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Astronomy Exam 1
N/A
64
Astronomy
Undergraduate 2
09/25/2011

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Cards

Term
Speed of Light
Definition
C=3x10^8 m/s
Term
Light Year
Definition
The distance light travels in one year. About 6 trillion miles.
Term
Astronomical Unit (AU)
Definition
Distance from the Earth to the Sun. About 150 million km.
Term
Scientific Method Steps
Definition
Observation, hypothesis, prediction, experiment.
Term
Ecliptic Plane
Definition
-Plane of Earth's orbit about the sun
-Line across the sky that the sun follows
-Moon's apparent path in the sky
-Planets' apparent paths in the sky
-Location of zodiac
Term
Copernicus
Definition
Proposed heliocentric model. He was wrong because he thought the orbits were circles.
Term
Heliocentric
Definition
Sun is the center of the solar system.
Term
Geocentric
Definition
Earth is the center of the solar system.
Term
Solstices
Definition
Winter- shortest day of the year
Summer- longest day of the year
Term
Equinoxes
Definition
Spring and Fall- days and nights are equal in length.
Term
Zodiac
Definition
Constellations that are visible at different times of the year.
Term
Location of the sunrise on the horizon
Definition
Depends on latitude and time of year
Term
Tycho Brahe
Definition
Improved the accuracy of observations
Term
Kepler
Definition
Found rules that govern how the planets move
Term
Parallax
Definition
The effect where the position of an object differs when viewed from different positions.
Term
Arc Second
Definition
Angle measurement that equals 1/3600 of a degree.
Term
Aristarchus of Samos
Definition
Measured size of Sun and Moon. (Angular measurement)
Term
Eratosthanes
Definition
Measured radius of the Earth. (Well)
Term
Newton's 1st Law
Definition
An object at rest remains at rest unless acted upon by a force. An object in motion continues at the same speed and direction unless acted upon by a force. (Law of Inertia)
Term
Newton's 2nd Law
Definition
Unbalanced force causes an object to accelerate in the direction of the force, proportional to the force and inversely proportional to the mass. (F=ma)
Term
Newton's 3rd Law
Definition
For every force there's an equal and opposite force.
Term
Newton's Law of Gravity
Definition
F=(GMm)/r
Term
Basic Properties of Matter
Definition
Inertia, weight, volume, mass, and density.
Term
Which property of matter depends on location?
Definition
Weight
Term
Law of Gravity depends on?
Definition
Mass and location. An increase in mass results in an increase in the force of gravity.
Term
Semi-major Axis
Definition
Average distance between the sun and a planet
Term
Eccentricity
Definition
non-circularity
Term
Inclination
Definition
Tilt
Term
Retrograde Motion
Definition
Motion opposite to the norm.
Term
Where do planets move faster?
Definition
When they're closer to the sun.
Term
Properties of light
Definition
-travels through a vacuum
-carries energy
-travels as a wave and behaves like a particle
Term
Wave/Particle Duality
Definition
Light travels as a wave and behaves as a particle when measured.
Term
Four Fundamental Forces of Nature
Definition
1. Strong force (binds protons and neutrons together)
2. Electromagnetic
3. Weak Force (radioactive decay)
4. Gravity
Term
Spectroscopy
Definition
Study of the electromagnetic spectrum
Term
Electromagnetic Spectrum (High energy/frequency to Low)
Definition
Gamma, X-Rays, UV, Visible, Infrared, Microwaves, Radio
Term
Electromagnetic Spectrum (Long Wavelength to Short Wavelength)
Definition
Radio, Microwaves, Infrared, Visible, UV, X-Rays, Gamma.
Term
Emission vs. Absorption Spectrum
Definition
Emission- White=all colors, black=no color
Absorption- White=no color, black/brown=all colors
Term
Wien's Law
Definition
Connects wavelength and surface temperature of a black body radiator
Term
Doppler Shift
Definition
A change in observed frequency of a wave (sound or light) when the object and observer are in motion relative to each other.
Term
Red Shift
Definition
Moving away
Term
Blue Shift
Definition
Moving toward
Term
Collecting Power
Definition
Amount of photons collected.
Term
Resolving Power
Definition
Amount of detail
Term
Refracting Telescopes
Definition
Light passes through a lens and bends
Term
Reflecting Telescopes
Definition
Light is reflected by a mirror and focused
Term
Deficiencies of Refracting Telescopes
Definition
-colors split out (color aberration)
-absorption of colors
-heavy lenses that sag and are expensive
Term
Reflecting Telescope Strengths and Deficiencies
Definition
Strengths- no bending of light when it reflects from a mirror, light of wavelengths don't bend different amounts.
Deficiencies- slight blockage from collecting piece, sagging is more of an issue, reflecting surface must be more precise.
Term
Radio Telescopes
Definition
Reflectors
Term
Interferometry
Definition
Observation of an object from 2 different locations
Term
Eye as a light collection method
Definition
-can't see faint objects
-no storage
Term
Film as a light collection method
Definition
-stores images
-can see fainter objects
-can see outside visible spectrum
Term
Charged Couple Device (CCD) as light collection method
Definition
-store images digitally
-can apply software to the images
-can see outside visible spectrum
-can see fainter objects
Term
Atmospheric Scintillation
Definition
"Twinkle"
Term
How big can telescopes get?
Definition
Refractors- 1m diameter
Reflectors- 10m diameter
Term
Syzygy
Definition
Alignment of 3 or more astronomical bodies
Term
Celestial Equator
Definition
The projection of Earth's equator into space
Term
Azimuth
Definition
Horizontal angular distance starting from the north point of the horizon
Term
Elevation
Definition
Vertical angular distance from the horizon.
Term
Declination
Definition
Latitude in the celestial sphere
Term
Right Ascension
Definition
Longitude in the celestial sphere
Term
Zenith
Definition
The point in the sky directly above the observer. (90 degrees from the north point of the horizon).
Term
Conjunction
Definition
Alignment of the Sun and 2 planets
Term
Conjunction
Definition
Alignment of the Sun and 2 planets
Term
Synodic Period
Definition
Time between superior conjunctions for two planets.
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