Physics of Astronomy
Dr. E.J. Zita, The Evergreen State College, 5.Jan.2004
Lab II Rm 2272, zita@evergreen.edu, 360-867-6853
http://academic.evergreen.edu/curricular/ PhyAstro /home.htm
TA = Emily Himmelright and (your name here?)
Outline
• Introduction to the program
• Jigsaw learning and peer instruction
• Survey + discussion
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Introduction to Modern Astrophysics Ch.1
Prepare 15-minute presentations
Integrating Physics + Astronomy + Math
Plan for week 1
Introduction to the Program
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Physics
Astronomy
Math
Seminar
• Research
• Assignments and WebX
• Covenant
http://192.211.16.13/curricular/PhyAstro/home.htm
Seminar, research, and time budgeting
Seminar: Relativity on Monday, Journal Club on Thursday (WebX)
http://192.211.16.13/curricular/PhyAstro/home.htm#seminar
Research: Planning in winter, execution in spring
http://192.211.16.13/curricular/PhyAstro/research.htm
Budgeting time:
3 x 4 = 12 hours science (MTR 1-5)
2 x 2 = 4 hours seminar (MR 5-7)
2-3 x 16 = 32-48 hours preparation (reading, HW, team meetings, research…)
Total ~ 48-60 hours/week, so be sure to schedule in R&R, to stay healthy
Covenant, Clubs, TAs, Office hours
Covenent: Please read the draft covenant online, to discuss tomorrow.
http://192.211.16.13/curricular/PhyAstro/home.htm#seminar
Clubs: Society for Physics Students: join to get Physics Today
Astronomy club: for Sky & Telescope
http://192.211.16.13/curricular/PhyAstro/research.htm
TAs = Emily Himmelright and (your name here?)
Office hours: 5-6 in the CAB (bring your dinner or snack)
(Except this week I have to leave at 5:30 to testify.)
Jigsaw learning and Peer instruction
Educational research shows
that students learn best
when:
• Actively engaged
• Working in teams
• Taking ownership of
knowledge
• Expressing understanding
in own words
Here is our first exercise in peer instruction: a survey.
Survey and discussion
• Purpose: to teach your
prof what we need to
review, and to practice
peer instruction
• Put your name on p.3
• Please do pages 1 and 3-5
• We will discuss it together
• After discussion, do page
2, then turn it in.
• After class, do page 6
(online covenant)
Intro to Modern Astrophysics
Carroll and Ostlie = CO
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Basic astronomy
Gravity + orbits
Light + spectra
Modern physics + QM
Electromagnetism
Sun and Stars
Thermal + radiation
Cosmology
Ch.1: The Celestial Sphere
(Figures from Freedman and Kaufmann, Universe)
1.1: The Greek Tradition; Team 1: Celestial Sphere
1.2 The Copernican Revolution; Team 2: Periods; prob.1.3
1.3 Positions on the Cel.Sph.
Team 3.a: Altitude+ Azimuth (p.10-13), prob. 1.5
Team 3.b: Right Ascension and Declination (p.13-15), prob.1.4
Team 3.c: Precession and motion of the stars (p.15-19), prob.1.6
1.4 Physics and Astronomy
1.1 The Greek Tradition
The Celestial Sphere
Geocentric Ptolemaic System
Epicycles and Deferents
Angles measure the sky:
2p radians = 360 degrees = 360 °
1° = 60 arcminutes = 60’
1’ = 60 arcseconds = 60 ’’
Example: Moon subtends 1/2°
Freedman and Kaufmann #1.30: The average distance to the Moon is 384,000
km, and the Moon subtends an angle of 1/2°. Use this information to
calculate the diameter of the Moon in km.
arclength D = d a when a is in radians
1.2 The Copernican Revolution
Geocentric model actually uses
MORE epicycles and deferents,
but it is conceptually simpler
Synodic period S = how long we
see a planet take to return to the
same place on the sky (e.g. near
the same star)
Sidereal period P = how long the
planet takes to orbit Sun
 1 1
1
   
S
 P P 
1.3.a. Positions on the Celestial Sphere
Altitude h = angle above horizon
(depends on position on Earth)
Azimuth A = angle from North
1.3.b Positions on the Celestial Sphere
Right Ascension a = longitude
east from vernal equinox
Vernal equinox = place and time
of Sun’s crossing the celestial
equator, going north
Declination d = latitude north of
celestial equator
1.4 Physics and Astronomy
Physics: What fundamental, quantitative principles explain the
structure and evolution of the natural world?
Astronomy: What do we see in the sky, and how do things move and
change?
Astrophysics: How can Physics explain what Astronomy observes?
Four realms of physics
Classical Mechanics
Quantum Mechanics
(big and slow:
everyday experience)
(small: particles, waves)
Special relativity
Quantum field theory
(fast: light, fast particles)
(small and fast: quarks)
Four fundamental forces
Physics, Astronomy, and Math for week 1:
Astronomy (Freedman & Kaufmann)
Ch.1: Astronomy and the Universe
Team 1: Ch.1.1 – 1.5 (intro + angles)
Team 2: Ch.1.6 – 1.8 ( scientific notation and distances)
Ch.2: Knowing the Heavens
Team 3: 2.1-2.3 (constellations and diurnal motion)
Team 4: 2.4-2.5 (celestial sphere and seasonal changes)
Team 5: 2.6-2.7 (precession and time)
Mathematical Methods in the Physical Sciences (Boas)
Spherical geometry, Ch.5, Section 4
Candidate HW questions for week 1:
Astrophysics (Carroll and Ostlie)
Ch.1:
Problems 1, 3, 4, 5, 6
Astronomy (Freedman & Kaufmann)
Ch.1:
Review: 5, 11, 12, 15; Advanced: 18, 20, 22, 26, 27, 28, 30, 33
Observing: 42, 43 (Teams 1, 2)
Ch.2:
Review: 6- 8, 10- 14, 16, 17, 20, 22;
Advanced: 23, 29, 32, 34, 37, 38
Observing: 54, 56, 57 (Teams 3, 4, 5)
Mathematical Methods in the Physical Sciences (Boas)
Ch.5, Section 4, Problems 1 (a, d), 2(a), 4(a, b), 24, 25