十分钟速成课 - 天文学

  • 名称:十分钟速成课 - 天文学
  • 分类:公共课程  
  • 观看人数:加载中
  • 时间:2020/3/15 17:10:28

Thanks to Phil Plait, the host, who makes astronomy course more interesting. Here are some my notes.

1. Introduction to Astronomy: It irks me a bit, since it got the good name, and now we are stuck with "astronomy"(Lol, vs astrology)

2. Naked Eye Observations: We still use a variation of this system(magnitude) today, thousands of years later. //By eye, only the brightest stars seem to have color, while the fainter ones all just look white. That's because the color receptors in your eye aren't very light-sensitive, and the only brightest star can trigger them. //They form patterns, shapes. This is mostly coincidence, but humans are pattern-recognizing animals, ...constellations. //Making a big circle over the course of the night. This is really just a reflection of the Earth spinning.. //So this, in turn, means that which stars you see depends on where you are on Earth.

3. Cycles in the Sky: It's the angle of the sun's rays that makes winter cold and summer hot, not our distance from the sun.

4. Moon Phases: Earth Shine.

5. Eclipse: A coincidence of time and space.

6. Telescopes: Magnification and Resolution. Refraction and Reflectors.

7 The Gravity of the situation: As Douglas Adams said in "Hitchhiker's Guide to the Galaxy," Flying is just falling and missing the ground.

8 Tides: a rising tide lifts all surfaces. Affect water, solid land, a distance between the moon and earth, rotation of the earth, the length of one day, and the reason why the moon only shows one side of the face.

9. Introduction to Solar System: A rigid definition is a mistake. "Planet" cannot be defined. LOL, Pluto is a planet. //We are quite really star-stuff.

10. The Sun: The light you see from the Sun now got its start in the Sun's core around the time Homo Sapiens first appeared in Africa. // Magnetism can snap. 

11. The Earth: You don't feel the pressure of the atmosphere.

12. The Moon: Earth was once a fireball that toasts the Moon. 

13. Mercury: the weird day on Mercury, watching the Sun rise, slow, stop, stop, set again, then rise again.

14. Venus: lazy rotation and retrograde motion( backward rotation)

15. Mars: red and oxidized iron.

16. Jupiter: Belts and zones circulate around the planet in opposite directions. // The Great Red Spot. // A liquid metallic hydrogen, sharing electrons. // Has a core? 1. has; 2. has not and just draw in gases; 3. has not but top-down formulation.// get energy from itself, emitting more than receiving. // strong magnetic field.// has a ring.

17. Jupiter's Moons: Jupiter's aurora causing from these moons.// Europa.

18. Saturn: hexagonal vortex, Saturn's 10 meters thin rings, resonance, rippling wave, cryovolcano, //have you saw a Saturn from a telescope

19. Uranus & Neptune: Methane is good at absorbing red light, which means the light we see reflected from Uranus is mostly green and blue. // infrared Uranus. icy mantle // tip to 98 degrees. magnetic field axis is tipped by over 50 degrees from the planet spin axis and its way off center// 

Neptune's wind speed faster than sound speed on earth.// predict the unseen planet from the calculating

20. Asteroids: star-like, by Jupiter gravitation, like Saturn's rings, space and added up all are smaller than moon. Lagrange points.  

21. Comets: iron tail and dust tail; 

22. The Oort Cloud: a spherical cloud of icy objects; plutinos, 3:2 or 2:1; reflective surface makes it look bigger than it seems; 

23. Meteors: meteoroid, meteor, and metorize, as tiny as a grain of sand; compression more than friction; a bolide with a grapefruit size; chelyabinsk meteor; crash course ... ;

24. Light: electromagnetism, wavelength, energy, spectrum, visible and invisible  lights, EM spectrum, I emit the far infrared light, electron from different atoms has different staircases jump and emit different energy or light, spectrometer, how the universe made of, sounds and redshift, 

25. Distances: Greeks can caculated the circumference of the Earth, Can I? The distance to the sun and to the moon as well as their sizes and accept them, can I? // The astronomical unit, LOL. until now it could be nailed down. //AU vs parallax. // light year vs parsec// bright and distance// 

26. stars: OBAFGKM, Oh be a fine guy/gal kiss me// size temperature color distance//luminosity versus temperature: HR Diagram,main sequence: blue-hotter-more massive-more luminous

27. Exoplanets: 

28 Brown Drawf: objects intermediate in mass between giant planets(Jupiter) and small stars(0.075 mass of Sun). //with lithium... //OBAFGKM, LTY.// more mass, more denser or smaller. // no planets or stars

29 30 Low Mass Stars, red dwraf, white dwraf, nebula: The line of low mass stars and high mass stars lies around 8 times the mass of the Sun.

// lower mass, 1/3 mass of the Sun, red dwrafs: all low mass stars are infant

// mass above 1/3 mass of the Sun, subgiant, our sun, core hotter, grow, suface cooler // then to be a red giant, increase in luminosity, gravity drop at surface, shed mass, heliu fusion, outerlayer contrack, helium as the ash, core heat up, expand and cool, a red giant again, epic eruption as helium//white dwarf, dense, +//if over the mass of Sun, Planetary Nebulae, lol "avoid these objects list" turn to  "amateur astronomers' book", planetaries, various fantastic shapes, 

//31 32 33 High Mass Stars, neutron star, black hole: 8 times mass of sun, hydrogen-helium, red or blue  supergiant-carbon-sodium/magnesium/neon-magnesium/oxygen-sillicon-iron

if less than 20 times the Sun's mass, neutron star, supernova, form calcium, iron, phosphorus,

if higher than 20 timess Sun's mass, black hole, escape velocity, event horizon, Orbiting a ten-solar-mass black hole would be just like orbiting a ten-solar-mass star, stellar mass black holes, spaghettification, supermassive balck holes, space-time, gravitational redshift, 

34 Binary and Multiple Stars: optical double stars, binary stars, visual binary,//spectroscopic binaries, triple, quadruple, pentuple, sextuple,// eclipsing binaries, contact binary// stellar novae, recurrent novae//

35 star clusters: open( galactic) clusters, globular clusters

36 Nebulae: emission nebula; reflection nebulae; the orion nebula; the Eagle Nebula; 

37 The Milky Way: 

38, 39 Galaxies: eliptical, spiral, peculiar, irregular// quasar, active galaxy// the local group, Andromeda and the Milky Way// galaxy cluster, Virgo cluster// superclusters, Virgo Supercluster,

40 Gamma Ray Bursts: cold war paranoia//hypernova and two neutron stars merge// birth announcements of black holes

41 dark matters: an axion would pass right through you like you were not there

42 The Big Bang: lookback time// the galaxies are standing still// every spot in the universe appears like the center// singularity//

43 Dark Energy: accelerating universe// we can see galaxies that are moving away grom us faster than light, obsevable universe, the galaxy disappears over time// 

44 a brief history of universe: ionized time, pior to recombination, was opaque, A photon coul not get very far before an electron sucked it up//inflation

45 Deep Time: Primordial Era, stelliferous Era, Degenerate Era, Black Hole Era, Dark Era/the Big Rip, multi-univese, second-step univese, quantum fluctuation in other universe, 

46 Everything the universe and life: