Time Travel has been one of the most fascinating topics since HG Wells published his book ‘The Time Machine.’ The concept existed even before that but it was during that time the topic went into a heated debate related to the possibility of it.
Let’s have a look at some of the time travel facts:
1. Time Is The Fourth Dimension
Simply stated, the first three dimensions are used to specify an object’s location/movement in space (forward-backwards, left-right and up-down), while the fourth dimension locates its position in time. All four dimensions are used to specify completely the location or dynamism of an object in space. Collectively the four dimensions are inseparably interlinked and known as space-time.
2. A Time Traveller to the Past Cannot Change History
According to people who claim to have taken retrocognitive time trips, you may see people and buildings from past times. You may be aware that the weather has suddenly changed. You may see many things that no longer exist in the present. But you will not be able to touch or pick up any objects you see. And the people you see in the past will not speak or even see you. They exist in their time, you exist in yours–and the two never seem to interact.
This is quite a different picture from the one presented in the movie Back to the Future and its sequels. Not only does Marty interact with everyone he meets in the past, but he also interferes with history to the extent that his brother and sister become “erased” from the future. In real time travel, no such possibility exists.
3. Retrocognitive Time Travel Is Difficult to Prove
Unfortunately, the biggest problem with retrocognitive time travel is that people can’t prove that they actually traveled to the past. For example, Mr. Dawson had only his own testimony to prove that he had seen a store from his childhood. After all, he hadn’t walked into the store and picked up a few items to bring back to the present as proof that the trip took place.
4. Three Dimensional Creatures
Being three-dimensional creatures (possessing length, width, and height), humans are unable to see the fourth dimension as our physical world is constructed within these three physical dimensions. We might feel or intuit time’s presence, but we can never actually detect it with our three-dimensional senses because it extends beyond our universe. Humans only perceive the fourth dimension time as memories lodged at variable intervals, the result of which is our apparent perception of time moving forward in a straight line. However, time still exists as a dimension, and objects can cross it in a similar way as they do the others, although three dimensional like humans can only move in one direction forward through time. If we could see an object’s fourth-dimensional space-time (or world-line) it may resemble a spaghetti-like line stretching from the past to the future showing the spatial location of the object at every instant in time.
5. Time And The Speed Of Light
A property of light is that it always travels at the same constant speed in a vacuum of 186,000 miles a second (700 million mph) and you can’t go any faster. The reason for this is that mass increases with speed all the way to infinity and so an infinite amount of energy would then be needed to travel beyond the speed of light.
6. Time Travel to the Future Is Called Precognition
Travel to the future is called precognition, or “knowledge of future events before they happen.” You can travel to the future to gain a glimpse of what will happen to you, usually, or to someone you know. You won’t find yourself beaming aboard the Starship Enterprise, though, or even the space shuttle Endeavor. Neither will you find yourself in some future city trying to find or avoid a “terminator.”