For this lab, you’ll use the following lab write-up as a template. Record your answers to each question and activity this document, and upload as a .doc or .pdf document to the following module item for grading:
1) Write a paragraph or two summarizing what you learned from the background information. Include anything you found interesting, and propose how you think this information would be helpful in astronomy and astrophysics.
2) Consider the following formula: Here z is the redshift and the lambdas represent the observed and emitted wavelengths for the light in consideration. What does a redshift of zero mean? What does a redshift of one mean? How many times longer is the observed wavelength than the emitted wavelength if the redshift is seven?
3) Consider the following link: https://lco.global/spacebook/distance-and-lookback-time/ The lookback time tells us how long the light has taken to reach us. Why is this not equal to the current distance to the galaxy? In order to calculate the current distance to the galaxy, several assumptions about the Universe must be made. How fast is the Universe expanding? Has it always been expanding at this rate? These are questions beyond the scope of this lab.
4) In astrophysics we assume that there is no preferred spot in the Universe and that the laws of physics are the same everywhere in the Universe. As a result, we would expect objects to be moving randomly throughout space. Let’s assume that all of the galactic motion in the Universe is classical in nature. What would we expect to see as far as redshift and blueshift are concerned? Would this change in any significant way with distance? Why or why not? Now assume that all of the galactic motion in the Universe is cosmological in nature. What would we expect to see as far as redshift and blueshift are concerned? Would this change in any significant way with distance? Why or why not?
5) In reality the galactic motion in the Universe is a mixture of the two. Consider looking at galaxies with several different redshift values. Consider the following two cases:
a. Classical motion dominates over cosmological motion. The magnitude of the random velocity is greater than the magnitude of the recessional velocity. Now what would we expect to see as far as redshift and blueshift are concerned? Would this change in any significant way with distance? Why or why not?
b. Again repeat, but now assume that cosmological motion dominates over classical motion. The magnitude of the recessional velocity is greater than the magnitude of the random velocity.
6) Consider that light was emitted from a galaxy with a wavelength of 2.50 * 10-10 meters. What would be the observed wavelength for the following redshifts?
7) Assume that visible light is in the range of 400 nanometers to 700 nanometers. Which of the above would result in observations being made in the visible light spectrum?
8) Write a two paragraph conclusion of what you have done. Include any results that may have surprised you.