7/31/2019 Quiz 3 Essay Answers
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Quiz 3 essay answers.
1.They believe in the big bang theory, there are 3 evidences
that help support their beliefs.
1. 1. The Universal Expansion: Scientist proposed a steady state
universe. Which galaxies areconstantly being in the spaces that are
vacated, with the steady state model describes a
universe that is constantly expanding and forming new galaxies,
but with no trace of a
beginning.
2. 2. The Cosmic Background: 1964 Arno Penzias and Robert W.
Wilson. They worked during theearly days of satellite broadcasting.
They measured microwave radiation to document the kinds
of background signals that might interfere with radio
transmission. They found that whichever
way they pointed their receiver, they heard a faint hiss. There
seemed to be microwave
radiation falling on the earth from all directions, we call this
radiation the cosmic microwave
background radiation. However theorist pointed out that if the
universe had indeed begun at
some point in the past, than today it would still be giving of
electromagnetic radiation in the
microwave range.
3. 3. The Abundance of Light Elements: for a short period in
early history of the universe atomicnuclei could form from
elementary particles. Cosmologist believes that the only nuclei
that
could have formed in the big bang are isotopes of hydrogen,
helium, and lithium. Calculations
based on density and collision frequency, together with known
nuclear reactions rates, make
rather specific predations about how much of each isotope could
have been made before
matter spread too thinly. Studies of the abundances of these
isotopes find that they agree quite
well with the predictions made in this way.
2. Two sources of energy contribute to the Earth's interior
heat. Some of this heat energ is left overfrom the gravtional
potenial energy released during the great bombardment and
differentiation of
the mantle an core as Earth formed. They decay of uranium and
other radioactive elements, ehich
fairly common throughout Earth's core and mantle, provides a
second important soruce of heat
energy. these radioactive elements decay over time and produce
energetic, fast moving decay
products-particles that collide with atoms mocules in
surrounding rocks and give up their energy as
heat. Once generated, must move spontanously toward cooler
regions. If the Earth was somewhat
smaller, or if smaller amounts of heat were generated the energy
could be carried to the surface
entirely by conduction the movement of heat by collisions. Rocks
in the mantle have been heated to
the point where they are able to flow slowly, immense convection
cells ar set up deep within the
Earth's mantle. Mantle rocks behave something like water in a
boiling pot. Solid rock cannot flow
significantly on timescales comparable to human lifetimes.
Earth's scientist now estimate the
Earth's covection cells go through a full cycle with hot roks
rising from the lower mantle, cooling
near the surfac, and falling back to be replaced by other,
warmer rocks. In effect, if the Earth
behaves something like a giant spherical stove, with burners on
the inside and circulating rocks
bringing the heat to the surface. the theory of plate tecctonics
caused a revolution in the Earth
sciences. this theory includes the oceans, the landmass, the
plants deep interior, and the
