What is Universe?

Universe, cosmos, and space mean the same-the space all around us and what is contains as far as we can see and think. We do not know whether the space is endless or is finite. If there were a border, what would be behind it? The astronomers are still dealing with the question of the origin of the universe and its end. An important factor to support the Big Bang theory of the origin of the universe is the 'cosmic background radiation', which was discovered in 1964. We still wonder whether there are intelligent civilizations somewhere in space and are looking for them.

How did space originate?

The starting point of the universe was a tiny, very compact core, with an unimaginably high temperature. About 14 billion years ago, this core exploded in the event called Big Bang. Space and time were created only after this, so one cannot say what was present before the Big Bang. After the Big Bang, the space expanded within a few seconds. This is known as 'cosmic inflation'. Electromagnetic radiation arose, and after 15 minutes there were the first atomic nuclei. About 300,000 years later, atoms were formed and the universe had cooled down to a temperature of 3000 c . After around 5000 million years the first stars originated.

How far can we see in the Universe?

With the naked eyes, we can see the stars and the planets within the Milky Way. With a telescope we can see the Andromeda galaxy, which is 3 million light years away. With a strong magnifying telescope, a lot of galaxies and stars can be viewed. Telescopes are of different kinds. Earlier, telescopes were built using lenses- the largest measured 1 m in diameter, but the later telescopes worked mainly with mirrors. The Hubble space telescope can see the farthest in the space. In 2004, it took a picture of a region of the sky that is 13-7 billion light years away. One can see the galaxies, the way they looked like just after the Big Bang.