Chapter Questions
If the Milky Way were the size of a nickel (about 2 centimeters in diameter):a. How big would the Local Group be?b. How big would the Local Supercluster be?c. How big would the visible universe be? (The data in Table 2.1 may help you here.)
If we detected radio signals of intelligent origin from the Andromeda Galaxy (M31) and immediately responded with a radio message of our own, how long would we have to wait for a reply?
Are galaxies father apart (compared to their diameters) than solar systems?
If the Milky Way is moving away from the Virgo Cluster at 1000 kilometers per second, how long does it take for the distance between them to increase by 1 light-year?
The Milky Way is moving toward the larger galaxy $\mathrm{M} 31$ at about 100 kilometers per second. $\mathrm{M} 31$ is about 2 million light years away. How long will it take before the Milky Way collides with $\mathrm{M} 31$ if it continues at this speed?
The most distant galaxies seen by the Hubble Space Telescope are 12 billion light-years away. Using the scale in Section 2.4 (where the Milky Way is about the size of a large city), how far would that be in the model?