The Cosmic Empire

Reverse Arrow Of Time                 Hello friends, in this blog you will get to know about the reversible arrow of time. Are the arrows of time reversible? We have already published a blog in which we have discussed on the arrows of time. If you have not read that, we request you to read that before. Let’s start this-                 Have you ever thought that what would happen if and when the universe stopped expanding and began to contract again? Would the thermodynamic arrow reverse and disorder begin to decrease with time? Would we be able to remember our future then?                 You all can feel very boring in it because we this exists only on theories to find out what would happen if the universe collapse. And the universe will not sta...

The Boundary Condition Of The Universe                       Welcome friends, we will describe here the boundary condition of the universe. In this theory, we can solve many our difficulties about the universe. We all know that the universe was completely in ordered state in its origin as we have described in arrow of time . But why should it be at complete ordered state? Why was it not in the state of complete disorder at all time? And why is the direction of time in which disorder increases the same as that in which the universe expands?                                It seems that the universe evolves according to well defined laws which we can be discovered and understood. Can’t we think that the similar rules will work at the beginning of the univers...

The No Boundary Condition Of The Universe                             Hello friends, in this blog we will discuss on the no boundary condition of the universe. At first, I would like to introduce you from the topic. No boundary condition means a limited space-time. Actually we have some theories that predict the starting of the universe. Let’s discuss on it-                           If we talk about the classical theory of gravity, we find that there are only two ways of starting of the universe, either with the starting of time or with infinite time. But if we talk about the quantum gravity , it shows another way of beginning of the universe, in which the time direction is on same footing as directions in space, it is possible for space-time to ...

Quantum Gravity                                          You must have heard about gravity which works between large bodies. But here quantum gravity is different from general gravity. Quantum gravity works on quantum particles like electron and proton.                                    In order to predict how the universe should have started off. The singularity theorem predicted that the beginning of time would have been a point of infinite density and infinite curvature of space-time. All our rules of science would break down in such points because our rules work in nearly flat space-time. There should be another theory for such points that is very difficult to generate because we don’t hav...

The Inflationary Model                         The inflationary model of the universe was published by Alan Guth from MIT.                                When the hot big bang theory published, we found so many difficulties about the universe. If you want to read such difficulties click here . In order to avoid such difficulties with the very early stages of the hot big bang model, the inflationary model was published.                               According to this theory the early universe might have had the period of very rapid, or exponential, expansion. This expansion is said to be inflationary- an analogy with the inflation in prices that occurs to a great or lesser in every count...

Black Holes                                         Hello friends, black holes are such dead stars which had mass at least 1.44 times greater than the sun. We should know about a star’s lifecycle, if we want to know about black hole. We have already published a blog on a star’s lifecycle. If you have not read, click here . In this blog we will discuss on advance properties of a black hole. So let’s start-                            Chandrashekhar, an Indian scientist, had shown that exclusion principle could not halt the collapse of a star more massive than the Chandrashekhar limit, but the problem of understanding what would happen to such a star, according to general relativity, was first solved by Robert Oppenheimer. His result suggested tha...

                                                   The arrow of Time                          Hello friend, have you ever thought why we are able to remember our past only. Why the time goes to end? We have some scientific theories to understand this system.               In the universe, there are at least three arrows of time- 1. Thermodynamic arrow of time. 2. Psychological arrow of time. 3. Cosmological arrow of time. Thermodynamic arrow of time: It is something related to the second law of thermodynamics which says that the entropy of a system always increases. And there present many disordered states than ordered once. Suppose you have a jigsaw in a box. There is only one certain ordered state o...

Unanswered questions of the Universe 1. Why was the early universe so hot?                   According to the hot big bang theory , our early universe had too much temperature. Universe existed in a point with too much density. But if one asks why the universe was so hot, we are blank. 2. Why does the universe look same in all directions? Why is the universe so uniform? Why is the temperature same in whole universe?                    Hot big bang theory says when the big bang would have occurred, universe started expanding with so high speed that even light had not enough time to reach from one point to another. And according to the theory of relativity, if light is unable to go from one point to another, no other information can. So how can the temperature be same? Some people give a sugg...

Anthropic Principle                    Anthropic principle tells us about the universe after big bang. Why we exist in the universe? Anthropic principle solves such kind of questions. There are two versions of anthropic principle, weak and strong.               According to the weak anthropic principle, in this infinite universe, the conditions, necessary for the development of intelligent life, will met only in few regions. The intelligent beings in such regions should therefore not be surprised if they observe that their locality in the universe satisfies the conditions that are necessary for their existence. It is a bit like a rich person living in a wealthy area not seeing any poverty.            One example to use of the weak anthropic principle is to explain why the big bang occurred about ten thousand million years ago, it takes abou...

Lifecycle of A Star               Stars are such astronomical bodies which spontaneously emits light and heat. There is 70% Hydrogen, 28% Helium, 1.5% Carbon and 0.5% Neon and Nitrogen in a star. We can classify stars by their colours, size and brightness. Generally, there are three colours of stars- red white and blue. Colours show the temperature of a star. White colour shows a high temperature while the blue colour shows a high temperature of a star. Origin of a Protostar: The life of a star starts in galaxy by condensation of Hydrogen and Helium. This gas transforms in cloud which have temperature of about -173 0 C. As these clouds become greater, their gravity becomes higher. When the size the size of a cloud becomes high enough, it stars contract itself. This body is called a protostar which does not emits light. Formation of a Star from Protostar: Protostar is very dense body which continues contracting because of hig...