Exploring the amazing universe
Our universe, which contains millions and millions of galaxies, is a fascinating celestial phenomenon It continues to intrigue mankind because of its mysterious deep space objects and a number of other extra terrestrial bodies, yet unseen and undiscovered Creation of the universe A century ago, the concept of the origin of universe was neglected by scientists and astronomers. The reason was general acceptance of the idea that the universe existed. in ‘infinite time The universe was thought to be Just a collection of substance with no beginning. At that time philosophy of maternalism and the idea ‘infinite time’ filled well This philosophy, which gained strength in the ancient Greek time, projected the idea that matter was the only thing that existed in the universe and that the universe existed in infinite time and will exist endlessly In the beginning of 19th century, the idea that the universe had no beginning, that there was never any moment at which it was created, was widely accepted It was carried into the 20th century through the works of dialectical materialists The Big Bang Theory During the 1920’s, a Russian physicist, Alexandra Friedman showed through calculations, which were based on the theory of relativity, that the structure of the universe was not static Based on these computations a Belgian astronomer, G Lemaitre, inferred that the universe indeed had a beginning and that is expanding at a constant rate as a result of something of heat had triggered it In 1920, Hubble discovered that the light from stars was shifted towards the red end of the spectrum According to the known laws of Physics, “The spectra of light beams are traveling towards the point of observation and tend towards violet, while the spectrum of light beams is moving away from the point of observation which tends towards the red Hubble’s discovery was followed by a new model for the universe if the universe was constantly getting bigger traveling back in time meant that it was getting smaller The conclusion derived was that at some time, all the matter in the universe was condensed at a single point mass, “Zero volume because of its immense (concentrated) gravitational force Our universe came into being as the result of the explosion of this point-mass that has zero volume This explosion came to be called “The Big Bang” Therefore, the whole idea has given birth to “The Big Bang” theory Galaxies The universe consists of approximately 380 billion sun-like stars, which have planets and their moons. orbiting around them and thus form a collection of stars gases and dust, held together by immense g forces A few thousand stars, that you can see, belong to our home galaxy, called the Milky Way It contains more than 100,000 million stars and is just one of the million in the universe Far behind the Milky Way. we many the universe, some similar to our other galaxies in own and some very different, spreading throughout the cosmos to the very boundaries of the visible univene. Galaxies can be classified into three main types spiral elliptical and irregular The spiral galaxies look like nat while disks, with bulk of older yellow and redish stars in their centre, having beautiful spiral arms Elliptical galaxies are shaped. with a very bright central heart of densely cked stars Ineguliu galaxies have no definite shape and appear as lazy clouds They only make three percent of all known galaxies The Milky Way and the Solar System The whole solar system, together with the local star is visible on a clear night, which orbits the centre of our home galaxy, a spiral disk of about 200 billion stars, called the Milky Way The other objects in our solar system beside the nine planets’ are asteroids meteors and metallic objects that orbit the sun, which are too small to be considered planets Other members of our solar system are comets that revolve around the sun in highly elliptical orbits that bring them extremely close to the sun The core of a comet 15 made up rock and dust, which strikes together with ice and frozen gases, such as, ammonia and methane When the comet approaches the sun, the gases reflect sunlight and thus give the comet a glowing trail The most famous s Halley’s Comet Named after its discoverer, this comet was seen in 1861 and will not come back for 2.8 million years Life of stars Millions of stars, that are part of our home galaxy are of dillerent sizes and structures The stars live illions of years, Astronomers believe that they are formed from clouds of dust and gases that occur throughout the universe When a star is formed. it initially glows very light Then settles down for a long stable period of ten billion years The sun is at middle life now and it has approximately five billion years to go, before it burns out completely. When all the hydrogen fuel is used up, the star becomes a red giant. With the passage of time, it looses its mass and gas to space. After converting into a small bulk of white dwarf it will fade away.