The Universe

• Universe is defined as the collection of everything that exists.
• It is the only isolated system in the world.
• The word Universe is derived from the french word Unviers, which in turn is taken from the Latin word Universum.
• The age of the earth is estimated to be 13.75 billion years.
• There are probably more than 100 billion galaxies in the universe.
• Our galaxy, the Milky way galaxy is roughly around 100,000 light years in Diameter.
• A light year is defined as the distance covered by light in one year.
• A galaxy may have stars from 10 million to 1 trillion.
• Many cultures and mythologies have stories describing the origin of the universe.
• The matter in the universe in expanding continuously .
• The most accepted theory is the creation of universe is the Big Bang Theory.
• Niclolaus Copernicus was the first person to say that sun is at the center and earth rotates around the sun. Before this, earth was thought to be stationary and sun rotates around the sun.