Time Dilation
Before we jump into time travel, we need to understand time dilation. In 1904 there was a big issue on the speed of light:
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( c = speed of light )
If an observer is moving towards a light beam, he should record c as, c =186,000 miles per second + the speed of the observer.
If an observer is moving away from a light beam, he should record c as, c = 186,000 miles per second - (minus) the speed of the observer.
If an observer is moving along with a light beam (in the same direction), he should record that c = 186,000 miles per second - (minus) the speed of the observer.
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Of course, light can only be observed, it has no other use in the universe and if light is observed to be traveling at more than 186,000 miles per sec, it has has no speed limit. This could ruin the 200 years of research that scientists have been doing on the speed of light and time travel. They would have to start all over again and many theories in physics would be of no use.
A young patent clerk by the name of Albert Einstein saved the day. He suggested that if observers (moving and stationary) have to agree on the speed, they will have to disagree on time. Which means time will be running at different speeds for different observers. I know this sounds weird but I will give you an example and try my best to explain what Einstein said.
Let's say we have a spaceship A that is stationary in space while another spaceship B is moving at 93,000 miles per sec (half the speed of light). The spaceships are parallel to each other. Spaceship (a) is stationary at point (c) and 12 light seconds away is point (d) (light second means the distance light travels in one second; 186,000 miles). The halfway line is 6 light seconds away. (click on the diagram below)
When spaceship (b) approaches point c, both spaceships fire a light beam and spaceship (b) continues to go forward. When the light beams reach point (d), Spaceship (a) records that light travels 12 light seconds in 12 seconds; 1 light second per second. Correct.
{ Normally, observers will disagree on the speed of an object. For example, imagine you are traveling on a highway at 80 mph and a car traveling at 100 mph overtakes you; To a person standing at the side of the road, the car will be traveling at a 100 mph but for you it would be only 20 mph because you are already traveling at 80 mph. }
So what about spaceship (b)? It is moving towards the light beam (in the same direction), so will it see the light beam go slower? No. This is because time, in spaceship (b), slows down. 2 seconds in the stationary world will only be 1 second inside spaceship (b) because it’s traveling at half the speed of light. When speed is at 0%, time is at 100%. 100% speed is c (speed of light) so when speed is at 100% or 186,000 miles per hour, time is at 0%.
To sum it up, the faster you move through space, the slower you move through time. So at the speed of light, time will completely stop. Are you with me so far?
When spaceship (b) reaches the half way mark, light has reached point (d) (in 12 seconds). Now spaceship (b) will record that light travels at 6 light seconds in 6 seconds; 1 light second per second. Correct. Without time slowing down, spaceship (b) will observe the light beam travel 6 light seconds in 12 seconds and that’s basically why observers have to disagree on the time.
I can give you a brief explanation on time slowing down. Imagine that there is a clock shaped like this, with a top and a bottom. It has a light beam reflecting back and forth form the top and the bottom. Each time the light beam hits the top or bottom, the clock advances by one second.
Now, imagine the clock starts moving in one direction (click the diagram).
Notice that the the light beam will take a longer time to travel between the plates when the clock is moving and time will slow down. This is similar to how time slows down when we move.
Now, imagine a car going East at 100 mph. It stops, and goes North at the same speed. It decides it wants to go Northeast at 100 mph. When it's going East at a 100 mph, it is going North at 0 mph and vice versa. But when it's going Northeast (the speed is 100 mph), it's going East at 50 mph and North at 50 mph.
In here, North is represented by space and East is represented by time. The car is an object traveling through space. So again, the faster you move through space, the slower you move through time. This phenomenon is called Time Dilation. Several researches have been done by some of the best scientists in world and they all show that time dilation actually occurs.
This is the end of part 1. Part 2 will be coming out soon. Please comment and give me your feedback, tell me if I have missed anything.
And the next time you are traveling in a plane or a car, remember this:
You are traveling fast through space but slower through time...
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