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Re: [Phys-L] 'correct physics' was Energy & Bonds



I don't want to debate this at length--we've been doing so since the last millennium--but just want to note that other quite knowledgeable people approach these issues differently. For example, I've just finished an audio course on TIME by Sean Carroll of Cal Tech which dealt mostly with issues of entropy. While he clearly points to the Boltzmann formulation as the 'correct' definition of entropy, he also often talks of entropy in terms of disorder. He explicitly states that he does so when the context warrants. This may not be a course for professional physicists, but it is well beyond the HS physics level. Similarly, I've seen, heard, and read much recently by 'high-level' physicists who, again in the context of talking to non-professional physicists, will talk about clocks moving at different rates, lengths contracting, and even mass changing with velocity.

We may know what is 'correct' for practicing theoretical physicists, but there are many audiences and many contexts (a purely audio lecture for example) where it can be more efficacious to use less formal descriptions that still get the main ideas across.

rwt

On 11/13/2013 8:56 AM, John Denker wrote:
On 11/13/2013 05:15 AM, Ron Mcdermott wrote:
a 10th grader. That would make them 15.
Quantum mechanics, calculus, etc are not a very good option for teaching
them.
OK, so you can't teach them calculus and QM in 10th grade.

1) That's a red herring, because nobody said you could.

2) In any case, that's no excuse for teaching them
wildly wrong stuff about stability and disorder and
the "overriding tendencies" of chemistry and physics.

It is grossly fallacious to suggest that the only choice is
between teaching wrong stuff and nothing, or between wrong
stuff and something age-inappropriate.

Requiring students to "learn" stuff that cannot possibly
be true is the opposite and the enemy of critical thinking.

==================

FWIW, basic concepts of probability and statistics -- including
the distinction between the overall distribution and a single
observation drawn from the distribution -- are part of the
common core standards starting in 6th grade if not earlier.
That would make the the students 11 years old. Also, an 11
year old kid grows up a lot in 4 years.

I mention this because it connects directly to the idea that
entropy is a property of the distribution as a whole, whereas
disorder -- /to the extent that it can be defined at all/ -- is
a property of a single observation drawn from the distribution.

I'm not saying that I like the common core standards overall,
but they stand as evidence that somebody besides me thinks
these topics can be handled in an age-appropriate way.
http://www.corestandards.org/Math/Content/6/SP
http://www.corestandards.org/Math/Content/7/SP
http://www.corestandards.org/Math/Content/8/SP

Also, the idea that an unstable molecule such as RDX or
nitroglycerin can be favored as the /product/ of a reaction
should be obvious to any 15 year old, or even 11 year old,
who thinks about it at all. Whining about calculus and
quantum mechanics is irrelevant. It does not change the
facts.

Again: requiring students to "learn" stuff that cannot
possibly be true is the opposite and the enemy of critical
thinking.

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Richard Tarara
Professor of Physics
Saint Mary's College

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