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29 Cards in this Set
- Front
- Back
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What causes tides?
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The moon's gravity creates a tidal force that stretches Earth along the Earth Moon line, causing Earth to bulge both toward and away from the Moon. Earth's rotation carries us through each of the two bulges each day, giving us two daily high tides and two daily low tides. Tidal forces also lead to tidal fraction, which is gradually slowing Earth's rotation and explains the synchronous rotation of the Moon.
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How does that correlate with lunar phases?
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When the tidal forces of the Sun and Moon work together, as is the case at both new moon and full moon,we get the especially pronounced (spring tides) (so named because the water tends to "spring up" from the Earth). When the tidal forces of the Sun and the Moon counteract with each other, as is the case at 1st and 3rd quarter moon, we get the relatively small tides known as neap tides.
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What are the ways that light interacts with matter?
p151 |
EMISSION: A light bulb emits visible light;the energy of the light comes from electrical potential energy supplied to the light bulb.
Absorption: When you place your hand near an incandescent light bulb, your hand absorbs some of the light, and this absorbed energy warms your hand. Transmission: Some forms of matter, such as glass or air, transmit light. That is they allow light to pass through. Reflection/scattering: Light can bounce off matter, leading to what we call reflection (when the bouncing is all in the same general direction) or scattering (when the bouncing is more random). Matter can emit light, absorb light, transmit light, or reflect (or scatter) light. |
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What are the properties of waves?
p152 |
Wavelength: The distance from one peak to the next (or one trough to the next).
Frequency: The number of peaks passing by any point each second. Speed: tells us how fast their peaks travel across the pond. wavelength X frequency = speed |
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How is the speed of a wave defined?
p152 |
The speed of the waves tels us how fast their peaks travel across the pond. Because the waves carry energy, the speed essiantally tells us how fast the energy travels from one place to another.
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Speed of light?
p153 |
300,000 km/s
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What is a photon?
p154 |
We therefore say that light comes in individual "pieces" called PHOTONS, that have properties of both particles and waves.
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What is the energy of a photon?
p154 |
Just as a moving baseball carries a specific amount of kinetic energy, each photon of light carries a specific amount of radiative energy. The shorter the wavelength of the light the higher the energy of the photons.
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What is the electromagnetic spectrum?
p155 |
Because we somtimes describe light as an electromagnetic wave, the complete spectrum of light is usually called the ELECTROMAGNETIC SPECTRUM. Light itself is often called electromagnetic radiation.
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Know generally which end is high or low energy, where different radiation types fall in relation to visible light?
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Visible light has wavelengths ranging from 400 nanometers at the blue or violet end of the rainbow to about 700 nanometers at the red end. Light with wavelengths somewhat longer than red light is called infrared, because it lies beyond the red end of the rainbow.
Radio Waves are the longest-wavelength light. Ultraviolet Waves - light with wavelengths somewhat shorter than blue light. X rays- light with even shorter wavelengths Gamma rays- the shortest wavelength light |
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What is an atom?
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All ordinary matter is composed of atoms, and the properties of ordinary matter depend on the physical characteristics of their atoms.
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What makes up an atom?
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Protons, neutrons, and electrons.
The properties of an atom depend mainly on the electrical charge in its nucleus. |
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What are the phases of matter?
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–Solid (ice)
–Liquid (water) –Gas (water vapor) –Plasma Adding heat to a substance changes its phase by breaking chemical bonds. –As temperature rises, a substance transforms from a solid to a liquid to a gas, then the molecules can dissociate into atoms –Stripping of electrons from atoms (ionization) turns the substance into a plasma The appearance of matter depends on its phase: solid, liquid, or gas. Gas is always present along with solid or liquid phases; solids sublimate into gas and liquids evaporate into gas. At very high temperatures, molecular dissociation breaks up molecules and ionization strips electrons from atoms; an ionized gas is called a plasma |
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How does matter store energy? (Electromagnetic energy in particular)
p162 |
First, by virtue of their mass, the possess mass-energy in the amount mc^2. Second, the posses kinetic energ by virtue of their motion. Third, and most important to reading the messages encoded in light, atoms contain electrical potential energy that depends on the arrangement of their electrons around their nuclei.
–The energies of electrons in atoms correspond to particular energy levels. –Atoms gain and lose energy only in amount corresponding to particular changes in energy levels. |
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What are 3 spectral types?
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Continuous spectrum- (thermal radiation spectrum) The spectrum of a common (incandescent) light bulb is a rainbow of color. Because the rainbow spans a broad range of wavelengths without interruption we call it a continuous spectrum.
Emission line spectrum- A thin or low-density cloud of gas emits light only at specific wavelengths that depend on its composition and temperature, producing a spectrum with bright emission lines. Absorbtion line spectrum- (light absorbed) A cloud of gas between us and a light bulb can absorb light of specific wavelengths, leaving dark absorption lines in the spectrum. |
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What does thermal radiation spectrum tell us?
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1.Hotter objects emit more light at all frequencies per unit area.
2.Hotter objects emit photons with a higher average energy. |
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What is the Doppler Shift?
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We can learn about the motion of a distant object (relative to us) from changes in its spectrum caused by the doppler effect.
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What are the main types of telescopes?
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Refracting telescopes- operates much like an eye, using transparent glass lenses to collect and focus light.
Reflecting telescope-uses a precisely curved primary mirror to gather light. This mirror reflects the gathered light to a secondary mirror then reflects the light to a focus at a places where the eye or instruments can observe it. |
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What are the most important features of a telescope?
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–Collecting area determines how much light a telescope can gather
–Angular resolution is the minimum angular separation a telescope can distinguish |
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What are the experimental techniques used with telescopes?
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–Imaging•Astronomical detectors can record forms of light our eyes can’t see
•Color is sometimes used to represent different energies of nonvisible light –SpectroscopyA spectrograph or spectrometer separates the different wavelengths of light before they hit the detector –TimingA light curve represents a series of brightness measurements made over a period of timeWant |
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What do we typically use to detect light?
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Reflecting telescopes because they use mirrors to bring light to a focus.
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Why do starts twinkle?
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Turbulent air flow in Earth’s atmosphere distorts our view, causing stars to appear to twinkle
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What is a false color image and why do we need it?
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n
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What factors come into play when choosing the best place for a telescope?
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Telescope sites are chosen to minimize the problems of light pollution, atmospheric turbulence, and bad weather.
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Why do we put telescopes into space?
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–Forms of light other than radio and visible do not pass through Earth’s atmosphere.
–Also, much sharper images are possible because there is no turbulence. |
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What is comparative planetology?
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•We can learn more about a world like our Earth by studying in context with other worlds in the solar system.
•Stay focused on processes common to multiple worlds instead of individual facts specific to a particular world. |
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What are the main types of robotic missions?
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Flyby-A spacecraft on a flyby goes past a world just once and then continues on its way
Orbiter- An orbiter is a spacecraft that orbits the world it is studying, allowing longer-term study. Lander or probe- These spacecraft are designed to land on a planet's surface or probe a planet's atmosephere by flying through it. Some landers carry rovers to explore wider regions. Sample return mission-a spacecraft designed to return to Earth carrying a sample of the world it has studied. |
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What is the electromagnetic spectrum?
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Radio waves, microwaves, infrared, visible, ultraviolet, x rays, and gamma rays
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Isotopes and Molecules
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Isotopes of a particular chemical element all have the same number of protons but different number of neutrons.
Molecules are made from two or more atoms. |
