Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-L] strange things in chem book



As for the items that started this discussion: Those are bad, but I'll
wager there are far worse things in your chemistry book ... things far
more insidious and destructive. Check for
-- significant figures
-- filled "Lewis octets" in molecules
-- distinguishing "physical change" from "chemical change" based on
qualitative macroscopic observations
-- bogus explanation of "the scientific method"
-- bogus definition of energy
-- bogus definition of entropy
-- bogus definition of heat
-- bogus definition of molecule
-- bogus explanation of osmosis
-- Bohr atoms with electrons following Keplerian orbits
-- oxidation numbers
-- Le Chatelier's principle
-- ludicrously unsystematic approach to balancing equations
-- etc. etc. etc.

Links to explanations of the corresponding /correct/ ideas can be
found at
http://www.av8n.com/physics/pedagogy.htm#sec-misconception-list
along with a few dozen other misconceptions. On the other hand,
beware that focusing attention on misconceptions is almost always
a bad idea. For more on this, see
http://www.av8n.com/physics/pedagogy.htm#sec-miscon

======================================
Turning now to the recent sub-thread: on 13 Sep 2012 at 20:02, Turner, Jacob
wrote in part:

Standard High School approach. Semantics are frequently argued though.

Arguments over semantics are indeed frequent, but they are not wise.

The recent discussion of the alleged distinction of theory versus law
versus explanation is an expedition in search of something that does
not exist.

All evidence available to me indicates that scientists (and everyone
else) uses words such as law, theory, rule, formula, principle, relation,
equation, etc. /without/ any significant, systematic difference in meaning.
I'm not saying there are never any differences at all, just that any
differences are small, unreliable, unsystematic, and unimportant.

Just because we can think of N different ideas and N different words,
that doesn't mean there is a one-to-one correspondence between the
ideas and the words.

The way it really works is this:
A) Any given idea can be called a law or formula or rule or whatever.
It doesn't matter.
B) No matter what you call it, it goes through a life cycle where it
starts out rough and ill-supported by the data, and gradually becomes
more refined and better-supported. During this process it does /not/
change its name from law to formula to rule or vice versa or anything
like that.

Common sense and long experience tell us that to truly describe the
status of a law / rule / principle / theory / whatever takes many
words, perhaps many sentences, perhaps many paragraphs. For example,
the rule might work well in such-and-such limit but not so well in
some other limit. Trying to convey such information by renaming it
from law to rule to theory or vice versa would be a ludicrously bad
idea.

What's worse, even if you think you can draw sharp distinctions between
these terms, and even if you think you can teach your students to do
the same, you have accomplished nothing, because when the students go
out into the real world, they will be talking to people who do not
agree with what you have done, and the fancy terminology will be more
unhelpful than helpful.

===========

The word "theory" is a special case because it is ambiguous. For thousands
of years, it has had two distinct meanings:

A) One usage refers to a coherent system of evidence, principles,
and methods, offering a comprehensive understanding of a broad topic.
(This is much grander than any single rule or fact.)

B) The other usage refers to a hypothesis, conjecture, or mere speculation.

Because of this ambiguity, I strong recommend not using the word "theory" at
all. It is just begging to be misunderstood. What's worse, if you speak of
the "theory of evolution" and clearly explain that you intend meaning (A),
dishonest persons will leap at the opportunity to twist what you've said by
pretending that you used meaning (B).

Specifically, rather than "the theory of evolution predicts X" you can usually
just say evolution predicts X. Rather than speaking of the "theory of
evolution" you can speak of the fact of evolution, or of our long-established
comprehensive understanding of evolution.

For more on all this, see
http://www.av8n.com/physics/scientific-methods.htm#main-rule-law
http://www.av8n.com/physics/scientific-methods.htm#main-theory
http://www.av8n.com/physics/scientific-methods.htm#main-model
http://www.av8n.com/physics/scientific-methods.htm#main-method