I have recently got this book called “COSMOS” by Dr. Carl Sagan. It is related to the TV series having the same name which was hosted by him.
First line of the first chapter is indeed beautiful and worth to mention here: The cosmos is all that is or ever was or ever will be.
No doubt, we humans are curious species and out of our curiosity, we have known what we know about cosmos now. We are gradually opened up to this beautiful reality. We are generally taught in our childhood about solar system and that’s where our thoughts end at that time. But as we grow, we became aware of our home galaxy, The Milky Way. Then if we look from further above, we got to know, it is not only our galaxy! In fact, there are many galaxies like ours forming a universe. In a similar way, there are many universes, forming what we call today as COSMOS.
“The surface of earth is the shore to cosmic ocean. Recently we have waded a little out to sea, enough to dampen our toes, wet our ankles The water seems inviting and the ocean calls…”
What a beautiful lines are these, describing perfectly the state of my mind. If we think of ourselves in this huge huge cosmos, we might feel alone! We grow up in isolation. Just a matter of fact, if we randomly choose a place into the cosmos, the chance that we will find ourselves near a planet would be less than one in a billion trillion trillion. That’s how big (and hollow) the cosmos is. It is a dark night out there.
Cosmos has a lot of stars and when I say stars, it doesn’t mean something that is small and has a lesser gravitational field than earth. If you probably think again, one of the stars we know a lot about is the giant ball of burning hydrogen and helium, it is our sun. Again, all the stars in the cosmos posses different properties. Some of them are very young, some are in their middle age and some of them are about to die. Perhaps, many stars could have a planetary system similar to what our sun has. If by any chance, if there is some life on those planets, then there is no denying the fact that they are our brothers and sisters in cosmos.
Let’s return back home, our Earth. In some third century B.C. (about 2200 years back), when the people at that time had known that the Earth was flat (I wonder how many of us would even think about it if it is not known today that the earth is spherical). It was one of the most wonderful thinker of his time, Eratosthenes who did a very simple experiment. He observed when the sun is overhead at a certain position so that there is no shadow cast by a stick at that instant. At the same instant, at some place 800 kilometers apart, the same stick could cast a shadow. If both of the sticks had not produced any shadow, it would be easy: Earth is flat. But it didn’t happen and the only possible answer was that the Earth is indeed curved. Eratosthenes only used these sticks, his feet, eyes and his brains to quite accurately predict the circumference of earth about 2200 years before. This is the essence of observation. Without any mathematics or science, just with the fundamental observations and experimentation, he did what nobody at his time could even think of doing.
Last thing to write here, I did not know that cosmos is actually a Greek word for the “order of universe”. In a way, it is opposite to that of chaos. When there was nothing at the beginning of time except a fireball filling up all the space, this passage of chaos of the Big Bang to the cosmos that we are into today is probably the most awesome transformation of matter and energy that we have witnessed so far.