“See you… same place same time tomorrow…”, we say this often when we take leave from someone whom we again meet next day usually at a fixed place may be in our office to our colleagues. We even return back to our home from office or from an outing and usually declare, “I’m back”. We return to the origin from where we started earlier. We rest in our same bed every day in the same house and same room. We go to office to the same building, same floor, same street, same city every day. We see ourselves at same place every day but are we actually at the same place or is it just another of such illusions where life takes us everywhere, but it seems that we are still at the same place. During our plane or a train journey we get up from our seat, go to the lavatory and then return back to our seat, thus effectively we didn’t go anywhere in the plane or the train and have returned to the same place but in reality, the plane or train has already moved you hundreds of kilometres away from where you were on your seat earlier before going to the lavatory and returning. What if this earth is also just like a plane where we are sitting and moving and returning back to the same place while in reality, we are already moving gigantic distances in space?
Earth rotates at a speed of approximately 1600 kms per hour, many times faster than you can drive on an expressway or even faster than a Boeing plane which you take to travel to nations, in fact a large commercial plane also travels at a speed of approximately 1000 kms per hour, so earth is rotating even faster than that. So, when we talk about the space, we are moving even faster than a plane and are travelling a distance of about 400 meters every second. But this is only the speed of earth rotating on its axis, but the earth is also revolving around the Sun at a speed of 30kms per second or 1,08,000 kms per hour. Which means while the earth is moving around the Sun in an orbit it is also moving at an extremely high speed of approximately a lakh kilometres per hour which is a speed much higher than anything can move on this planet. Did you guess we are actually moving in space with a much higher speed than we can even imagine? We are displacing from our original position around the Sun by 30 kms every second. Did you feel now that where we were a second before, we have actually moved 30kms ahead the next second and by the time you read this line you may have moved more than a 100kms away from your position where you were at the last full stop.
Earth takes one year to complete this revolution around the Sun. But then again do we actually reach the same place once in a year when the earth reaches the same place in space around the Sun. Our Solar system includes the Sun and the planets and moon which revolve around it but this whole solar system is also a part of a galaxy where several such Solar systems are themselves revolving around the center of our galaxy. Our own solar system with our Sun along with Earth and other planets revolves around that center at a speed of 220 kms per second or 7,92,000 kms per hour. Now if we again measure our displacement from the original place in the space we have actually moved 220 kms more in that very second that means the Earth has already moved 250 kms away from where it was a second before and even if we forget the 400 meters we have moved due to rotation of earth we are still more than 250 kms away from where we were a second before. Since our galaxy is a very large place in space to cover hence it takes approximately 250 million years, called the cosmic year, for our solar system to complete one revolution around the center of the galaxy. To reach our original place we will have to wait for about 250million years and even then, we may not be exactly at the same place since earth may be at a different place in space during its own revolution around the Sun.
But is it the end of our movement, is it as fast as we can move? No, even our galaxy with all its solar systems is said to be moving towards a central mass called the Great Attractor with a speed of around 1000 kms per second or 36,00,000 kms per hour. This is not revolution but is said to be moving in one direction towards the Great Attractor, which means we are continuously moving 1000 kms ahead towards The Great Attractor every second, which in turn means we are never going to return to the same place any time in another billion years or so and ultimately are going to merge into some extremely large mass in the intergalactic space.
What do you think, are we ever at the same place where we were earlier? With the statistics of motion of our earth and its associated planetary bodies can we ever be at the same place again, can we ever return to where we started? It seems no, we are always moving to a point of no return and that is why the time that has elapsed will never come back neither will we be ever able to come back to the same place and same time ever. We do not ever feel that we are moving with such fast speed in our intergalactic space travel, but then do we feel we are even moving when we are in a plane or a train with all our windows closed? It is because we always measure motion and distance with respect to some point and that point is usually a point of reference which is stationary with respect to our own movement and thus we only measure and feel the relative movement while if we look at the reality from and eye in the space we are always on the move towards some point from where there is no return to origin.