Universe chapter Flashcards
the big bang
14-20 million years ago
how did the universe begin?
during a cataclysmic release of energy from a point source of infinite mass
evidence of the big bang
an expanding universe, everything gets bigger
how do we know the universe is expanding?
red shift, spectrum of light, doppler effect, galaxies are moving away from us
red shift
hubble 1927; the shifting of the color of light from galaxies toward red. The galaxies moved closer to the red
doppler effect
changing frequency due to the relative motion of a sound source
origin of the solar system
nebular disk hypothesis
when did the solar system begin?
5 billion years ago
how did the solar system begin?
a large, slowly rotating cloud of dust and gas
solar nebula
slowly rotating cloud of dust and gas; material from a super nova
cooling and gravity
from cloud to sphere
velocity of rotation increases
sphere to disk
most of mass near center of disk
proto-sun
sun turns on
nuclear fusion
how do planets form?
chemical condensation/accretion
evidence of the solar system
planets orbit in same plane, planets revolve around the sun in the same direction
how old is the earth?
4.6 billion years old
how did earth form?
condensation/ accretion
Earth
it heats up, density differention
where are galaxies moving?
away from us:the greater the red shift
what did the Big Bang create?
clumps of cosmic debris that eventually formed galaxies throught the universe
Nuclear fusion
occurs when hydrogen nuclei are mashed together under high temperatures and pressures to form helium
White dwarf
the outer layers of the sun disappear, leaving a hot core
black dwarf
was once a white dwarf
