Monday, June 23, 2008

Teacher: Big ideas without science methods are blank cheque

Recently, I responded to Brian Greene's suggestion that science teachers should teach the big ideas in science, to get students interested. My point was that without a grasp of the underlying principles and fact base, the big ideas in science will not be distinguishable from big ideas in science fiction. A physics teacher kindly writes to comment:

A few thoughts here:

1. The small details in Science are what actually makes up the big picture. Scientific knowledge is like a jigsaw puzzle made up of many small interlocking pieces. One cannot intelligently embrace a large idea, e.g., the Big Bang, without first comprehending the many little ideas that built up to it. Otherwise one is signing a blank cheque.

2. Science is much more an epistemology than a body of knowledge. The goal of science teaching is to get students to think this way: recognise a problem, formulate hypotheses which can be tested experimentally, design and carry out experiments which test one variable at a time, repeat experiments for clarity of results, and draw conclusions from those results to modify or validate the hypotheses. That's the scientific method, limited in scope but powerful in application.

3. Unless one has undergone the discipline of thinking through the steps of the method, one has no idea how much certainty one can place in the various pieces of the puzzle. I have a great deal of confidence in some aspects of modern cosmology because I know the experimental basis for them; an example of this would be the tri-hydrogen reaction. On the other hand, some aspects are almost pure speculation (gravitons, for example) and I can hold onto them very lightly. The speculation is necessary, not only because the human mind wants to see the whole picture even when a puzzle piece is missing, but also because the missing pieces provide a locus for new experimentation.

Signing a blank cheque? That reminds me of the spectacular claim in the May 2003 SciAm article by Max Tegmark that

Cosmologists infer the presence of Level II parallel universes by scrutinizing the properties of our universe. These properties, including the strength of the forces of nature and the number of observable space and time dimensions, were established by random processes during the birth of our universe. Yet they have exactly the values that sustain life. That suggests the existence of other universes with other values.
Now, talk about a blank cheque! Our universe looks fine-tuned so there must be a zillion flops out there.