MOD1 - Big Bang and Nucleosynthesis Flashcards
A broadly accepted theory about the universe.
Big Bang Theory
Big Bang began as an incredibly hot, dense point how many years ago?
13.7 billion years
What was the universe like at the beginning?
An infinitely small and inifinetely hot point, called singularity.
Is it expansion or explosion?
expansion, also called inflation. universe grew exponentially at least 90 times.
Is the universe still expanding?
Yes, but at a very slow rate.
What was the universe like at 1 billionth second after the big bang?
A dense sea of quarks and particles
What happened at the trillionth second?
Quarks underwent baryogenesis and formed protons and nuetrons
What happened 380,000 years after the big bang?
The universe became too hot to shine, and too hot to form atoms.
What happened when the universe cooled down?
Cold enough to form neutral atoms and light. the light’s radiation were detectable in the form cosmic microwave background.
1st element to ever form
deuterium, a hydrogen isotope
2nd element to form
Helium, deuterium combined to form helium.
What happened after the era of recombination?
Dark ages followed.
What happened after more than a half million years (after BB)?
The fisr stars and galaxies were formed.
How are stars formed again?
Ultraviolet from cosmic events cleared out neutral hydrogen. Re-ionization and the clearing of foggy hydrogen gases caused the light to emit for the first time.
