The big bang theory
Boom.
Though it may seem like there was a big 'bang' that started it all, that's not how it happened. The big bang was really just an expansion that put the universe into motion. And ever since then, the universe has been constantly expanding. The Big Bang Theory is the most known theory on how the universe started. The theory was introduced by a team called the Wilkinson Microwave Anisotropy Probe, or WMAP, from NASA. In their mission they created a map of the oldest light in the universe. Based on their map they created a more precise age of the universe, and estimate of 13.7 billion years.
Though it may seem like there was a big 'bang' that started it all, that's not how it happened. The big bang was really just an expansion that put the universe into motion. And ever since then, the universe has been constantly expanding. The Big Bang Theory is the most known theory on how the universe started. The theory was introduced by a team called the Wilkinson Microwave Anisotropy Probe, or WMAP, from NASA. In their mission they created a map of the oldest light in the universe. Based on their map they created a more precise age of the universe, and estimate of 13.7 billion years.
Before the big expansion the universe was compacted into a small pin point. The estimated temperature was about 5.5 billion degrees Celsius. Within 100 seconds of the expansion, the universe went from about 5.5 billion to about 1 billion degrees Celsius. After a few years, 13.7 billion to be exact, the universe is at -270 degrees Celsius. The universe is still expanding and cooling today.
After 324,000 years of the expansion protons and electrons finally combined to form neutral hydrogen atoms. At about 380,000 years the universe was finally transparent, and light could shine through. As the universe continued to expand small gravitational forces formed and pieces started clumping together. Same goes for gasses, the gravitational force caused them to compact into small, dense cavities. Over time as more gasses came together, and the gas clusters became extremely hot and very dense. These small clusters are called molecular clouds, and eventually these clouds turn into stars.
Q1 The Big Bang was a/an
Q2 Who introduced the theory?
Q3 How hot was the universe before it expanded?
Q4 The universe is not longer expanding
Q5 How long did it take for the universe to allow light to pass through?