physics final part 1

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  1. scientific notation
    Scientific notation is a way of writing numbers that are too big or too small to be conveniently written in decimal form
  2. earth-sun distance
    • 1 AU
    • 150 million km
  3. Milky Way
    • stars in spiral arms
    • 75,000ly diameter
  4. Zenith
    point on the celestial sphere directly overhead
  5. Nadir
    point on the c. s. directly underneath(not visible!)
  6. Celestial equator
    projection of the Earth’s equator onto the c. s.
  7. Celestial Sphere
    Hypothetical sphere surrounding the earth
  8. Magnitude
    • brightest stars 1st magnitude
    • dullest 6th magnitude
  9. degrees, minutes, seconds
    • full circle has 360o (degrees),
    • 1o has 60’ (arc minutes),1’ has 60” (arc seconds)
  10. Precession
    the earth wobbles on an axis due to the suns gravity pulling it
  11. Constellation
    • group of stars that appear to be near each other forming a shape
    • the projection effect creates the apparent closeness of the stars
  12. asterism
    the pattern of stars recognized on the night sky
  13. star trails
    a type of photography used to see the stars apparent motion in the sky
  14. seasons
    • The different incidence angle of the Sun’s rays causes the seasons on Earth
    • northern summer= southern winter
    • southern summer= northern winter
  15. rotation
    earth turns counter-clockwise on it's own axis
  16. revolution
    earths celestial path around the sun
  17. ecliptic
    apparent path of the sun on the celestial sphere
  18. equinox
    • day and night are the same length
    • spring and fall
  19. aphelion
    point furthest from the sun
  20. perihelion
    point closest to the sun
  21. planets
    sun, mercury, Venus, earth, mars, Jupiter, Saturn, Uranus, neptune
  22. total solar eclpise
    • the moon completely covers the sun creating a ring of light around the sun
    • the solar chromosphere, corona, and prominences can be seen
  23. nodes
    the intersection of the orbit plane of some celestial body with the plane of the ecliptic as projected on the celestial sphere
  24. sidereal
    • a time-keeping system astronomers use to keep track of the direction to point their telescopes to view a given star in the night sky
    • the moon's sidereal period around the earth is 27.32 days
  25. synodic
    • the time it takes for a celestial object to return to its position with the sun
    • the moons synodic period is 29.53 days (a month)
  26. umbra
    the earth's zone of a full shadow
  27. penumbra
    the earths zone of partial shadow
  28. saros
    18 year period in which solar and lunar eclipses repeat
  29. Image Upload 1moon phases
    tidally locked orbit
  30. angular diameter
    • the moon's angular diameter is .05 degrees
    • almost exactly the same as the sun
  31. heliocentric
    astronomical model in which the planets orbit around the sun
  32. geocentric
    astronomical model in which all the planets orbit around the earth
  33. epicycles
    ptolematic explanation for thee apparent movement of the planets
  34. deferent
    a large circle in which the epicycles orbit around
  35. retrograde motion
    westward motion of a planet occurs when the Earth passes the planet
  36. spring tide
    • caused by the difference of the moons gravity on the earths water
    • strong and occur near new and full moon
  37. neap tide
    • mild
    • occur in 1st and 3rd quarter
  38. ellipse
    Kepler's description of the planets orbits around the sun
  39. eccentricity
    Orbits of planets are virtually indistinguishable from circles
  40. geosynchronous
    an orbit around the earth that is exactly 24 hours linking up with the earth
  41. parallex
    • displacement of an apparent objet
    • flaw in Aristotle astronomy
  42. gravity
    • discovered by Isaac Newton
    • the attraction of two objects to one another
  43. Newton's 1st law
    An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force
  44. Newton's 2nd law
    The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
  45. Newton's 3rd law
    For every action, there is an equal and opposite reaction
  46. Kepler's 1st law
    The orbits of the planets are ellipses with the Sun at one focus.
  47. Kepler's 2nd law
    A line from a planet to the Sun sweeps over equal areas in equal intervals of time.
  48. Kepler's 3rd Law
    • A planet’s orbital period (P) squared is
    • proportional to its average distance from the Sun (a) cubed
  49. wavelengths
    • measured in nanometers
    • visible light is between 4000A and 7000A
  50. frequency
    number of cycles per second
  51. amplitude
    the angular distance of a celestial object from the true east or west point of the horizon at rising or setting
  52. electromagnetic spectrum
    the range of all possible frequencies of electromagnetic radiation
  53. grating
    a prism that splits up light into different wavelengths to create a spectrum
  54. spectrograph
    an instrument that splits up light into a spectrum
  55. charge-couples device
    • more sensitive then photographic plates
    • data can be read directly into computer memory, allowing easy electronic manipulations
  56. resolving power
    minimum angular distance amin between two objects that can be separated
  57. light-gathering power
    Depends on the surface area A of the primary lens / mirror, proportional to diameter squared
  58. energy of light
    • proportional to the frequency
    • does not rely on intensity
  59. refraction
    the bending of light t create images
  60. reflection
    concave mirror focuses light onto focal plane
  61. temperature scale
    • smaller on B-V scale hotter
    • larger on B-V scale cooler
  62. Doppler effect
    the change in frequency of a wave (or other periodic event) for an observer moving relative to its source
  63. continuous spectrum
    a spectrum in which all wavelengths are present
  64. absorption spectrum
    spectrum that's been through gas that is missing wavelengths
  65. emission wavelengths
    scattering of wavelengths
Card Set
physics final part 1
physics of the universe part 1 review
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