Time travel is possible, at least according to Caroline Mallary, a doctoral student at the University of Massachusetts Dartmouth.
In a paper published in the journal Classical and Quantum Gravity, Mallary has proposed a new model for a time machine. This model does not need a negative mass exotic material and can be built using a rather simple construction.
Time Travel
For her study, the doctoral student looked into closed time-like curves or CTCs as well as the superluminal travel in a spacetime that is made up of naked line singularities known as "wires." Each of the wires can either be a straight-line or a ring singularity.
Mallary explained that parallel to this wire, "effective" superluminal travel is possible, as the wire could serve as a shortcut between distant regions of spacetime.
"Our purpose in presenting the superluminal aspects of the wire is to dispel the commonly held view that explicit WEC violation is necessary for effective superluminal travel, whereas in truth the strictures against superluminal travel are more complicated," Mallary wrote in her study. "We also demonstrate how the existence of such "wires" could create CTCs."
What Are CTCs
Co-author of the study Gaurav Khanna, professor of physics at the University of Massachusetts Dartmouth, describes closed time-like curves. Otherwise known as time machines, CTCs are a "byproduct of effective faster-than-light travel schemes."
Citing Einstein's general theory of relativity, Khanna said while traveling along a time loop, which is a result of warping time to a high degree it folds upon itself, one would wind up at a time in the past at some point. Then they would start to feel like being back to the exact moment or having some sort of déjà vu,
How To Build The Time Machine Based On Mallary's Model
Mallary suggests that the time machine could come in a simple design. Her new model is made up of two super long cars parked in parallel that have positive mass and not built of exotic materials. She was able to demonstrate that in this setup, there is a time loop in the space between these two cars.
However, here's the catch: to build the time machine based on Mallary's new model, the center of each car must have "infinite density," meaning they should have "singularities" or objects with infinite density, temperature, and pressure.
Khanna pointed out that even physicists such as himself don't think these objects could exist in nature. This means time travel, although possible, is not happening just yet.
