Jan 15: Project 1: Scale Model (homework, due Wednesday) pre-test: http://www.physics.csbsju.edu/assess/ADT2.html Read Chapter 1 expect a quiz Wednesday (and every day for a couple of weeks) decide on a lab group (sign up Wednesday) Jan 17: Sign up for a Night Lab Group handouts: Horizon & Equator Coordinate Systems ("Sky Vocabulary"), sky maps same as: Spherical astronomy terms http://www.physics.csbsju.edu/astro/terms.html Project 2: Sky Maps (in class) homework: tutorial & quiz: sky map: starts at http://www.physics.csbsju.edu/astro/sky/sky.01.html read: tutorial: sky vocabulary starts at http://www.physics.csbsju.edu/astro/CS/CSintro.html the textbooks coverage of these topic is spotty, but for another viewpoint: text: p 31-40, 103-136 mostly we'll be following the sequence online Jan 19: handouts: star finder + manual Project 3: Star and Planet Locator (in class) homework: tutorial & quiz: star finder: starts at http://www.physics.csbsju.edu/astro/SF/SF.01.html Jan 22: handouts: SC001 + SC002 Project 4: Right Ascension & Declination (in class) homework: tutorial & quiz: SC001 star map: starts at http://www.physics.csbsju.edu/astro/SC1/SC1.01.html tutorial & quiz: SC002 star map: starts at http://www.physics.csbsju.edu/astro/SC2/SC2.01.html Under the "videos" link on the class web page watch: Moon_Home_Lab If you're using a obsolete browser (like IE or Edge) click on the mp4 file if you're using a modern browser (like chrome or firefox or safari) use the webm file. Note: this deals with the Moon Motions home lab and you may feel you lack background to fully understand what's discussed. Be assured we'll be doing an in class project on this material, but you will have homework on it due Friday. Remark: we're in the process of covering the material that in the textbook makes up chapters 2-4. My take on this material is a bit different from our textbook's. You should in the end read all those textbook chapters. Let me suggest you start with pp. 31-41, 104-124 soon. Jan 24: handouts: Home Lab Manual, Lunar Project Practice (Project 5) homework: finish the Lunar Project Practice (turn in Friday) Under the "videos" link on the class web page watch: Polar_Home_Lab If you're using a obsolete browser (like IE or Edge) click on the mp4 file if you're using a modern browser (like chrome or firefox or safari) use the webm file. online text (no quiz): compare: SC and Sky Map tutorial: latitude & your sky Simon Newcomb on the Revolution of the Earth round the Sun Jan 26: in class matching sky vocabulary quiz similar to online: Quiz on sky terms handouts: Polar Project Practice (Project 6) (start in class, finish at home) homework: Under the "videos" link on the class web page watch: seasons : culminate1B If you're using a obsolete browser (like IE or Edge) click on the mp4 file if you're using a modern browser (like chrome or firefox or safari) use the webm file. Lab starts next week; Exam 1 in two weeks Jan 29: in class culmination quizzes start Lab 1 at the Observatory tonight homework: online: "Name These Moons Quiz" under: Piagetian-based diagnostic quizzes... 3. Martian Moons Under the "videos" link on the class web page watch: moon_unlD2 If you're using a obsolete browser (like IE or Edge) click on the mp4 file if you're using a modern browser (like chrome or firefox or safari) use the webm file. Note: there are culmination quiz videos here also: culminate1B & culminate2B Jan 31: in class culmination quizzes continue homework: online "Moon Quiz" Under the "videos" link on the class web page watch: moon_phase_SH+NH2 If you're using a obsolete browser (like IE or Edge) click on the mp4 file if you're using a modern browser (like chrome or firefox or safari) use the webm file. Note: we will not be returning to the class web site for quizzes & videos for a couple of weeks! Read all of textbook: chapter 2 we'll be particularly working on the material in pp 42-60 note that the seasons material we've done in class is textbook pp 103-114 the moon material is sections 4.5 & 4.7 Feb 2: in class culmination quizzes continue Previous: How objects in the sky seem to move: *phenomenology* Topics: How the "Greeks" *explained* sky motions: Ptolemy, geocentric, epicycle, deferent, equant, retrograde motion, conjunction (2x), opposition, inferior/superior planet No online quizzes or additional reading Next up: textbook chapter 3 Feb 5: in class culmination quizzes continue copernicus, tycho, kepler, galileo, newton kepler's three laws, galileo's telescopic proofs of heliocentric, newton's four laws read chapter 3 Kepler's 3rd Law plot: 9 planets on each side (p.87, 1154) Feb 7: in class culmination quizzes continue (60% 10s most recent) galileo: different mass, same motion with force of gravity; x & y directions separate galilean invariance; acceleration; experiments! newton's four laws read chapter 4 (the only part of this that is new is tides) Feb 9: exam1 in 1 week...help? deadline for polar home lab start approaches in class culmination quizzes continue (60% 10s most recent) newton's four laws 3 great conservations laws: energy, linear momentum, angular momentum read chapter 4 (the only part of this that is new is tides) Feb 12: Home Labs! deadline for polar home lab start approaches (15 Feb) approaching new moon, so if you missed the moon today, it will be hard to see until Saturday end culmination quizzes (80%) tides 3 great conservations laws: energy, linear momentum, angular momentum energy: thermal, kinetic, potential (gravitational, electric+magnetic, nuclear, chemical, ...) entropy: 2nd law of thermodynamics high temperatures break apart composites linear momentum: mv (conserve if no external force) angular momentum (mr^2)x(#rmp) (conserve if no external torque) ice skater effect start chapter 5 NASA downlink: Feb 20 (Tuesday) 12:35 - 12:55 ...trade release for ticket! exam1: Feb 16 help: thursday...7pm?? Feb 14: start chapter 5 waves: wavelength, frequency, amplitude, wave velocity water waves, sound waves, light waves: what is waving? Feb 16: Exam 1 Feb 19: Doppler: moving source or observer: changed frequency related to velocity Light is an EM wave; humans experience a small fraction of what is light ~.5 μm human experience of color is 2D because just 3 colored-light receptors; RGB light ordered by frequency (low to high) is ROYGBIV AM radio, FM radio, microwave, infrared, visible, ultraviolet, X-ray, gamma ray claim: light is produced by accelerating charge (often electrons) Feb 21: spectra: plot of amount of light vs wavelength (or frequency) continuous, bright line (emission), dark line (absorption) start black body (aka thermal, Planck) spectra dispersion: prism, grating in class project: spectra Feb 23: Spectra Quiz I (Blackbody) [from class web site] more details on Blackbody (aka thermal, planck) light what is stuff?: molecules, atoms, orbiting electrons+ nucleus=(neutrons+protons), proton-(uud) quarks, neutron=(ddu) quarks 3 generations of lepton/quark. quarks: (ud), (cs), (tb), leptons: (e neutrino, electron), (mu neutrino, muon), (tau neutrino, tau) 4 forces: gravity, electromagnetic, strong (color) nuclear, weak nuclear gravity waves=graviton, EM waves=light=photon, color waves=gluons, weak waves=W+,W-,Z NOTE: photon energy = hc/wavelength, so short wavelength photons carry a big punch! Quantum Mechanics (~1925: Schroedinger, Heisenberg, Dirac) The idea that waves & particles are separate things is wrong. Everything is one sort of thing which we call a wave/particle, as in various situations it might act like either. Orbiting electrons replaced by a standing wave cloud of electron wave...only certain standing waves are allowed: orbitals, shells, state, energy level Except for the lowest energy state (which has nothing to decay into), these standing wave patterns are not stable: a high energy pattern may become a lower energy pattern with the missing energy coming out in the form of a photon (a bit of light) the exact reverse is also possible: lower energy state+photon becomes high energy state what orchestrates the frequencies put out by atoms? Feb 26: Spectra Quiz II (Spectrometer) online more quantum mechanics how fluorescent lights work (photon emission due to excited electrons) start telescopes refractors, reflectors prime, newtonian, cassegrain, coude focus focal length (f), aperture (d), f#=f/d image size controlled by f, image brightness by f#, total light collection by d objective, eyepiece start chapter 6 Feb 28: more telescopes magnification=fo/fe resolution, seeing why telescopes in space hands-on lens project Mar 2 big quiz on spectra, atoms, telescopes refractors vs. reflectors mounts: equatorial, alt-azi Mar 12 solar system overview: chapter 7 labs at observatory this week! terrestrial/gas giant planets exoplanet intensive/extensive equations: temperature of a planet, gas molecules speed, escape velocity escape velocity proportional to R (for fixed density) molecule speed = sqrt(3 k T/m) planet temperature=T⊙ sqrt(R⊙ /2a) ((1-A)/ɛ)^(1/4) cold planet, high escape speed to retain H2 as in gas giants Mar 14 start chapter 8 Earth's atmosphere: N2 (70%), O2 (20%), Ar (1%), small varying amounts: CO2, H2O pressure is weight of air above (e.g., psi=pounds/in^2) △P = △z g ρ P =pressure, ρ="rho"= density, g acceleration of gravity ρ = P m/kT -> exponential relation between P and altitude: P=P0 exp(-z/H) H=scale height = kT/mg (approx 10 km for Earth) (for actual Earth: temperature varies with altitude) troposphere, stratosphere, mesosphere, thermosphere, [ionospheres] heating at ground due to visible light absorption heating in middle due to O3 (ozone) absorption of UV light heating at top due to absorption of UV/X-ray light jet streams Mar 16 long story: heating of Earth, greenhouse how do blankets work? heat transfer: conduction, convection, radiation conduction: H=(1/R) dT/dz (dT/dz= temperature gradient) convection: adiabatic lapse rate ~ m g/k (about 10 C/km on Earth) radiation: T^4= (3/4) T0^4 ( τ +2/3) τ="tau"=optical depth=z/(mean free path of light), τ=0 is top of atmosphere, τ approx 1 is ground level Mar 19 Why CO2, H2O absorb/scatter IR light where as the major constituents do not (N2, O2, Ar, H2, He) nuclear winter dynamics: Coriolis force (2*spin*velocity*sin(latitude), to right in north), circulation around High & Low, force balance for situations that survive, "geostrophic" Thermal wind, jet streams Hadley cells, ITCZ, deserts The meteorology of the planets rhymes with that of Earth (the same and not the same) Mar 21 help thursday 7:30 Note: the geology of the Earth seems to differ from other terrestrial planets in part due to size (residual heat lost quickly from small planets, and less radioactive mass since less mass) Earth is hot on inside both due to primordial heat & radioactive materials (like K & U...not so much in core) This heat drives geologic convection much as sunlight drives atmospheric convection Geology: layers, seismic waves (Pressure=sound & Shear...but not through liquids) layers by composition: crust, mantle, outer core (liquid), inner core (solid) by flexibility: lithosphere, asthenosphere plates outlined by earthquakes plates, hot spots, low density continental crust floats high on asthenosphere...roots crust creation/destruction, subduction (convergent), mid-ocean rift zone (divergent), transform crust as solid scum on top of a convecting liquid (over stated) Mar 23 Exam 2 (no geology) Mar 26 evidence for plates? differentiated magnetic field rock vs mineral types: igneous, metamorphic, sedimentary (Clastic, Chemical, Organic) felsic ("acidic"), mafic ("basic"), key feature: SiO2 content grain size, Texture volcanic vs plutonic...flood basalt Mar 28 chapter 9 more on radioactive decay dating of rocks 14 Carbon: approximately constant concentration of 14C in air due to cosmic rays. When no longer exchanging air (i.e. dead), 14C decays with 5,730 year half life Problems: Sun's effect on cosmic ray flux; varying take-up of 14C in various plants, burning coal K-Ar 40K becomes (in part) 40Ar with a half-life of 1.25 Gyears; Ar (as an inert gas) would not typically be present in solid rock, so build up of 40Ar allows dating of time since rock was liquid. Problem: contamination of sample with air (which is mostly 36Ar) More typically initially present daughters can be determined by concentration of stable isotopes of those daughters along with fact that different minerals in rock will take up various amounts of the parent. Moon exceptionally low albedo: slightly brighter than that of worn asphalt. features: highlands, maria, rilles, impact craters synchronous rotation asymmetry: near/far terrain age via crater counts calibrated using Apollo rocks Apr 4 Moon synchronous rotation lower density than other terrestrials, less central concentrated exceptionally low albedo: slightly brighter than that of worn asphalt. features: highlands, maria, rilles, asymmetry: near/far Giant-impact hypothesis Late Heavy Bombardment Mercury: 2:3 rotation looks much like Moon except with less variation in albedo higher density than other terrestrials, larger core?, impact?, nebula sorting? weak magnetic field (convecting liquid core?) 1% of Earths, polar aligned shrinkage Apr 6 chapter 10 Venus: geology: linear features like subduction zones, spreading centers, mountain ranges missing mostly basaltic plains with 2 "continents", pictures from surface of "fresh" basaltic plains large volcanoes (Maxwell) fewish impact craters (more than Earth way fewer than Moon) similar size/density suggest similar interior (but note hot surface due to huge atmosphere & marginal nature of Earth's solid inner core) no magnetic field (but slow spin; slower than Mercury) episodic resurfacing? a change once & forever? Why the Earth/Venus differences in moving plates? (hot & dry) meteorlogy: Why the Earth/Venus differences in CO2 (limestone), O2 (life) 100x CO2+N2 atmosphere with huge greenhouse effect near near a 13:8 orbital resonance exactly four retrograde rotations, as seen from the Earth (five, as seen from the sun) between two consecutive inferior conjunctions. Apr 9 chapter 10 Venus: meteorology: revisit greenhouse with adiabatic lapse rate (IR emitting region is high: 50 km of adiabatic lapse rate ~10 K/km) 100% H2SO4+H2O cloud cover 50 km up (but visible light does get thru...surface photos) super rotating equatorial wind (at cloud level), interesting double-eye polar vortex small Coriolis force; one Hadley cell cyclostrophic wind What happened to the H2O? D/H ratio Mars: 2 small moons geology: lower density, not as central concentrated, Fe on surface...not as differentiated? Core of Fe/Ni with added sulfur? No magnetic field currently; suggestions of magnetic stripes from before 4 Gyears? 3 volcanoes in a row...hot spot?; Valles Marineris plate boundary or expansion rift? in any case: nothing like Earth is happening now Olympus Mons: biggest shield volcano in the Solar System (NOT due to smaller gravity) north (plains)/south (highlands) difference polar caps change with seasons liquid water currently impossible due to low atmospheric pressure, BUT generally accepted WAS present channels, current gullies (salt water?), evaporite minerals, D/H ratio and water loss martian meteorites meteorlogy: 1/100x CO2+N2+Ar atmosphere with small greenhouse effect Why the Earth/Mars differences? spin like Earth: coriolis, geostrophic: jets & Hadley with a difference strong seasons due to timing of perihelion massive dust storms, dust devils Apr 11 star name quizzes start: Polaris & Algol mars: meteorlogy: 1/100x CO2+N2+Ar atmosphere with small greenhouse effect Why the Earth/Mars differences? spin like Earth: coriolis, geostrophic: jets & Hadley with a difference strong seasons due to timing of perihelion massive dust storms, dust devils chapter 11 jupiter meteorlogy: H2+He mostly with rock/Fe core & ice (does not mean solid...way too hot: H2O, CO2, NH3, ...) mantle zone & belt...thermal wind revisited strong magnetic field dark ring 4 important moons (& lots more) Apr 13 star name quiz: Big Arc chapter 11 jupiter/saturn/uranus/neptune meteorlogy: start with "me too": mostly H2 & He (remark: we once thought Earth & Venus were twins...then came data) alternating zones/belts strong magnetic fields rings & moons ice vs gas giants differences: internal ("geothermal") heating: absent in Uranus composition: less (5%) He in Saturn, more (20%) in Uranus/Neptune CH4 makes urnaus/neptune look blue no liquid metalic H in uranus/neptune generally strong equatorial jets as move out (supersonic in neptune) retrograde equatorial wind in uranus/neptune odd magnetic fields: uranus/neptune neptune rings are arcs uranus tipped on side Apr 16 star name quiz: Summer Triangle jump to Sun: chapter 15 & 16 positive feedback: explain why things explode & why they don't why doesn't the Sun explode? Virial theorem, positive feedback Virial Thm: IF (made of normal gas, held together by gravity) THEN (add energy: star cools & expands; remove energy: star heats & contracts) how see inside sun: core, radiation zone, convection zone which reaction power the Sun? surface features: sunsplots, granules, flares, spicules, filaments, prominences, coronal-mass ejections, holes Apr 18 star name quiz: Winter Hex Sun: chapter 15 & 16 plasma+magnetic field=interesting surface features: sun spots, granules, flares, spicules, filaments, prominences, coronal-mass ejections, holes magnetic field reversals, sunspot cycle (and its stop?) corona, solar wind, northern lights = aurora borealis Apr 19 help: 7:15 pm Apr 20 exam 3 Apr 23 forgot: atmosphere layers: photosphere, chromosphere, corona, solar wind problem: why is corona hot? solar neutrino problem chapter 12: moons of Jupiter: rocky close, rock+ice far; tidal heating makes close geologically active Callisto: cratered Ganymede: 2 types of terrain: cratered dark, light grooves and ridges; magnetic field Europa: ice ball, cracks, fresh icy surface (plumes sighted), ice capped ocean...life? Io: pizza; always active volcanoes big moon of Saturn: titan deep N2 atmosphere, 100% cloud covered, superrotation like Venus, "young" surface, lakes, rivers, clouds but of hydrocarbons big moon of Neptune: triton retrograde orbit: captured? plumes sighted: young surface, thin N2 atmosphere...solid N2 on surface Apr 25: chapter 12: Pluto & rings Pluto has diverse terrain: crater free region (sputnik), like triton: very rarefied N2 atmosphere, cryovolcanoes moon Charon: also diverse but more cratered rings: (forward scatter vs backward scatter); Roche limit (approx 2.5 planet radius) Jupiter: relatively narrow, dark dusty ring Saturn: huge bright icy ring system: A/cassini gap/B; cassini=1:2 mimas, tiny twisted F with shepherds prometheus+pandora zillions of ringlets: invisible shepherds and/or resonances Uranus; 2nd discovered during transit; dark & mostly gap; some eccentric Neptune: odd arc rings; dark; thin Apr 27: chapter 13 meteoroids (chapter 14) & asteroids & comets stoney, irons, stony-irons chondrites and achondrites: carbonaceous vesta (basalt), mars, moon dino killer: NEO asteroids; Ceres, match spectra with meteorites comets: dirty snowball, apparent size is lost atmosphere (from individual jets), actual body ~10km head, coma, nucleus, ion tail, dust tail...tail points away from sun no swoosh long/short period Kuiper belt, oort cloud Apr 30: chapter 14: origins consistencies everything rotates the same way (exceptions: spins: venus, uranus, pluto; orbit: triton); disk note: conservation of angular momentum (but why sun such a slow rotation?) rocks close to fire; ice further out (but water on earth?) early impacts, fewer but still impacts today calculations show system stable for millions of years, but unpredictable for billions of years; low mass mercury & mars most affected escape velocity+temperature affect atmospheric composition generally small is geologically dead unless tidal heating chapter 21.3- exoplanets (planets around other stars) May 2: chapter 30: life 1860: Darwin, Mendel, Pasteur spontaneous generation, pasteur evolution: Darwin's "warm litle pond" remark: early dim sun & snowball earth bio molecules: lipids (fats), sugars, amino acids, polymers: starch, protein, nucleic acids (DNA, RNA) the entropy problem...lower energy or higher entropy; G=H-TS critical biochemical pathways (e.g., ribosomes) are nearly conserved during evolution DNA code -> phylogeny RNA world? May 4: chapter 30: life 3 domains: bacteria, archaea, eucaryote cooperation seems hard DNA code -> phylogeny SETI: Drake equation: N=R* fp ne fL fi fc L Help May 7 11 am