Video Resource: YouTube Channel: Second Thought Is Time Travel Really Possible?
Time traveling has been an interesting topic for a long time. In 1985, a movie called Back to the Future caught great attentions from the crowds about time traveling. In 1988, the publication of the great book named A Brief History of Time written by Stephen Hawking raised people’s attention about time traveling again. Since traveling through time is such an interesting topic, is time travel possible in real life?
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There are two parts of time traveling. The first one is traveling to the past, and the second one is traveling to the future. Let’s talk about travelling to the past first. It is usually stated that people cannot go back to the past. A very common way to explain it is the Grandfather paradox. It says that if a time traveler can go back in time and kill his grandfather before their their mother or father was born, then he will not be born himself and the killing would not be possible. Another recent explanation was given by Stephen Hawking, one of the greatest physicists in the world. He said that if we want to achieve time travel, we need to consider time as the fourth dimension like length, width and height. However, unlike those three spatial dimensions, time does not have multi-directional property. We are only able to move forwards on the time dimension. Although lots of people still believe that traveling to the past is possible, current knowledge and theories do not support it.
We cannot move backwards on the time dimension, but we can move forwards. If we want to go to the future, we must consider one important thing, speed. There is a speed limit in our universe, which is 186 thousand miles per second. This is the speed of light. If we can travel near this speed, we can go to the future. Imagine that we were in a spaceship that travels at 99 percent of the speed of light, every minute on the spaceship is a year on earth. Therefore, if scientists can invent spaceships that are fast enough, human will be able to travel to the future. Also, Albert Einstein once said that mass is also a factor that will influence time. Time on earth is slower than it is in the universe because of the mass of earth. Therefore, if we can find a planet that is large and heavy enough, the time we spend on it will be much slower than it on earth. When we come back from it to earth, we will be in the future.
All the theories and conclusions are all based on the knowledge we have right know. Maybe in the future all of this could be wrong, and people can go back to the past. However, since going back in time is impossible now, we should just cherish the present and live every day to the fullest because we cannot go back in time.
Liang Zou
Image Resource: Iter.org
Image Resource: Pexels
