Why Time Travel Will Never Be Possible

Is it really possible for humans to travel into the past? Or to overcome speculation by slipping into the distant future?

The subject has fueled many dreams and also much controversy. But could it happen?

Many of the arguments supporting the possibility of time travel are based upon a stack of dependent theories. However, time will likely show these theories to be insubstantial. Much like the past cosmologists who put the earth at the center of the universe, these theorists will eventually find their ideas crumbling forever into the realm of fantasy.

Debunking these myths and getting to the root of the matter requires a definition of time.

Time is not a simple illusion. Things really do change. However, the concept of time is simply a man-made system for measuring change.

Because time is conceptual, there is no physical or tangible substance that can be physically altered. The only physical reality involved is the state of each particle in the universe. These particles change state constantly, but this changing of state does not allow for time travel as has been proposed.

Since time is merely a measurement of state, traveling through it would require knowing the exact state of all things at the target time, as well as the ability to put every particle in the universe back to that state. In other words, humans would need to be both omniscient and omnipotent. (This has the frightening implication that recreating a past state would obliterate the current state of everything. There would be no other-dimensional continuation of what might have been.)

Until scientists can create a sensor capable of recording the state of all particles in the universe, and of continually taking snapshots of these particles every time a minute change occurs, there is no way humans will achieve such omniscience.

If brilliant minds managed to achieve such an accomplishment, they would face the more daunting task of simulating omnipotence. They would need to devise a way to put all particles in the universe back to the state they were in at the desired time.

Many argue that time travel is possible based on the theory Einstein proposed. By traveling at light-speed, they say, a person could outrun time and freeze it. However, this argument has some obvious limitations. First of all, outrunning light would only impact your perception of time, and only the perception of those things you are running away from. Such a method would not make the future arrive any faster. Also, just because you cannot perceive with your eyes the changes happening behind you, they are still occurring. If you didn't pay your phone bill before you started to run at light speed, the phone company would still turn off your service whether you perceived it or not. Stopping your perception of things is not time travel; it is voluntary ignorance of what is actually occurring.

The idea of traveling forward in time is ludicrous. There is no future until it happens. How can you change all particles in the universe to a future state if there is no definition of that state to work from? Until a given state arrives, all states are possible. Therefore, there is no future. The future is only a concept. Only the present state of things and any past states have definition. Beyond anticipation, no future exists, and scientists will have a harder time anticipating the future than they will simulating omniscience or omnipotence. There are simply too many variables to guess what will actually happen to every particle in the universe ten minutes from now, much less ten years. If scientists were omnipotent, they could only bring into being their best guess of what would have happened naturally.

While speculation of time travel makes for great science fiction, the reality is that humans will never achieve such a feat. And if time travel was possible, who among us would have the wisdom to use it responsibly?