Just think you want to make a trip around the sun. What will you need? First of all, you will need a rocket robust enough to fly around the sun along a particular orbit, maybe close to that of earth. For such a rocket you have to spend a huge amount of money (billions of dollars, of course). You build the rocket employing hired scientists and engineers or you buy it from any rocket manufacturing company. In any case it is not an easy deal. Moreover, there is always risk in rocket travelling. Any time it can break down, causing your death along with other astronauts with you.
Now, if you are really interested in a journey around the sun, I have a point to make. Look around and see, you are already on such a journey. You complete a circular travel around the sun in about 365 days from a distance of about 93 million miles from the huge central burning ball. You cross over a million and a half miles per day. This means you rush through space around the sun at a rate of about 67,000 miles per hour! It's no joke. You are indeed moving at a speed far greater than the most sophisticated aeroplane built by men. It's true, literally. Your vehicle is your mother earth itself. It is going around the sun in the manner described above with all of you in her lap. The remarkable thing is that you get the merry-go-round all free. And it's so safe!
Free of charge, you also enjoy another kind of journey a spin. As you are on the surface of the earth at its axis, you spin at a speed of about 1,000 miles per hour. In about 24 hours you complete the spin. zHalfway, that is every 12 hours, you are exposed to the opposite side of the sky; you are upside down.
On orbit, in about 182.5 days, you reach the other end of the diagonal, facing the opposite side of the sun. So every moment the sky around you is changing by virtue of the movement of earth on its axis and orbit. We get new cosmic scene all the time. Our bare eyes are, however, unable to figure it out. As we travel around, we get days and nights, we get different seasons. A marvellous journey, indeed, with so exciting variation, mostly remaining out of mundane realisation.
We are travellers not only as a passenger of the earth, but also as a part of the solar system. The solar system -- sun with its planets and satellites, is moving at a speed of about 170 miles per second around the centre of the Milky Way galaxy. That is, our solar system orbits around the galactic centre once every 200 million years or so. What's more, the Milky Way, in which our solar system is located at the region called Orion Arm, itself with around 400 billion stars travels at approximately 600 km per second. Our galaxy, again, is grouped in a cluster called Local Group which is taking us away from other clusters of galaxies in the expanding universe. We are essential part of all those journeys.
We get many a journey together, inseparable from one other. It sounds like a miracle, a wonder. Journey inside journey -- a hierarchy of journey. And how adventurous the journeys are! Moving through the sky at breakneck speed. But Alas! We hardly enjoy them as we do not feel them at all. We do not feel any of the motions because these speeds are constant. We do not feel the rotation of the earth on its axis and orbit; neither do we feel the speed of our solar system, Milky Way and Local Group. We only feel the speed when it is variable. For instance, when a car accelerates or when the brake is applied, we will feel motion. On a car journey, we understand the motion looking at the passing-by scene. On a cosmic journey we can also understand motion with changing scene of the sky, though not so clearly.
But what is the meaning of our cosmic journey? We seem to be cosmic travellers by born. We travel through the sky riding on the boat of earth throughout our life. We have no life without journey. We take birth, live and die through journey. We accomplish all our earthly deeds in journey. There is no escape from it for a moment. We cannot change the direction of the journey. It runs as it is set. It is not in our control and within our perception. There is only motion, no station. There is only dynamics, no statics. We are the seed of speed, germinating and terminating in time, without understanding any purpose or need. We are destined not to stop.
When did our journey start and when will it end? There is no sure answer. Some scientists would say all our journeys started with the Big Bang, primal eruption of things into existence, about 15 billion years ago and it will end in another 15 billion years or so. At the end there may be Big Crunch, the opposite state of Big Bang, when everything will collapse into a singularity. But some say the universe will be expanding for an indefinite period and there is no turn-back. In that case there is no end of journey. Probably human race will be extinct before the final state of the universe. The journey of human beings will end before the universe comes to 'an end' or 'no end'. Or, is it possible that the wise bipeds will conquer the universe and control its course in remote future before being extinct? In that case they will initiate a new journey through a new universe in new shape. Let's ponder positively and keep our fingers crossed!
(R) thedailystar.net 2008