10th Planet Discovered
 

[url]http://www.msnbc.msn.com/id/8760309/[/url]

If you visit Brown's website, you should find something not in the article...

I guess that depends on how you define a planet. The guys trying to do just this have been hard at it for 5 years without arriving at any consensus, so it would seem that despite what we might intuitively feel is the definition we would almost certainly be wrong.

Two things about this interest me though. The article says the plane of its orbit is at about 45 degrees to the rest of our planets, which would seem to imply that it must at some point cross the orbit of our planets, though a long way out. Also, does its distance from the sun fit in with the pattern of the others. I read somewhere that our planets are spaced at distances from the sun that are Fibonacci numbers of AU. Is that correct and does this new object fit in with that?

[QUOTE=Numbers]Two things about this interest me though. The article says the plane of its orbit is at about 45 degrees to the rest of our planets, which would seem to imply that it must at some point cross the orbit of our planets, though a long way out.[/QUOTE]

Actually, many scientists do not regard Pluto as a planet; and one reason is that the plane of Pluto's orbit is also inclined relative to the plane of the 8 "surefire" planets. However, this new "planet" is even more inclined.

[QUOTE=Numbers]Also, does its distance from the sun fit in with the pattern of the others. I read somewhere that our planets are spaced at distances from the sun that are Fibonacci numbers of AU. Is that correct and does this new object fit in with that?[/QUOTE]

I thnk I know what you're thinking of. Until the last few centuries, only 6 planets were known: Mercury, Venus, Earth, Mars, Jupiter and Saturn.

Today Kepler is mainly famous for his observation that planetary orbits are elliptical, rather than being made up of perfect circles. However, he also had other ideas about the solar system that are no longer taught today because they have turned out to be wrong. Being a strong believer in the "perfection of the heavens", Kepler developed a model of the solar system based on the five Platonic Solids. He imagined that the orbit of each planet contained inside the surface of spheres, which were nested inside Platonic solids.

Even with the limited (by modern standards) technology of his day, it was clear to the scientists of Kepler's day that this model of the universe was severely flawed, since it didn't fit observations particularly well. The correspondence between the ratios wasn't very precise. Although, Kepler attributed the "pattern" to divine intervention, we now know that it is due mainly to chance. In short, if you stare at a collection of data for long enough (especially a small collection of data), you can always "discover" a pattern.

For more information, you can Google search for something like: Kepler +"Platonic Solid"

Actually, it sounds like [URL=http://en.wikipedia.org/wiki/Bodes_law]Bode's Law[/URL], which "predicted" the existence of the asteroid belt. By that rule, Pluto should be the 8th planet (Neptune doesn't fit in at all), and the 9th planet should be around 77.2 AU from the sun, which doesn't fit especially well with 97 AU.

[quote=Numbers]The article says the plane of its orbit is at about 45 degrees to the rest of our planets, which would seem to imply that it must at some point cross the orbit of our planets, though a long way out.[/quote]It must at some point cross [i]the plane of[/i] the orbit of each other Sun-orbiting object, but that's true of all the planets, asteroids, comets, etc.

[quote]does its distance from the sun fit in with the pattern of the others. I read somewhere that our planets are spaced at distances from the sun that are Fibonacci numbers of AU. Is that correct and does this new object fit in with that?[/quote]Bode's Law, AKA Titius-Bode Law, is an example of the Strong Law of Small Numbers ([url="http://mathworld.wolfram.com/StrongLawofSmallNumbers.html"]http://mathworld.wolfram.com/StrongLawofSmallNumbers.html[/url]). As jinydu explained, Bode's (or Titius's or Christian Wolff's) formula has no real basis in physics.

What should they name the new planet? How about "Bob"?

:banana:

I'm partial to Persephone. Doesn't quite roll off the tongue the way "Bob" does though.

Did anyone hear that the minimum size of this rock is actually bigger than Pluto? If you call Pluto a planet, then you have a really hard time not calling this thing a planet. (Think size; orbit eccentricity, orientation; .....)

Perhaps another possibility is to eliminate the term "planet" from science altogether:

[url]http://www.space.com/scienceastronomy/050802_planet_definition.html[/url]

And it looks like Brown's webpage has undergone a major update:

[url]http://www.gps.caltech.edu/~mbrown/planetlila/index.html[/url]

[QUOTE=dominicanpapi82]Did anyone hear that the minimum size of this rock is actually bigger than Pluto? If you call Pluto a planet, then you have a really hard time not calling this thing a planet. (Think size; orbit eccentricity, orientation; .....)[/QUOTE]

Actually many scientists think it is almost impossible for this planet to be bigger than pluto due to other details about it.

[QUOTE=Jwb52z]Actually many scientists think it is almost impossible for this planet to be bigger than pluto due to other details about it.[/QUOTE]

Do you have a link? Brown is sure that this object is bigger than Pluto.

[QUOTE=Jwb52z]Actually many scientists think it is almost impossible for this planet to be bigger than pluto due to other details about it.[/QUOTE]
[quote=jinydu]Do you have a link? Brown is sure that this object is bigger than Pluto.[/quote]You two are talking about two different discoveries!! And it doesn't help any that many journalists share the same misunderstanding.

Confusingly, [b]on successive days two teams announced 3 different bright Kuiper Belt object (KBO) discoveries: 2003 EL61 (by Ortiz et al.), 2003 UB313 and 2005 FY9 (both by Brown et al.)[/b]. See the last table (near the bottom, under the subheading "What else is out there?") on page [url="http://www.gps.caltech.edu/~mbrown/planetlila/index.html"]http://www.gps.caltech.edu/~mbrown/planetlila/index.html[/url] .

2003 EL61 is smaller than Pluto. It was the first announced.

2003 UB313 is the one that's bigger than Pluto. It was announced a day after 2003 EL61 was announced, and is the one being called the "tenth planet" by those who are not confused by the multiple announcements.

2005 FY9 is smaller than Pluto, but brighter than 2003 UB313 because it's closer to us. Indeed, it's now the second-brightest (after Pluto) known KBO. (2003 EL61 is now the third-brightest known KBO, though it ranked as second-brightest for one day. 2003 UB313 is now the fourth-brightest known KBO, even though it's the largest, because it's farther away than the others.)

I read about this in one of the online news services, but Brown's webpage really make it sound like a mystery novel - nefarious rival astronomers prowling the web in black hats and trench coats, that sort of thing. :Unsure:

[QUOTE=ewmayer]I read about this in one of the online news services, but Brown's webpage really make it sound like a mystery novel - nefarious rival astronomers prowling the web in black hats and trench coats, that sort of thing. :Unsure:[/QUOTE]Well, astronomers are people, too. And discovering/naming a new planet of our own solar system is a [b][i]Very, Very Big Deal[/i][/b] in astronomy.

Following the announcement of the discovery of this record-size Kuiper Belt object, the NY Times ran an editorial ("Too Many Planets Numb the Mind", Aug. 2) arguing that with further such discoveries inevitable and possible quite numerous, Pluto's official status should be changed from its current one as the 9th and most-distant planet of the solar system, to that of the nearest large KBO. (The distinction is somewhat arbitrary, but considered strictly scientifically Pluto is definitely a KBO, and in key aspects quite different than the other 8 planets). Several readers responded, some quite passionately, all in defense of Pluto-as-a-planet. Here is my favorite of the replies:

To the Editor:

You say that "few in our culture want to memorize the names of 20 or more planets."

Several years ago I read that many children by the age of 3 can recognize up to 50 corporate logos. I decided that if my baby granddaughter could distinguish between McDonald's and Wendy's, she should be able to learn other things as well.

By the time she was 2½, she knew the names of the planets. We added play dough replicas of Quaoar, Sedna and now 2003 UB313 to her solar system mobile. We talk often about the amazing macro- and microcosmos into which she has been born.

I believe that if I nurture curiosity, appreciation and awe, she will never feel that she is just memorizing a list. With deep knowledge about her cosmic home, she should come to know the names of planets and other bodies - whatever their number - as easily as she can rattle off the names of Disney princesses.

Linda Peeno
Louisville, Ky., Aug. 2, 2005

This news is already over two weeks old, but I just noticed it: A paper has been submitted to the Astrophysical Journal:

[url]http://www.gps.caltech.edu/%7Embrown/papers/ps/xena.pdf[/url]

Brown's webpage states that it is currently being peer-reviewed.

has the name of this thing been released yet?

[QUOTE=E_tron]has the name of this thing been released yet?[/QUOTE]No, and won't be for quite a while. (Actually, "2003 UB313" is its official name/designation now, but that's not what you meant.)

1) Discoverers [i]propose[/i] names, but the International Astronomical Union ( [url="http://www.iau.org/"]http://www.iau.org/[/url] ) makes the decisions. Usually, the IAU will approve the discoverer's choice, but not always.

2) The IAU has established rules for naming objects in various categories. Thus, planetary satellites' names follow one set of rules, asteroids' names follow another set of rules, KBOs have still another set of naming rules, and so on.

3) However, the IAU has never established an official set of rules for naming planets in our own solar system (it has rules for extrasolar planets, but not solar planets). This has never been a problem until now, because the IAU's system had not yet been established at the time of the most recent prior solar planet discovery, Pluto in 1930. Now the size of 2003 UB313 makes it necessary for the IAU to make an official decision on the definition of "planet". It has already created an IAU Working Group for "Definition of a Planete" ( [url="http://www.iau.org/IAU/Organization/divcom/wg_2003_2006.html#DIII-004"]http://www.iau.org/IAU/Organization/divcom/wg_2003_2006.html#DIII-004[/url] ), but that group's work in still in progress.

4) Object 2003 UB313 will not be named until the IAU decides whether it's a planet or not, and that won't happen until the Working Group for Definition of a Planete establishes an official definition and the IAU approves that. Then there also has to be established an official set of naming rules for new Solar System planets.

5) Mike Brown has submitted his choice of name subject to the condition that 2003 UB313 is decided not to be a planet (in which case it'll be a KBO; Brown's choice fits the KBO naming rules). Brown won't reveal his choice until it's made official by IAU.

But if IAU decides that 2003 UB313 is a planet, Brown will need to choose another name that fits the to-be-decided IAU planet-naming rules.

Hackers exposed the findings
 

Did anybody happen to see this? OK, jinydu, this is old news, too.

[url]http://news.com.com/2061-11204_3-5814229.html[/url]

[QUOTE=cheesehead]5) Mike Brown has submitted his choice of name subject to the condition that 2003 UB313 is decided not to be a planet (in which case it'll be a KBO; Brown's choice fits the KBO naming rules). Brown won't reveal his choice until it's made official by IAU.

But if IAU decides that 2003 UB313 is a planet, Brown will need to choose another name that fits the to-be-decided IAU planet-naming rules.[/QUOTE]
[b]Correction:[/b] I should have labelled that section 5) as [b][i]my speculation,[/i][/b] not presented it as though it were known fact like my sections 1) through 4) above. In particular, I did and do not have actual knowledge that Brown submitted a name that fit the KBO naming rules. I recall having read something like that, but can't find it now -- it may have been someone else's speculation. Anyway, AFAIK Mike Brown has not stated what I attributed to him in my speculative section 5.

Indeed, upon further consideration of Brown's comments it seems to me that his opinion (at least his [i]public[/i] opinion) is firmly that 2003 UB313 [u]is[/u] a planet, so it would make sense that he has at least submitted a proposed planetary name to the IAU, perhaps along with a proposed KBO name.

[QUOTE=ekugimps][url="http://news.com.com/2061-11204_3-5814229.html"]http://news.com.com/2061-11204_3-5814229.html[/url][/QUOTE]It is unfortunate that some are writing about this as though (or at least hinting that) Mike Brown did something improper or unethical by not having announced the discovery earlier. AFAIK from all I've read, I agree with Brown that he was properly and ethically following standard scientific procedure.

Astronomy involves an extremely wide range of objects and events. Some discoveries, such as novae and supernovae, asteroids discovered just as they closely approach Earth, gamma-ray bursts, and comets crashing into Jupiter, need to be announced promptly so that others may make observations during the short time available before the events end or the objects become too faint to observe.

But other discoveries are of objects or phenomena that are long-lasting and relatively quiescent, for which it is not necessary to make prompt announcement in order to avoid losing valuable observations. 2003 UB313 is in this latter category. In such cases, it is entirely right, proper, and precedented that the discoverer be allowed to conduct careful study so as to be able to present as full and detailed a description as possible in his/her original announcement. without being "scooped" by someone else zipping in to glean some tidbits then basking in the glory of making a first announcement.

- - - -

I have read that the folks who complained that Brown was improperly "sitting" on his discovery were amateur astronomers who were accustomed to discovering transient stuff as in the first category above and did not have an appreciation of the differences in the proper ways of studying/announcing items in the two different categories.

There's nothing wrong or inferior about being an amateur in astronomy. Many observations and discoveries are more suited to the circumstances of amateurs than to those of professionals.

(I am proud to have been an amateur astronomer who was at age 14 able to contribute my first teeny bit of scientifically-worthwhile observation -- of the December 1963 total lunar eclipse -- which was acknowledged in a leading astronomy magazine, which really impressed my ninth-grade biology teacher.

There remain many things an amateur astronomer, even a relative beginner, can valuably contribute.)

Yet another new twist to the story:

[url]http://news.yahoo.com/s/ap/20051002/ap_on_sc/new_planet_moon;_ylt=AlZ2UzFvbTiBC4uax5Po0A.s0NUE;_ylu=X3oDMTA3MzV0MTdmBHNlYwM3NTM-[/url]

And for some unknown reason, it seems that the (proposed?) name of the "planet" has now been made public.

[QUOTE=jinydu]And for some unknown reason, it seems that the (proposed?) name of the "planet" has now been made public.[/QUOTE]"Xena" isn't the proposed official name; it's just an informal nickname that has never been a secret. :-)

It's only natural that many journalists are going to use the nickname "Xena" instead of the official temporary designation "2003 UB313".

[quote=cheesehead]There remain many things an amateur astronomer, even a relative beginner, can valuably contribute.[/quote] You mean like the guy in Illinois who has applied to the IAU for status as a planet ?
In his application he allegedly said, “I’ve put on a few pounds these past couple of years, but I’m clearly below the limiting mass for thermonuclear fusion, and I orbit the sun, obviously, so technically I qualify.”

Only in America :wink:

[QUOTE=cheesehead]There remain many things an amateur astronomer, even a relative beginner, can valuably contribute.)[/QUOTE]If you want NASA's explanation of the type of lunar eclipse observation I made in December 1963 [i]and which can still be a valuable contribution by amateur astronomers[/i], see "Crater Timings During Lunar Eclipses" at [url="http://sunearth.gsfc.nasa.gov/eclipse/OH/crater/Crater.html"]http://sunearth.gsfc.nasa.gov/eclipse/OH/crater/Crater.html[/url]

Perhaps you're wondering about the scientific importance. It provides a way to measure the opacity of Earth's atmosphere. When hundreds of amateurs' timings are statistically analyzed, the averages provide a way to calculate how much sunlight was absorbed by dust in the Earth's atmosphere as that light skimmed through on its way to the Moon.

Among other things, this can be used in predicting global warming.

In December 1963, there had just been a large volcanic eruption that sent vast amounts of ash and dust into the air. Scientists knew that would increase opacity, but eclipse crater timing is a method of quantitatively measuring how much.

10th Planet Discovered.
 

[QUOTE=cheesehead]"Xena" isn't the proposed official name; it's just an informal nickname that has never been a secret. :-)

It's only natural that many journalists are going to use the nickname "Xena" instead of the official temporary designation "2003 UB313".[/QUOTE]
:unsure: Asfaik it is now officially declared the name is Zena as its more practical than an 'insignifcant' number which will not remain for long in memory except for number freaks.
Whats more they have now found a moon encircling it and named it Gabrielle!
Mally :coffee:

10th Planet Discovered.
 

FYI: :rolleyes:
The Indian Vedic scholars had theorised 10 planets centuries ago.
The extra planet named Rahu plays an important part in their astrological zodiacs :whistle:
Mally :coffee:

[QUOTE=mfgoode] Asfaik it is now officially declared the name[/quote]No, "Xena" is an [u]un[/u]official name. As I explained above, the [u]official[/u] name will be decided by the International Astronomical Union.

[quote]is Zena as its more practical than an 'insignifcant' number which will not remain for long in memory except for number freaks.[/quote]I agree that many people will use the nickname "Xena" for now; that doesn't make it the official name.

[quote]Whats more they have now found a moon encircling it and named it Gabrielle[/QUOTE]Again, an unofficial nickname, not an official name, that will be popularly used for now.

It's in the news again!

[QUOTE=clowns789]It's in the news again![/QUOTE]

Really? Where?

Pluto has had an airing in this thread as well as the new "planet" and I wonder if it means this:
[url]http://au.news.yahoo.com/060120/2/xnr2.html[/url]

New information on the "10th planet":

[url]http://sciencenow.sciencemag.org/cgi/content/full/2006/127/1[/url]

10th Planet Discovered.
 

:smile: here is some more jen on the rocky planet discovered. Note the method of discovery,-micro-lensing- which is an entirely new procedure to the discovery of future planets.

[url]http://www.space.com/scienceastronomy/060125_smallest_planet.html[/url]
Mally :coffee:

Stay tuned for an announcement ...
 

The International Astronomical Union will hold its 26th General Assembly in Prague, Czech Republic, August 14-25. See [URL="http://www.astronomy2006.com/"]http://www.astronomy2006.com/[/URL] for details.

Note (on [URL="http://www.astronomy2006.com/science-business-meetings.php"]http://www.astronomy2006.com/science-business-meetings.php[/URL]) that the Committee on Small Bodies Nomenclature (CSBN) and the Working Group Planetary System Nomenclature (WGSN) both meet on August 23. The WGSN morning meeting would be a likely forum for announcing an official ruling on the definition of "planet". That day's lunch would then be convenient for attendees' speculation about revelation, during the early afternoon CSBN meeting, of a permanent name for the object currently designated 2003 UB313.

8 planets?
 

I believe pluto is , as the 'borderline' defining case has after a wasted 70 years, been eliminated. Sound like a case of eat cake and don't dot any
local 'I's.
I would like to see a full report on the influence of pluto in the solar system
in the past 300 years, including whether its center of gravity with the sun lies
outside the sun, before giving the astro first , the benefit of our planets
acceptance.
If they haven't answered whether pluto is in fact a 'border' defining body,
or not , they are negligent.
Certainly, we have all known, that it was not part of the solar dynamo, all
along. But not a planet of the sun?
Was its summer unfelt on earth?
Of course when things get too big , the little guys are eliminated.This time
its a planet.Hogwash.

[quote=David John Hill Jr;85706]after a wasted 70 years,[/quote]In what respect do you think the time has been "wasted"?

Astronomers have acquired a great amount of knowledge about planets since Pluto's discovery, and now have a much more thorough understanding of the range of planetary properties than they did in 1930. For certain technical reasons, it became neccessary for the IAU to create a formal definition of "planet" for use in certain astronomical contexts where the traditional informal definition did not suffice, and they have now done so.

There are other examples in science in which technical definitions of certain terms have had to be created because the common informal definitions became inadequate for particular contexts, and we're getting along just fine with those distinctions.

[quote]I would like to see a full report on the influence of pluto in the solar system in the past 300 years, including whether its center of gravity with the sun lies outside the sun,[/quote]The Sun-Pluto barycenter is always within the Sun.

IIRC, all other Sun-planet barycenters except Sun-Jupiter also are always within the sun.

[quote]If they haven't answered whether pluto is in fact a 'border' defining body, or not , they are negligent.[/quote]Why do you think that omission implies negligence -- within professional astronomy, that is?

[quote]But not a planet of the sun?[/quote]Well, you're free to continue calling Pluto a "planet" without qualification, if you so wish. You'll encounter no real trouble doing so except within certain IAU committee proceedings. Have you ever attended an IAU convention or committee meeting?

[quote]Was its summer unfelt on earth?[/quote]Basically, yes, it was unfelt.

[QUOTE=cheesehead;85769]In what respect do you think the time has been "wasted"?

Astronomers have acquired a great amount of knowledge about planets since Pluto's discovery, and now have a much more thorough understanding of the range of planetary properties than they did in 1930. For certain technical reasons, it became neccessary for the IAU to create a formal definition of "planet" for use in certain astronomical contexts where the traditional informal definition did not suffice, and they have now done so.[/QUOTE]
Ceres was called a planet for ~50 years.

From: [URL="http://en.wikipedia.org/wiki/1_Ceres#Status"]http://en.wikipedia.org/wiki/1_Ceres#Status[/URL]
Ceres was assigned a planetary symbol, and remained listed as a planet in astronomy books and tables (along with 2 Pallas, 3 Juno and 4 Vesta) for about half a century until further asteroids were discovered. Ceres turned out to be disappointingly small for a planet, showing no discernible disc, so Sir William Herschel coined the term "asteroid" ("star-like") to describe it.

This was reasonable. Cylde Tombaugh's widow stated that, although he was sure at the time that Pluto was a planet, that he would be fine with the current decison.

One thing that I have noticed regarding the news articles is that although lots of attention was paid to the fact that Pluto is no longer officially considered a planet, there is little to no reporting about the new definition of a planet, which in my opinion is far more important news scientifically.

The negligent inference....
 

I agree that on macro systems pluto would be too small.Hence in an attempt
to align with searching the universe (other than our local solar system)
calling pluto sized objects, planets ,is ludicrous.
I might say , that the re-definition for Pluto inter alia discoveries IS
important . Perhaps they could waite for more detail ---it looks like for
the moment that the 'moon' of pluto is twice a planet, of at times-our sun,
and pluto. I would like to read the detail on this aspect.When the
Nasa probe gets there in 2015, a better idea might be forthcoming, whatever
a defined object it will be examining.
Wasted? Take heart, by definition, the pope once threw away 10 days to get from Julian to Gregorian.
Funny it was in 1976 I first noticed a deep shadow in the skies, followed a few years by whiteness that was cloudless.
Yellow or white skies without much blue,and in fact green has only now begun to get back to previous standards on most occassions.
Putting pollution the main culprit aside, as the main component,
I might ask where Pluto was and in what season?
When did it pass to this side (from sun) of Neptune, and pass back.
I believe 1999 was approximately the end of its full blown summer-29=1970.
This is a soap box and if I were at the meetings too, I would be sparcely
talking here. Signed H I (ll)

Parallel discussion on this:

[url=http://www.mersenneforum.org/showthread.php?p=86061]http://www.mersenneforum.org/showthread.php?p=86061[/url]

I think it is perfectly reasonable from a scientific standpoint to consider Pluto and all the other eccentric-orbited frozen slushballs beyond Neptune as a different category than "main sequence" planets. On the other hand, I think the IAU's latest set of official criteria for planethood, while better than the first proposal, is still deeply flawed.

Special to pluto
 

What I found interesting about pluto was the 1/2 size of charon.
This made me think it was right on the button of a 4 space definition' as
a single element defined.
In some way, this might show how the geometry,including distance increments defined, volume vs surfaces with density as appropriate, all then compared to the dynamic system(as we already define the forces).
The paint I have under hobbies vaguelly sets up some of the notions.
It is the outermost object and only one, that enjoins this with 2 to 3 dimensional aspect of the whole solar system, I find intriguing. ??????

This object has now been assigned an official name:

[url]http://www.space.com/scienceastronomy/060914_eris_named.html[/url]

[QUOTE=jinydu;87167]This object has now been assigned an official name:

[url]http://www.space.com/scienceastronomy/060914_eris_named.html[/url][/QUOTE]

Too bad Brown seems to like the official name - I was contemplating an anagrammatic headline along the lines of "Naming of 'Eris' causes sire's ire to rise."

When I first heard about the official name on last night's news I though they meant [url=http://en.wikipedia.org/wiki/Ares]Ares[/url], the ancient Greek god of war. That would've been a nice compromise, since Ares (as played by the late [url=http://imdb.com/name/nm0808963/]Kevin Smith[/url]) was a recurring character on the [url=http://imdb.com/title/tt0112230/]"Xena" TV series[/url].

[quote=ewmayer;87182]Too bad Brown seems to like the official name[/quote]He proposed it!

[quote]When I first heard about the official name on last night's news I though they meant [URL="http://en.wikipedia.org/wiki/Ares"]Ares[/URL], the ancient Greek god of war. That would've been a nice compromise, since Ares (as played by the late [URL="http://imdb.com/name/nm0808963/"]Kevin Smith[/URL]) was a recurring character on the [URL="http://imdb.com/title/tt0112230/"]"Xena" TV series[/URL].[/quote]But there's [I]an even better tie-in[/I] that was missed by the author of the AP article quoted on space.com:

As explained on SkyTonight.com's article "All Hail Eris and Dysnomia" at [URL]http://skytonight.com/news/home/3916126.html[/URL],
[quote=skytonight.com]The satellite, now called Dysnomia, is named for Eris's daughter, the goddess of lawlessness — a tribute, says Brown, to the actress who played Xena, Warrior Princess: Lucy Lawless.[/quote]
Furthermore, adding to the perfection of Brown's choice, [quote]the moon also follows another tradition for "dwarf planet" satellite names: Pluto's moon Charon was discovered in 1978 by James W. Christy, and the first syllable in Charon matches the first syllable in Christy's wife's name, Charlene. Brown's wife's name is Diane. "We're going to call the moon Di," says Brown.[/quote]

[QUOTE=cheesehead;87226]He proposed it![/quote]
Yeah, I saw a note about that in a an article I read later.

[quote]Furthermore, adding to the perfection of Brown's choice,[/QUOTE]

[quote=skytonight.com]The satellite, now called Dysnomia, is named for Eris's daughter, the goddess of lawlessness — a tribute, says Brown, to the actress who played Xena, Warrior Princess: Lucy Lawless.[/quote]

Ooh, that's good - that's very good. Xena still gets her props via an oblique route ([i]"...Reflecting the obliquity of the object's orbit, Brown said, with an icy stare..."[/i]) - very nice. Now we just need to figure out a way to sneakily name the next one after Bruce Campbell ([url=http://imdb.com/Find?select=Characters&for=Autolycus]"Autolycus"[/url] makes for a nice-sounding a nice-sounding astro-name) ... and before anyone in the peanut gallery starts to snicker, consider that the late musician Frank Zappa has an [url=http://en.wikipedia.org/wiki/3834_Zappafrank]asteroid named after him.[/url]

OK, I'm hapy now - thanks for the addtional info, Richard!

A matter of definitions
 

I would have preferred to agree with the redefinitions as:
Pluto-major asteroid as newly defined.Including a definition and word for space orientated C of G.

Current asteroid redefined planetary miniscoid,wherever occuring.
Hence if it turns out there are 16 or 17 major planets and asteroids(with 17 pluto in the middle) we wont have to go through depression to understand
that solids and space interconnect, with yet another definition rehassle.

7th Planet
 

[QUOTE=jinydu;58282]Actually, many scientists do not regard Pluto as a planet; and one reason is that the plane of Pluto's orbit is also inclined relative to the plane of the 8 "surefire" planets. However, this new "planet" is even more inclined.

[QUOTE=jinydu] I think I know what you're thinking of. Until the last few centuries, only 6 planets were known: Mercury, Venus, Earth, Mars, Jupiter and Saturn.[/QUOTE]

FYI: Indian astronomers/astrologers had postulated a seventh planet at the time of Christ called Ketu purely because it completed the mystical number 7, and its effects on humans, though they could not and did not observe it.
Such is the power of hypothetical conjecture!
Mally :coffee:

[QUOTE=mfgoode;88384]FYI: Indian astronomers/astrologers had postulated a seventh planet at the time of Christ called Ketu purely because it completed the mystical number 7, and its effects on humans, though they could not and did not observe it.[/QUOTE]For what it is worth, there are several other suggestions from various places that other cultures may have in fact seen Uranus. It is with in the limits of a sharp eyed person under very good conditions. As are some asteroids on occasion. I recently tried to see an asteroid, how ever I was not able to get to a good dark sky location during the best night.

I personally have seen Uranus with out optical aid a few years ago. In a dark sky location, I used averted vision to see it. It was in the exact right spot as the chart and it had just enough color to not be a star.

Colour
 

[QUOTE=Uncwilly;88400]For what it is worth, there are several other ....

I personally have seen Uranus with out optical aid a few years ago. In a dark sky location, I used averted vision to see it. It was in the exact right spot as the chart and it had just enough color to not be a star.[/QUOTE]
:cool:
Uncwilly how can you tell a star from a planet by its colour? I always thought that a sure fire way, is to see that a star blinks but a planet doesnt.
Mally

[QUOTE=mfgoode;88447]I always thought that a sure fire way, is to see that a star blinks but a planet doesnt.[/QUOTE]
A good rule of thumb, but not "sure fire".

"Blinking" (the technical term is scintillation) is caused by rapidly changing variations in the refractive index of the atmosphere between the source and the observer. Astronomers call these variations "seeing". The effect of the seeing is to change the apparent position of a point source from moment to moment.

If the changes occur more rapidly than the observer can see, the effect of seeing is to blur an image.

If the changes are slow enough, point sources appear to jiggle around and/or change intensity. For point sources, this gives rise to scintillation.

If the changes are slow enough the effect on sources depend on the relative sizes of the seeing, the source and the resolution of the detector. The limiting cases are:

1) source larger than the seeing, seeing smaller than detector resolution. In this case, the source appears blurred and slightly fainter.

2) source larger than the seeing, seeing larger than detector resolution. In this case, the image shows "boiling". You see this effect when looking through the hot air rising above a fire, for instance.

The amount of scintillation depends on the amount of churn in the atmosphere. From very good sites on very good nights the amount of scintillation can be indetectable with the naked eye, even for point sources like stars. On very bad nights, the seeing can be so bad that images of even non-point sources like planets can be moved around and so scintillate. I've experienced both extremes during my sessions of astronomical observing.

Paul

:rolleyes:
Very well explained Paul. I really have learnt something as many times I have experienced the effects you have mentioned in both extremes.

However you have not mentioned the colour of stars and planets and I agree my rule of thumb is not 'sure fire' except for the planet Mars the 'red' planet and Venus the silvery one.

The largest star Betelgeuse (the red giant) in the constellation Orion ? and the dog star Sirius about the brightest in the 'heavens' can also be distinguished by the naked eye.

Are there some other tips you can give as to tell by colour which is which?
Thank you
Mally :coffee:

[QUOTE=mfgoode;88459]However you have not mentioned the colour of stars and planets and I agree my rule of thumb is not 'sure fire' except for the planet Mars the 'red' planet and Venus the silvery one.
Are there some other tips you can give as to tell by colour which is which?[/QUOTE]
Uranus has blue-green hue to it. Jupiter and Saturn are toward the yellow part of the spectrum, which make them hard to distinguish from 'white' stars. Uranus has more hue than any other greenish object you are likely to see (except meteors.)

It is so faint of an object, that to see it with the unaided eye, one needs to use averted vision. Using a star chart (preferably with the location of the planet marked), find the appropriate area and lock into the stars that are closest. Then, begin to look off to the side. Pay attention to the area of vision off centre. If you are lucky, you will see the area light up with more stars. Dark adapted eyes and dark skies are important to see it. It is not bad to have a tree line blocking the horizon too.

[QUOTE=Uncwilly;88470]Uranus has blue-green hue to it. Jupiter and Saturn are toward the yellow part of the spectrum, which make them hard to distinguish from 'white' stars. Uranus has more hue than any other greenish object you are likely to see (except meteors.) [/QUOTE]

Venus is bright-white, but usually much brighter than any nearby stars. Mercury has a distinct metallic yellow-orange tint. Both of the above are always seen as distinct crescents from earth, and that gives them a somewhat non-stellar aspect, even to the unaided eye, which can't clearly make the crescent out.

On the subject of new extrasolar planets, nice [url=http://www.nytimes.com/2006/10/05/science/space/05planet.html?ref=science]article in today's [i]New York Times[/i][/url]:
[quote][b]New Planets Astound Astronomers in Speed and Distance[/b]
By DENNIS OVERBYE
[i]Published: October 5, 2006
[/i]
In the quest for other worlds beyond the solar system, astronomers keep turning up planetary systems with curiouser and curiouser traits. Yesterday, astronomers who use the Hubble Space Telescope announced that they had done it again, this time locating the fastest moving and most distant ever found.

Among a batch of new planets found by training the Hubble telescope on a small patch of sky far across the galaxy in Sagittarius are as many as five that orbit their home stars in less than a day.

One planet orbits its star, a so-called dwarf slightly smaller than the Sun, in only 10 hours, “the likes of which we had never seen before,” Kailash Sahu of the Space Telescope Science Institute, leader of the team that did the work, said, calling the results “a big surprise.”

By comparison, Mercury, swiftest in the our solar system, races around the Sun once every 88 days.

The new planets, all roughly the size of Jupiter, orbit so near their stars that they are heated to 3,000 degrees Fahrenheit, said Dr. Sahu, who noted that if their home stars were any bigger, the planets would simply evaporate.

The astronomers reported their results at a news conference at NASA headquarters in Washington, and their findings will be published in the journal Nature today.

The results, astronomers said, confirm that planets occur across the galaxy with the same frequency that they do in the neighborhood around the Sun.

“We’ve learned now that planets are everywhere,” said Alan P. Boss, a theorist at the Carnegie Institution of Washington, who was not part of the team.

“We’re beginning to be able to calculate how many Earths there are, how many planets are habitable, if not inhabited,” Dr. Boss added.

More than 200 planets have now been found around other stars.

In all, the project — known as Sagittarius Window Eclipsing Extrasolar Planet Search, or Sweeps — found 16 possible planets by monitoring the light from 180,000 stars over seven days, looking for the periodic dimming caused by the passage of a planet. The astronomers have calculated by statistical methods that at least seven of the bodies are actually planets.

So far, two have been confirmed as planets by measuring the wobbles in the starlight caused by the passing masses, using the giant eight-meter Very Large Telescope at the European Southern Observatory on Cerro Paranal, in Chile.

Dr. Sahu said those findings gave him confidence that at least a large fraction of the 16, if not all, are really planets.

Dr. Boss noted that astronomers now had found in the Milky Way all the types of planets that are in our solar system: gas giants like Jupiter, ice giants like Neptune and rocky “super-Earths” orbiting other stars. “Everything we were looking for,” he said, “just not in the arrangement we were looking for.”

As potential planets are found in increasing numbers, Dr. Boss said, the odds increase that planets and planetary systems like Earth’s would be found.

Mario Livio, an astronomer at the Space Telescope Science Institute and a member of Dr. Sahu’s team, said, “There are literally billions of planets in our galaxy.”[/quote]

[quote]As potential planets are found in increasing numbers, Dr. Boss said, the odds increase that planets and planetary systems like Earth’s would be found.[/quote]People seem to be very eager to find and Earth equivalent. I don't understand why that is. I think there must be many ways that life can be formed. Let's not expect all life to be formed like our own. There could be life on some of the small moons around Jupiter, they could be methane based and live underground unseen by our probes. Perhaps these distant planets also have life of "weird and stange" forms that would be truly alien to us in almost everyway.

[QUOTE=retina;88515]People seem to be very eager to find and Earth equivalent. I don't understand why that is.[/QUOTE]

Not wanting to feel like one is all alone (as a species) in an awfully big universe, perhaps? To understand more about the origin and ultimate fate of our own solar system? Natural human curiosity? I don't understand why you don't understand why that would be so, especially on a science/maths-oriented forum such as this, where one could similarly ask:

[i]"People seem to be very eager to find ever-larger prime numbers. Why is that?"[/i]

And in the case of the extrasolar planetary systems (unlike that of the primes), you have a combination of both scientific and a deeply human motives. I find it shocking that anyone would *not* be interested in knowing whether there is other intelligent life in the universe. That's probably the second-biggest of the Big Questions, right behind "where did the universe come from and what is its ultimate fate?"

[QUOTE=ewmayer;88512]Venus is bright-white, but usually much brighter than any nearby stars. Mercury has a distinct metallic yellow-orange tint. Both of the above are always seen as distinct crescents from earth, and that gives them a somewhat non-stellar aspect, even to the unaided eye, which can't clearly make the crescent out.[/QUOTE]
Your first two sentences are true. The third, unfortunately, is not. The paragraphs below describe what really happens.

Venus and Mercury each go through all the phases shown by the moon, from new (only the night hemisphere turned towards us) to full. Draw a diagram to see why.

The new phase is extremely hard to see, except when the planet passes in front of the Sun; both planets do this somewhat infrequently but by chance each has done it in recent years.

The full phase is also hard to see, not only because the planet appears extremely close to the Sun in the sky (or behind it) but because it is also the furthest away from us in its orbit and so smaller and fainter.

The brightness of the planet depends on their distance and the amount of the illuminated hemisphere we can see. The two quantities are anti-correlated (again, refer to the diagram you drew) and so the phase at maximum brightness is a fat crescent which is the compromise between distance and illumination. Venus is still easily visible to the naked eye when it's at half phase, strongly gibbous or a narrow crescent.

Some people, my wife included, can resolve the crescent of Venus with the naked eye when the planet is showing the thin crescent phase. I can see it only as distinctly non-stellar, perhaps elongated.


Paul

[QUOTE="ewmayer"]I find it shocking that anyone would *not* be interested in knowing whether there is other intelligent life in the universe.[/QUOTE]I would be disappointed to learn that someone is *not* interested in knowing whether there is other intelligent life in the universe. I [b]am[/b] very much interested to know. But looking for an Earth equivalent might be too narrow a search for life. With so much variety of planets and environments I expect there are more exotic forms of life aside from the carbon based DNA things like ourselves. I would not be too surprised if it is discovered that there is some type of tiny living life form on a moon around Jupiter. I would also be delighted by such a discovery. But I fear that a narrow search for things like water, 0-30 degrees C temperature, oxygen etc. would miss other possibilities for life of a different kind.

The versatility of carbon-based compounds surpasses that of compounds based on any other element. I've never seen any sincere serious attempt to show how a non-carbon-based system of living organisms could arise naturally. Yes, I've seen expositions of how, say, silicon-based life could operate, but never accompanied by an explanation of the silicon analog of how simple carbon compounds with H, O, N, S, P ... can join together to form proteins, lipids, amino acids, RNA and so on up the chain.

(IMHO the problem with silicon is that it's just too big to have as flexible a geometry in its bonds as carbon -- the angles just don't work as well in as many cases.

Anyone who thinks non-carbon-based possibilities are being unfarly ignored should try showing how hydrosilicons and silicohydrates are as versatile as hydrocarbons and carbohydrates. And the silicon analog of DNA is ...?)

[QUOTE=cheesehead;88604]'ve never seen any sincere serious attempt to show how a non-carbon-based system of living organisms could arise naturally.[/QUOTE]
I suggest you read [i]Dragon's Egg[/i] by Robert Forward.

A silicon-based lifeform seems to be arising here on Earth, though that may not meet your "naturally" criterion.

See, also, [i]The Black Cloud[/i] by Fred Hoyle. Though other authors have treated the theme better, IMO, that's the earliest source of which I'm aware.

Even if we limit our discussion to carbon-based life forms, we're not restricted to Earth-like environments. I remember a statement (I wish I could also remember by whom it was stated) that to an outsider Jupiter is the most likely place in the Solar system to contain life --- [i]including the Earth in the list of candidates[/i].

It's certainly not the case that almost pure water is the only usable solvent for the complex reactions that occur in carbon-based life forms. Impure ammonia, especially if the impurity is a few percent of water, will do very nicely. Cyanogen should work, though its use as a solvent in labs here on earth has been limited because of its toxicity to our kind of life. Personally, I seen no particular reason why impure sulphuric or nitric acids couldn't also serve. Some of our existing lifeforms are perfectly happy living at very low pH and any objections against the oxidizing powers and reactivity of those acids will be met by pointing out that free oxygen is viciously reactive. Come to that, water is also a very reactive chemical and is much more acidic than, say, ammonia.

Paul

[QUOTE="cheesehead"]Yes, I've seen expositions of how, say, silicon-based life could operate, but never accompanied by an explanation of the silicon analog of how simple carbon compounds with H, O, N, S, P ... can join together to form proteins, lipids, amino acids, RNA and so on up the chain.[/QUOTE]But that supposes that other life will be organised the same as us, perhaps things like proteins, RNA etc. are unique to Earth based life. Maybe the life can be of much simpler form using different available atoms and molecules. Or maybe the opposite with more complexity, I see a range of possibilities and arrangements.

For sure Earth type plants may allow us to hope for other carbon DNA water based life, but let's not be too narrow in the search and keep watching for other possibilities.

If there are all these other forms of life out there that are truly so vastly different from humans, how would we ever know they were alive? It's likely that such beings, or whatever you want to call them, would live in environments that humans could not enter and even if we could, we wouldn't be able to communicate as far as I understand it.

[QUOTE="Jwb52z"]... forms of life out there that are truly so vastly different from humans, how would we ever know they were alive?[/QUOTE]By their effect on the surroundings, and they would most likely be big enough to see.[QUOTE="Jwb52z"]... would live in environments that humans could not enter ...[/QUOTE]but we can use our eyes (telescopes, microscopes, cameras, probes etc.)[QUOTE="Jwb52z"]... we wouldn't be able to communicate as far as I understand it.[/QUOTE]sure we could, sound or EM waves (laser, radio etc.), depending on their actual level of sophistication. For microbe sized beings/things perhaps they would not be intelligent enough to communicate with [b]anything[/b], but larger aliens might be capable of some form of sound or sight.

If they are at the level of, say, a dog then we can do simple tests for intelligence and communication abilities with a probe, if they are at our level or higher then radio would probably be the communication channel of choice. If we ever get to a point of actually [b]meeting[/b] them then suitable arrangements could be made.

[QUOTE=retina;88798]For microbe sized beings/things perhaps they would not be intelligent enough to communicate with [b]anything[/b], but larger aliens might be capable of some form of sound or sight.[/QUOTE]I've already recommended [i]Dragon's Egg[/i] as a source of ideas about the form non-human intelligence may take.

An organism with a mass of 100kg living on the surface of a neutron star would be about the size of a grain of rice. Bigger than a microbe, certainly, but not a lot bigger.

A grain of rice is a few millimeters across. A microbe is a about 1% of that in each dimension, so something of that size at the density of neutron star crust would have a mass of around a tenth of a gram, or about that of an insect. Terrestial insects are not overly bright (not individually, though a bee, ant or termite colony appears to be about as intelligent as a good many individual birds and mammals) but they certainly show quite complex behaviour when interacting with each other and their environment.

Paul

[quote=xilman;88631]I suggest you read [I]Dragon's Egg[/I] by Robert Forward.[/quote]Does he specify how a non-carbon-based system of living organisms could arise naturally?

I've read lots of SF about alien lifeforms unlike our own, and that's fine. But what I'm asking for here is a sincere attempt to explain how the non-carbon-based life arises naturally, and I've never seen that.

[quote]A silicon-based lifeform seems to be arising here on Earth, though that may not meet your "naturally" criterion.[/quote]No, in that case the non-carbon-based form is created by a carbon-based lifeform, so doesn't count because that has the same prerequisite conditions (liquid water, etc.). Neither does it count if we were to find, e.g., a planet inhabited only by silcon-based life that was originated by carbon-based life that subsequently went extinct (perhaps exterminated by the silicon-based life, or perhaps not able to survive a change in environment).

[quote]Even if we limit our discussion to carbon-based life forms, we're not restricted to Earth-like environments.[/quote]Well, that depends on just how far the environment is not like Earth. +-80% gravity -- fine. +30-10 degrees K -- fine. Zero atmosphere -- I don't think so.

[quote]It's certainly not the case that almost pure water is the only usable solvent for the complex reactions that occur in carbon-based life forms.[/quote]100% pure water without contaminants won't do much to form those carbon compounds in the first place, of course ...

[quote]Some of our existing lifeforms are perfectly happy living at very low pH and any objections against the oxidizing powers and reactivity of those acids will be met by pointing out that free oxygen is viciously reactive.[/quote]Early Earth apparently had no free oxygen for at least a billion years, until photosynthetic organisms manufactured enough to more than saturate all ocean/land oxidation. But the question is: could those existing extremophiles have evolved without going through earlier stages of lifeforms not so happy at low pH?

- - - - - - -

[quote=retina]But that supposes that other life will be organised the same as us,[/quote]No, I specified silicon-based [I]analogs[/I] to the carbon stuff, not exact replacements. My "... can join together to form proteins, lipids, amino acids, RNA and so on up the chain" phrase refers to what carbon compounds can do, not (necessarily) to the silicon compounds.

[quote]perhaps things like proteins, RNA etc. are unique to Earth based life.[/quote]Fine, so the explanation will have to show what differences are feasible.

[quote]Maybe the life can be of much simpler form using different available atoms and molecules.[/quote]I think that feasible alternatives will require at least as much complexity as the carbon system.

[quote]Or maybe the opposite with more complexity, I see a range of possibilities and arrangements.[/quote]Can the range of possibilities in the non-carbon system match that of the carbon system? Not that I know of. Carbon is way close to the front of the periodic table. Bigger atoms are more cumbersome to combine.

[quote]For sure Earth type plants may allow us to hope for other carbon DNA water based life, but let's not be too narrow in the search and keep watching for other possibilities.[/quote]Until someone demonstrates (in serious detail, not just science fiction hand-waving) that the feasibility of a non-carbon alternative evolution is nonzero, I prefer placing my bets on places that can be possible winners.

[QUOTE="cheesehead"]No, I specified silicon-based analogs to the carbon stuff, not exact replacements. My "... can join together to form proteins, lipids, amino acids, RNA and so on up the chain" phrase refers to what carbon compounds can do, not (necessarily) to the silicon compounds.[/QUOTE]But perhaps other life doesn't need such an analogous system organisation.[QUOTE="cheesehead"]Can the range of possibilities in the non-carbon system match that of the carbon system?[/QUOTE]Perhaps not, but also parhaps a myriad of possibilities is not actually required, maybe just a few choice molecules can do the trick.[QUOTE="cheesehead"]Until someone demonstrates (in serious detail, not just science fiction hand-waving) that the feasibility of a non-carbon alternative evolution is nonzero, I prefer placing my bets on places that can be possible winners.[/QUOTE]I hope you are not expecting too much detail, else one might think it requires actually demonstating the alternative life for real in a lab.[QUOTE="cheesehead"][QUOTE]A silicon-based lifeform seems to be arising here on Earth, though that may not meet your "naturally" criterion.[/QUOTE] No, in that case the non-carbon-based form is created by a carbon-based lifeform, so doesn't count because that has the same prerequisite conditions (liquid water, etc.). Neither does it count if we were to find, e.g., a planet inhabited only by silcon-based life that was originated by carbon-based life that subsequently went extinct (perhaps exterminated by the silicon-based life, or perhaps not able to survive a change in environment).[/QUOTE]Actually that already happened here on Earth, the original environment 1BY ago was modified by earlier life and new life came along to replace it. One can argue that the new life was created by the previous life, so perhaps we and the non-natural life. So why not also we (humans) create life (loosely speaking), say, a robot, then the environment is modified and all that remains is the robots. Then aliens come along and visit Earth, see the robots and conclude that, through natural processes, robots can come into existence. If the aliens make a thorough survey and discover the extinct humans and then further the extinct life from 4BY ago they assume it is all just the expected progression of things. Perhaps they've already seen it happening in lots of places.

Great... Guess it's time to update my [URL="http://www.robotcombat.com/video_oldglory_hi.html"]robot insurance[/URL]. :alien:

[quote=retina;88878]But perhaps other life doesn't need such an analogous system organisation.[/quote]Show me a viable alternative.

[quote]Perhaps not, but also parhaps a myriad of possibilities is not actually required, maybe just a few choice molecules can do the trick.[/quote]Show me a realistic example.

[quote]I hope you are not expecting too much detail,[/quote]I've been arguing in the context of our having limited resources, too limited to squander on zero-probability searches, so what I want to see is enough detail to persuade me that diverting resources has a reasonable chance of succeeding.

Once we have an abundance of resources for life-hunting, so that we can easily afford to spend some on more speculative alternatives, I say fine, look for it in enviroments inimicable to Earth-type lifeforms (and I mean more inimicable than Mars or Europa, e.g.).

[quote]else one might think it requires actually demonstating the alternative life for real in a lab.[/quote]It requires demonstrating enough evidence for the alternative life to justify the expenditure of resources on the search for it.

[quote]Actually that already happened here on Earth, the original environment 1BY ago was modified by earlier life and new life came along to replace it.[/quote]Nope, doesn't count. It was the original environment in which life developed from non-life, and that's the development I'm talking about.

Of course, any ET life we find may also [I]currently[/I] live in a similarly altered environment, so of course our searches have to take that into account.

[quote]One can argue that the new life was created by the previous life,

< snip >

Perhaps they've already seen it happening in lots of places.[/quote]Perhaps. But I'm talking about the conditions necessary for evolution of life from non-life, not life from life.

[QUOTE=retina;88878]Actually that already happened here on Earth, the original environment 1BY ago was modified by earlier life and new life came along to replace it. One can argue that the new life was created by the previous life, so perhaps we and the non-natural life.[/QUOTE]That's a very acute observation, IMO.

The Earth suffered a massive runaway ecological catastrophe a gigayear or so ago. Some organisms started excreting a viciously reactive metabolic by-product. Almost everything else went extinct, though a few pathetic remnants still manage to cling on in especially protective environments. If those remnants had gone extinct, everything around us would be in the position of hypothetical robots that wiped out their biological precursors.

I refer, of course, to the invention of photosynthesis.
Paul

[QUOTE=cheesehead;88859]Well, that depends on just how far the environment is not like Earth. +-80% gravity -- fine. +30-10 degrees K -- fine. Zero atmosphere -- I don't think so[/quote]

It's not at all clear to me why gravity can't be much stronger than 1.8g without precluding life. It certainly can't have anything to do with the structural strength of organisms as there are many here on Earth that can't withstand even 0.2g without collapsing under their own weight. Consider jellyfish ...

Perhaps the argument is that very massive planets attract dense atmospheres, which is true in our solar system. Even assuming that dense atmospheres preclude the development of Iife, I see no reason why massive planets necessarily have dense atmospheres. Atmosphere-stripping mechanisms have been proposed by planetary geologists. For instance, a massive planet close in to a young star would have quite a lot of its initial envelope blown off when the star went through its T Tauri phase. Planetary collisions can also remove volatiles very effectively. The moon, for example, is very deficient in hydrogen, nitrogen and halogens compared with the Earth and Mars, though it has much the same fraction of oxygen as its neighbours. It's believed that these elements were boiled off when the moon was formed from the debris of the collision which formed it. The Earth subsequently collected its hydrogen from comets; it was massive enough to hold on to the water and ammonia so provided but the moon was not.

I accept that planets with <0.2g may have difficulty maintaining a dense atmosphere unless it is very cold. On the other hand, see my comments about atmospheric pressure below.

As for temperature ranges, I suggest you look up the phase diagram of water --- it is liquid at temperatures much higher than we see here on the Earth's surface (which is just as well, if you think about the conditions around thermal vents on the ocean floor). When performing that research, you should check the phase diagram of ammonia/water mixtures. They are liquid at temperatures much lower than zero Celsius.

I see no particular need for a dense atmosphere. An ocean kept liquid under an ice crust has nothing obviously wrong with it as a habitat. Think Europa if you want a concrete example.

[QUOTE=cheesehead;88859]]100% pure water without contaminants won't do much to form those carbon compounds in the first place, of course ...[/quote]My comment was intended to suggest [i]substantial[/i] contamination, of the order of several per cent or more of water in ammonia.

[QUOTE=cheesehead;88859]No, I specified silicon-based [I]analogs[/I] to the carbon stuff, not exact replacements. My "... can join together to form proteins, lipids, amino acids, RNA and so on up the chain" phrase refers to what carbon compounds can do, not (necessarily) to the silicon compounds.

Fine, so the explanation will have to show what differences are feasible.

I think that feasible alternatives will require at least as much complexity as the carbon system.

Can the range of possibilities in the non-carbon system match that of the carbon system? Not that I know of. Carbon is way close to the front of the periodic table. Bigger atoms are more cumbersome to combine.[/quote]Pure silicon chains are notoriously fragile, in much the way that pure carbon chains are not. Silicone chains, on the other hand, are robust and permit a very wide range of structures to be built up. For the non-chemists reading, a silicone chain is -Si-O-Si-O-Si-... with two free bonds at each Si where side-groups can be attached. The side-groups can be other silicone chains or most anything that we're familiar with from organic chemistry.

There are very serious proposals that life started in a silicone-like environment. This is the theory that clays had the correct chemistry and microstructure to bring together the first complex organic molecules where they could react to form more complex molecules. "Silicone-like" becauses clays are alumino-silicates with complex AlSiO structures.

Some other chemical systems also show complexity which appears to be comparable with that of organic chemistry. Only "appears" because much of the research goes back only a few decades and some of the compounds are extremely oxygen and/or water sensitve so are difficult to work with, whereas organic chemistry has had several gigayears to show us some of its capabilities. One such system of which I'm aware is provided by boron-nitrogen compounds. Unfortunately, the low cosmic abundance of boron makes it unlikely, IMO, that BN-based life is very common.

[QUOTE=cheesehead;88859]Until someone demonstrates (in serious detail, not just science fiction hand-waving) that the feasibility of a non-carbon alternative evolution is nonzero, I prefer placing my bets on places that can be possible winners.[/QUOTE]The above, especially that about silicone chemistry and the clay biogenesis hypthothesis may start you investigating what feasible alternatives are already being considered by chemists and biologists.

Paul

[QUOTE="retina"]One can argue that the new life was created by the previous life, so perhaps we [b]and[/b] the non-natural life.[/QUOTE]There was a typo there, the "and" should be "are".

One can argue that the new life was created by the previous life, so perhaps we [b]are[/b] the non-natural life.

One thing about water, is that, because of its electrically polarised molecule all its characteristics are very different from other possible solvents (melting and boiling temperatures, the temperature range of its liquid phase, specific heat, energy needed for phase changes, the fact that the liquid phase increases in volume when cooled after reaching a peak at 277 K or 4 C...) Just compare it with molecules formed with other elements in the neighbourhood of oxygen be it vertically or horizontally in the periodic table : water remains a "loner".

Other life supporting universal solvents may be possible but are not very probable because of the small range of conditions appropriate, this would not allow for seasons for instance, meaning that a planet with a non circular orbit or with a tilt of its axis could not harbour the “non water” chemistry.

[QUOTE=Jacob Visser;88939]One thing about water, is that, because of its electrically polarised molecule all its characteristics are very different from other possible solvents (melting and boiling temperatures, the temperature range of its liquid phase, specific heat, energy needed for phase changes, the fact that the liquid phase increases in volume when cooled after reaching a peak at 277 K or 4 C...) Just compare it with molecules formed with other elements in the neighbourhood of oxygen be it vertically or horizontally in the periodic table : water remains a "loner".[/QUOTE]Some of this statement is almost trivially true --- all solvents are different from all other solvents in some respects. For example propan-2-ol has a different liquid range from propan-1-ol. I'll therefore concentrate on the other claims made in the statement quoted. In particular, I'll compare it with a couple of other solvents formed by neighbouring elements as requested. To keep the posting from becoming too large, I'll restrict myself to horizontal neighbours. I could very easily include phosphorus and sulphur as well.


First consider ammonia. It is an excellent polar solvent with a wide liquid range. It is liquid between 195K (-78C) and 405K (+132C), those being its triple point and critical point respectively. Do not make the mistake of quoting its melting and boiling points measured at 1 standard atmosphere. There is nothing magic about that particular pressure!

Those figures are for the pure liquid. Dissolved salts lower the melting point (as they do for water); solutes such as water raise the boiling point at anygiven pressure.

The specifc heat capacity at the triple point is about 75 kJ/kg/K, very similar to that of water which has a value of around 81.

The solid is always denser than the liquuid with which it is in equilibrium, so the solid sinks. So what? A convecting ocean will transport heat from warm surface areas to colder deeper areas.

Ammonia is very widely used in chemistry labs where water is too hot and/or too acidic to be used as a solvent. For instance, sodium dissolves nicely in NH_3, (producing Na+ and a solvated electron) and reacting only very slowly, but the solvated electron has a very short lifetime in water and the reaction is vigorous, to put it mildly. Some substances don't react particularly rapidly with either H2O or NH3 but are temperature sensitive; ammonia is much the better choice for these.

The dielectric constant of ammonia at its triple point is about 25. For comparison, that of water is about 88. Ammonia is less polar than water, but it's still a fine polar solvent!


Ok, now for another solvent, one from the more acidic side this time. I'll choose nitric acid, HNO3. Again, a superb polar solvent. Its dielectric constant is 50 at 14C. Unfortunately, I haven't been able to find a value at the triple point.

Its liquid range is 231K to 520K (-42C to +247C). It actually has a wider liquid range at 1 atmosphere than water, -42C to +83C.

The specifc heat capacity at the triple point is close to 50 kJ/kg/K, again comparable with that of water

It is much more acidic than water and although it's occasionally used as a solvent for substances where water is too basic, its major use in the lab and in industry is as a powerful oxidising agent.


Returning to weak acids similar to water and ammonia, consider hydrogen cyanide, HCN, another excellent polar solvent. Its dieletric constant is 95.4 at 25C, even higher than that of water!

Again, it has a wide liquid range from 260K to 457K (-13C to +184C).

The specifc heat capacity at the triple point is 88 kJ/kg/K, almost the same as that of water.

HCN isn't much used as a solvent in chemstry labs, largely because of its extreme toxicity to organisms that have evolved in its absence. That reason, of course, makes sense only to human health & safety concerns. The compound itself works just fine as a solvent.


In summary: water is indeed a remarkable substance, but there are several other compounds which are also remarkable in their own way and which are thoroughly capable of being used as very versatile solvents.


Paul

(Hmm, it's been several decades since I last wrote a chemistry essay on this scale. It probably shows!)

[QUOTE=xilman;88949]The solid is always denser than the liquuid with which it is in equilibrium, so the solid sinks. So what? A convecting ocean will transport heat from warm surface areas to colder deeper areas.[/QUOTE]

Convection would certainly not be enough : imagine a big lake (or sea or ocean) of fluid, it freezes bit by bit, the solid part sinks, this is the case with almost all fluids except water. Once the solid is in the bottom, it is isolated from heat by all the fluid above it. When the temperature rises again only the upper part of the lake will melt. The main body of the lake will be frozen for ever, except in cases where the temperature changes are extreme. Water near the freezing point and ice of course "floats" and isolates the rest of the water from the cold, meaning that most "lakes" do not freeze all over.

When comparing water with other elements, I was comparing it with FH, NH3, CH4... or with SH2, SeH2...

Also water is abundant in in space (a lot of meteroids are basically dirty water for instance.) As far as I know that it is not the case with the alternate compounds you named, execpt NH3 perhaps.

I do not claim that another life supporting chemistry is impossible, just that it is not very likely. On the other hand the possible places where life could have started is so huge, that other life supporting chemistries are a definite possibility. To go back to the origine of this discussion, in my opinion it is easier to limit the search for life to the most probable places first.

[QUOTE=Jacob Visser;88955]Convection would certainly not be enough : imagine a big lake (or sea or ocean) of fluid, it freezes bit by bit, the solid part sinks, this is the case with almost all fluids except water. Once the solid is in the bottom, it is isolated from heat by all the fluid above it. When the temperature rises again only the upper part of the lake will melt. The main body of the lake will be frozen for ever, except in cases where the temperature changes are extreme. Water near the freezing point and ice of course "floats" and isolates the rest of the water from the cold, meaning that most "lakes" do not freeze all over.[/quote]I suggest that you carry out an experiment. Try using a low-melting fat for your ocean (goose fat is particularly good as it melts at only slightly above room temperature) for your ocean and a bright light bulb to mimic the Sun. Bring the bulb in closer during "summer" and further away during "winter". Switch it on during the day and off at night. The requirement on the fat is that the day time temperature, or summer temperature if you prefer, is well above the melting point but the night time or winter temperature is not.

You will find that during day time, and especially during the summer, substantial amounts of the ocean will be liquid. Thermal inertia will very likely result in some remaining liquid even during winter nights though, clearly, this will depend on the precise details of the temperature change regime and the mass of your ocean. Convection will ensure that even reasonably deep locations are liquid throughout the summer So what if the bottom remains frozen all year round? Life here on earth has adapted quite well to locations where water is a hard rock for much of the year. As long as it is available as a liquid somewhere in reasonable amounts, it gets on just fine.

If you want to make your model more elaborate and more realistic, work out how to mimic volcanic vents at the base of your ocean and see what effect that has.

[QUOTE=Jacob Visser;88955]
When comparing water with other elements, I was comparing it with FH, NH3, CH4... or with SH2, SeH2...[/quote]I know you were. However, that comparson is irrelevant and misleading when the subject under discussion was the suitability of compounds as solvents for supporting life. If you wish to ignore perfectly good solvents, feel free, but don't be surprised if that blinds you to the possibilities. Why the concentration on hydrides anyway?

[QUOTE=Jacob Visser;88955]Also water is abundant in in space (a lot of meteroids are basically dirty water for instance.) As far as I know that it is not the case with the alternate compounds you named, execpt NH3 perhaps.[/quote]I suggest you read up more on the chemistry of solar system objects. For a start, it's comets that are largely dirty ice, meteoroids tend to be stony. However, comets in the inner solar system release significant quantities of cyanogen (C2N2) and cyanide (CN-). Pristine comets, those which have not been baked dry by solar heating, also have significant amounts of NH3. I really don't know whether HCN is common in comets but, given the evidence from C2N2 and CN- emission, I would expect there to be quite a lot --- again until it's been baked out.

[QUOTE=Jacob Visser;88955]I do not claim that another life supporting chemistry is impossible, just that it is not very likely. On the other hand the possible places where life could have started is so huge, that other life supporting chemistries are a definite possibility. To go back to the origine of this discussion, in my opinion it is easier to limit the search for life to the most probable places first.[/QUOTE]Given that we know so little about the nature of life, having only one example to study, it's rather hard to tell whether reasonably pure liquid water is the most likely life-supporting solvent or not. We can surely say that life is possible in liquid water but that's about all. Given that there are other solvents with useful properties, as I've indicated, and that those solvents (possibly not HNO3, I'll accept) appear to be common in our solar system, it seems to me that we should investigate their possibilities and the locations elsewhere in the galaxy where they may support life.

Paul

[QUOTE=xilman;88958]comets in the inner solar system release significant quantities of cyanogen (C2N2) and cyanide (CN-). Pristine comets, those which have not been baked dry by solar heating, also have significant amounts of NH3. I really don't know whether HCN is common in comets but, given the evidence from C2N2 and CN- emission, I would expect there to be quite a lot --- again until it's been baked out.[/QUOTE]Sorry. Although I intended to write "cyanide", I did not mean to write "CN-". The spectrum of neutral cyanide, CN, is what's observed in cometary comae.

CN dimerizes to cyanogen, C2N2, at moderate pressures; that's the chemical generally found in earthly labs, though it's easy enough to produce CN from C2N2 by photolysis or pyrolysis at low pressures.

I'm so used to thinking of cyanide as an anion...


Paul

[QUOTE=xilman;88985]I'm so used to thinking of cyanide as an anion...[/QUOTE]
Since my college chemistry classes, I've always wondered who the poor soul was who was the first to discover that colorless [url=http://en.wikipedia.org/wiki/Hydrogen_cyanide]HCN gas[/url] "smells like bitter almonds." Unless they were fortunate enough to catch only a slight non-fatal whiff, I keep envisioning a Pythonesque "well, he wouldn't have *written*, 'Smells ... like ... bitter ... almonds ... aaaaaaaaaaaaaaarghhhhh ...' before he died, would he?" scenario.

[quote=xilman;88906]It's not at all clear to me why gravity can't be much stronger than 1.8g without precluding life.[/quote]Nor is it to me. I didn't say +.81 or -.81 was [I]not[/I] fine. I just picked .8 as a figure to help illustrate what I meant by "just how far the environment is not like Earth".

[quote]Atmosphere-stripping mechanisms have been proposed by planetary geologists. For instance, a massive planet close in to a young star would have quite a lot of its initial envelope blown off when the star went through its T Tauri phase.[/quote]... or by the UV blast from a massive star born nearby after the first star's planets had time to gather themselves.

[quote]As for temperature ranges, [/quote]My figures were simply casual, and I had averages in mind. But thanks for the details anyway!

[quote]The above, especially that about silicone chemistry and the clay biogenesis hypthothesis may start you investigating what feasible alternatives are already being considered by chemists and biologists.[/quote]This isn't high enough of a priority to me to put much work into research. I'll wait for a [I]Scientific American[/I]-type article or a book laying it out like [U]Rare Earth[/U] (especially if it refutes the latter's thesis).

[QUOTE=ewmayer;88987]Since my college chemistry classes, I've always wondered who the poor soul was who was the first to discover that colorless [url=http://en.wikipedia.org/wiki/Hydrogen_cyanide]HCN gas[/url] "smells like bitter almonds." Unless they were fortunate enough to catch only a slight non-fatal whiff, I keep envisioning a Pythonesque "well, he wouldn't have *written*, 'Smells ... like ... bitter ... almonds ... aaaaaaaaaaaaaaarghhhhh ...' before he died, would he?" scenario.[/QUOTE]I've smelled HCN on several occasions and it does, indeed, smell of bitter almonds.

Have you ever smelled hydrogen sulphide? It's what rotten eggs smell of.

H2S is significantly [i]more[/i] toxic than HCN.

I never really understood why there is so much fear of HCN and of cyanides in general. They are just another class of fairly toxic compounds. There are many many much nastier chemicals out there. Organo-tin compounds, for instance, used in anti-fouling paints for boats.


Paul

[QUOTE=xilman;89017]I never really understood why there is so much fear of HCN and of cyanides in general.[/QUOTE]
Yes, looking more closely at the Wikipedia page I linked to it cites danger levels of hundreds of PPM for HCN, which is really quite high - like I said, when we were warned about this in freshman chemistry, the lab assistant made it sound like the stuff was nerve-gas fatal.

So, sniff any tetrodotoxin or brevetoxin lately?

[QUOTE=xilman;89017]I've smelled HCN on several occasions and it does, indeed, smell of bitter almonds.

Have you ever smelled hydrogen sulphide? It's what rotten eggs smell of.

H2S is significantly [i]more[/i] toxic than HCN.

I never really understood why there is so much fear of HCN and of cyanides in general. They are just another class of fairly toxic compounds. There are many many much nastier chemicals out there. Organo-tin compounds, for instance, used in anti-fouling paints for boats.


Paul[/QUOTE]
:smile:
Well, Hitler poisoned his Alsatian dogs as a test to see how potent it was if used on himself, his generals and his recent wife. Eventually, he preferred his Mauser pistol.

Yes I have had liberal doses of H2S in my high school days. For some reason we always had it on tap in big jars as it was easy to produce.
It did smell of rotten eggs.

There is a theory that brief sniffs of bad smells opens the brain cells and increases alertness. There are a variety ways of doing this but I leave it to others to imaginatively experiment.

In India a common cure for epileptic seizures is to put a slipper on the patients nose to revive the person, and from my own personal experience of effecting a cure, it does work. But be wary, as certain body odours can be addictive to the nasal passages.

IN Art galleries there is sometimes a foul smell from Large Paintings due to H2S from the paint. Many of the so called miracles of crying Madonna's is due to the moisture in the air converting SO2 into H2SO3
Mally :coffee:

[COLOR="Sienna"][SIZE="3"][B]Happy Uranus Day! Today marks the 231st anniversary of the astronomer William Herschel first observing Uranus.
[/B][/SIZE][/COLOR]
[QUOTE=Uncwilly;88400]For what it is worth, there are several other suggestions from various places that other cultures may have in fact seen Uranus. It is with in the limits of a sharp eyed person under very good conditions.
I personally have seen Uranus with out optical aid a few years ago. In a dark sky location, I used averted vision to see it. It was in the exact right spot as the chart and it had just enough color to not be a star.[/QUOTE]
[QUOTE=xilman;68623]By this argument, Neptune was discovered before Uranus. An intelligent system (Galileo) found the planet close to Jupiter in the early 17th century and one of his drawings of it has survived. Needless to say, he thought it was a star and although he found it, he didn't recognize it.

Flamsteed found Uranus in the 18th century. He included it in his star catalogue (as 5 Tauri if I remember correctly --- I haven't checked) but failed to recognize it as a planet. The latter is quite inexcusable. If he'd gone back to check his measurements some time later he would have found it had moved in the interim, a behaviour for which the fixed stars are not noted but which planets most certainly are.[/QUOTE]

[QUOTE=mfgoode;89054]There is a theory that brief sniffs of bad smells opens the brain cells and increases alertness. There are a variety ways of doing this but I leave it to others to imaginatively experiment.[/QUOTE]

Perhaps attempting to observe Uranus is one way to expose yourself to such brain-alerting vapors.

[Sorry about the sophomoric tasteless joke, but somehow the juxtaposition of Uncwilly's Herschel-anniversary post with this post by the late mfgoode was too curious pass up].

[QUOTE=xilman;89017]Have you ever smelled hydrogen sulphide? It's what rotten eggs smell of. H2S is significantly [I]more[/I] toxic than HCN.
[/QUOTE]
When I was in highschool we used to play nasty jokes on other colleagues. We could buy aluminum powder from chemical shops (used for painting, for pyrotechnics, etc), well everybody knew how to mix it with [URL="http://en.wikipedia.org/wiki/Lead_tetroxide"]lead tetroxide[/URL] (or [URL="http://en.wikipedia.org/wiki/Minium_%28mineral%29"]minium[/URL] - by the way, here is where the English math related "minimum" or not-math related "miniature" is comming from!) to make [URL="http://en.wikipedia.org/wiki/Flash_powder"]flash powders[/URL] or firecrackers, all the materials were very easy to buy from chemical or plumbing shops. I had a real "arsenal" of small plastic recipients filled with all kind of chemicals. Of course, sulfur and carbon powder were not missing, as basic components of gunpowder. We did not have the "regulations" as existing today, and every one of my friends were able to make small firecrackers and petards for different festivals or amusement purposes. But noone knew, except me, that you can mix aluminum powder with sulfur and burn them together to make [URL="http://en.wikipedia.org/wiki/Aluminium_sulfide"]aluminium sulfide[/URL]. Maybe some of them discovered it, same way as me: mixing the powders together and try to ignite them, with the goal to discover some new type of flash powder.

The procedure is very easy, you mix about 10-20 grams of each of the powders (aluminium and sulfur) together, make a small cone (as a small "hill" or "volcano") and using a long match or a stick (about 20 cm, to protect your hand) set it on fire (ignite it in a side). It does not explode, and in fact it is very difficult to ignite it, that is why it presented no interest as flash powder, and nobody bothered with it. If you at least succeed to ignite it, it will burn moderately, exhausting a lot of heat, the temperature goes over 1000 degrees, and it can cut through the steel tray, so you should be careful to have a stone or brick under (see [URL="http://en.wikipedia.org/wiki/Aluminothermic_reaction"]aluminothermy[/URL]). I tell you from my personal experience. I spent ages trying to make "[URL="http://en.wikipedia.org/wiki/Bengal_fire#Bengal_fire"]bengal fires[/URL]", hehe, the holidays and weekends were a wonderful time when I could go home and make some new experiments... well, this thing was no use for firecrackers, no one was interested in it. After the small mound burned, the "leftover" was the aluminum sulfide. It looks like hard gray stone, you can do nothing with it, except break it with a hammer. When I first discovered it, I said to myself, well, it is not good for [URL="http://en.wikipedia.org/wiki/Salute_%28pyrotechnics%29"]salutes[/URL], let's see if it is good for some percussion cracker, so I took the hammer hit it hard, but it broke into very small grains (like a car window, but smaller, 2 cubical millimeters each). It did not explode, it did not make any loud noise... well, I was ready to get rid of it. Then, when I put my fingers on it, I notified the smell..

What the hack, I said, and looked into the book... There was no wikipedia that time :smile:. Then the "brilliant idea" rooted under my hair..

The aluminum sulfide is very water-hungry. It will react with the water from the air, and with the water from your skin sweat, if you touch it with your fingers, producing lots of [URL="http://en.wikipedia.org/wiki/Hydrogen_sulfide#Production"]hydrogen sulfide[/URL] by the reaction: Al[SUB]2[/SUB]S[SUB]3[/SUB] + 6 H[SUB]2[/SUB]O = 3 H[SUB]2[/SUB]S + 2 Al(OH)[SUB]3[/SUB].

So, once you have it, you should manipulate it with the tweezers only, and keep it dry. A small air-tight plastic recipient like the one for pills is perfect.

How to use it? well, here the LaurV's genius come into play :smile:.

When you are in highschool and live in a boarding campus and your roommates got angry on some guys from another room, you can take a small grain (2 cubical mm is enough) of the well-guarded secret substance and put it in a small piece of tissue paper. Then you colloquially go to the other room, to ask for some homework help, or whatever... In the mid of the discussion, you - like any human being - feel the need to cough or blow your nose, or just take out the tissue paper from the pocket, spit on it an put it on the rubbish basket. Then you discretely live the room no later then two-three minutes after. The "fart-bomb" will "detonate" in about this amount of time, to a level when noone would be able to stay in the room. The nasty part is that no one can tell where the smell is coming from, and they start accusing each other, sometime fights burst open, etc., eventually they start opening the doors and windows and taking things out of the room, etc. Even if they take out the rubbish basket, they can't find the source of the smell (which is long gone from the basket, and already impregnated in different objects in the room) and the smell won't disappear for hours.

I remember once a roommate dropped "the bomb" in another room. The guys from the other room were so confused, they didn't know what is going on, but they realized that my colleague is to blame for it. They went to the principal and requested some punishment for my colleague, who "went to their room and fart so hard they need to keep the door and windows open for an hour". It was an investigation and everybody negated, and we all (including the principal and the homestay teachers) laughed so hard, and the other guys were so ashamed... and at the end everybody rolled with laugh..

[QUOTE=LaurV;292972]The "fart-bomb" will "detonate" in about this amount of time, to a level when noone would be able to stay in the room. The nasty part is that no one can tell where the smell is coming from, and they start accusing each other, sometime fights burst open, etc., eventually they start opening the doors and windows and taking things out of the room, etc. Even if they take out the rubbish basket, they can't find the source of the smell (which is long gone from the basket, and already impregnated in different objects in the room) and the smell won't disappear for hours.[/QUOTE]In my student days a similar practical joke was to tape the wrapper from a Camembert or the like to the rear of a radiator. A much slower but much longer lasting effect.

For instant-acting amusement we'd use "nitrogen triiodide" as it is commonly but not strictly correctly called.


Paul

Jeeziz, the rules at my boarding school were so freakin strict, and they keep getting worse every year. (Then again, all the rules they have now were created because someone in the past broke them.)

[QUOTE=xilman;292973]In my student days a similar practical joke was to tape the wrapper from a Camembert or the like to the rear of a radiator. A much slower but much longer lasting effect.

For instant-acting amusement we'd use "nitrogen triiodide" as it is commonly but not strictly correctly called.


Paul[/QUOTE]

Limburger works even better. I've been in an exam that got scrapped about two-thirds of the way through because of a mysterious stink; turns out it was Limburger cheese strategically placed in the physics lab. Wasn't much fun having to retake (a different form of) the exam the next week.

[QUOTE=NBtarheel_33;293172]Limburger works even better. I've been in an exam that got scrapped about two-thirds of the way through because of a mysterious stink; turns out it was Limburger cheese strategically placed in the physics lab. Wasn't much fun having to retake (a different form of) the exam the next week.[/QUOTE]Limburger is indeed much better, both for eating and for using the wrapper afterwards.

Unfortunately, Limburger is especially difficult to get hold of in these part.

I have a second hand account of someone leaving a 'road apple' in a rival dorm. It was left in a bit of foil, with some hole, in an oven on the lowest setting. It was a gift for the dean's arrival later that day. :poop:

[QUOTE=xilman;293181]Limburger is indeed much better, both for eating and for using the wrapper afterwards.[/QUOTE]
I've long thought that stinky chesses - especially the ones that smell distinctly like human body odor - are happy accidents (assuming you actually enjoy eating the stuff) resulting from human/milk contact, possibly now separated by many thousands of culture-generational refinements. [url=http://en.wikipedia.org/wiki/Limburger_cheese]According to Wikipedia[/url], at least for Limburger this is literally true:
[QUOTE]Limburger is a cheese that originated during the 19th century in the historical Duchy of Limburg, which is now divided among modern-day Belgium, Germany, and Netherlands. The cheese is especially known for its pungent odor commonly compared to body odor.[/QUOTE]
"What might the reason for the stink-foot odor be?" wonders the inquiring mind.
[QUOTE]Once it reaches three months, the cheese produces its notorious smell because the bacterium used to ferment Limburger cheese and many other smear-ripened cheeses[2] is [i]Brevibacterium linens[/i], the same one found on human skin that is partially responsible for body odor and particularly foot odor.[/QUOTE]

Back to Paul's complaint about the local shortage of inter-toe-fermented cheeses:
[QUOTE]Unfortunately, Limburger is especially difficult to get hold of in these part.[/QUOTE]
According to the same Wikipiece:

[i]"Herve cheese is a type of Limburger cheese still produced in the Land of Herve, in the territory of the old Duchy of Limburg. Herve is located near Liège, and the borders separating Belgium from the Netherlands and Germany. The "Pays de Herve" is a hilly area between the Vesdre and Meuse rivers."[/i]

Do they carry that at your local cheese shoppe?

[QUOTE=ewmayer;293343]Do they carry that at your local cheese shoppe?[/QUOTE]Cue the Monty Python skit reenactments. Somebody please quickly close this thread before we all get bombarded with tired old quotes. :stirpot:

:bear:

[QUOTE=retina;293344]Cue the Monty Python skit reenactments. Somebody please quickly close this thread before we all get bombarded with tired old quotes. :stirpot:

:bear:[/QUOTE]I don't care how runny it is.

Lovely plumage on that Norwegian Blue cheese, innit?

[QUOTE=ewmayer;293401]Lovely plumage on that Norwegian Blue cheese, innit?[/QUOTE]It's just tired and shagged out after a long squawk.
Stun easy the Norwegian blue.

Back to Uranus. You know what a stickler I am for staying OT(T?).
On which syllable do you place the emphasis?

[QUOTE=davieddy;293404]It's just tired and shagged out after a long squawk.
Stun easy the Norwegian blue.

Back to Uranus. You know what a stickler I am for staying OT(T?).
On which syllable do you place the emphasis?[/QUOTE]

I think what's weird is how almost regardless of how you try to pronounce it you get a phrase:

Ur a-nus

U ran us

[QUOTE=science_man_88;293410]I think what's weird is how almost regardless of how you try to pronounce it you get a phrase:

Ur a-nus

U ran us[/QUOTE]THX SM
That one is worthy of Jasong (or even Mally)
I'm 62 today so Cheers:smile:
David

Hmm, I still wonder what is going on with the 9th planet?