Intro
How many different ways has pop culture tried to explain time travel to us? There are the old-fashioned 1.21 gigawatts of power for the flux capacitor. Or the “wrinkles” in the fabric of time. Or the plot-convenient mathematical solution Tony Stark came up with. Or the hundreds of other iterations of time travel over the years that have given different possibilities and different explanations for one of life’s biggest questions: Can we travel through time? But how realistic are these ideas, and do they have any truth to them?
Can we time travel?
The short answer is no, but the more complicated – and more interesting – answer is, maybe, depending on how you choose to define time travel. Currently, we have no equipment that can perform time travel, and, based on what we currently know about science, there will never be a way to travel backward through time. Once something is done, it’s done. But what about traveling forward in time? That’s where things start to get messy.
Time dilation
While traditional time travel is not feasible based on our current understanding of how time works, a phenomenon known as time dilation is the closest possible process to replicating our idea of time travel. Time dilation is all about relative frames of motion. Your reference frame matters: a person on the ground doesn’t feel the motion of the Earth spinning on its axis, but that doesn’t mean it isn’t spinning.
Time dilation is the difference in time between an observer in one frame of motion and that of an object moving at a given speed. When an object moves close to the speed of light, time appears to slow down from the perspective of a relatively stationary observer. In movies like Interstellar and Contact, this form of travel is explored in that the traveler will return from their close-to-the-speed-of-light journey having aged significantly less than the relatively stationary people back on Earth.
So the question now becomes: is time dilation the same as time travel? Not exactly, but it’s as close as we can get using scientific principles.
Current state of science
The biggest problem with time travel actually occurring is that in order for time dilation to occur to the extent depicted in movies, we would have to be moving at incredible speeds. Currently, the fastest manned spaceflight we have achieved traveled at about 24,709 mph which is 0.0037% of the speed of light. We’re not even close. The types of technological advancements needed to reach those speeds are monumental and likely won’t come for centuries, if ever.
Conclusion
Basically, time travel is not possible in the sense that we see in movies. The closest we can get to resembling time travel is through time dilation, but even then, the chances of that happening anytime soon are very slim.
I’m not saying that there won’t be a point where we can travel forward and potentially even backward, but personally, I believe that the only resemblance we will ever achieve will come through time dilation. Because think of it this way: if our descendants figured out how to travel back in time, wouldn’t we have met them by now?