Astronomy: Our picture of the Universe

 


Welcome readers!


 

Here is my post about the chapter which is included in study, BA Sem 5, Main English.The paper Name is Compulsory English 05. So Let's see the first chapter Named "Our picture of the Universe".


 


  "Stephen Hawking" - a great name of theoretical physics. "A brief history of time" is very famous book which is written by Stephen Hawking. In these book, the first chapter of the book is "Our picture of the Universe". Hawking mentioned in the chapter that about the different theories,different theoretic points of the great names of scientific field and philosophic field also.

Hawking Frist described the Aristotelian theory. Aristotle portray in his book named "On the heavens" he put forward two Good arguments which is as follows : 

1) He came to know that the eclipses of the moon were caused by the earth coming between the sun and the moon.

 

2) From his traveling experience the North star appeared lower in the sky when viewed in the south than it did it more northerly regions.




He also believed that the earth was Stationary and other planets, the sun,the moon and the stars also were moved in circular orbits around the earth. In the second century AD, there was a complete cosmological model which is happened by Ptolemy who also followed Aristotelian theory. His Aristotelian or Ptolemaic theory was build with the name of five planets which know at that time :

 




1) Mercury
2) Venus
3) Mars
4) Jupiter
5) Saturn

 





 

Ptolemyy specified these planets and also he put the think about that the earth stood at the central, surrounded by eight spheres that carried the moon the sun the stars and other five planets included.





 


In 1514, a polish priest named Nicholas Copernicus who gave the sense on the sun. His ideology believing in that the sun was Stationary at the centre and the earth the planets moved in circular orbits around the sun. Which more believable think so.

 


 


But when a century passed before this idea was taken seriously two Astronomer--The German Johanne Kepler and The Italian Galileo Galilei -- theses two great thinkers were publicly to support the copernican theory.

After Inspection of Galileo about the Universe observing with telescope he noticed that everything did not have to orbit Aristotle and Ptolemy had thought. Kepler had modified Copernican's theory and he also suggesting that the planets moved not in circles but in ellipses. And Now, the predictions finding matched the Observations.

 



 


Kepler's doctrine was that planets were made to orbit the sun by magnetic forces. His this ideology kept running an explanation was provided only much later, in 1687 when Sir Issac Newton --- The Star of Morden Physics who published his book named Philosophia Naturalis Principia Mathematica in which he mentioned postulated a law of universal gravitation according to which each body in the universe was attracted towards every other body by a force that was stronger the more massive the bodies and the closer they were to each other. He also recognized the Universe that the earth and the planets to follow elliptical paths around the sun.Here is three laws giving by Kepler :

 

 


In short we can say that he only make the Focus on gravitational force between the Universal elements.Newton also mentioned about two forces, one is repulsive force and second is attractive force. And then these two forces make each other totaly opposite and then the gravity is born.

When at that time most people believed in that the universe is Static or unending. They also believed that the universe had (Newton's theory) that it was at some finite time. Newtonian theory of gravity, which is tell us that the gravitational force between two bodies depands only on one number associated with each body.

 


 


In 1929, Edwin Hubble shown his doctrine that the universe is Expanding. His observations suggested that there was a time called Big Bang, when the Universe was infinitesimally small and unending dense.

In these point Hubble said that an unchanging universe a beginning in time is something that has to be imposed by some being outside the universe on the other hand he also said that one can imagine that God created the universe at literally any time in the past.Here is a gif of The Big Bang :

 




Karl popper has emphasised a good theory is characterized by the fact that it make a number of predictions that could in principle be disproved or falsified by observation. The eventual goal of science provide a single theory that describes the whole universe, most scientists actually follow is to separate the problem into two parts : 

1) Universe changes with time.
2) The intial situation as a matter for metaphysics or religion.( God being Omnipotent)

Nowadays scientists described the Universe in terms of two basic partial theories :

1.The General theory of Relativity
2.The General theory of Quantum Mechanics.

The whole universe is such a beautiful or full of magical elements. It's also connected with Mythological thinking or theorical thinking. But on the presence we can say that the knowledge about the science or Physics is very expanding or greater than rumours.

On the other hand, we can see that in mythological thinking there are not to be stopped, because of there are low educated people, in specially Indian mythology.
So, the question about universe that who is creator? 
It's never stopped. Then how we start the solution?
It's depends to us and our ideology about that how we know the ideology of the great thinkers and how we believe in that or not.

 


Thank you for reading!