Astronomy and Cosmologies

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Tuesday, week 4

• Arney on Systems and more
• Zita on Astrophysics in crisis
• Kuhn and Social constructionism
• This week Library workshop 2
• Next week - Research proposals (in teams)
• - midquarter conferences (seminar teams)

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Arney on Systems
Where is the Life we have lost in living?Where
is the wisdom we have lost in knowledge?Where is
the knowledge we have lost in information?The
cycles of Heaven in twenty centuriesBring us
farther from God and nearer to the Dust.T. S.
Eliot, "Two Choruses from the Rock"
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Kuhn on revolutions
Original paradigm good framework for solving
old puzzles Anomalies outstanding problems,
inconsistencies? Crisis proliferation of
theories New paradigm how can it replace the
old?
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Astrophysics in crisis
Black holes what have you heard? Big Bang
Youve heard that the laws of physics break
down in the earliest moment. Black holes can
help us understand what that means.
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Evidence for the Big Bang
The 3-degree background radiation reveals the
origin of structure in the universe
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More evidence for the Big Bang
Expansion of the universe further galaxies are
receding faster Amount of Hydrogen and Helium in
the universe beginning was very hot 3K
radiation universe has cooled to the present
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Questions about the Big Bang
What happened in the first tenth of a millionth
of a billionth of a billionth of a billionth of a
billionth of a second (10-43 sec)? The universe
was very small, so ask Quantum Mechanics. The
universe was very massive and dense, so ask
General Relativity (theory of gravity).
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Current paradigms in physics
Quantum Mechanics explains the very
small General Relativity explains the very
massive (theory of gravity)
http//www.phys.lsu.edu/dept/gifs/quantum.gif
http//fusionanomaly.net/quantummechanics.html
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How big was the universe in the beginning?
R
http//academic.evergreen.edu/curricular/astro/ast
ro2005/lectures/LastLecture.ppt
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General Relativity (gravity)
The early universe was a singularity like a
black hole. Event horizon R distance
inside which everything is trapped
R
BH
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Quantum Mechanics
The early universe was very small a
point. Small quantum objects have an
uncertain size or wavelength
DR
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Problem the early singularity could be outside
its own event horizon?!
DR
Laws of physics break down
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We need a new theory of quantum gravity
String theory? Loop quantum
gravity? http//www.columbia.edu/cu/record/archive
s/vol23/vol23_iss18/28c.gif
http//www.cpt.univ-mrs.fr/rov
elli/rovelli.html Will one of these resolve the
crisis and become our new paradigm? GUT?
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Outstanding cosmological questions
What physics operated before the Planck
time? What is gravity? Higgs? Graviton?
Other? What is dark matter? Neutrino mass?
Wimps? What is dark energy? Why does universes
expansion accelerate? How to unite gravity with
QM? Loop quantum gravity? Superstrings?
D-branes? Supersymmetric particles?
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How to choose which model?
Criteria New model answers old Q
Predictions pass tests New puzzles solvable
Simplicity, beauty More? My generation
articulated this problem. Your generation will
solve it.
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Can science discover truth?
Facts are theory-laden? Theories are created
by humans and reflect their biases, language,
culture? In what sense can science be
objective, if it is socially constructed? Stay
tuned
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Tuesday Wednesday
Thursday