According to the Online Etymology dictionary (
http://www.etymonline.com/index.php?term=reflection):
reflection (n.)
<http://www.etymonline.com/index.php?term=reflection&allowed_in_frame=0>
[image:
Look up reflection at Dictionary.com]
<http://dictionary.reference.com/search?q=reflection>late 14c., reflexion,
in reference to surfaces throwing back light or heat, from Late Latin
reflexionem (nominative reflexio) "a reflection," literally "a bending
back," noun of action from past participle stem of Latin reflectere "to
bend back, bend backwards, turn away," from re- "back" (see re-
<http://www.etymonline.com/index.php?term=re-&allowed_in_frame=0>) +
flectere "to bend" (see flexible
<http://www.etymonline.com/index.php?term=flexible&allowed_in_frame=0>). Of
the mind, from 1670s. Meaning "remark made after turning back one's thought
on some subject" is from 1640s. Spelling with -ct- recorded from late 14c.,
established 18c., by influence of the verb.
So it seems not to be an American/British spelling divergence in this case
since both the original "reflexion" and the variant "reflection" have
co-existed on this side of the pond since the late 14th c. (and I don't
think there were any American English speakers around then!). Both forms
were in use in British English well before the European colonisation of
N.America in the early 17th c. .
Also Wiktionary (http://en.wiktionary.org/wiki/reflexion) says:
reflexion (n.)
From the Late Latin *reflexionem*, from *reflexio*; the variant
spelling *reflection* is due to influence from *correction*.
Cheers
-- Ian
On 8 July 2014 22:53, Boaz Shaanan <[log in to unmask]> wrote:
> I thought (I think I was told that way early during my PhD studies) that
> reflexion/reflection is a matter of British/American spelling. In fact
> Merriam-Webster Dictionary says just that:
> Definition of REFLEXION
> *chiefly British variant of* reflection
> <http://www.merriam-webster.com/dictionary/reflection>
>
> and the American Heritage and Oxford dictionaries agree on that too.
>
> Boaz
>
>
>
>
>
>
>
>
>
>
> *Boaz Shaanan, Ph.D. Dept. of Life
> Sciences Ben-Gurion University of the
> Negev Beer-Sheva
> 84105
> Israel
> E-mail:
> [log in to unmask] <[log in to unmask]> Phone: 972-8-647-2220 Skype:
> boaz.shaanan Fax: 972-8-647-2992 or 972-8-646-1710 *
>
>
>
>
>
> ------------------------------
> *From:* CCP4 bulletin board [[log in to unmask]] on behalf of Ian
> Tickle [[log in to unmask]]
> *Sent:* Wednesday, July 09, 2014 12:19 AM
> *To:* [log in to unmask]
> *Subject:* Re: [ccp4bb] question about powder diffraction
>
> Yes, the way I like to think of it as a double condition, the
>
>> reflection‐in‐a‐mirror condition *plus* the special condition imposed
>> by Bragg’s Law. This is why I often prefer the unfashionable spelling
>> “reflexion”.
>>
>> --
>> Ian ◎
>>
>
> Me too. Actually "reflexion" (but the verb is "reflect") is the
> original correct spelling (from Latin reflectere & reflexio); apparently at
> some point in its history it became misspelt due to a false analogy with
> "correct" & "correction" (Latin corrigere & correctio).
>
> Now back to the science! It's important to understand that a "powder"
> is not amorphous which would indeed give a continuous pattern: it's a bunch
> of micro-crystals in random orientations. Therefore a powder diffraction
> pattern is a single crystal pattern averaged over all orientations.
> Rotating the crystal does not change the Bragg angles of the spots, however
> it does change their angular positions so each diffracted beam is smeared
> out over conical surface. Each of these cones then projects as a circle on
> a flat area detector (of course in powder diffraction one would use a
> linear detector since it's not necessary to measure a complete circle).
>
> Cheers
>
> -- Ian
>
