This is How Time Travel is Possible

BB-8 Binary Sunset On Tatooine
[Image via The Walt Disney Company]

Time Travel; it’s something we all wish we could do so we could go back and fix something. However, we sadly cannot do this because time travel doesn’t exist, right? Well, so far as we know, there is no such thing as time travel outside of science fiction currently.

Yet this might not actually be true. In fact, there are several things science now knows and has proven to be fact, all of which proves we might be able to do it. Of course, we want to make sure you understand that some of the things needed for it to happen can be considered quite complicated.

Meanwhile, other stuff is incredibly easy and very well could have already happened. However, we will explain a lot of this to you as well as major discoveries science has made that could affect time travel. First, we need you to be aware of a few other things too.

This article will use a lot of theoretical concepts. The reason for this is that time travel itself is theoretical and therefore, anything we say that relates to it will be too. Even if those concepts are scientific facts, they will still be a victim to the theoretical territory because of their connection to the subject.

We also want you to be aware that our goal for this article is to inform, but you will not walk away learning how to build a time machine. In fact, this is one of the things we will touch on soon.

Without further delay, let’s get started.


Black Hole
[Image via NASA]

Albert Einstein’s Theory Of Relativity

We should mention that a lot of the stuff we discuss to start off this article will be based around the Theory of Relativity proposed by Albert Einstein decades ago. Technically, Einstein’s ideas are no longer a theory but rather, a fact. Why are his concepts on relativity so important? Beyond the infamous E=MC2 equation, the Theory of Relativity connects both Special Relativity and General Relativity.

Both are important but they are what helps us determine how gravity and time are connected. Gravity itself was technically discovered and analyzed by Isaac Newton. However, he could not figure out how gravity operated instantaneously at a distance. Einstein helped us see gravity as a force that moved matter along the shortest space, all within a curved spacetime. He found that the Sun bends spacetime and tells planets how to move.

Newton could not know time and space were not technically fixed. Einstein could and when he figured it all out with his relativity concepts, he infamously wrote “Newton, forgive me.” This was to signify that he found that Isaac could not, as he ruined Newton’s theory with his own. Einstein’s discoveries led to Quantum Physics we use today. Albert also discovered the Cosmological Constant and Unified Field Theories. Both are also useful when discussing time travel.

Space Cloud with Heartbeat
[Image via DESY National Research Center]


It is very important that you keep in mind that when discussing time travel, often spacetime will come up. The reason for this is that it connects to several different areas of how time itself passes. For example, GPS systems are not connected technically to on-ground sources. They connect to satellites in low-orbit. They’re roughly 12,500 miles above the Earth’s surface.

Due to being outside of the Earth and rotating around with it, one would assume that time-wise they are connected to the same time as our own. However, they’re actually off by 1 second per second. Since Albert Einstein was able to accurately find that gravity actually curves space and time, scientists knew how to calculate for this time difference.

Since gravity is weaker in low-orbit, time is altered. In this area, they even run faster in time. Yet Spacetime overall is important to keep in mind. Gravity dictates how spacetime operates, in that, the more gravity something has, the slower time will pass.

Gravitational Time Dilation

Gravitational Time Dilation is present to help us make assumptions about how time will pass for us. Meaning, if we did visit a new planet with different forms of gravity to our own, we can make an accurate assumption of how this gravity will impact our species. Einstein came up with this under his Special Relativity concept.

Gravitational Time Dilation is essentially a comparison model where we bring in two things or events and give them different forms of gravity. The time dilation will be how the time is altered between the two. Einstein found that when the potential for gravity lowers, time will pass slower. However, as gravity increases, the faster the time will be.

In fact, we were even able to find that the Earth’s core is roughly 2.5 years younger than its surface due to this model. This proved to us that larger effects will require a bigger distance or a larger source of gravity.

KIC 2856960
[Image via PBS]

NASA Twins

How space & gravity affected humans intrigued NASA, so they wanted to do a comparison experiment with twins. Therefore, they used Mark & Scott Kelly. They were perfect because they’re identical and did not have any major differences. In fact, both men were checked for everything known to man and seemed to match up in every major category pre-flight.

Scott went into space while Mark remained on Earth. The testing NASA wanted to do was immense. They wanted to test how the immune system responded as well as information on epigenetic changes, gut bacteria, body weight, serum metabolites, and much more.


Scott spent a year in space and upon returning, he showed positive numbers that gave scientists a lot of hope when it comes to possible long-term space travel. Some numbers were even considered shocking. However, compared to his brother Mark, Scott was a bit taller, had less facial aging, and much more. If you want to read a full summary of the study.