Q&A Hero

Q: Fluorescence occurs when ________. A) visible light is converted to ultraviolet light B) visible light is converted to infrared light C) infrared light is converted to visible light D) ultraviolet light is converted to visible light E) Infrared light is converted to ultraviolet light

Q: The main difference between Bright and Dark Nebulae is ________. A) the composition of their gases B) the composition of their dust C) their proximity to a black hole D) their proximity to a blue star E) none of the above

Q: Interstellar matter is composed primarily of ________. A) ions B) dust C) oxygen D) hydrogen E) helium

Q: What two elements formed first? A) electrons and protons B) hydrogen and oxygen C) helium and oxygen D) helium and hydrogen E) protons and neutrons

Q: Which of the following events is not part of the history associated with the Big Bang Theory? A) Just before Big Bang occurred, there was only energy and disassociated electrons and protons. B) About 13.7 billion years ago, our universe started with a huge explosion. C) The first matter formed 380,000 years after the formation of the universe. D) Our Sun formed approximately 9 billion years after the universe formed.

Q: What was Hubble's major contribution to Cosmology? A) He identified Cepheid Variable stars. B) He measured the size of the universe. C) He identified numerous new galaxies outside the Milky Way. D) He developed a new method for measuring the absolute magnitude of stars. E) He proved the Big Bang Theory.

Q: Why did Hubble think the Cepheid variables he saw in "Fuzzy Patches" were outside the milky way? A) They were dim. B) They were small. C) Their brightness varied. D) They had a red shift character.

Q: Cepheid Variables are stars whose brightness varies in a predictable manner so that the absolute magnitude of the star can be determined, and this allows the ________ of the star to be determined. A) size B) distance from Earth C) velocity D) direction of motion E) composition

Q: In the early 1700's Kant suggested there were many galaxies visible from Earth but the idea was not popular because ________. A) at that time, people generally believed the earth was the center of the universe. B) only modern satellite data supports that point of view C) that hypothesis would require a significantly larger universe than was widely accepted at that time D) that hypothesis would require that objects travel faster than the speed of light E) the "Big Bang" theory did not support that concept

Q: How do we calculate or determine the distances to stars? What units do we use and what are the limitations (if any) of the method used for such calculations?

Q: Briefly discuss stellar evolution. What forces are opposing one another throughout the life of a star and how do they influence the various stages in the life cycle of a star?

Q: Label the Giant and Supergiant stars, the Main Sequence stars, and the White dwarf stars on the H-R diagram below.

Q: Which fate of the universe is currently favored: Big Crunch or Big Chill?

Q: Has the Big Bang hypothesis been successfully tested?

Q: Hubble's law states that galaxies are receding from us at a speed that is proportional to their ________.

Q: Most galaxies are of this type.

Q: Stars that are composed of matter in which electrons have combined with protons are called ________ stars.

Q: A star in which light cannot escape because of the immense gravitational pull is called a(n) ________.

Q: Very large red stars, such as Betelgeuse in the constellation Orion, are called ________.

Q: The name applied to large quantities of interstellar dust and gas is ________.

Q: Possibly the most cataclysmic event associated with the death of a star is the ________.

Q: The distance light travels in a year, called a(n) ________, is used by astronomers to measure stellar distances.

Q: The "true" brightness of a star is called its ________ magnitude.

Q: Dark Energy and Dark Matter are similar in that they both appear to be slowing the expansion of the universe.

Q: The red shift refers to the tendency of stars to cool and become red in color.

Q: The Milky Way is classified as an irregular galaxy.

Q: The greatest number of galaxies belong to the type known as elliptical galaxies.

Q: Our galaxy is called the Milky Way.

Q: Our galaxy is currently absorbing other galaxies.

Q: The most dense objects known are black holes.

Q: Stars spend most of their life span as giants.

Q: Cool stars evolve much more quickly than do hot stars.

Q: The hottest main-sequence stars are also the most massive.

Q: Stars with a surface temperature 3000 K appear red in color.

Q: The least massive main-sequence stars are blue in color.

Q: The measure of a star's brightness is called its magnitude.

Q: Stars spend most of their life span as main-sequence stars.

Q: Stars having the same surface temperature radiate the same amount of energy per unit area.

Q: The larger the magnitude number, the brighter will be the star.

Q: Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern. neutron star supernova white dwarf black hole

Q: Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern. Red Giant neutron star main sequence Red Supergiants

Q: Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern. magnitude color temperature composition

Q: Evidence for the existence of dark matter includes ________. A) the observation that Mercury rotates about the Sun faster than Pluto B) the observation that the universe is not expanding as fast as predicted by Big Bang Theory C) the observation that stars near the center of galaxies do not rotate as fast as expected D) the observation that the universe appears to be slowing down

Q: There are three possible fates for the universe: 1) eternal expansion; 2) total collapse; or 3) some equilibrium condition with no further motion. What conditions might favor one result over the other? A) Critical velocityis there enough momentum to continue expansion forever? B) Critical densityis there enough mass in the universe to cause gravitational collapse? C) Critical energyis there enough energy in the universe to maintain either expansion or collapse? D) Critical volumeis the universe large enough for unlimited expansion?

Q: What was the test of the Big Bang Hypothesis discussed in your text? A) The universe should be expanding. B) There should be more expansion in older galaxies than in young ones. C) We should be able to model how the galaxies have moved and reconstruct the original explosion. D) We should be able to detect remnants of the initial heat of the universe. E) We should be able to measure how atoms have changed through fusion since the original explosion.

Q: Big Bang Theory suggests that prior to the Big Bang, the universe was ________. A) nothing B) a giant neutron star C) in a very hot and massive state D) a collapsed supernova

Q: Based on the observed red shifts in the spectral lines of distant galaxies, astronomers conclude that ________. A) Earth is in the center of the universe B) the universe is contracting C) the universe is expanding D) the universe is in a steady state

Q: Hubble's law states that galaxies are receding from us at a speed that is proportional to their ________. A) distance B) orientation C) volume D) mass

Q: Discuss the features and characteristics of the Sun? Are they thought to be unique to the Sun or are they typical of other stars? How do any of these structures relate to the process of nuclear fusion which is thought to produce the Sun's energy?

Q: Compare and contrast the various types of telescopes, including radio telescopes. What are the advantages and disadvantages of each one? Are there other considerations when choosing one telescope over another besides optical clarity or magnification?

Q: Describe the concept of "red shift" and how this observation relates to theories that the universe is expanding.

Q: Einstein's equation E = mc2 describes the conversion of mass to energy that occurs during nuclear fusion. If a billion joules of energy are released by this process, how much mass has been consumed? (Recall, a joule is a Nt-m or kg-m2/s2 and the speed of light is ~300 million m/s.)

Q: The Sun produces energy by converting ________ to energy.

Q: The amount of energy released during a nuclear reaction was established by the well-known scientist named ________.

Q: The Sun is composed almost entirely of two gases. They are ________ and ________.

Q: The nuclear reaction process of converting hydrogen nuclei into helium nuclei is called the ________ chain.

Q: The most conspicuous features on the surface of the Sun are dark areas called ________.

Q: Streams of protons and electrons emitted from the Sun are known as the ________.

Q: When several radio telescopes are connected together, the resulting network is called a(n) ________.

Q: A(n) ________ spectrum is produced when white light is passed through a comparatively cool gas under low pressure.

Q: The motion of a star can be determined using the ________ effect.

Q: Light can be described as a stream of fast-moving particles called ________.

Q: Visible light emitted from the celestial bodies is only a small part of an array of energy called ________ radiation.

Q: Astronomers currently estimate the internal temperature of the Sun at 1500C.

Q: The energy from nuclear fusion is produced by the conversion of mass to energy.

Q: The Sun is considered an average star.

Q: The Sun's energy results from the conversion of hydrogen nuclei into helium nuclei.

Q: Bright centers of solar activity are called filaments.

Q: Sunspots appear dark because they are cooler than the surrounding solar surface.

Q: The outermost portion of the solar atmosphere is called the photosphere.

Q: Radio telescopes are generally much larger in size than are optical telescopes.

Q: Radio telescopes have an advantage over optical telescopes in that they can be used during daylight hours.

Q: Radio telescopes are able to detect very short wave radiation emitted by celestial objects.

Q: Although current technology will allow the construction of much larger optical telescopes, astronomers see no advantage in building these larger instruments.

Q: All of the world's largest telescopes are of the refracting type.

Q: Sir Isaac Newton built and used reflecting telescopes.

Q: Galileo built the first known telescope.

Q: In the case of light, when a source is moving away, its light appears redder than it actually is.

Q: Dark-line (absorption) spectra can be used to identify the elements present in stars.

Q: A hot (incandescent) gas under low pressure produces a continuous spectrum.