Here at Online Clock we’re obsessed with all things associated with time. We like keep track of time, set alarms for special times, and record how much time has passed between when something starts and when it stops. We also like to keep tabs on the theoretical applications of time. One of the more interesting theoretical adventures of our old buddy time comes from Albert “it works in theory” Einstein in his theory of Special Relativity. The theory of Special Relativity allows for the mathematical possibility of time travel.
Time travel is a mainstay of science fiction and a foray into fun for people obsessed with time. Before we get into any kind of “time travel: fact or fiction” debate, it’s important to define at least one concept. What is time?
Time itself it difficult to define. Carl Sagan once said that time was “resistant to simple definition” and he was right. It’s easy to think time is what happens between the moments when the numbers on a clock change. We think of a second starting, fulfilling its fate, and then ending. We can watch a clock and observe seconds becoming minutes which turn into hours and so on.
The Theory of Special Relativity states that as an object approaches the speed of light, time slows down. At first that seems impossible. A second is a second is a second, right? Yes and no. A second is a second. A second doesn’t turn into a minute as one approaches the speed of light for the person with the second. Time is relative to where in the space-time continuum the person measuring the time is and where the time that is being measured is.
Let’s back up a second and take a moment to think about what a second actually is. When we were going through elementary school, we were taught that a day is the time it takes for the Earth to rotate on its axis. There were roughly 24 hours in a day, 60 minutes in an hour and 60 seconds in a minute. Time was connected to the movement of astrological bodies. If you recall our blog post about atomic clocks, you’ll know that time is no longer based upon astrological bodies. Time is based upon the vibrations of a certain type of atom.
These atomic vibrations which serve as the true foundation of time change as one approaches the speed of light. The space shuttle doesn’t travel anywhere near the speed of light, but scientists have already noticed that–in relation to the people on Earth–astronauts travel several nanoseconds into the future.
Time travel is not metaphysical conjecture. It’s a scientifically noted fact. The trick is how to take this physics phenomenon and turn it into a real usable practical process. For that, we’d need a time machine.
The universe may have already provided us with time machines. Black holes, wormholes, and cosmic strings might turn out to be gateways to the past or future. Black holes are theorized to come in two different types. The Schwarzschild Black Hole is the most familiar. Gravity crushes all. The end. No time travel. The other type of black hole is the Schwarzschild Black Hole. This black hole does not end in a singularity. It ends in a rotating core that is like a column with a “white hole” on the other side. This black hole-“white hole” connection could be a conduit to time travel or a parallel universe.
Wormholes, also called Einstein-Rosen Bridges, work in a similar fashion. They are tunnels that pierce the fabric of the space-time continuum. If two twins hold onto opposite ends of a wormhole and one stands still while the other travels near the speed of light, the two twins could observe the different passages of time. The twin standing still would age while the twin moving would not. The twin standing still would experience several years as opposed to the twin moving. This is known as the Twin Paradox. Using the tunnel created by the wormhole, either twin could travel to the other time.
Wormholes could be used to traverse the universe more quickly than through conventional means. Traveling through a wormhole is like tunneling through a mountain instead of traveling around it.
Cosmic-strings can be likened to an intergalactic magnetic monorail. The “pearls” on the cosmic string contain a very powerful gravitational force. This force moves objects from “pearl” to “pearl” along the string. The force is so very strong that it warps the space-time continuum. Cosmic-strings also challenge one of Einstein’s “facts”. With this theory, the speed of light isn’t constant.
The science around time travel is all very theoretical. The science fiction that deals with time travel is much easier to understand once someone is willing to live with a willing suspension of disbelief. Gene Roddenberry seemed to have coined the concept of “slingshotting around the sun” to propel the Enterprise into the past or future. The episode “The City on the Edge of Forever” shows the burden of time travelers. The Edith Keeler had to die to restore the correct timeline.
HG Wells gave us a fantastical steampunk time machine in his work The Time Machine. This story broke open the concept of time travel and presented it to the general public. Ever since then, time travel has been a source of scientific theories and fantastical conjecture.
The debate is no longer an HG Wells “what if time travel was real” scenario, but a very real scientific “when will time travel be available to us” scenario.
So, to answer the question posed by the title of this blog post: yes, time travel will be for real, sometime sooner than we think!