Welcome Astro 7 Students
Excuse my typos
Due: Thursday, May 18, 2000, Beginning of class
Chapter 17
#1
Progress in many scientific fields, such as the study of stars, plants and animals, has included the classification of different types of specimens, followed by comparisons of the different classes. How does a cosmologist suffer a disadvantage in this regard?
#5
The measurement of cosmological parameters requires distant astronomical targets whose properties are well understood. a) Why is it difficult in practice t use galaxies for cosmological tests? b) Quasars are the most distant known objects. Why do astronomers not use them to measure the size and shape of the universe?
#8
Why was the discovery of the cosmic background radiation from all over the sky heralded as the strong evidence in favor of the big bang theory? Does comparing the radiation from different parts of the sky give any evidence of asymmetry of inhomogeneity in the universe? How do astronomers interpret the departures from constant temperature?
#12
Big Bang cosmology involves some mind-bending concepts. Imagine that you are talking to a curious and intelligent 13 year old cousin. Try to convey the following ideas as clearly as you can. Explain how we can look back in the time by observing distant objects. Explain how the universe might have no center or edge, even though all galaxies are moving away from us. Explain how a flat universe contains objects whose angular size actually starts to increase with increasing redshift. Explain how distant quasars and galaxies can be moving away from us faster than he speed of light. Explain how the physical universe could be much larger than the observable universe. Explain how we can possibly have information of the universe in the first few minutes of its existence.