Observations about the Universe Flashcards
what was formed after particles and antiparticles annihilate each other
photons of radiation
these photons also materialize into what
particle-antiparticle pairs
the only ones that could form during this point
Hydrogen and Helium
Explain why Hydrogen and Helium are the only ones that could form during that point
the universe was still too hot for neutral atoms to exist
formation of neutral atoms
the universe cooled down
It interacts weakly with neutral particles
photons
something interacts weakly with neutral particles so matter and photons ______ and the universe became _______
decoupled - transparent
the expansion of the universe red-shifted its radiation to longer wavelengths
cosmic microwave background radiation
the universe was created by the creator-sun god Ra from a vast, cosmic ocean of nothingness
Egyptian mythology
the universe and all life in it was created by God
Creation story
universe has no beginning and no end
steady state theory
the expanding universe has an unchanging density due to continuous creation of matter
steady state theory
neutral atoms of what elements were the first ones to be formed
Hydrogen and Helium
neutral atoms are not feasible in extremely ____ temperatures
high
it is essentially constant
density