big bang quiz

describe the universe before the big bang started

the universe was unknown before the big bang started 

planck era

• we don’t know what was happening during this era

• all forces unified as one

GUT era

• GUT = Grand Unified Theory Force 

• gravity emerged as separate force 

• the expansion of the universe began

electroweak era

• forces: gravity, strong & electrostatic forces separate

particle era

• electrostatic force split into electromagnetic & weak forces

• elementary particles are made, filling the universe

• matter & antimatter formed

• end of era: particles formed protons & neutrons

era of nucleosynthesis

• all 4 forces: gravity, strong, electrostatic, electromagnetic, weak

• nuclei were formed

• matter formed from antiprotons annihilating protons

• fusion produced helium from protons (hydrogen)

era of nuclei

• 75% H and 25% He

• plasma of free electrons, H & He nuclei filled universe

• universe 380,000 years old: cooled down for stable atoms to form

• universe became transparent

era of atoms

• universe consisted of neutral atoms, plasma, & photons

• first stars were born

• ended when first galaxies formed

era of galaxies

• from the formation of the galaxies until now

• the universe is a cosmic recycling plant-using matter over and over again

how long ago did the big bang happen? 

13.7 billion years ago

how long ago did the first galaxies form?

2 hundred million years ago

how long ago did the first stars form?

1 billion years

what did edwin hubble discover about the spectra of the galaxies in the universe

galaxies were being redshifted, (expanding and moving away from us)

what are the major pieces of physical evidence for the big bang?

• cosmic background radiation

• universe’s expansion

• abundance of light elements (helium, hydrogen, lithium)

how has the universe’s density changed?

the universe’s density decreased because of rapid expansion

which was the first force to separate out? the second?

• first: gravity

• second: electromagnetic force