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Re: Explaining "explain".



At 06:16 PM 1/25/98 -0800, Leigh Palmer wrote:
# What I don't wish to forget
#at any time is that at the foundation of all our explanations lies a
#small number of principles that are tentatively accepted on faith. In
#my lifetime I have seen such articles of faith overturned in the
#sciences, yes, even in physics. We must always recognize the potential
#ephemerality of the tenets of our Faith, or it will truly become a
#religion. (Yes, I do think my belief system is better than religion,
#and I do not apologize for that opinion.)
#

Well said, Leigh, well said.

Coming back to what all this means for students, I'm reminded of a very nice
section in the Chabay/Sherwood text for freshman calc-based E&M, Electric
and Magnetic Interactions, page 66. There the authors differentiate between
explanation and description. (How many other intro books do that?)

To copy the first few sentences:

When asked to explain, some students only describe. A description tells what
happened; an explanation tells why it happened, in terms of fundamental
principles.

A description: "The charges spread out all over the surface of the metal."

An explanation based on fundamental principles (Coulomb's Law, properties of
metals): "Because like charges repel, and the electrons are free to move,
the excess electrons spread out over the surface of the metal."

A basic goal of science is to explain a wide range of phenomena in terms of
a small number of powerful fundamental physical principles.


Isn't that nice? I found that one paragraph to be very helpful with
students.

Another good thing about this book, to enter another thread, is that it is
just black and white printing. No publisher's excess here.

JEG

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John E. Gastineau mailto: gastineau@mindspring.com KC8IEW
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