Planetary systems: How does accretion form planetary systems? Where did Earth’s water come from?

First, you must select a topic that meets the stated criteria (unsolved problem in science, two disjoint theories (i.e., if one theory is right, the other is wrong), an existing body of empirical research supporting each theory). If you have any doubts about your topic selection, you may ask me for confirmation. If you write on a topic not meeting the criteria, you risk getting a zero score. Next, even if there exist many theories attempting to explain the unsolved problem, you should just identify the two strongest (in your opinion) competing theories.

Investigate each theory and its supporting research carefully. You will write your paper with the same subheadings as used in your homework assignments involving crucial experiments: Real World, Model 1, Model 2, Prediction 1, Prediction 2, Data, Negative Evidence, Positive Evidence. Make sure you are putting the right content in the appropriate places (e.g., don’t tell me about data in the “Model” section, etc.). Also, you want to find differing predictions for each model, not matching ones. In the evaluative sections, I will be looking to see how you have carefully weighed the evidence and come to a judicious verdict, declaring one theory the stronger one over the other. In the evaluative sections (Positive/Negative Evidence sections), you will declare your verdict regarding which theory is the “winner” and which is not, based on your consideration of the quality/quantity of supportive (and/or disconfirming) research. If the empirical evidence makes it difficult to declare a winner, then appeal to satisfaction (or dissatisfaction) of the theoretical virtues.