Universe: The Infinite Frontier Quiz 6 The following questions are from Lesson 15 "Galaxies" and Lesson 17 " The Big Bang". Assume that the Multiple Choice alternatives go A B C D from top to bottom the same as in the quiz packet. Top of Form Lesson 15 "Galaxies" 1. Early debates over whether Andromeda was a true nebula or a galaxy, is still not completely settled. was settled by the discovery of Cepheid variables within the object. was settled by Hubble discovering that it had a red shift. was settled by Humason who realized that it was too large to be a nebula. 2. Edwin Hubble found that almost all galaxies (see Help & Hints) give spectra that are blue shifted. give spectra that are red shifted. are rotating spiral galaxies. are rotating elliptical galaxies. 3. Choose the correct statement concerning Hubble's Law. Hubble's Law applies to the universe and indicates that greater red shifts mean a smaller universe. Hubble's Law applies to the universe and indicates that greater red shifts mean a larger universe. Hubble's Law applies directly to galaxies and indicates that greater red shifts mean a smaller distance. Hubble's Law applies directly to galaxies and indicates that greater red shifts mean a greater distance. 4. From his study of galaxies, Hubble was able to show that individual galaxies are expanding. the universe is contracting. the universe is expanding. the universe is more than 10 billion years old but not over 16 billion years old. 5. A typical galaxy contains about one million stars. 10 million stars. 100 million stars. 100 billion stars. 6. Galaxies can be classified as three main types, they are spiral, elliptical and peculiar. disk, elliptical and peculiar. disk, elliptical and irregular. spiral, elliptical and irregular. 7. Choose the statement that gives some basic differences between spiral and elliptical galaxies. Spirals contain more dust and gas between stars, they tend to be dimmer and bluer. Spirals contain less dust and gas between stars; they tend to be brighter and bluer. Spirals contain more dust and gas between stars; they continue to form stars. Elliptical galaxies are usually larger, older and bluer. 8. Choose the correct statement concerning the shape of galaxies. A galaxy's shape was largely determined when it formed 5 billion years ago; collisions can alter its shape. A galaxy's shape may have been partially determined when it formed 10 billion years ago; collisions and mergers also play a role in defining its shape. Collisions between galaxies are the only factor responsible for their shape. Collisions between galaxies are mainly responsible for their shape because most collisions occurred within the last million years. 9. "Star burst" galaxies are places where several supernova occur at the same time. smaller stars explode at very high rates. giant molecular clouds collide, collapse and explode. giant molecular clouds collide, collapse and form stars. 10. Evidence for galaxy cannibalism comes from central areas of clusters of galaxies that have huge spirals and lack ellipticals. central areas of clusters of galaxies that have huge ellipticals and lack spirals. the edges of superclusters of galaxies that have huge ellipticals and lack spirals. the edges of superclusters of galaxies that have huge spirals and lack ellipticals. 11. The Local Group is a cluster of galaxies that contains the Milky Way, Andromeda and about 20 others within a sphere about 3 M l.y. across. Andromeda and about 20 others within a sphere 4 B l.y. across. the Magellanic Clouds and about 20 others within a sphere 4 B l.y. across. the Magellanic Clouds and thousands of others within a sphere 3 M l.y. across. 12. The irregular galaxy called the Large Magellanic Cloud is presently merging with the Milky Way. approaching the Milky Way head on. orbiting the Milky Way and will merge with it in the future. orbiting the Milky Way and will continue to do so. 13. In the Bubble Model of the universe, superclusters of galaxies form spherical regions that are referred to as bubbles. spherical regions that are referred to as voids. the walls of the bubbles. linear regions referred to as Great Attractors. 14. If the Hubble constant equals 50 km/sec/Mpc, and a galaxy has a recessional velocity of 10,000 km/sec, then its distance would be 20 Mpc 100 Mpc 200 Mpc 50,000 Mpc Lesson 17 "The Big Bang" 15. If the universe is infinite, then according to Olber's paradox, the night sky would appear larger. be very bright. be somewhat brighter. be dimmer. 16. One of the reasons the night sky is not very bright is: we receive a finite amount of light shining through an infinite amount of space. there is only a finite number of galaxies shining through an infinite amount of space. we receive a finite amount of light from a finite number of galaxies. we are looking back in time and much of the light has not reached us yet. 17. According to Hubble's Law the most distant galaxies have the greatest red shifts and velocity. greatest red shifts and luminosity. smallest red shifts and luminosity. smallest blue shifts and velocity. 18. If an expanding balloon covered with dots is used as a model for the universe, the balloon represents galaxies and the dots stars. balloon represents space and the dots stars. surface of the balloon represents space and the dots galaxies. surface of the balloon represents space and the dots stars. 19. For a universe expanding like a balloon, the center is near our solar system. the Milky Way. towards the constellation Sagittarius. nonexistent, there is no center of expansion. 20. The cosmic microwave background radiation may be (see Helps & Hints) the result of energy coming from distant galaxies in all directions. the "relic" energy from the once very hot beginnings of the Big Bang. from a few cooler clouds of gas at the fringes of the universe. from warmer clouds of gas at the fringes of the universe. 21. According to the Big Bang theory all matter, energy and space formed from a point (singularly) no larger than the head of a pin. all matter and light started from some star-like object's explosion. all matter and space started from some star-like object's explosion. energy and space exploded from a point hundreds of billions of years ago. 22. In the beginning all the basic forces like gravity and electromagnetic forces (the attraction between positive and negative) played a role in creating different elements. co-existed as one force. caused different fluctuations in space-time. disappeared by 10-43 seconds after the Big Bang. 23. The most abundant element in the earliest universe was helium. carbon. hydrogen. beryllium. 24. In the early universe, cooling led to the formation of matter. increased radiation. the destruction of matter. the production of energy. 25. According to Hubble's Law, if galaxy A is moving three times faster than galaxy B, it is also three times larger. three times closer. shifted three times more toward the blue portion of the spectra. three times farther away. or Bottom of Form Prepared by: Mike Mitchell Be sure to review your quizzes before taking the test. Test Pilot (4.4.3) is Copyright (c)2003, The McGraw Hill Companies, All Rights Reserved.