Early in the course, I took about 30 minutes out of a lecture to present the exercise to the students, as follows:
I would like you to imagine that you are all inhabitants of the planet Zog. Zog is remarkably similar to the Earth in every way. For example, the astronomers of Zog have all the same telescope facilities that we have.
There is only one difference: the universe of Zog has a quite different cosmology to our universe. Your task, over the next few weeks, will be to figure out what the cosmology of Zog's universe really is. I've invented a detailed, self-consistent cosmology for Zog. Your task is to discover it.
I then show a computer presentation (included with the Web links below), describing the night sky of Zog. This has no Milky Way and no galaxies. Instead it has such novel features as the Greater and Lesser Milkstains, the Northern and Southern Blue Spots with their jets, and the fuzzballs. All these are features of the fake cosmology I had devised. This presentation was made available to the students on the web.
Your should divide yourselves up into groups of about three people, and talk through what you have just learned. At present, you do not know anything like enough to figure out the cosmology of Zog's universe. Just as earthly astronomers did, you will have to make some new observations to figure things out.
Once you are in your groups, try and figure out some observations that will help unravel the mystery of this universe. The techniques you are learning about in this course, by which we learned about our universe, should give you somewhere to start. Remember: you have all the telescope facilities of Earth at your disposal. You can coordinate your observations between groups to avoid overlaps, if you wish.
One week from now, you should send me your proposed observations. If they are technically feasible, I will calculate what you would observe, fake the appropriate data and put them on-line for the whole class to see.
You will then have two weeks to mull over this data, and come up with a second set of observations. I will fake the data from these new observations, and once again place them on-line.
You will then have a further two weeks to consider all this data, work out a cosmology for this universe, and write it up in your groups. Your write-up should describe both the cosmology you have deduced, but more importantly the process whereby you arrived at this conclusion.