Term
| What is the celestial sphere |
|
Definition
celestial equator
north and south celestial
horizon
zenith |
|
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Term
|
Definition
| marks the path of the sun. it's the projection of the earth's orbit onto the sky |
|
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Term
|
Definition
| 18 degree wide belt around the ecliptic |
|
|
Term
| Constellation today means |
|
Definition
| one of the 88 sectors into which we divide |
|
|
Term
| what is the celestial tilt |
|
Definition
| everything around the sun is tilt |
|
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Term
|
Definition
| contributions to sicence was the development of new sun-centered or heliocentric model of the solar system |
|
|
Term
| What was the initial analysis of kepler |
|
Definition
| orbits of the planets were circles |
|
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Term
|
Definition
| orbit of mars had the shape of a somewhat flattened circle, ellipse |
|
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Term
|
Definition
| sum of the distances from two special points inside the ellipse to any point on the ellipse is always the same |
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Term
|
Definition
| the two points inside of the ellipse |
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Term
|
Definition
| the widest diameter of ellipse |
|
|
Term
| what is the semimajor axis |
|
Definition
| distance from the center of the ellipse to one end |
|
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Term
|
Definition
| the ratio of the distance between the foci to the length of the major axis |
|
|
Term
| Laws of planetary motion has how many laws |
|
Definition
|
|
Term
|
Definition
| each planet moves about the sun in an orbit that is an ellipse, with the sun at one focus of the ellipse |
|
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Term
|
Definition
| the straight line joining a planet and the sun sweeps out equal areas in space in equal intervals of time |
|
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Term
|
Definition
| the squares of the planets' periods of revolution are in direct proportion to the cubes of the semimajor axes of their orbits |
|
|
Term
| How many laws of motion are there |
|
Definition
|
|
Term
|
Definition
| every body continues doing what is already doing--being in a state of rest or moving uniformly in a straight line- |
|
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Term
|
Definition
| the change of motion of a body is proportional to the force acting on it, and is made in the direction in which that force is acting. |
|
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Term
|
Definition
| to every action there is an equal and opposite reaction |
|
|
Term
| what was Galileo's discoveries |
|
Definition
|
|
Term
| what is the conservation of momentum |
|
Definition
| where momentum is a measure of a body's motion |
|
|
Term
| what is newton's first law sometimes called |
|
Definition
|
|
Term
|
Definition
| the rate of change in an object's velocity |
|
|
Term
| which law is the most profound |
|
Definition
| newton's third law (gives us a way to define mass) |
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Term
|
Definition
| measures the momentum of an object as it rotates or revloves about some fixed points |
|
|
Term
| what does angular momentum depend on |
|
Definition
| mass, velocity, and distance |
|
|
Term
| what is ordinary momentum |
|
Definition
| measure of an object's tendency to move at constant speed along its straight path |
|
|
Term
| what conservation of the angular momentum |
|
Definition
| when there are no outside forces acting on the object in a way to produce torques that would disturb the angular motion of the object |
|
|
Term
| what defines the most nature state of motion |
|
Definition
|
|
Term
| What was netwon able to conclude about the force of gravity |
|
Definition
| it must drop off with increasing distance between the sun and planet in proportion to the inverse square |
|
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Term
|
Definition
number of dgrees of arc away from the equator
|
|
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Term
|
Definition
| number of degrees of arc along the equator from the meridian passing through Greenwich to the one passing from the point of interest |
|
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Term
|
Definition
| is like longtitude, except that instead of Greenwich, its arbitrarily chosen point where we start counting is vernal equinox |
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Term
|
Definition
| since 17th century it was generally accepted that earth rotates, but not until the 19th century this proven umbiguously |
|
|
Term
| what happens to the sun in the summer |
|
Definition
| the sun appears high in the sky and its rays hit the earth more direclty, spreading out less |
|
|
Term
| what happens in the winter |
|
Definition
| the sun is low in the sky and its rays spread out over a much wider area, becoming less effective at heating the ground |
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|
Term
| the measurement of time is based on |
|
Definition
| the rotation of the earth |
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Term
|
Definition
| the length of a day is usually, the rotation period of the Earth with respect to the sun |
|
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Term
|
Definition
| is defined in terms of the rotation period of the earth with respect to the stars |
|
|
Term
| What was Maxwell's theory of electromagnetism |
|
Definition
| in the vicinity of an electric charge, another charge feels a force of attraction or repulsion: opposite charges attract; likes charge repel |
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|
Term
| stationary electric charges produces |
|
Definition
|
|
Term
| moving electric charges also produce |
|
Definition
|
|
Term
| changing magnetic fields could produce |
|
Definition
|
|
Term
| changing electric currents could |
|
Definition
| produce changing magnetic fields |
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|
Term
| what is equal to the speed of light |
|
Definition
| speed of electromagnetic disturbance through space |
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|
Term
| electromagnetic waves do not require what |
|
Definition
| air or water, like water or sound waves |
|
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Term
|
Definition
| 19th century made up a substance to fill of all space so that light waves could have something to travel through. |
|
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Term
|
Definition
| the distance between crests |
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Term
|
Definition
| number of cycles per second (mesured in Hertz) |
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Term
|
Definition
| the distance the wave covers over time |
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|
Term
| Light sometimes behave like what |
|
Definition
|
|
Term
|
Definition
| more complicated theory of waves and particles |
|
|
Term
| what are the types of electromagnetic radiation |
|
Definition
gamma
x-rays
ultraviolet
visible
infrared
radio waves |
|
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Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| all molecular motion ceases at |
|
Definition
|
|
Term
|
Definition
| gives the wavelength at which maximum power is emitted |
|
|
Term
|
Definition
| total power emitted per square meter |
|
|
Term
| what is stefan boltzman law |
|
Definition
| the energy flux from a black body at temperature is proportional to the forth power of its absolute temperature |
|
|
Term
| what are the four terrestrial planets |
|
Definition
| mercury, venus, earth, mars |
|
|
Term
| what are the characteristics of terrestrial planets |
|
Definition
relatively small worlds
composed of rock and metal
solid surface
have geological history in the form of craters, mountains, and volcanoes |
|
|
Term
| what are the Jovian planets |
|
Definition
4 giant planets
Jupiter, Saturn, Uranus and Neptune |
|
|
Term
| characteristics of giant planets |
|
Definition
much larger than terrestrial planets
composed primarily of lighter ices, liquids and gases
do not have solid surface and the surface is a vast ocean of liquefied gases |
|
|
Term
| what are the smaller members of the solar system |
|
Definition
satellites
planets rings
asteroids
comets
cosmic dust |
|
|
Term
| what two planets do not have satellites |
|
Definition
|
|
Term
|
Definition
| small bodies made of frozen gas and ice, formed and continue to orbit the Sun in distant cooler regions |
|
|
Term
|
Definition
| solar system is filed with countless grains of broken rock and when they collide with Earth they give rise to Meteors and Meteorites |
|
|
Term
| what are the two largest planets |
|
Definition
|
|
Term
| what are jupiter and saturn composed of |
|
Definition
hydrogen and helium
core is composed of: heavier rock and metal and ice |
|
|
Term
| uranus and neptune are dominated by |
|
Definition
| hydrogen and its called chemistry reduced |
|
|
Term
| Characteristics of terrestrial planets |
|
Definition
- Much smaller than giant planets
- composed mainly of rocks and metals: silicates (silicon and oxygen) but most common is iron
- Earth, Venus, Mars: 1/3 composed of iron-nickel or iron-sulfur
- Chemistry is said to be oxidized
- Differentiation
|
|
|
Term
|
Definition
| name given to the process by which gravity helps separate a planet's interior into layers of different compositions and densities |
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|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| which two planets have experienced the most geological acitivity |
|
Definition
|
|
Term
| how do you measure the ages of rocks |
|
Definition
|
|
Term
|
Definition
| for a very large number of radiactive atoms of one type there is a specific period, during which the chances are fifity-fifty that decay will occur for any of the nuclei |
|
|
Term
| radioactive atoms can be called |
|
Definition
|
|
Term
|
Definition
|
|
Term
| the top layer of the earth is made up of |
|
Definition
|
|
Term
| the crust is mainly made of |
|
Definition
volcanic rocks basalt which consists of consist primary of the elements silicon,
oxygen, iron, aluminum, and magnesium |
|
|
Term
| how is the earth's magnetic field generated |
|
Definition
| by movign material in Earth's liquid metalic core |
|
|
Term
|
Definition
| zone within which the Earth's magnetic field dominates over the weak interplanetary magnetic field that extends outward from the sun |
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|
Term
|
Definition
| the charged particles trapped in the magnetosphere |
|
|
Term
| what is the Van Allen Belts |
|
Definition
| the regions with high energy ions in the magnetosphere |
|
|
Term
| what is the center of earth |
|
Definition
metallic core
outside is liquid |
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|
Term
| what is the structure of the atmosphere |
|
Definition
troposphere
H20 clouds
stratosphere
mesosphere
ionosphere |
|
|
Term
| where is the atmosphere mostly concentrated |
|
Definition
| troposphere (generates clouds and wind) |
|
|
Term
| Near the top of the stratosphere is a layer of ozone O3..which is |
|
Definition
| heavy form of oxygen with three atoms per molecule |
|
|
Term
| Earth's surface atmopshere consists of |
|
Definition
78% of nirtrogen
21% oxygen
1% argon |
|
|
Term
| which planets are like earth |
|
Definition
|
|
Term
| what is the atmosphere like on Venus |
|
Definition
| produces high surface temperature and dry |
|
|
Term
| what is venus and mars mainly composed of |
|
Definition
|
|
Term
| jupiter is mainly compsed of |
|
Definition
|
|
Term
| saturn is mainly composed of |
|
Definition
|
|
Term
| uranus and neptune is mainly composed of |
|
Definition
|
|
Term
| what are the parts of the atmosphere |
|
Definition
| photosphere, chromosphere, corona |
|
|
Term
| what is the sun mainly composed of |
|
Definition
|
|
Term
| what part of the sun is visible to us |
|
Definition
|
|
Term
| the energy generated inside of the sun is in forms of |
|
Definition
|
|
Term
|
Definition
| the confusion that this wave-particle duality of light caused in physics was eventually resolved by the introduction of a more complicated theory of waves and particles |
|
|
Term
solar atmosphere changes from
|
|
Definition
| almost perfectly transparent to almost completely opaque |
|
|
Term
| the diameter of the sun is |
|
Definition
| the size of the region surrounded by photosphere |
|
|
Term
| the region of the Sun's atmosphere that lies immediately above the photosphere is |
|
Definition
|
|
Term
| what is the chromosphere composed of |
|
Definition
| hot transparent gasses emitting light at discrete wavelengths |
|
|
Term
| the observations of the chromospheric spectrum revealed a yellow emission line that did not correspond to any previously known element on Earth |
|
Definition
|
|
Term
| the hottest part of the solar atmosphere is |
|
Definition
|
|
Term
| the part of the sun where the rapid temperature rise occurs is called the |
|
Definition
|
|
Term
| the sun produces a stram of charged particles (protons and electrons) |
|
Definition
|
|
Term
| the solar wind exists because |
|
Definition
| the gases int he corona are so hot and moving so rapidly that they cannot be held back by solar gravity |
|
|
Term
|
Definition
| when particles stirke molecules of air in Earth Atmosphere, they cause them to glow, producing beautiful curtains of light |
|
|
Term
| large dark regions of the corona that are relatively cool and quiet are called |
|
Definition
|
|
Term
| what happens in the coronal holes |
|
Definition
| magnetic field lines stretch far out into space away from the sun, rather than looping back to the surface |
|
|
Term
|
Definition
| large dark features seen on the surfcace of the sun |
|
|
Term
| what does the sunspots consists of two parts |
|
Definition
inner darker core: umbra
surrounding less dark region: penumbra |
|
|
Term
| what is the zeeman effect |
|
Definition
| solar magnetic field that is measured using a property of atoms |
|
|
Term
| what is the fundamental components of matter |
|
Definition
|
|
Term
|
Definition
| if the particle carries a charge, the antiparticle has the opposite charge |
|
|
Term
| what is strong nuclear force |
|
Definition
| inside the nucleus particles are held together by a very powerful force |
|
|
Term
| what is the binding energy |
|
Definition
| the energy given up in bringing the protons and neutrons |
|
|
Term
|
Definition
| when the light atomic nuclei come together to form a heavier one, mass is lost and energy is released |
|
|
Term
|
Definition
| energy can be also produced by breaking up heavy atomic nuclei into lighter ones down to iron |
|
|
Term
|
Definition
| elementary particle very weakly interacting with matter |
|
|
Term
| protons will rebound from other protons int he Sun's crowded core for about 14 billion years at the rate of |
|
Definition
| 100 million collisions per second, before it fuses with a second proton |
|
|
Term
| how many hydrogen atoms are needed to fuse to form helium |
|
Definition
|
|
Term
| the initial steps required to form one helium nucleus from fou hydrogen nuclei is reaction of two protons making a |
|
Definition
|
|
Term
| how do form gamma ray photons |
|
Definition
| the produced positron is antimatter, thus will collide with a nearby electronand both will be annihilated |
|
|
Term
|
Definition
| the distance that light travels in 1 year |
|
|
Term
| what is the closest star 4LY away |
|
Definition
|
|
Term
|
Definition
| two stars that orbit each other, bound together by gravity |
|
|
Term
| why do we we see changes in velocity with the stars |
|
Definition
| because when one star is moving toward the earth, the other is movign away, half a cycle later the situation is reversed |
|
|
Term
| what does the doppler shift cause |
|
Definition
| the spectral lines to move back and forth |
|
|
Term
| when two stars are moving perpendicular to our line of sight what happens |
|
Definition
| the two lines are exactly superimposed and so we only see a single spectral line |
|
|
Term
| according to the theoretical calculations, the smallest mass that a true star can have is what |
|
Definition
|
|
Term
|
Definition
| such objects that are intermediate in mass between stars and planets |
|
|
Term
| what is the death of low-mass stars |
|
Definition
| The stars with final mas just before death is less than 1.4 mass of the sun, in a brief period, helium in the core can get hot enough to fuse into carbon and oxygen. But then because there is no source of pressure to balance gravity, it beigs to contract |
|
|
Term
|
Definition
| the core of star continues to shrink until it reaches a density equal to nearly million times the density of water |
|
|
Term
| what is the matter like in white dwarfs |
|
Definition
| since they are more dense than any substance on earth, the matter inside them behaves in a very strange way-unlike anything we known from everyday experience. At this high density, electrons resists being squeezed closer together annd set up a powerful pressure inside the core |
|
|
Term
| the mater in white dwarfs is said to be |
|
Definition
|
|
Term
| a white dwarf with a mass like that of the sun has a diameter about the same as of |
|
Definition
|
|
Term
| the size of a white dward shrinks as the.. |
|
Definition
| mass in the star increases |
|
|
Term
what is the chandrasekhar limit?
|
|
Definition
| the force of the degenerate electrons cannot stop the collapse of a star with more mass than 1.4 solar masses |
|
|
Term
| massive stars becomes hot enough to fuse |
|
Definition
| carbon into oxygen, neon and magnesium |
|
|
Term
| products of carbon burning can be further converted to |
|
Definition
| silicon, sulfur, calcium, and argon |
|
|
Term
|
Definition
| the upper limit on the mass of stars made only of neutrons is about 3msun |
|
|
Term
| each time an electron and a proton in the star's core merge to make a neutron, the merger releases a |
|
Definition
|
|
Term
|
Definition
| the huge, sudden input of energy from neturinos reverses the infall of these layers and drives them explosively outward. |
|
|
Term
| the supernova explosion produces a |
|
Definition
| flood of energetic neutrons that barrel through the expanding material. these neutrons can be absorbed by iron and other nuclei where they can turn into protons, thus they build up elements that are more massive than iron |
|
|
Term
| calculations suggest that a supernova less than _ LY away form us would certainly end all life on earth |
|
Definition
|
|
Term
| what is the equivalence principle |
|
Definition
| for an observer in an isolated system there is no way to determine if she/he is floating in space or falling freely in a gravitational field |
|
|
Term
| light always follows the _ path between two points |
|
Definition
|
|
Term
| einstein suggested that a gravitation fields bends the |
|
Definition
|
|
Term
| according to newton_and_ are separate and independent |
|
Definition
|
|
Term
| einstien showed that tere was an intimate connection between space and time and that only by considering... |
|
Definition
| the two together (Spacetime) we can have a correct picture of the physical world |
|
|
Term
| what tells spacetime how to curve |
|
Definition
|
|
Term
| what tells other matter how to move |
|
Definition
| the curvature of spacetime |
|
|
Term
| the amount of distortion dpeends on |
|
Definition
|
|
Term
| which planet is most affected by the distortion of spacetime and why |
|
Definition
| Mercury because it orbits closest to the sun |
|
|
Term
| what does the general relativity theory predict |
|
Definition
| that due to the curvature of spacetime there should be a tiny addtional push on Mercury, over and above that predicted Newtonian theory, at each perihelion (makes mercury orbit rotate slowly in space) |
|
|
Term
since spacetime is more curved in regions where the gravitational field is strong, we would expect
|
|
Definition
| light passing very near the sun to appear to follow a curved path |
|
|
Term
| what happens during the total solar eclipse |
|
Definition
| much of the sun's light is blocked out allowing the stars near the sun to be photographed |
|
|
Term
| one predictions of general relativity is that the stronger the gravity |
|
Definition
| the slower the pace of time |
|
|
Term
| when light enters a region of strong gravity and time slows down, the light experiences |
|
Definition
| a change in its frequency and wavelength |
|
|
Term
If stronger gravity slows down the pace of time, then the rate at which crest follows
crest must slow down-the waves become less |
|
Definition
|
|
Term
Ultimately, as a star shrinks, the escape velocity would |
|
Definition
| exceed the speed of light |
|
|
Term
| how is the black hole formed |
|
Definition
As the same mass falls into a smaller sphere, the gravity at the surface goes up,
making it harder for anything to escape from the stellar surface. |
|
|
Term
|
Definition
The star's geometry cut off communication with the rest of the universe precisely at
the moment when the escape velocity becomes equal to the speed of light. The size of
the star at this moment defines a surface that we call |
|
|
Term
| what is Scharzschild radius. |
|
Definition
| The radius of the event horizon |
|
|
Term
| how can the galaxy be observed |
|
Definition
| radio and infrared radiation |
|
|
Term
|
Definition
Close in to the galactic center (within about 12,000 LY), the stars are no longer
confined to the disk but form a |
|
|
Term
| the globular clusters can be found in |
|
Definition
|
|
Term
| what is the milky way surrounded by |
|
Definition
|
|
Term
The Galaxy has four major |
|
Definition
| spiral arms with some smaller spurs |
|
|
Term
| The Sun is near the inner edge of a short arm or spur called |
|
Definition
|
|
Term
This theory for how spiral arms form is called |
|
Definition
| spiral density wave model |
|
|
Term
Our own Galaxy and M31, the Andromeda Galaxy, which is believed to be much like
it, are typical large |
|
Definition
|
|
Term
| spiral galaxies consists of |
|
Definition
nuclear bulge, a halo, a disk, and spiral arms. Interstellar material
is usually spread throughout the disks of spiral galaxies. |
|
|
Term
|
Definition
-Found ways to estimate distance of spiral nebulae
-recession velocities of galaxies are directly
proportional to their distances from us
- Hubble’s original velocity–distance relation, adapted from his 1929 paper in the Proceedings of the National Academy of Sciences
- Hubble and Humason’s velocity–distance relation, adapted from their 1931 paper in
The Astrophysical Journal |
|
|
Term
In a expanding universe we and all other observers, no matter were they are located,
must observe a |
|
Definition
| proportionality between the velocities and distances of remote galaxies |
|
|
