Universe



The universe (Latin: universus) is all of space and time and its contents like planets, stars, galaxies, matter, energy etc. The Big Bang theory is the cosmological description of the development of the universe. According to the estimation, space and time emerged together 13.799 billion years ago with an approximate modern diameter of 93 billion light-years across.The earliest models of the universe were developed by ancient Greek philosophers who placed Earth at the center. Further observational developments to the realization that the Sun is one of hundreds of billions of stars in the Milky Way, which is one of a few hundred billion galaxies which are huddled into clusters and superclusters which is one of billions of them. Many stars have planets whisking around them. Space has been expanding at an ever increasing rate since the beginning. Since the Big Bang, the universe has been full of mysteries and unfathomable wonders, some of them exciting, some of them horrifying. The universe is known to have much more matter then visible matter. It is labeled as dark matter. The ΛCDM model is the most widely accepted model of the universe. It suggests that 4.84% of the universe is made of ordinary ('baryonic') matter, 25.8% is dark matter and the rest of the 68.3% is made of dark energy.