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"Pluto's Defenders Prepare to Fight for Its ..." Topic


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Tango0104 Mar 2017 2:43 p.m. PST

…Planethood (Again)

"What is a planet? Prior to August 24, 2006, the answer was simple, vague, but generally agreed-upon: large, round-ish, orbiting a star, perhaps. Most people could name nine examples without much controversy. But the ninth planet became suddenly controversial on that Thursday in August—the last day of the International Astronomical Union's 26th triennial General Assembly.

Many of the meeting's 2,700 attendees had already left Prague by then. The few hundred who remained sat in a large auditorium facing a screen bearing the IAU's proposed definition of a planet, which had a curious addition—that a planet, on top of being round and orbiting the sun, should also clear the neighborhood around its orbit. Pluto, which orbits in the cluttered Kuiper Belt, was on trial. The crowd voted, raising canary-colored sheets of paper for or against the definition—and with a margin of fewer than 10 votes, the Ayes won.

Planet: a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighborhood around its orbit.

You know what happened next. Pluto became a joke, a martyr, an object of sympathy; its demotion to dwarf planet was meme-ified and turned into t-shirt slogans. That was popular culture. In scientific culture, its reclassification opened a rift in the continuum of specialists who study planets. On one end were the orbital mechanicians, who generally support the IAU's definition because fits their top-down view of how moving objects harmonize with the surrounding cosmic orchestra. At the other, geophysicists have spent the past decade harumphing against the illogic of a definition that ignores their bottom-up, size-agnostic view of accumulated space dust. Well, the geophysicists are done protesting. They've gone ahead and written their own definition of "planet."…"
Main page
link

Amicalement
Armand

Waco Joe04 Mar 2017 2:52 p.m. PST

No planetary status no peace!

zoneofcontrol04 Mar 2017 6:06 p.m. PST

I think it is just Goofy that such a Mickey Mouse operation has turned this Pluto thing into a Minnie Controversy.

Thanks folks. I'll be doing stand up in Orlando all week…
Don't forget to trip your waitress!

Bowman05 Mar 2017 7:30 a.m. PST

Pluto became a joke, a martyr……

Oh please. Will the hyperbole about this "tempest in a tea pot" ever stop? Who cares?

Look I know when you were young you were told there were 9 planets. Now there are 8 in the current classification. Get over it. Maybe it'll be reclassified again. If so, great. Maybe we should all hold parades.

Hate to tell you, but our beautiful and wondrous Sun is a Yellow dwarf. Once Pluto gets redeemed, you can move on to the next "cause célèbre" and rescue the Sun from it's ignoble martyrdom.

And "size-agnosticism" is the remedy for "planet shaming"? Sheesh. BTW, Zoneofcontrol nailed it. thumbs up

GarrisonMiniatures05 Mar 2017 10:11 a.m. PST

Tell you what, when the aliens find Voyager and look at the map of the solar system on it, they're going to get very confused.

Personal logo Parzival Supporting Member of TMP05 Mar 2017 4:19 p.m. PST

I've got news for speakers of English like Mark Brown. "Dwarf" in this context is an adjective. "Planet" is a noun. "Dwarf planet" is not a noun, it is a phrase, consisting of the adjective "dwarf" modifying the noun "planet." In context, "dwarf" means "smaller than other objects of the same category," referring to the category defined by the noun "planet." Thus the noun "planet" must necessarily have a definition which is linguistically indepedent of the definition implied by "dwarf." This renders the IAU definition "dwarf planet" inherently linguistically nonsensical; one cannot have a "planet" that is not a "planet," no matter how one modifies it. The English language simply does not allow such a construction to exist as a logical statement. It would be like saying that a "dwarf human" is not a human. Certainly one can make the phrase occur, but the statement being made is inherently contradictory, if by planet one means the definition the IAU has asserted; if a dwarf planet does not meet the definition for "planet" then logically it cannot be a "dwarf planet" at all, but must be another sort of object entirely. Therefore, the definition is a linguistic non-starter. Either large, spherical objects which have not fused are not "planets" or all such objects are "planets," while any other considerations require specific modifiers to clarify what sort of planet one means. This is the only way in which the term "dwarf planet" actually makes any linguistic sense. If Brown, et al, wish to define such objects by orbital characteristics, then they should come up with orbitally-based adjectives to make those clarifications, not mangle the English language into nonsensical definitions it cannot constructually support.

Don't mess with me, Mr. Brown. I was an English major.

Bowman05 Mar 2017 5:49 p.m. PST

Thanks for the English lesson. I'm just not sure why you are singling out Dr. Brown.

A quick look at his book, will show that he totally agrees with your comment:

Certainly one can make the phrase occur, but the statement being made is inherently contradictory, if by planet one means the definition the IAU has asserted; if a dwarf planet does not meet the definition for "planet" then logically it cannot be a "dwarf planet" at all, but must be another sort of object entirely.

According to Brown, the term "dwarf planet" is "dumb" and he prefers the older term "planetoid". And for the exact reasons you have given.

Brown states that planetoid is "a perfectly good word" that has been used for these bodies for years, and that the use of the term dwarf planet for a non-planet is "dumb", but that it was motivated by an attempt by the IAU division III plenary session to reinstate Pluto as a planet in a second resolution.

Brown, Mike (2010). How I Killed Pluto and Why It Had It Coming. Spiegel & Grau. p. 223.

According to Wiki, the term "Dwarf planet" was coined by astronomer Alan Stern.

Alan Stern, "On the number of planets in the outer solar system: Evidence of a substantial population of 1000-km bodies", Icarus 90:2, April 1991

It seems the "official" term for dwarf Planets should be "Plutoids" according to the IAU.

link

Bowman05 Mar 2017 6:07 p.m. PST

As for English, I hate to tell you but colloquial English and scientific English do not have to jive perfectly in all instances. Just think how the public and scientists define the word "theory" and the trouble that ensues.

For an astronomy example, look up the IAU designation of "minor planet". It doesn't follow your and Brown's argument.

As of November 2016 there are 480,806 numbered minor planets, and 242,561 unnumbered.

link

Remember, "Planetes" is Greek for 'wanderer". So it describes any object, that we see in the sky, that is not fixed.

gladue05 Mar 2017 8:18 p.m. PST

The problem has always been the people who want to assert that there are 9, and only 9, planets. There is no classification that includes Pluto that doesn't include Ceres, Sedna, and uncounted others. It's fine if Pluto and others are planets, so long as people don't want to able to recite the full list by memory, because it is going to be a very long list.

Personal logo Parzival Supporting Member of TMP05 Mar 2017 8:38 p.m. PST

Regarding "singling out" Brown, I was, of course, being humorous. (I rather thought that was obvious, but perhaps not. I conceded that tone is hard to read.)

Kudos to Dr. Brown for recognizing that the IAU's definition is bad English, and bad scientific English, too. (I am not worried about colloquial English in this case; I am specifically referring to scientific English, which, above all, should be clear and precise, which the terms introduced by the IAU are not.

I dispute "planetoids" as the best term here, as its early use was indeed in the tradition of the Greek origins of the word planet (which I was thinking of bringing up in a later post, but kudos to you for bringing it up)— that is, a "wandering object," in this case distinctly smaller than the recognized planets of the day. What we now call "asteroids"* were indeed originally named "planetoids." Thus, the term originally includes things which are neither spherical nor planet-like, except in the context of "wandering." It would be silly to assert that Eros, for example, is anything like Pluto.

I never had a problem with "Plutoids." However, I don't think Plutoids as a term is distinct from planets, but rather is a defined type of planet, as "gas giant" is a defined type.

I find absurd the complaint that the objects orbiting Jupiter (and Earth, for that matter) would, under the physical definition, also be planets. They would have been to the Greeks, as you point out! Why can't a planet (a physical term) also be a moon (a positional term)?

Perhaps the terms should be "solar planet" (spherical, orbits the Sun), and then other definitions be added for clarity.

(* "Asteroids" is, admittedly, a mistaken borrowing on nearly every level, such things very much not being "small stars" by any measure, as the name implies.)

Bowman06 Mar 2017 7:16 a.m. PST

Regarding "singling out" Brown, I was, of course, being humorous.

Then I apologize as I totally missed the humour.

I find absurd the complaint that the objects orbiting Jupiter (and Earth, for that matter) would, under the physical definition, also be planets. They would have been to the Greeks, as you point out! Why can't a planet (a physical term) also be a moon (a positional term)?

Well I think the Greeks can be absolved of that predicament as none of the planet's moons were discovered until much later (our Moon being the obvious exception).

(* "Asteroids" is, admittedly, a mistaken borrowing on nearly every level, such things very much not being "small stars" by any measure, as the name implies.)

Again, to the Greeks, the asteroid burning up in our atmosphere would look "star-like". My understanding is that this term is also very modern.

My initial complaint is about the "panty twisting" that goes on in the public realm because experts are arguing about classifications. In Biology, there are some creatures that behave like reptiles and amphibians and there are (much smaller) fights about how to classify them. An older controversy is still whether viruses are alive. In colloquial English we still claim that this soap "kills" viruses. Is that accurate? No one seems to be as frantic about any of that. On another thread a fellow stated that he despised Neil deGrasse Tyson because, "when head of the IAU he spearheaded the movement to demote Pluto". Ok, so the fellow was actually wrong on both counts (Tyson was in favour of the new classification, but hardly lead the movement) but I'm shocked that someone would be hated for his side on a scientific argument that doesn't involve religion or political leanings.

I will still call out statements like, "Pluto was martyred" for what they are. Unadulterated, hyperbolic nonsense.

Bowman06 Mar 2017 7:25 a.m. PST

I'll leave everyone with this. In 2006, the IAU had a vote on the status of Pluto at their General Assembly. It was in the program, at the end of the meeting.

link

Out of the 2,500+ attendees, only about 450 or so members bothered to stay and vote on this. The rest thought they'd go out and visit Prague and have a nice Budějovický Budvar beer instead.

That's how much this issue bothered the majority of the astronomers. I'm no astronomer, but I'll follow suit.

Hafen von Schlockenberg06 Mar 2017 8:57 a.m. PST

Well now I've learned something. I had no idea there was such a thing as antiviral soap.

Think I'll get some to use before going on the Internet.

Edit: AND afterwards,of course.

Great War Ace06 Mar 2017 9:36 a.m. PST

"Planet X", renamed Pluto, was known long before it was noticed. Does Pluto's orbit get visibly altered by any of the other Kuiper Belt objects? Do any others than Pluto affect Neptune? If not, then Pluto is in a class by itself. For two reasons: it alone affects Neptune, and its discovery predates subsequent telescopes that reach into deep space. The venerable quality of Pluto, plus its effect upon Neptune, plus no other object affecting Pluto, separate it from all subsequently detected "planetoids". All of the latter are too numerous to name, and were withal discovered en masse, or over such a brief span of time as to be considered as discovered virtually at the same time.

For historical curiosity reasons, Pluto ought to therefore be considered as part of the "Nine Planets". All other subsequently detected planetoids can remain categorized together as outside the select "club" of real planets. Astronomy down the ages from this time will recall the separating point in history when Pluto was permanently joined to the Eight. Such curiosities arrest the attention of students. Trying to teach them of the controversy regarding Pluto's "status", without an actual distinction still being made, will likely become a non factoid. Whereas the retaining/reinstating of Pluto as part of the special "Nine" will ensure that this piece of astronomic history will not be lost.

Bowman06 Mar 2017 12:38 p.m. PST

Well now I've learned something. I had no idea there was such a thing as antiviral soap.

Happy to be of help: quaternary ammonium soaps, bis-phenol soups, household bleach or chlorine soap, hydrogen peroxide, regular soap, alchohol based soap and iodine based soaps.

Bowman06 Mar 2017 12:56 p.m. PST

Planet X", renamed Pluto, was known long before it was noticed.

You seen confused. Planet X or Planet 9 are not Pluto.

Pluto was discovered in 1930. The Kuiper belt was suspected by Kuiper 1951. The existence of the belt was discovered in 1992.

Cacique Caribe06 Mar 2017 3:04 p.m. PST

HE'S confused?

Lol. So if Pluto goes back to being our 9th planet, will Planet 9 still be called Planet 9 (just because)? :)

Dan

TMP link

Personal logo piper909 Supporting Member of TMP06 Mar 2017 5:08 p.m. PST

What Waco Joe said! Pluto forever! And remember, Pluto HEARTS (loves) you and wants only to be loved in return.

Cacique Caribe06 Mar 2017 5:21 p.m. PST

"No planetary status, no peace!"

Lol. I agree! Defy the Establishment! Restore Pluto to its proper status! Down with the Fascists! :)

Dan

Bowman06 Mar 2017 7:02 p.m. PST

….bis-phenol soups…..

That should be soap. A soup of bisphenol based disinfectives will kill more than viruses.

Charlie 1206 Mar 2017 8:05 p.m. PST

And probably not taste too good, either!

Hafen von Schlockenberg06 Mar 2017 9:30 p.m. PST

I wasn't going to say anything. . .

gladue06 Mar 2017 10:00 p.m. PST

Ceres was the 9th planet *before* Pluto, and Eros was the tenth. "Historical reasons" are no more clear than any other attempt to define 9 or fewer planets.

Cacique Caribe06 Mar 2017 10:40 p.m. PST

Gladue,

And Neptune wasn't always the eighth. :)

Dan

gladue07 Mar 2017 8:31 a.m. PST

Personally I think we should simply give up the idea that the single nomenclature "planet" should apply to all of them. Just accept that there are different types of planets and go from there. So we have 6 or more rocky planets (including Eros and Ceres at a minimum), 4 known gas giants, and uncounted numbers of kuiper belt planets. They have different characteristics, so give them different categories and move on. New planets with entirely different characteristics cause new categories.

gladue07 Mar 2017 8:41 a.m. PST

So, for instance, Pluto and Charon are not planet and moon, but rather they are closer to a binary planet system. Charon does not orbit Pluto, but Pluto and Charon both orbit a point outside of of Pluto's surface.

Great War Ace07 Mar 2017 9:22 a.m. PST

You seen confused. Planet X or Planet 9 are not Pluto.

Tombaugh walked into Slipher's office and declared, "Doctor Slipher, I have found your Planet X."

Which was named Pluto. So for a while Pluto was synonymous with "Planet X". link

Now, of course, "Planet X" (or Planet Nine) is hypothesized for a giant far beyond Pluto. So, we are back to where we were over a hundred years ago, and the name(s) apply to another anticipated, yet undiscovered, planet. A real planet, not some "dwarf"………. link

Bowman07 Mar 2017 11:37 a.m. PST

Which was named Pluto. So for a while Pluto was synonymous with "Planet X"

You're correct Sir! However, in my defense, there have been many Planet Xs. I was thinking about the last 40 years, and especially the one being hunted by Mike Brown and others.

Personal logo Parzival Supporting Member of TMP07 Mar 2017 5:42 p.m. PST

I've held (and stated) for some years that the proper terminology should simply acknowledge that ANY naturally occurring spherical body (rendered so by its own gravity) that is not, has not, and will not undergo fusion, is a "planet," whatever else it may be. From there, we then begin to derive very reasonable subclassifications to further define the beasts in question (not unlike biology, if one stares at my metaphor directly).
So, Pluto is a planet that is also a dwarf planet, or a Plutoid, or a Kuiper object, or whatever classification is necessary for effective discussion. And if that means our solar system hosts a double (or triple) digit number of planets, well, that's just the way things are.

Great War Ace07 Mar 2017 8:38 p.m. PST

We could allow that Pluto is "special" because of when it was discovered. And count the planets as "inner" (Nine), and "outer" (the rest beyond Pluto) planets………..

Personal logo Parzival Supporting Member of TMP08 Mar 2017 11:51 a.m. PST

The orbital concept is not entirely flawed, just flawed as a primary definer of terms. I would suggest that when examining orbital states, objects be classified as "primary" or "dominant" "orbitals," meaning more or less what the IAU says about "clearing its orbit" (which is somewhat logically nonsensical wording), to whit that the object is the dominant object along its ellipitical path, with any other objects in that orbital region either orbiting the primary itself as moons or rings (or, if possible, as moonlets or ringlets of moons, though I'm not aware such have ever been observed) or trapped in the Lagrangian points of the primary. Objects with eccentric orbits that cross other orbits (as comets, some asteroids, etc.) are neither dominant or primary, but remain "eccentric" as that term currently covers the concept quite nicely without any real need of further classification of which I am aware.
"Rogue" is, of course, the term for an object which does not orbit a central gravitational stellar mass, but appears to be on a free trajectory (or perhaps only orbits a broad stellar region, if such is possible, or a galactic center).
Thus, the noun definition of a thing applies and is derived from the physical nature of that thing, whereas the adjective modifier of a thing can either further define that physical nature, or branch into the situational state of the object's movement (as I suggest above).
So, for example, the physical astronomers (my term) might announce that they've discovered an "ice giant planet" out past the Kuiper Belt, while the orbital astronomers (my term) might full well further announce that it appears to be either a "dominant primary planet" (orbits the Sun) or even an uncaptured rogue passing through the stellar region. But regardless of these tighter classifications, such an object correctly remains a "planet."

John the OFM12 Mar 2017 6:15 p.m. PST

It was a bunch of Commie pinko ne'er do wells that stripped Pluto of its birthright in the dead of night.
Away with them!

Don't worry about Planet 9. We'll deal with it when it shows up as a blurry smudge on a plate 35 years old that nobody paid all that much attention to.
Then some Agency with little credibility will name it after some Hollywood fertility goddess.
Behold Planet Kardashian?

Hafen von Schlockenberg13 Mar 2017 8:40 a.m. PST

At least it's always sunny on Kardashia.

picture

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