Astronomy Exam 1
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- What are the 6 Steps of the Scientific Method?
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1. Observation
2. Hypothesis (Model)
3. Predict
4. Experiment
5. Check against Hypothesis
6. If no match modify Hypothesis and return to predict. - What distinguished Copernicus’ model of the solar system from previous models?
- The Heliocentric model was the frist to say the Sun was the center of the universe. It was wrong because the planets did not move in perfect circles.
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What is the term for the solar system model in which the Sun is assumed as the center of the solar system? The
model in which the Earth is the center? -
Heliocentric=Sun Center
Geocentric=Earth Center - Upon what conditions does the location of the sunrise on the horizon depend?
- Your latitude and time of year.
- What contributions did Tycho Brahe make to astronomy?
- Tycho collected lots of data.
- What contributions did Kepler make?
- Developed the theory behind planetary motion.
- What does the term “parallax†mean?
- An apparent change in the direction of an object, caused by a change in observational position that provides a new line of sight.
- What is an arc-second?
- Tiny measurement of an angle=to 1/3600 of a degree.
- What astronomical property did Aristarchus of Samos measure?
- Measured the Distance of the Sun/Moon.
- What did Eratosthanes measure?
- Diameter of the Earth.
- What are some of the basic properties of matter? Which depends on location: mass or weight?
- All matter has inertia and mass. Weight depends on location, mass is always mass.
- The Law of Gravity depends on what two quantities? How do changes in the values affect the force of gravity?
- Mass and distance. Force grows with mass and drops with distance.
- For orbits, what does the semi-major axis represent?
- The major axis of an ellipse is its longest diameter, a line that runs through the centre and both foci.
- What are the properties of light and all electro-magnetic radiation?
- All have wavelength/frequency.
- What is meant by wave/particle duality in dealing with light?
- They show characteristics of both.
- What are the four fundamental forces of nature?
- Gravity, Electro-Magnetism, Strong Force, Weak Force.
- How is spectroscopy defined?
- Study of the Light Spectrum.
- How is the light from stars used in measuring their properties (relative motion, position, temperature, composition)?
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Motion=Doppler shifting
Temperature=Number of photons in a certain color.
Composition=Using the Emissions spectrum, Full spectrum, Absorption Spectrum. - Gamma in order of frequency, energy, and/or wavelength.
- High Energy, Short Wavelength, Short Frequency.
- Radio in order of frequency, energy, and/or wavelength.
- Low Energy, Long Wavelength, Long Frequency.
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How are emission and absorption spectra different? How are they the same? How are they used to detect the
composition and amount of elements in stars, and the star’s motion? -
Emissions Spectrum=Colored lines on a black background
Absorption Spectrum=Colored background with black lines. - What two properties of stars and other radiating black bodies does Wien’s Law link together?
- Color of star and composition.
- What happens when electrons change levels?
- Creates light.
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Understand the meaning and effect of the Doppler shift (blue- and red-shift) in the spectrum of a star and how it
relates to the star’s motion toward/away from us. -
Blue shift=Star is moving towards you.
Red shift=Star is moving away. - What areas of the electro-magnetic spectrum are absorbed by our atmosphere?
- Gamma, X-ray, some UV are absorbed.
- What is meant by the collecting power of a telescope?
- Amount of light. Diameter increases this collecting power.
- What are refracting telescopes and what are their deficiencies?
- Regular telescopes with lenses. Their deficiencies include; Absorption, Clarity, Inverted Image, CA, Expensive, Heavy, Warped Easily, Max Size ~1 Meter.
- What are reflecting telescopes and what are their strengths and deficiencies?
- Mirrored Telescopes. Their deficiencies include; Sagging, Image is infront of mirror, Max Diameter ~10M.
- How does the process of interferometry help astronomers in viewing the universe?
- Computer generates very clear detail from points in the sky that would be impossible for humans to create.
- How are the basic ways to collect light from telescopes (eye, film, CCD) similar?
- Basic ways to collect light from telescope; (Eye, Film, CCD).
- What is atmospheric scintillation?
- twinkling=variations in apparent brightness or color of a distant luminous object viewed through a medium, most commonly the atmosphere (atmospheric scintillation).
- Syzygy
- When 3 or more astronomical bodies line up.
- Azimuth
- Where you are in relation to N/S/E/W
- Right Ascension
- Longitude
- Declination
- Latitude
- Zenith
- Right above you
- Conjunction
- When planets are lined up/close to each other.
- Synodic Period
- Time between Conjunctions.
- Conjunction or Opposition?
- When Earth, Sun, and One other planet in a line.
- Inferior Conjunction?
- When a body passes between Earth and Sun.
- Superior Conjunction?
- When a body passes behind the Sun, away from Earth.
- Opposition?
- When planet appears opposite of the Sun in the sky.
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1. The Law of Orbits: All planets move in elliptical orbits, with the sun at one focus.
2. The Law of Areas: A line that connects a planet to the sun sweeps out equal areas in equal times.
3. The Law of Periods: The square of the period of a - Keplars Laws