonic mechanical point of view, the rotating cylindrical mass disperses and prevents the tachyonic particles from getting inside the cylindrical shell, and consequently creates a relatively higher ether vacuum, which corresponds to the increased gravitational force when viewed from the outside, but reduced inertia on the object inside the shell.

In the extremely strong field regime, when the cylinder rotates in a relativistic frequency, the inertial mass of the object inside the shell will virtually disappear. Therefore, any slight external force will make the object inside the shell to accelerate with a tremendous speed.

The time and the spatial coordinates are entangled in such a way that the motion inside the shell can no longer follow the conventional Newtonian mechanics. But the question on the time machine is a great mystery. Will it be possible to violate the causality? Even if we can travel at the speed greater than the speed of light, after the round trip, we will still be at the later time than we started, once we arrive at the original location, although we may find our friends and relatives are already deceased and we may be looking at their children. I think the key mystery is in the practical length of the cylinder. Since any physically realistic cylinder can not be infinite, there is a point in the middle of the cylinder where the field reverses its direction, or one may call it a discontinuity. Like a rotating spherical shell, the truncated cylinder must have a field reversal point in the middle that corresponds to the center of the rotating spherical shell. And we know there is a tremendously strong potential wall in the middle that doesn't allow the both way stream of the travel in the case of the rotating spherical mass shell. The symmetry is broken due to dipole gravity. To treat this problem rigorously in mathematics, one may have to assume a tiny bulge delta r of the radius near the center of the finite cylinder and let it approach to zero or let the two open ends of the cylinder to be tapered into a point with a lower density material which can be made to approach to zero. In either cases, the result will be a discontinuous field along the direction of the axis of the cylinder.

What this means in reality of the plain English is that the time travel for a physical body is prohibited by general relativity. The known general relativity interpreted by the conventional Princeton-Wheeler group of the school of gravitation was not a complete understanding of the full scope of general relativity which has resulted in the erroneous concept of the time travel by the physical body. I hope the popularists of the Sci-Fi physics realize this fact and stop propagating the time travel of the physical body nonsense. At least we do not have that possibility within the full scope of our known physics.

However, this does not exclude the possibility of the tachyonic particles travel across the channel of the rotating cylinder. The information carried by the tachyonic particles can be transmitted from the future to the past or vice versa, which may hint the fact that the successful predictions of the short or the long term future, commonly known as the prophecy may be possible.