You may remember a television program back in the 1960s called “Dr. Who”. According to the Guinness Book of World Records, “Doctor Who” is the longest-running science fiction television program in the world (sorry “Trekkers”). Doctor Who, you may remember, had the ability to travel through space and time using a phenomenon called TARDIS. According to Dr. Who, TARDIS means Time And Relative Dimension In Space, or sometimes, Tethered Aerial Release Developed in Style.”
TARDIS seems to be a popular acronym In real life as well. It can mean TarDigrades In Space (a European Space Agency research project;) or Tornado Advanced Radar Display Information System, used by various armed forces. Now, two physicists have written a paper entitled “Traversable Achronal Retrograde Domains in Spacetime” (TARDIS) that proposes a “bubble” following the path of a “closed loop in space and time” as a theoretical means of space-time travel.
The concept of a hypothetical “Space-time Bubble” is based on Einstein’s “Theory of General Relativity”, which introduced concepts now familiar to science fictions fans, such as “Warp Drive” and “wormholes” (proposed by Einstein in the 1930s). According to the physicists, this “bubble” could travel to any point in time or space: and if a number of space-time loops, or Closed Timelike Curves (CTC), could somehow be joined together, a “bubble” travelling on a CTC could only move in a circular path. But by splicing multiple CTCs together, it would allow the bubble to travel along the paths of other circles, subsequently reaching different points in space-time.
But don‘t arm your phasers yet. Such a device would not be possible in real life. Creating a TARDIS requires using unphysical or exotic matter that repels gravity and can travel faster than the speed of light, which, so far, doesn’t exist; except in science fiction.