Introduction

While time travel is a very broad subject, there still exist many ways we could bring the idea of time travel—seen in movies like Back to the Future or The Time Machine—to life. Through different techniques that I will touch on, we can see how the concept might move from fiction to reality.

Time Dilation

Time dilation is the process where an object nearing the speed of light makes time slow down relative to stationary observers. This allows for travel into the future, but not back. While this is a well-understood phenomenon in special relativity, it was also popularized by Albert Einstein’s theory of general relativity. This theory includes the fact that the same phenomenon can be caused by strong gravitational forces; for example, a fast spaceship could travel forward in time by a matter of months or years.

(Speculative) Wormholes

Time travel with wormholes is currently nothing more than a sci-fi construct or theoretical concept, but it remains a very important theory regarding time travel. While a rip through the space-time continuum is not something that we can harness without destroying that continuum, it is still a process thought to exist throughout the vast universe. However, it would likely be so unstable that harnessing it would be impossible even if we could find one. This leads me to another subject.

Black Holes (Also speculative)

A black hole is one of the most mysterious (and dangerous) objects floating around in the vast ocean of bleakness we call space. A black hole is a region of space that exerts such massive gravitational force that it sucks in any matter that comes too close. That matter—whether a comet, planet, or cloud of gas—gets crushed at a hypothetical infinite density. The gravity is so intense that not even light can escape it, and it warps time to a point where time travel could be possible. If scientists can figure out a way to control a black hole, we could potentially harvest its power for the ability to travel through time.