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Peter B
2001-Nov-29, 12:25 AM
What's the difference between "pericynthion" and "perilune", if any?

Most would be familiar with the PC+2 burn of Apollo 13 (2 hours after pericynthion), but the book "The Race" mentions use of perilune and apolune for orbits around the moon, which seem to be correct terms.

Anyone help, please?

David Simmons
2001-Nov-29, 01:48 AM
The difference seems to be highly technical, maybe even picayune.

This site Perilune (http://www.lineone.net/dictionaryof/difficultwords/d0009842.html) gives perilune as the low point of the orbit of a moon orbiter.

This site Pericynthion (http://www.hq.nasa.gov/office/pao/History/SP-4009/v2p1b.htm) says they both mean the same thing except "perilune" is reserved for an obiter that is launched from the moon, while "pericyntion" is for lunar orbiters launched from elsewhere. See the entry after January 16, 1963 in this reference.


<font size=-1>[ This Message was edited by: David Simmons on 2001-11-28 20:53 ]</font>

Peter B
2001-Nov-29, 03:57 AM
Thanks for that David.

I suppose my point is that it's easy to work out which object perilune relates to (La Luna, obviously), while "pericynthion" means closest approach to...Cynthia...? (I have a vague image of a Gary Larson-esque female on the far side of the Moon, looking uncomprehendingly at those spacecraft as they shoot overhead, so near and yet so far.)

However, the existence of two terms, with potentially slightly different meanings, suggests that if an alien spacecraft took up orbit around the Earth, the low point of its orbit wouldn't be its perigee, but something else.

(Idle thoughts on a quiet Thursday afternoon - it's 4.30pm here in Canberra.)

David Hall
2001-Nov-29, 12:23 PM
Talk about splitting hairs. I'd never heard of either of these terms before, but now I have to remember two different ones based on such a trivial difference in meaning? /phpBB/images/smiles/icon_rolleyes.gif

So are there other terms that have the same difference in meaning? What about orbiters of Mars? Titan? Ceres? If I could launch a Mars orbiter from Mars would it have different terms from one shot from the Earth? Sheesh. /phpBB/images/smiles/icon_razz.gif /phpBB/images/smiles/icon_biggrin.gif /phpBB/images/smiles/icon_razz.gif

ToSeek
2001-Nov-29, 01:52 PM
I believe the generic terms are "periapsis" and "apoapsis," which apply to an orbit around any body.

I have also heard the terms perihelion and aphelion (for solar orbits) and perijove and apojove (for Jupiter orbits).

This from Jonathan [McDowell's] Space reports:



I can't believe I did this - thanks to alert reader Mike Grabois who pointed out my use of 'perigee' and 'apogee' when I meant to type the generic terms 'periapsis' and 'apoapsis'. In the 1960s-70s the planet-specific terms - in this case I believe `periares', `apoares' - had a brief popularity, although the difficulty of coming up with new terms for each new body (how about `perieroticon' for NEAR about Eros? /phpBB/images/smiles/icon_smile.gif) has led to the generic terms winning out for the most part. Exceptions are perihelion/aphelion which is well-hallowed in use for the Sun; perijove and apojove which seem to be in common use for Galileo at Jupiter; in astronomy, periastron/apastron and perigalacticon/apogalacticon are sometimes seen for stars and galaxies respectively.


From http://hea-www.harvard.edu/~jcm/space/jsr/back/news.467

Argos
2001-Nov-29, 02:35 PM
Cynthia is the other name for Diana, Roman goddess for the Moon (besides presiding the huntsmen lives), who was born in the Mount Cynthus. Cynthian is an adjective relative to the Moon. You can say "I'm in Cynthian approach", meaning (rather pedantically) that you are approaching the Moon. This seems to make the distinction perilune/pericynthion relevant only to the scholars.



(Idle thoughts on a quiet Thursday afternoon - it's 4.30pm here in Canberra.)


How's the late spring going down under? Here in the country of Samba is going hot (meteorologically speaking) like hell.



<font size=-1>[ This Message was edited by: Argos on 2001-11-29 11:13 ]</font>

Argos
2001-Nov-29, 02:38 PM
So are there other terms that have the same difference in meaning? What about orbiters of Mars? Titan? Ceres?


What about perimartes (close to mars), periveneris (close to Venus), perichronos (close to Saturn), perijoves (close to Jupiter), peripluto...

Actually I don't think these words exist. But I can assure you that they are written in the Caesar's Latin.

<font size=-1>[ This Message was edited by: Argos on 2001-11-29 17:53 ]</font>

David Simmons
2001-Nov-29, 03:59 PM
On 2001-11-29 09:35, Argos wrote:

This seems to make the distinction perilune/pericynthion relevant only to the scholars.



Hey, Language PhD's are being continuously created. There has to be something for them to do. /phpBB/images/smiles/icon_wink.gif


<font size=-1>[ This Message was edited by: David Simmons on 2001-11-29 11:01 ]</font>

Argos
2001-Nov-29, 04:18 PM
On 2001-11-29 10:59, David Simmons wrote:

Hey, Language PhD's are being continuously created. There has to be something for them to do. /phpBB/images/smiles/icon_wink.gif


<font size=-1>[ This Message was edited by: David Simmons on 2001-11-29 11:01 ]</font>


That's true, my friend!:lol:

<font size=-1>[ This Message was edited by: Argos on 2001-11-29 11:20 ]</font>

Wiley
2001-Nov-29, 04:44 PM
On 2001-11-29 10:59, David Simmons wrote:


On 2001-11-29 09:35, Argos wrote:

This seems to make the distinction perilune/pericynthion relevant only to the scholars.



Hey, Language PhD's are being continuously created. There has to be something for them to do. /phpBB/images/smiles/icon_wink.gif


<font size=-1>[ This Message was edited by: David Simmons on 2001-11-29 11:01 ]</font>


As a logophile, I appreciate the distinction. Granted, knowing the difference between a Big Mac and a Whopper is much more useful, but not as much (pretentious) fun. /phpBB/images/smiles/icon_smile.gif

Slightly off topic, but ...
When I lived in Atlanta, I had the opportunity to see the world's largest flower bloom. The name of this flower is Anthrophallus Titanus. Those of you who know the difference between perihelion and perijove can probably guess how this name translates.

Wally
2001-Nov-29, 05:08 PM
On 2001-11-29 11:44, Wiley wrote:


On 2001-11-29 10:59, David Simmons wrote:


On 2001-11-29 09:35, Argos wrote:

This seems to make the distinction perilune/pericynthion relevant only to the scholars.



Hey, Language PhD's are being continuously created. There has to be something for them to do. /phpBB/images/smiles/icon_wink.gif


<font size=-1>[ This Message was edited by: David Simmons on 2001-11-29 11:01 ]</font>


As a logophile, I appreciate the distinction. Granted, knowing the difference between a Big Mac and a Whopper is much more useful, but not as much (pretentious) fun. /phpBB/images/smiles/icon_smile.gif

Slightly off topic, but ...
When I lived in Atlanta, I had the opportunity to see the world's largest flower bloom. The name of this flower is Anthrophallus Titanus. Those of you who know the difference between perihelion and perijove can probably guess how this name translates.




Hmmm. . . phallus Titanus huh. Must be a joke in there somewhere, but doubtful that Phil would allow it to remain!

Just curious, is this the flower that smells like rotten meat?

Wiley
2001-Nov-29, 06:48 PM
On 2001-11-29 12:08, Wally wrote:

Hmmm. . . phallus Titanus huh. Must be a joke in there somewhere, but doubtful that Phil would allow it to remain!

Just curious, is this the flower that smells like rotten meat?



'Tis indeed the flower that reeks of decaying flesh.

The Curtmudgeon
2001-Nov-29, 07:41 PM
Okay, I've just come from giving Greek lessons on another thread, so here's my feeble (and boy, is it feeble! /phpBB/images/smiles/icon_smile.gif ) attempt to provide sufficient adjectival forms to bore the mightiest. Some of these may actually be correct (i.e., in use at one time or another by Real Astronomers), and some might be close; more likely, nobody but me would have thunk of 'em. And I'm a purist about meaningless things like this: no Latin roots here, if you please! /phpBB/images/smiles/icon_biggrin.gif

peri-, apo- combined with:


-helion = Sun (Gk. Helios)
-hermion = Mercury (Hermes)
-krition = Venus (Kritias, older name for Aphrodite)
-selenion = Moon (Selene was the actual Greek goddess of the Moon, although the Moon was also associated with Artemis/Cynthia)
-areion = Mars ([i]Ares)
-zeuion = Jupiter (Zeus)
-kronion = Saturn (Kronos, not Chronos as sometimes given; k [kappa] and ch [chi] are different and unrelated letters in Greek)
-ouranion = Uranus (Ouranos is the more usual ancient Greek spelling)
-poseidion = Neptune (Poseidon)
-hadion = Pluto (Hades in Greek was the name for both the god and his dwelling place)
-demetrion = Ceres (Demeter)
-titanion = Titan (Titanos actually is the Greek form, for once!)
-ioion = Io (couldn't resist; most of the other satellites [excepting Uranus'] are Greek in name, so the derivations should be obvious)
-sitchion = Nibiru /phpBB/images/smiles/icon_rolleyes.gif /phpBB/images/smiles/icon_biggrin.gif /phpBB/images/smiles/icon_rolleyes.gif


The ("Timonian" could be Greek for...) Curtmudgeon

Argos
2001-Nov-29, 10:58 PM
The name of this flower is Anthrophallus Titanus. Those of you who know the difference between perihelion and perijove can probably guess how this name translates.


At a glance it looked like the name was Anthropophallus Titanus. That would be naughty!

Peter B
2001-Nov-29, 11:37 PM
Oh you beauty. /phpBB/images/smiles/icon_biggrin.gif The closest approach to Io is the Periioion, and furthest point is Apoioion. Any other English words with five successive vowels?

And just to split the thread, yes it's starting to warm up here in Canberra. Summer starts tomorrow (1 December) here in Australia, and we might just start getting some summery weather.

David Hall
2001-Nov-30, 04:47 AM
Whoo, opened up a can of worms here. Thanks everyone for a very enjoyable thread.

Thanks ToSeek, for the actual non-specific terms. Your quote was great. I almost guessed at periareion myself, but I thought I would save myself the trouble of looking foolish if I was wrong. Leave it to others to say it anyway. /phpBB/images/smiles/icon_smile.gif

My WordWeb dictionary program lists perigee, perihelion, perijove, perilune, and periselene as types of periapsis. Of course the antonyms are included as well.

Curtmugeon, your list is a marvel. Quite good. I hope someday people will be using these terms on a regular basis. (Think about the implications of that for a moment. /phpBB/images/smiles/icon_smile.gif)

Irishman
2001-Nov-30, 02:02 PM
Wiley said:

The name of this flower is Anthrophallus Titanus. Those of you who know the difference between perihelion and perijove can probably guess how this name translates.

Wally replied:

Hmmm. . . phallus Titanus huh. Must be a joke in there somewhere, but doubtful that Phil would allow it to remain!

Mel Brooks already did that joke, in "History of The World, Part I".

SeanF
2001-Nov-30, 02:22 PM
On 2001-11-30 09:02, Irishman wrote:

Mel Brooks already did that joke, in "History of The World, Part I".


Isn't that in "Monty Python's Life of Brian"? I'm pretty sure I remember Michael Palin saying the name . . .

Donnie B.
2001-Nov-30, 02:25 PM
Mel Brooks already did that joke, in "History of The World, Part I".


So did Monty Python, in "Life of Brian". Check out the names of characters played by Graham Chapman:

http://us.imdb.com/Credits?0079470

GrapesOfWrath
2001-Nov-30, 03:04 PM
On 2001-11-29 17:58, Argos wrote:
At a glance it looked like the name was Anthropophallus Titanus. That would be naughty!


I'm confused. The "anthropo" in anthropophagus means "man" not "eating." It is the "phagus" part that means eating. Anthrophallus would be naughty enough, except it is also an error, I think. Amorphophallus titanum (http://www.washington.edu/newsroom/news/1999archive/07-99archive/k070999a.html) is the correct name. Who knows what that means, but I wouldn't want to be one. Heres a Amorphophallus titanum webcam (http://arum.doit.wisc.edu/).

Curtmudgeon

I think you should add -lune and -gee to your list, just for completeness.

_________________
rocks

<font size=-1>[Fixed webcam link]</font>

<font size=-1>[ This Message was edited by: GrapesOfWrath on 2001-11-30 10:06 ]</font>

David Simmons
2001-Nov-30, 03:15 PM
On 2001-11-30 10:04, GrapesOfWrath wrote:

Amorphophallus titanum[/url] is the correct name. Who knows what that means, but I wouldn't want to be one. Heres a Amorphophallus titanum webcam (http://arum.doit.wisc.edu/).



"Amorpho" is probably derived from the Greek "morphe" meaning "form" hence the latest computer generated verb "to morph" or "change form."

So "amorphophallus" should mean "having a phallic form." See GrapesOfWrath's link for further demonstration.

The prurient in the group can follow up "phallic" on their own.

<font size=-1>[ This Message was edited by: David Simmons on 2001-11-30 10:18 ]</font>

GrapesOfWrath
2001-Nov-30, 03:20 PM
Yes, I knew that much, but "amorphous," with the a (from Greek, a-, without) in front, means "Lacking definite form; shapeless" (Ame. Her. Dic.), so it's still a puzzle to me.

Wiley
2001-Nov-30, 05:23 PM
On 2001-11-30 10:04, GrapesOfWrath wrote:

I'm confused. The "anthropo" in anthropophagus means "man" not "eating." It is the "phagus" part that means eating. Anthrophallus would be naughty enough, except it is also an error, I think. Amorphophallus titanum (http://www.washington.edu/newsroom/news/1999archive/07-99archive/k070999a.html) is the correct name. Who knows what that means, but I wouldn't want to be one. Heres a Amorphophallus titanum webcam (http://arum.doit.wisc.edu/).



Thanks, O Great and Vengeful Grape. My memory is failing. Its been 4+ years since I saw the flower, and the "amorpho" changed "anthro" in my mind.

The name means "form of a big (just what you think)". Talk about activating your Wonder Twin's power. /phpBB/images/smiles/icon_smile.gif

For the prebloom flower, this name is pretty accurate.



<font size=-1>[ This Message was edited by: Wiley on 2001-11-30 12:31 ]</font>

David Simmons
2001-Nov-30, 05:27 PM
On 2001-11-30 10:20, GrapesOfWrath wrote:
Yes, I knew that much, but "amorphous," with the a (from Greek, a-, without) in front, means "Lacking definite form; shapeless" (Ame. Her. Dic.), so it's still a puzzle to me.


You are expecting, maybe, that the English language should be consistent?

"a" as a prefix can also mean "in such a state or condition as in 'afire'." It can also signify "in such a manner as in 'aloud'." Merriam-Webster Collegiate Dictionary

So in this case "amorpho" can be taken as "in the state or condition or in the manner of such-and-such a form," can't it?

GrapesOfWrath
2001-Nov-30, 05:48 PM
I still dunno. This webpage, What’s in a (Botanical) Name? (http://www.iconx.com/html/riffle_botanical_glossary.html), says amorphophallus breaks down into "without + form + male sexual organ". Amorphophallus is a genus, with other members (heh), so maybe the genesis of its name relates to one of them.

ObAstronomy: Zubeneschamali

The Curtmudgeon
2001-Nov-30, 06:59 PM
On 2001-11-30 10:04, GrapesOfWrath wrote:
Amorphophallus titanum (http://www.washington.edu/newsroom/news/1999archive/07-99archive/k070999a.html) is the correct name. Who knows what that means, but I wouldn't want to be one. Heres a Amorphophallus titanum webcam (http://arum.doit.wisc.edu/).

A-, not, anti-, lack of; morpho-, form, shape; phallus, uh-uh, yeah, that thing /phpBB/images/smiles/icon_smile.gif ;titanum, titanic, gigantic.

Gigantic shapeless whatchamacallit /phpBB/images/smiles/icon_biggrin.gif /phpBB/images/smiles/icon_rolleyes.gif


Curtmudgeon

I think you should add -lune and -gee to your list, just for completeness.

-Gee, yes, from Gaea or Ge, original Earth goddess. -Lune, no; I already said no Latin roots! /phpBB/images/smiles/icon_smile.gif

Some of that list, of course, was not original. Peri-/apo-helion, needless to say, is well-known. Although not in the peri-/apo- context, I have seen 'selenography' ("geography" of the moon) and 'areography' (ditto for Mars) used in serious texts before.

Of course, as shown by peri-/apo-lune and -jove, Real Astronomers (tm) are not restricted to Greek roots when coining new terms (and in general, we have a lot of English neologisms that have Greek roots with Latin prefices/suffices or vice versa) but "a foolish consistency is the hobgoblin of little minds," and although we're well past Hallowe'en hobgoblins are still fun to play with at times.

The (killing time when I ought to be working again) Curtmudgeon

Eroica
2004-May-07, 03:10 PM
The closest approach to Io is the Periioion, and furthest point is Apoioion. Any other English words with five successive vowels?
Queueing! 8)

JohnOwens
2004-May-07, 07:49 PM
The closest approach to Io is the Periioion, and furthest point is Apoioion. Any other English words with five successive vowels?
Queueing! 8)
Cooeeing!

George
2004-May-07, 09:32 PM
Hmmmm, ok. Back to related terminology... :)

What then is the closest ellipitical orbit point, to the Moon, of two "Moan Hoax" Woo-woo's forced into a Lunar orbit?


This stuff makes me hungry for some apple pie for some reason. :wink: