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Why Do We use B for the Magnetic Field? - Twelve Posting Suggestions



Re: Why Do We use B for the Magnetic Field? - Twelve Posting Suggestions

In his Sun, 29 Apr 2001 18:46:07-0400 Phys-L post "Why Do We use B
for the Magnetic Field?", Bruce Oldaker wrote:

"Why do we use 'B' for the magnetic field? One of my inquiring
instructors wants to know and I can't find it in my weird files."

After responses by Kowalski, Johnson, Craigen, and Green on this
thread, Jack Uretsky in his post of Sun, 29 Apr 2001 22:08:53-0500
wrote:

"Has everyone forgotten that there was a previous discussion that
seemingly resolved this question?"

Indeed there was! Go to the archives
<http://mailgate.nau.edu/archives/phys-l.html>, click on "Search the
archives," and then type "origin of B for magnetic field" into the
subject slot to obtain three hits: posts of 7/27/00 t0 7/29/00 by
Frank Cange, Doug Craigen, and Larry Smith.

The latter supplied a good source for the answer:

"The August AJP (vol 68, No. 8) addresses this on page 691."

In Larry's indicated reference,(1) Bauerlein writes:

"The symbols A, B, and H denote three prominent vector fields in
electromagnetism. The choice of those three letters appears to be an
alphabetical accident of history. . . . Maxwell . . .(ref. 2) . . .
introduces - with no explanation about usage - what we would write
today as B . . . "

My experience has been that valuable comments and insights on Phys-L
(and other discussion lists) are soon lost in cyberspace, and the
same questions and confusions are recycled over and over again with
no final resolution.

The Etzioni's(3) have extolled the virtues of "virtual communities,"
indicating that one of their strengths is "STRONG MEMORIES." But what
good do strong memories do if subscribers don't use them to "move
beyond forums for exchanging tidbits and opinions, to structures
which rapidly capture knowledge-value and foster rapid accumulation
and growth of a community's capability . . . tools to allow
contributors to share partially completed resources, and enable
others to improve upon them"? (5)

For what it's worth (not much, considering that it will probably be
ignored) I append a set of Posting Suggestions. (Yes, I know, I
posted such a list previously on Phys-L on 7/9/00 - also ignored.)

REFERENCES
1. Ralph Bauerlein, "Answer to Question #73. S is for entropy, Q is
for charge," Am. J. Phys. 68(8), 691 (2000); online at
<http://ojps.aip.org/journal_cgi/dbt?KEY=AJPIAS>.

2. James Clerk Maxwell, "A Treatise on Electricity and Magnetism"
(Clarenden, Oxford, 1873).

3. A. Etzioni and O. Etzioni, "Communities: Virtual vs. Real,"
editorial, Science 277, 29 (1997) and (as befits the theme) on-line
at < http://www.gwu.edu/~ccps/E30.html >: "Virtual on-line communities
complement and reinforce "real" off-line communities and have several
advantages over the latter, e.g.,
(a) easy communication over national borders and time zones;
(b) inclusion of homebound (aged, ill, or handicapped) people;
(c) accommodation of more individuals than off-line meeting rooms;
(d) STRONG MEMORIES;
(e) high safety;
(f) allowance for exploration of new relationships and identities - as
documented by MIT's Sherry Turkle (see, ref. 4 below ); and
(g) indifference to physical appearance and off-line identity.

(In regard to "g,' a famous cartoon by Peter Steiner (see at
<http://www.cartoonbank.com/index.asp> shows a dog turning his head
from a computer screen and saying to another dog "On the internet
nobody knows you're a dog.") Indeed, who would take this post
seriously if it were known that the author is a bloodhound?

For more information on A. Etzioni's work see his web page at
<http://www.gwu.edu/~ccps/etzioni/index.html>.

4. S. Turkle, "Life on the Screen: Identity in the Age of the
Internet" (Simon & Shuster, 1995). For more on Turkle's work see her
web page at <http://web.mit.edu/sturkle/www/>.

5. J. Roschelle and R. Pea, "Trajectories from Today's WWW to a
Powerful Educational Infrastructure," Educational Researcher,
June-July 1999, 22-25, 43: "tools for learning communities must move
beyond forums for exchanging tidbits and opinions, to structures
which rapidly capture knowledge-value and foster rapid accumulation
and growth of a community's capability . . . tools to allow
contributors to share partially completed resources, and enable
others to improve upon them. A related direction is 'knowledge
mining' - discovering efficient processes for quickly aggregating and
collating the knowledge of a community on a particular topic." See
also ref. 6.

6. Roy Pea, "New Media Communications Forums for Improving Education
Research and Practice," in E. Condliff Lagemann and L.S. Shulman
(eds.) Issues In Education Research (Jossey-Bass, 1999); an excerpt
is on the web at <http://www.sri.com/policy/ctl/html/context5.html>.

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
APPENDIX
TWELVE POSTING SUGGESTIONS (R.R. Hake, 4/30/01):

1. SEARCH THE ARCHIVES OF THE LIST BEFORE ASKING A QUESTION OR
OPENING A NEW TOPIC (it may already have been discussed ad nauseam).

2. Use subject headings that accurately convey the topic of the post
(especially important for following threads in archive searches).

3. INDICATE THE SPECIFIC POST (date, discussion list, title, and name
of poster) TO WHICH YOU ARE RESPONDING.

4. When convenient, give instructions for accessing SETS of
referenced posts by Subject and/or Author and/or time in the
archives, e.g., "see the archives for posts with Subject 'Monthly
Technical Posting,' by 'MacIsaac,' 'from 2000'."

5. QUOTE OR REPEAT ONLY THE RELEVANT SECTIONS OF THE POST TO WHICH
YOU ARE RESPONDING AND NOT THE COMPLETE POST (AS MAY OCCUR WHEN YOU
HIT THE "REPLY" BUTTON).

6. NEVER send attachments to lists (they will often appear as pages
of code and may introduce viruses).

7. NEVER send messages in HTML or "enriched text." Some subscribers
may receive your message interspersed with HTML tags so that it is
almost impossible to read.

8. GIVE COMPLETE AND ACCURATE SETS OF REFERENCES.

9. Give URL's as <http://www......> (note the angle brackets) so that
they will survive line breaks and are hot-linked [note that
<www.....> is NOT hot-linked]. CHECK ANY URL'S IN YOUR MESSAGE TO BE
SURE THEY WORK.

10. Use a BRIEF signature that includes your affiliation, mailing
address, and (if you have one) your homepage.

11. Carefully proofread your posts prior to posting - check English,
spelling (especially NAMES), and grammar; remove all ambiguous and
offensive material.

12. Pause a few minutes to review your post and THINK before you hit
the SEND button.