#timetravel #scifi H.G. Wells is the one who coined and popularized the concept of time travel by using a vehicle that allows an operator to travel purposely and selectively forwards or backwards in time.
Published in 1895, the novel present an “unnamed” narrator which recounts the traveller’s lecture to his weekly dinner guests explaining that time is simply a fourth dimension demonstrating the main principles of a tabletop model machine for travelling through it.
After H.G. Wells contributions, some theories, most notably special and general relativity, suggest that suitable geometries of spacetime or specific types of motion in space might allow time travel into the past and future if these geometries or motions were possible. In technical papers, physicists generally avoid the commonplace language of “moving” or “traveling” through time.
According to relativity there is no single objective answer to how much time has really passed between the departure and the return, but there is an objective answer to how much proper time has been experienced by both the Earth and the traveler, i.e., how much each has aged.
According to special relativity, it would take an infinite amount of energy to accelerate a slower-than-light object to the speed of light. Although relativity does not forbid the theoretical possibility of tachyons which move faster than light at all times, when analyzed using quantum field theory, it seems that it would not actually be possible to use them to transmit information faster than light. There is also no widely agreed-upon evidence for the existence of tachyons; the faster-than-light neutrino anomaly had opened the possibility that neutrinos might be tachyons, but the results of the experiment were found to be invalid upon further analysis.
In conclusion no results yet of a “working” machine or evidence of historic data where we can validate time travelers exist, not at least in our dimension…