Antoine Boutros

In the previous article we reviewed changes that occurred to the concepts of time and space in response to the emergence of the relativity theory. We compared how the Newtonian  concept that was the  prevailing paradigm  stipulated that if we send a light pulse from one place to another, observers, no matter what their number is, will agree on the time length of the light journey because time according to Newton is absolute. But for Einstein, this is untrue because the relativity theory does not recognize the existence of real time for an event that two individuals, one is mobile and the other is immobile, are trying to intercept each from his location and circumstance.

What are the practical implications and repercussions of this concept?

We again return to Einstein’s imagination-provoking assumptions: let us assume that the navigator of a spaceship, travelling at a speed nearing the speed of light, decided in the middle of the journey to reduce the speed at the same rate until it reaches its destination. For the most part of the journey, the speed will be close to that of light and with it time will become much slower. The reason for this is that the hours used in flying will become slower despite its preciseness compared to fixed hours. Furthermore, atomic accelerators are designed in a way that allows the expansion of the cluster as the speed grows, or else the accelerators would have smashed. Since the speed is the distance divided by time, if our speed is close to the speed of light then absolute time and space disappear and we will shrink while time will expand and slow down, as such our aging becomes slower. If this can be achieved in practice then the relativity theory would have been considered the elixir of life.

If we assume that we travel to a star in a system similar to our solar system, such as Barnard’s Star for example, located at a distance of six light years, then reaching it will take only eight years measuring the hours on the ship. We can also reach the heart of our galaxy (Milky Way) in 12 years and the Andromeda Galaxy in 82 years. As for the earth’s inhabitants the matter would be different because our journey would have taken 300,000 years and when we return to earth we will not recognize anything on it.

One would wonder how scientists could figure out what the effect of gravity on time is. Two atomic clocks are placed on the extremities of a speeding spaceship with each one transmitting light signals directed toward the base of the ship. Despite the simultaneous signals at the start of the experiment, the growing speed of the ship by the moment prevents signals from reaching the center point at the same time. 

The lower clock seems to be slower compared to the upper one. An external observer would think that the slowing speed is a result of the distance of the centre point which lengthens the distance that the signal will travel to reach the centre. But for an observer on the inside the clock is simply slower.

The other interesting question is how would it look to us as we travel at a speed close to that of light? With the increasing speed we will begin to see the extremities of the bodies we pass by. At the time when our bodies are pointed forward, the things behind us will appear in our field of vision. As we get closer to the speed of light, the universe, from our point of view, will appear strange since everything will seem pressurized as if they are part of a small circular painting that is always in front of us.

But from the point of view of a fixed observer, the light that emanates from us becomes redder as we move farther and bluer as we move closer. If we are travelling at the speed of light then we will appear as if surrounded by a colored radiation and we will contract toward the movement while our cluster will remain fixed and will not grow while time as we live it will become slower. And this is what we call time dilation. 

If we imagine ourselves coming from another civilization that still works by solar hours, non -mechanical and non- atomic,we will be surprised to notice the overwhelming presence time machines: Stations, airports, public buildings, public facilities such as offices, post and schools, street corners all displaying huge their clocks announcing the movement of time second by second. The life and activity of human being revolves around time and its concept.

Let us imagine that all the clocks on the planet suddenly came to a halt, what would happen then? The entire society will collapse and air, land and sea transportations will stop because they can only function according to precisely programmed schedules. It would be difficult for the industry to continue its activity because power plants will stop and education, army, customs, services and meetings will become paralyzed. Furthermore, all instant meals will not be functional.  Chaos will prevail.