# The Controversial Concept of Time Travel

Time is a very complex science. Venturing even further into the unknown, time travel is one of the most controversial concepts in physics. With so many possibilities and very few proven facts, understanding time and the endless opportunities opened up by this understanding is a great asset to any curious mind.

To begin to understand time travel, one must first understand time. A quote from a British television character sums up time rather well when he says, “People assume that time is a strict progression of cause to effect, but actually, from a non-linear, non-subjective point of view, time is more like a big ball of wibbly, wobbly, timey, wimey stuff.”( IMDB 1 ).

In other words, time is not as well defined as one might think. Albert Einstein and his Special Theory of Relativity conjectured that time is relative to how fast one object moves in relation to another (Howell Par. 3). Now this little tidbit is only noticeable close to the speed of light (c), which is 000000003335640952 meters per second or 186,282 miles per second (Hawking 13). This speed is also known as the cosmic or universal speed limit. This is found in Einstein’s General Theory of Relativity (Hawking 12). His famous equation E=mc2 (energy=mass times the speed of light squared) says that the faster something goes, the heavier it gets; consequently, the more energy it requires to go faster (Hawking 12).

Thus, at the speed of light, when the moving object would have a length of zero and an infinite mass, it would take an infinite amount of energy to go faster (Howell Par. 2). Since humans don’t possess the technology to create or harness infinite energy, surpassing the speed of light is temporarily impossible. This is one major problem with time travel. One more basic fundamental of time must be understood. Time must not be thought merely of as minutes, days, or years. Time must be thought of as movement through another dimension, space-time (Howell Par. 2). Humans see the first dimension, length; the second dimension, width; and the third dimension, depth.

Now one must see a fourth dimension, direction in time. Einstein understood this and said that time travel was impossible based upon his General Theory of Relativity (Hawking 77). Then, twenty years later, in 1935, Einstein and Nathan Rosen formulated the solution to this problem. Their new idea does allow for time travel (Hawking 79).

Their idea became known as Einstein-Rosen bridges (Hawking 79 ). One many known them by their newer name, wormholes. The term wormhole was coined in 1957 by American scientist John Wheeler (Anderson Par. 4). The bridges, or wormhole, are a sort of loophole in the universal speed limit. Wormholes are like taking a shortcut between and two points in time and space. For example, consider an average man in front of a very large house. He is trying to get to the backyard of this house. Now, if he runs around the house as fast as he can, he can compare his speed to the speed of light. He cannot run any faster, so that is his “speed limit”.

Now consider, instead of running around, he just opens the front door and walks to the backyard and gets there faster than he could have run around. He took a shortcut. He never surpassed his “speed limit”, but, because he got to the backyard faster, it appears like he did. The doors on the house work like wormholes, allowing him to not to have to go the long way around. Now if only these wormholes really existed. In fact, they do exist. They exist all around humanity (Klotz Par. 5). They exist in a level of matter so small, it is smaller than atoms (Klotz Par. 6). This level of matter is known as the quantum foam (Klotz Par. 6).

In reality, these tiny wormholes are just a billion-trillion-trillionths of a centimeter in diameter (Klotz Par. 7). Now contemplate the idea of an advanced civilization being able to enlarge and then stabilize these wormholes (Hawking 77). Now assuming this can be done, and humans can pass through them unharmed, the possibilities are limitless. If the ends of the wormhole were in different regions of space, someone could theoretically cross vast amounts of space in little time. And since time is just another direction, a wormhole could transport someone through time as well. Also, maybe, just maybe, a wormhole would transport someone to a parallel universe (Anderson Par. 13).

Even through wormholes are the most popular concept, there are a few other theories, that, if possible, could prove easier than having to locate, enlarge, and then stabilize a wormhole. One of these ideas is even an all natural way with the main component already in the stars, ready to use.

This all natural time machine is called a black hole (Daily Galaxy Par. 1). Matter slows time so a supermassive black hole, which is a point so dense, not even light or time can escape its gravity, slows down to time to half the speed of everywhere else (Klotz Par. 6) (Klotz Par.7). Also, approaching the speed to light slows down time (Howell Par. 3). We have proof of this in a particle accelerator in Geneva (Klotz Par.34). Particles called pimesons disintegrate in just 25 billionths of a second. But, when accelerated to near the speed of light in that particle accelerator, these particles survive up to thirty times longer (Klotz Par. 30). This is applicable around a black hole because if someone was flying around a black hole at near the speed of light, the travelers time would be slowed down to a fraction of an observer’s time (Howell Par. 3).

So technically, his space craft is a time machine, The stereotypical time machine is an energy sucking machine that punches a hole in time (Klotz Par. 4). This may one day come to be but for now we can create a time machine by slowing down time relative to an observer. For example, re-imagine the man in front of the house. This time there is another person in the house and the two people synchronize their watches. The man outside starts to run faster and faster until he is just under the speed of light. He runs for one hour then goes back inside. The two people compare watches and find that they are an hour different.

The runner, traveling near the speed of light, slowed down time for himself relative to the other person in the house. This runner just traveled one hour into the future, This is how circling a black hole near the speed of light would work, except, instead of traveling hours, they would travel years in time relative to the Earth (Howell Par.14). One drawback is that humans may not be able to withstand the forces that near the speed of light travel would put on a body (Howell Par. 27). Also future time travel would be all that is possible (Klotz Par. 4).

Unfortunately many scientists say time travel is impossible (Daily Galaxy Par. 4). But hopefully time and time travel are not quite as complex or impossible as they used to seem. And always remember Clarke’s Law, which states, “When a distinguished scientist states that something is impossible, he is very probably wrong.”