Hello World
Physics 315
Summer 2012
Homework #14 (due July 19)
To receive full credit, all answers must be typed, grammatically correct, and all sources must be properly referenced. Do not copy material; answer in your own words. The questions are each worth five points.
1. Suppose we look at a distant quasar. If an inhabitant of the host galaxy of that quasar looked at the Milky Way at the same time we looked at their galaxy, what kind of object might they see? Explain. How would the color of light they observe be different than the color of light emitted by the Milky Way? Explain.
2. What is Hubble’s Law and how can it tell us the distance to a galaxy? Hubble’s Law contains a constant (labeled H, the slope of a line). How is the value of the constant determined? Suppose the accepted value of the constant was found to be incorrect in the future. Would we have to change our ideas about the evolution of galaxies? Why or why not? Would it change our estimate of the age of the Universe? Explain.
1. I thought he might see the Milky Way Galaxy but not any stars in the MW galaxy because that quasar is the most distant galaxy from us, which is also brightest and most active. Comparing with it, other galaxies and their stars may look darker and the MW galaxy may look like a point or spot, which is little bright.
The color of light they observe could be more shinning than the light emitted by the Milky Way. It also displays differently on the spectrum of normal light because the apparent stars in the quasar are not actually stars and other stuff was found near the bright nucleus. This stuff may eventually be the reason of galaxy’s brightness and explanation of different color of light
2. The Hubble’s Law is an evolution of distance indicators, which used for calculated the distance of galaxies. It involves spherical distance compared with redshift of distant galaxies. Edwin Hubble found that the farther galaxies tend to have larger redshift than the
Summer 2012
Homework #14 (due July 19)
To receive full credit, all answers must be typed, grammatically correct, and all sources must be properly referenced. Do not copy material; answer in your own words. The questions are each worth five points.
1. Suppose we look at a distant quasar. If an inhabitant of the host galaxy of that quasar looked at the Milky Way at the same time we looked at their galaxy, what kind of object might they see? Explain. How would the color of light they observe be different than the color of light emitted by the Milky Way? Explain.
2. What is Hubble’s Law and how can it tell us the distance to a galaxy? Hubble’s Law contains a constant (labeled H, the slope of a line). How is the value of the constant determined? Suppose the accepted value of the constant was found to be incorrect in the future. Would we have to change our ideas about the evolution of galaxies? Why or why not? Would it change our estimate of the age of the Universe? Explain.
1. I thought he might see the Milky Way Galaxy but not any stars in the MW galaxy because that quasar is the most distant galaxy from us, which is also brightest and most active. Comparing with it, other galaxies and their stars may look darker and the MW galaxy may look like a point or spot, which is little bright.
The color of light they observe could be more shinning than the light emitted by the Milky Way. It also displays differently on the spectrum of normal light because the apparent stars in the quasar are not actually stars and other stuff was found near the bright nucleus. This stuff may eventually be the reason of galaxy’s brightness and explanation of different color of light
2. The Hubble’s Law is an evolution of distance indicators, which used for calculated the distance of galaxies. It involves spherical distance compared with redshift of distant galaxies. Edwin Hubble found that the farther galaxies tend to have larger redshift than the