I ended my last post with one life altering conclusion of theory of relativity – speed slows down time. If you are observing a rocket which is traveling at 90% the speed of light for 1 hour, for the people traveling in the rocket only 26 minutes would have passed. It may be hard to believe, this phenomenon has been observed in particles. Most of the subatomic particles are unstable, they degenerate after a certain time into other particles. It has been observed that the lifetime of the particle increased with the speed of the particle. Particles which move at 80% the speed of light live about 1.7 times longer than the one at rest and at 99% the speed of light they live 7 times as long. This does not mean that the intrinsic lifetime of the particle changes. From the point of view of the laboratory observer the particles internal clock has slowed down and therefore it lives longer**.
If this is what relativity does to time, what it does to space is even more amazing. This is fairly easy to understand. Let us say that two people are traveling in a train and measuring it’s length and two other people on the ground are also measuring it. Let us assume that they are using a light gun to do this measurement. X1 on the train shoots and the light hits x2, the time taken for this would determine the length of the train. Y1 on the ground observes x1 and y2 notes the time it reaches x2. Because the train is moving the time taken for this would be lesser for people observing from the ground. In effect the train would appear shorter for people on the ground and compared to people on board. What is the real length of the train? As per Relativity this question is invalid and incomplete. You can only ask what is the length of the train as per the observer x1. So we conclude speed squashes space.
What I find most fascinating about these conclusions is that you can never separate an experiment from the observer. He is an active participator in all the findings he gets from the experiment. The word ‘objectivity’ completely loses its meaning.
Based on these two conclusions of the relativity theory another scientist called Hermann Minkowski came up with concept of the 4th dimension. Interestingly he also happened to be Einstein’s school teacher who did not think much about Einstein.He concluded that this seemingly illogical shrinking of space and slowing of time is because we perceive them as two separate entities. There are no distinct space and time, there is only one single Space-Time. It is just like how you see shadows of three dimensional objects. They appear longer and shorter as we move them around, but in reality they don’t change shape. We are looking at a 3 dimensional entity from 2 dimensions only.
Let me explain this with another example. Let us assume you can only see two dimensions and a sphere is passing you by. What will you see? You will see a series of concentric circles which keep mysteriously increasing and decreasing. If you were able to see the third dimension you would know that there is nothing mysterious about it. It is only a simple sphere. Similarly, if our brain was tuned to transacting in 4 dimensions we would find nothing strange about the shrinking and slowing of time and space.
I was hoping Einstein would provide some tips for shrinking my dimensions. Looks like it a far too expensive option. I will have to resort to simple and straightforward exercising. Life does have a way of letting you down!!!!
Albert Einstein by Dr Mike Goldsmith
Brief History of Time by Stephen Hawking
Theory of Everything by Stephen Hawking
**The Tao of Physics by Fritjof Capra