Monday, February 28, 2011

Orion and the Big D

    Early in the morning in the summer a wonderful vista appears in the southern sky. It is well before sunrise and the stars are visible in the sky like beautiful diamonds in all their splendour. I know a little about astronomy and so I recognize some of the constellations, though I have a feeling I should know more. Now astronomy is a most fascinating subject, and observing the night sky is very exciting. However this study is complicated because of the nature of our wonderful universe. The stars are in constant motion and so are we on the planet earth. As such the constellations appear to move when in actuality, we have moved. So the stars that appear in the morning in the summer appear late at night in the winter.

    One constellation that is very recognizable is Orion, the hunter. All you have to find are the three stars that are almost in a perfect straight line, these are his belt, He has two stars above his belt and two stars below his belt and these are his arms and legs , respectively. Only recently, on an especially clear night have I seen the far flung stars that make up his spear and shield. Many a morning,as I walk to the streetcar stop, do I look up and greet my old friend Orion.

    Now another set of stars that is easier to pick out is the Big Dipper, After searching the northern sky you will eventually see a group of stars that look like a big dipper. An interesting fact about this constellation is that, if you connect the stars on the far side with an imaginary line and extend this line, you will almost hit another star. This bright is Polaris the north star. This star is where the axis of the tilted earth would go if it was extended for several light years. As such this star never moves. All the other stars appear to rotate.

    This measure of the distance, the light year boggles the mind. Light travels at 300,000,000 m/s. So you can imagine how far it travels in one years time. When we see the stars each night we are actually seeing the light from that star. That light has taken a journey, sometimes hundreds of years, as measured from earth, to reach our retinas. So it is humbling when you realize that you are actually looking at the past. A moment long passed for the star itself, but new to us. I read a book recently about science and the author stated that the universe started with the famous Big Bang Theory. It all began about 15 billion years ago, The light energy called photons were created just after the initial pop. Now according to the Theory of Relativity several things happen when you travel at the speed of light. One of the things that happens is that time stops flowing. So to a photon that has traveled from the place of the beginning to earth no time has passed. However to us billions of years have come and gone. Now there is no one on this photon to be aware of no time passing, however it is still fascinating to consider.

    A book by Robert Jastrow details the life of the universe and how the galaxies and stars were formed. He explained how stars evolved from the stellar gas that existed everywhere. This gas was composed of the first element , Hydrogen. As gravity condensed the star more and more internal forces took over to counteract the squeeze of the gravity.  The stars became large nuclear furnaces and in the process of producing more energy changed the element hydrogen. Through nuclear reactions great energy was released and the by product was helium. Eventually all the hydrogen was used up and the star had to burn, so to speak the helium. As such more  and more elements were created, until all the fuel was used up and the star could no longer fight the power of gravity. The increased pressure becomes to much for the mass in the star and it explodes. All the elements created are spread out into the universe. From this stuff other stars are made and at times planets as well. Our sun is one of those second generation stars and it is awe inspiring when you realize that the elements that make up your body were once inside a star. We are star stuff!!

    Humans seem to be at the focal point of life. We are not too small and we are not too big. Our connection to the stars is then our deep connection to the macrocosm.