ericmazur / PnPbook

Tracking of typos, errors, and improvements for "The Principles and Practice of Physics"
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mutation of change #172

Open JohnDenker opened 8 years ago

JohnDenker commented 8 years ago

In chapter 1 in the chapter summary on page 27 it defines change as the transition from one state to another.

This is not good. It's not the sort of thing one expects to see in a "research-based" or "principles-based" textbook.

This is a chip off the tip of an iceberg; the larger strategic issues are discussed in item #171. The whole idea of a «chapter glossary» doesn't make much sense, and physics concepts don't generally lend themselves to pithy dictionary-style definitions.

In any case, the word change is not the sort of thing one expects to be glossed. It is one of the most common and most basic English words. https://en.wiktionary.org/wiki/Category:1000_English_basic_words There is zero chance that a student in the calculus-based physics course needs this word to be defined, explained, or translated.

Furthermore, defining change in terms of «state» and «transition» is preposterous. It violates a basic pedagogical principle: _Learning proceeds from the known to the unknown._ Specifically:

I find it odd that neither change nor «transition» appears in the index. If it's important enough to be featured in the «chapter glossary» it ought to appear in the index. (See #181 for a catalog of index-related issues.)

Last but not least, this definition of change is simply wrong. In reality, change can refer to a lot of different things, depending on context. For example, I can change the location of an object without changing its internal state. The broad definition here, based on the exceedingly broad definition of «state» on page 105, is one possible meaning but absolutely not the only possible meaning.

An author should be free to define terms however he likes, within reason ... but this is quite beyond the bounds of reason. One symptom is that the word change is used throughout the book in ways that are not consistent with the definition on page 27.

Suggestion:

The word change does not need to be defined at all, much less emphasized in the «chapter glossary». Just don't say anything about it. The exceedingly peculiar notion suggested in chapter 1 can perfectly well be captured by the phrase "change of state" using the peculiar, sweeping definition of "state" from page 105.