Facts about the Big Bang
- 07
Roughly one second after the Big Bang, the universe had cooled to about 10 billion Kelvin, allowing quarks to combine into protons and neutrons that would form all matter.
- 06
Gravity separated from the other three fundamental forces just one billionth of a trillionth of a second after the Big Bang, making it the first force to become distinct.
- 05
Photons couldn't travel freely through the Big Bang's first 380,000 years because the universe was too hot and dense, making it completely opaque to light.
- 04
About 13.8 billion years ago, the Big Bang's first three minutes produced nearly all the helium and lithium in the universe through primordial nucleosynthesis.
- 03
Observations of distant supernovae in 1998 revealed that the universe's expansion is accelerating, driven by an unknown force now called dark energy comprising 68 percent of all matter and energy.
- 02
The cosmic microwave background radiation observed today by scientists originated approximately 380,000 years after the Big Bang, when the universe cooled enough for atoms to form.
- 01
Within one trillionth of a second after the Big Bang, the universe expanded exponentially in a process called cosmic inflation, doubling in size at least 90 times.