Time Machines... The Unfunny Side

Rotating cylinders and the possibility of global causality violation, what a title! In this paper, written by Frank J. Tipler in 1974, it is suggested that a finite rotating cylinder would also act as a time machine:

Rotating cylinders and the possibility of global causality violation

The idea was explored (literarily) in Larry Niven's short story Rotating Cylinders and the Possibility of Global Causality Violation that appears in

Microcosmic Tales: 100 Wondrous Science Fiction Short-Short Stories or Convergent Series




The original paper spawned a lengthy thread of research. For example:

Causality Violation in Asymptotically Flat Space-Times (1976)

Singularities and causality violation (1977)

Assumptions of the singularity theorems and the rejuvenation of universes (1978)

Some properties of time-machines (1978)

The rigidly rotating relativistic dust cylinder (1980)

A stationary cylindrically symmetric electrovac space-time (1982)

Rotating hollow cylinders: General solution and Machian effects (1983)

The breakdown of quantum mechanics in the presence of time machinest (1993)

Quantum propagator for a nonrelativistic particle in the vicinity of a time machine (1994)

Improved time-machine model (1996)

Time machine (1988--2001) (2003)

Can a Circulating Light Beam Produce a Time Machine (2005)

A Class of Time-Machine Solutions with a Compact Vacuum Core (2005)

Closed Timelike Curves and Time Travel: Dispelling the Myth (2005)

Time Machine at the LHC (2008)

Billiard ball in the space with a time machine (2010)

As you can see, plenty of peer-reviewed papers exist on time travel. The vast majority of them conclude that backwards time travel is impossible but they leave the forward door open. In other words, if travel through time is possible, the main problem is that you cannot buy a return ticket and tell everybody about you success. That may explain a few things!