Also known as the Tipler cylinder, named after its creator the U.S. astronomer Frank Tipler, the infinite cylinder is based on the idea of rolling an object ten times the mass of the sun into an extremely dense cylinder. This cylinder would essentially be a black hole that has been put through a spaghetti maker. Spinning this 'black-hole-spaghetti-strand' a few billion revolutions per minute around its longitudinal axis would create a frame-dragging effect, warping the fabric of space-time so that the light cones of objects near the cylinder spin and point backwards on the time axis (the time axis in the sense that it is the fourth dimension), allowing those objects to travel backwards in time on a closed time-like curve (CTC) created by the spinning cylinder. The fabric of spacetime would be folding backward on itself.
There is, however, a problem with the mathematics of this theory. Tipler's mathematics relied on an infinite cylinder, which would be difficult or impossible to create. A finite cylinder may be able to produce the same effect and time-like curve as an infinite cylinder if it were spinning fast enough, but according to Stephen Hawking and the theory of general relativity, "it is impossible to build a time machine in any finite region."
Simply the act of travelling backwards in time, which this theory allows, also creates problems. See the pages on paradoxes for more information.
There is, however, a problem with the mathematics of this theory. Tipler's mathematics relied on an infinite cylinder, which would be difficult or impossible to create. A finite cylinder may be able to produce the same effect and time-like curve as an infinite cylinder if it were spinning fast enough, but according to Stephen Hawking and the theory of general relativity, "it is impossible to build a time machine in any finite region."
Simply the act of travelling backwards in time, which this theory allows, also creates problems. See the pages on paradoxes for more information.