Download Introduction to Electromagnetism

Science Seminar
Winter week 9, Monday.6.March.2006
• Finishing up Physics of Star Trek
• Next week: eval conferences
 sign up today
 Friday: self-eval survey
 email peer evals, etc.
• Movie: Understanding the Universe
Next week
• Eval conferences in 2272 Lab II – come 5
minutes early!
• Bring your
 finished portfolio
 hardcopy self-eval (3 copies on official form)
 hardcopy eval of faculty (official form not
required – 1 copy to Zita or to secretaries in 2250 Lab
II)
Preparing:
• Discuss portfolios & evals. Read online
guidelines (skim together).
• Include all responses to your essays, with
authors and dates.
• Include all your responses, with original essays.
• E-portfolios are fine (optional). Make them
*complete and *easy to read, with all links in one
central, concisely annotated document (e.g. a web
page).
•Advising and Writing Center have portfolio & eval
This Friday: email to Zita
• Peer evaluations (a couple of sentences – be
honest and specific – not on official forms)
• Paragraph from your best essay (50-100
words), with WebX link and reference
Take Self-Eval survey online by Friday
No new essays due this week.
New physics
Changes since Physics of Star Trek and the
movie came out:
What is Dark Matter? We know better now:
NOT ordinary matter: less than 5% of dark
matter is protons, neutrons, stars, MACHOS, …
Neutrinos are significant – though they have tiny
mass, there are very many of them (over 1090), but
still they are less than 30% of dark matter
Probably WIMPS – Weakly Interacting Massive
Particles – not yet discovered...
Newer physics
Most of Dark Matter (70%?) may be Dark Energy!
 Dark Matter is whatever causes the observed (for
decades) gravitational dynamics in galaxies – most of it
does not shine
 Dark Energy is whatever causes the observed (since
about 2001) ACCELERATING expansion of the
universe
What is Dark Energy? Vacuum pressure due to virtual
particle creation? How strong is it? Does it change
through history?
Dark Energy, Dark Matter, and the Universe
More questions and some answers next quarter
in Science Seminar:
Cosmology
Quintessence
(A Very Short Introduction)
by Lawrence Krauss (same guy)
by Peter Coles