lecture 25, december 2, 2010 astr 101, section 3 instructor, jack brandt jcbrandt@unm.edu 1astr...

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LECTURE 25, DECEMBER 2, 2010

ASTR 101, SECTION 3INSTRUCTOR, JACK BRANDT

jcbrandt@unm.edu

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a) the size of the universe.b) the age of the universe.c) the shape of the universe.d) the temperature of the universe.e) the distance the universe has expanded.

Question 2

Hubble’s constant, H0, can be related to

a) the size of the universe.b) the age of the universe.c) the shape of the universe.d) the temperature of the universe.e) the distance the universe has expanded.

Question 2

Hubble’s constant, H0, can be related to

H0 is currently estimated to be about 70 km/sec/Mpc.

This translates to an age for the universe of about 14

billion years.

a) there is more matter than energy.b) the universe is closed, and will recollapse.c) the universe is open, and will keep expanding.d) dark matter will dominate, and galaxies will stop

expanding.e) there was more helium than hydrogen created in

the Big Bang.

Question 8

If the density of the universe is greater than “critical”,

a) there is more matter than energy.b) the universe is closed, and will recollapse.c) the universe is open, and will keep expanding.d) dark matter will dominate, and galaxies will stop

expanding.e) there was more helium than hydrogen created in

the Big Bang.

Question 8

If the density of the universe is greater than “critical”,

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Question 5

The cosmic microwave background radiation is

a) evidence supporting the Big Bang.b) proof that the universe is getting warmer.c) a result of the hot intergalactic gas between

clusters.d) the observable form of dark energy.e) released from the first generation of stars in the

universe.

a) evidence supporting the Big Bang.b) proof that the universe is getting warmer.c) a result of the hot intergalactic gas between

clusters.d) the observable form of dark energy.e) released from the first generation of stars in the

universe.

Question 5

The cosmic microwave background radiation is

The radiation observed is the “fossil remnant” of the

primeval fireball that existed at the very beginning of the

universe.

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COSMOLOGY SUMMARY

• Time since the Big Bang = 13.7 billion yrs.• First stars at 400 million years• The Universe is flat or Ωo = 1• CONTENTS: Ordinary Matter = 4%; Dark

Matter = 22%; Dark Energy = 74%