|Partial view of the universe: taken by hubble|
Gazing up at the night sky, you may wonder about the stars twinkling above you: How far away are these tiny glimmers of light? What lies beyond the stars? Where does our tiny planet fit in?
Join us on an exploration to answer some of these mysteries. This site will help you to find out how vast the Universe is, how and when it all began, what astronomical events could trigger doomsday on Earth, statistics on planets and much more... Happy Journey into the Cosmos!
The Universe can be defined as "all matter and energy, including the earth, the solar system, the galaxies, and the contents of intergalactic space, regarded as a whole".
Our universe is vast. To get an idea about how big our universe is, have a look at the following numbers. Our universe consists of more than 100 billion galaxies, and each galaxy, on average contains more that 100 billion stars, which accounts for more than a million trillion stars i.e. 1 followed by 22 zeros. Also the universe is around 93 billion light years accross(1 light year=9 trillion kilometers), which accounts for about 20 billion trillion kilometers accross i.e. 2 followed by 22 zeros. Mind boggling!. This is our elegant Universe. Now let us see how and when it all began and how it will end, in the following sections.
Our Universe originated around 13.7 billion years ago in the most spectacular and the most powerful explosion of all time, called the Big Bang. Before the Big Bang, all matter and energy of the observable universe was concentrated in one point of infinite density. The object of infinite density that existed before the Big Bang is called the cosmic egg. After the Big Bang, the Universe started to expand to its present form.
Future of our Universe
Cosmologists consider two scenarios for the future of our universe. If the density of the universe were greater than the critical density, then the universe would reach a maximum size and then begin to collapse. It would become denser and hotter again, ending with a state that was similar to that in which it started-a Big Crunch.Alternatively, if the density in the universe were equal to or below the critical density, the expansion would slow down, but never stop(recent observation suggest that the expansion of the universe is infact speeding up). Star formation would cease as all the interstellar gas in each galaxy is consumed; stars would burn out leaving white dwarfs, neutron stars, and black holes. Very gradually, collisions between these would result in mass accumulating into larger and larger black holes. The average temperature of the universe would asymptotically approach absolute zero-a Big Freeze. Moreover, if the proton were unstable, then baryonic matter would disappear, leaving only radiation and black holes. Eventually, black holes would evaporate by emitting Hawking radiation. The entropy of the universe would increase to the point where no organized form of energy could be extracted from it, a scenario known as heat death. The second event(infinite expansion) will likely be the fate of our Elegant Universe.