Astronomy 123: Second Homework Assignment
Provide some information in response to the following questions. This
is best done by using an Internet
search engine and typing in a key
word or phrase related to the question.
- Explain what is meant by an open or closed Universe. What
does most of the observational data suggest about the fate of the
- What was Supernova 1987A and what were some of the things that were
learned from it.
- What is the current media frenzy about "Life on Mars" all about?
How credible is the scientific evidence on which these new claims are being
- In the summer of 1999, researchers discovered some new important
clues about when eukaryotic cells first appeared in the oceans of the
early Earth. Where was this research done and how old does it suggest
that these first nucleated cells are?
- What are tube worm colonies? Where are they located and what is
their significance to the formation of life?
- What is the most probable origin for the Earth's moon?
- Suppose you were arguing with someone about the Age of the
Earth and your foe had an intrinsic distrust of science and its methods
and so therefore would not believe anything to do with radioactive
age dating. Outline what points of "common sense" about the nature
of the Earth that you could use to demonstrate that the Earth is geologically
old. You might want to consult this reference
for some ideas.
- Extra Credit:
Galaxies frequently run into each other and have a tidal interaction.
We can model this behavior and now you can too via use of this
Sophisticated JAVA applet - note if you don't have a fast machine
this applet will not run very well.
This applet is doing calculations in your browser concerning the
gravitational interaction between galaxies. You can twiddle the dials
with left or right mouse button to change orientations. You can
change mass ratios and distances of closest approach (peri parameter).
You can choose to have a big dark matter halo around the galaxies
or not (that's the Big Halo box).
Your mission, should you decide to accept it, is to see if you
can produce a simulation that looks like the real system below.
If so, then record the parameters of that simulation and the
time (in millions of years, its printed at the top of the applet)
when the simulation sort of looks like this real system: