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
Jan 04, 2016
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)
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"
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?
Astrophysics in crisis
Black holes:what have you heard?
Big Bang: You’ve heard that “the laws of physics break down” in the earliest moment.
Black holes can help us understand what that means.
Evidence for the Big Bang
The 3-degree background radiation reveals the origin of structure in the universe
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
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).
Current paradigms in physics
Quantum Mechanics explains the very small
General Relativity explains the very massive (theory of gravity)
http://fusionanomaly.net/quantummechanics.html
http://www.phys.lsu.edu/dept/gifs/quantum.gif
How big was the universe in the beginning?
R
http://academic.evergreen.edu/curricular/astro/astro2005/lectures/LastLecture.ppt
General Relativity (gravity)
The early universe was a singularity – like a black hole.
Event horizon R = distance inside which everything is trapped
BH
R
Quantum Mechanics
The early universe was very small – a point.
Small quantum objects have an uncertain size or wavelength
R
Problem: the early singularity could be outside its own event horizon?!
“Laws of physics break down”
R
R
We need a new theory of “quantum gravity”
String theory? Loop quantum gravity?http://www.columbia.edu/cu/record/archives/vol23/vol23_iss18/28c.gif http://www.cpt.univ-mrs.fr/~rovelli/rovelli.html
Will one of these resolve the crisis and become our new paradigm? GUT?
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 universe’s expansion accelerate?
How to unite gravity with QM? Loop quantum gravity? Superstrings? D-branes? Supersymmetric particles?
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.
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…
Tuesday Wednesday Thursday