The big bang’’ is the name for the leading theory behind the birth of everything: atoms, light, gravity, gases, stars, planets, galaxies, and even time itself. And while scientists have found plenty of evidence to back up the big bang theory, the name itself isn’t entirely accurate. The universe didn’t begin with a bang (sound didn’t exist yet) or even a mighty explosion (fire and matter didn’t exist either). Even light was a relatively late addition to the cosmic chronology. Confused? Here’s a guide to how scientists think it all began.
1. In the beginning: A long time ago, time didn’t even exist. Neither did space. And in this nothingness hung a supremely hot spot crammed with all the raw ingredients of the universe scrunched into a point thousands of times smaller than the period at the end of this sentence. Called a ‘’singularity,’’ this spot might even have been smaller than an atom, the basic unit of matter. (But it wasn’t an atom, because atoms didn’t exist yet.)
2. A trillion of a trillionth of a second later: Suddenly, the supremely hot, scrunched-up singularity doubles in size, and then doubles again, and again – at least 90 times – in a process known as inflation. This is the ‘’bang’’ in the big bang, and it get bigger. Expanding faster than the speed of light, this growth spurt defies the laws of physics. Everything in the universe explodes into existence, but at this point it’s little more than a mess of formless heat.
3. One second later: Inflation ends one-millionth of a second after the start of the big bang. The universe’s expansion slows and temperatures cool. At just one second old, the newborn universe contains nature’s fundamental forces. Including the gravity that keeps your feet on the ground and magnetic attraction.
4. 13.8 billion years later: present day: All the matter and energy created by the big bang continues to expand today. New stars form from clouds of gas; old stars die and expel sooty clouds known as nebulae. Planets orbit stars; stars orbit the centers of their galaxies dance with each other. Humans ponder the clockwork of the universe, just as you’re doing now. Got the gist? Good! Let’s move to topics a little less complicated than the birth of time and space.
5. 6 Billion years later: The first stars die and expel the heavier elements that eventually form new stars and planets.
6. 400 million years later: Gravity slowly tugs at the cosmic clouds of hydrogen and helium, squishing them all together to form the first stars. This marks the end of the universe’s dark age. The stars cluster together and form galaxies – including our own Milky Way galaxy.
7. 400,000 years later: The hot mess cools enough for subatomic electrons to join protons and neutrons in the formation of hydrogen atoms, the most common elements in the universe – and the stuff stars are made of. The fog fades so that light can finally shine, but the young universe is still without stars to create light. It continues its expansion in darkness.
8. Three minutes later: Expansion continues. Protons, neutrons, and electrons – the itty-bitty components of atoms – collide and interact to form a sort of super-heated fog, but this mess is much too hot to allow atoms to form – or even light to shine.
Picture Credit : Google