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'Yes, Pluto Is a Planet' (sfgate.com)
schwit1 quotes a Washington Post perspective piece by the authors of a new book about Pluto:
The process for redefining planet was deeply flawed and widely criticized even by those who accepted the outcome. At the 2006 IAU conference, which was held in Prague, the few scientists remaining at the very end of the week-long meeting (less than 4 percent of the world's astronomers and even a smaller percentage of the world's planetary scientists) ratified a hastily drawn definition that contains obvious flaws. For one thing, it defines a planet as an object orbiting around our sun -- thereby disqualifying the planets around other stars, ignoring the exoplanet revolution, and decreeing that essentially all the planets in the universe are not, in fact, planets.
Even within our solar system, the IAU scientists defined "planet" in a strange way, declaring that if an orbiting world has "cleared its zone," or thrown its weight around enough to eject all other nearby objects, it is a planet. Otherwise it is not. This criterion is imprecise and leaves many borderline cases, but what's worse is that they chose a definition that discounts the actual physical properties of a potential planet, electing instead to define "planet" in terms of the other objects that are -- or are not -- orbiting nearby. This leads to many bizarre and absurd conclusions. For example, it would mean that Earth was not a planet for its first 500 million years of history, because it orbited among a swarm of debris until that time, and also that if you took Earth today and moved it somewhere else, say out to the asteroid belt, it would cease being a planet.
To add insult to injury, they amended their convoluted definition with the vindictive and linguistically paradoxical statement that "a dwarf planet is not a planet." This seemingly served no purpose but to satisfy those motivated by a desire -- for whatever reason -- to ensure that Pluto was "demoted" by the new definition. By and large, astronomers ignore the new definition of "planet" every time they discuss all of the exciting discoveries of planets orbiting other stars.
Even within our solar system, the IAU scientists defined "planet" in a strange way, declaring that if an orbiting world has "cleared its zone," or thrown its weight around enough to eject all other nearby objects, it is a planet. Otherwise it is not. This criterion is imprecise and leaves many borderline cases, but what's worse is that they chose a definition that discounts the actual physical properties of a potential planet, electing instead to define "planet" in terms of the other objects that are -- or are not -- orbiting nearby. This leads to many bizarre and absurd conclusions. For example, it would mean that Earth was not a planet for its first 500 million years of history, because it orbited among a swarm of debris until that time, and also that if you took Earth today and moved it somewhere else, say out to the asteroid belt, it would cease being a planet.
To add insult to injury, they amended their convoluted definition with the vindictive and linguistically paradoxical statement that "a dwarf planet is not a planet." This seemingly served no purpose but to satisfy those motivated by a desire -- for whatever reason -- to ensure that Pluto was "demoted" by the new definition. By and large, astronomers ignore the new definition of "planet" every time they discuss all of the exciting discoveries of planets orbiting other stars.
If Pluto is a planet, aren't a large number of other bodies in the solar system also planets?
Pluto and it's moons are a pretty significant set of objects, and they cross Neptunes orbit, so does that mean Neptune is no longer a planet since it sure as heck hasn't "cleared it's zone" ?
Seriously, this again? Categories by nature have fuzzy boundaries. We'll have trouble telling how best to categorize the edge cases. What matters is what categories are most useful for understanding things. If the experts in an area decide to categorize something one way then let them.
To add insult to injury, they amended their convoluted definition with the vindictive and linguistically paradoxical statement that "a dwarf planet is not a planet." This seemingly served no purpose but to satisfy those motivated by a desire -- for whatever reason -- to ensure that Pluto was "demoted" by the new definition.
If I'm following this argument correctly, they are arguing that it is "linguistically paradoxical" to have something of the form "[adjective] x" to not also be in the category labeled "x". But we do this all the time. For example, in math a "skew field" is not necessarily a field https://en.wikipedia.org/wiki/Division_ring, and one can come up with many other examples in STEM fields. This is a natural thing that we do all the time. And the specific reason in this case that dwarf planets were not planets was to avoid then making Eris and Ceres and a a whole bunch of other objects also planets.
I'm fascinated that with everything else going on the world, serious people apparently think that arguing over what we call a planet or not is an important issue.
It's pretty simple. If Pluto identifies as a planet, then it is one. All of this classification by scientists is just an attempt to create a privileged, sexist, and racist system that discriminates against small planetoids.
Well I for one am glad this is finally settled.
I read at +2. If your post doesn't reach that level I will not see or respond to it.
The reason that they think the IAU's definition of a planet is ambiguous is because they have the definition wrong. A planet does not have to completely clear its neighborhood of all other objects (the earth would not qualify if that were the case, since it shares its orbit with Luna, its moon). What makes it a planet is when it has cleared the neighborhood of all similarly sized objects.
So yes, Earth would not be a planet if it shared an orbit with a planet like mars or venus, and would be considered either a moon or possibly even an asteroid if it shared an orbit with Jupiter or Saturn, depend on whether it was gravitationally captured by the gas giant or not.
File under 'M' for 'Manic ranting'
The whole reason for "demoting" Pluto had nothing to do with Pluto itself. It had to do with Eris. When Eris was discovered, it appeared to be (because of its albedo) larger than Pluto. It is, in fact, more massive tham Pluto is though slightly smaller. Because of its size, the discoverer was making a strong case for having it accepted as the solar system's 10th planet. While this gave NASA a huge ole woody, because they were counting the dollar signs of how a newly discovered actual planet would spur public opinion for exploration, it caused significant consternation at the IAU. That's actually understating things. A few members of the IAU were quite literally horrified at the prospect. They were looking at the fact Michael Brown's team had discovered scads of Trans-Neptunian-Objects, that there very well could be half a dozen or more additional ones the size of Pluto/Eris, and they were quite happy with the set of planets we already had, thank-you-very-much. There was a certain historical congruency to it and no upstart finding a TNO that happened to be as large as Pluto was going to get his name listed in the same breath as such nobility as William Herschel. So they decided that in the end, that since they really couldn't call Eris a planet if Pluto was a planet, they did what they thought was the lesser evil. They preserved the sanctity of the rest of the solar system by demoting Pluto.
Of course the definition has holes and is not even self-consistent. The whole purpose of it was to demote Pluto and all other similar objects and to ensure that it was worded such that no other TNO could ever be labelled a planet, by nature of being out in the area where nothing is "cleared".
What people need to ask themselves is this: does the fact that the IAU had its collective head up its ass tell me what I consider to be a planet? The answer for me personally is a big whopping no. And when it comes up in conversation, usually after I name all 9 traditional planets (sometimes adding Eris) and get "corrected" that, hey, don't I know Pluto isn't a planet any more, that's when I let the poor smarty-pants have it with both barrels. Not really their fault, but anyone toeing the IAU party line and not willing to think for themselves deserves to get it.
The IAU isn't an official body with any authority other than what they have taken on themselves. And if they are going to let historical politics cloud scientific thinking, they certainly aren't going to speak for me. I'd like to see some textbook publishers take a stand too.
I don't believe in scientific notation designed to limit a group to X. Either the definition is based on sound science or it is crap.
Pluto is structurally utterly unlike Ceres or any KBO, therefore it is not in the same category as those.
Pluto is structurally the same as Earth and Mars, therefore that is the category it belongs in.
Reality is not a popularity contest, I do not give a flying who thinks Pluto is what, it is structurally the same as a planet and is structurally distinct from anything not a planet. Far as I'm concerned, planetary science overrules any ego. The science comes first.
Any problem with that?
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
That's a GREAT idea! Send all the Lawyers to Pluto!
So you're saying the gas giants aren't planets? Same with the ice giants? And various large satellites are planets?
Besides I think you might find that Ceres is more like a rocky planet then an iceball like Pluto.
https://en.wikipedia.org/wiki/Inverted_totalitarianism
The classification does not change anything truly, but frankly the IAU kerfuffel DOES have a point : People want to keep Pluto out of sentiment. When you point them there is then more than 100 planet to add if Pluto is a planet, THEN they go back to the "but-this-is-what-i-learnt" BS defense. The IAU definition might not be 100% good, but some of the objection to it are stupid. Like the one it does not apply to other solar system. That one is frankly stupid , change the grammar to "its star" and bam, problem solved (and frankly when I read the definition the first time I read it that way too). I think that simply a lot of people cannot emotionally let go of that pluto-named TNO and will do anything including CT about not giving credit. Pretty much avoid recognizing that Pluto as a planet was pretty damn only an accident due to detection as opposed to a real definition. Just looking at the ecliptic should give IMO a hint.
C. Sagan : A demon haunted world:
http://www.amazon.com/gp/product/0345409469/
visit randi.org
Yes... because science and details never go together....
Fascism: An authoritarian and nationalistic right-wing system of government and social organization. See also: NAZI's
Hades is the Greek god of the underworld. Pluto is the Roman version.
And in old greek, Plouton is one of Hades' epithets - i.e.: adjectives often used together with His name to describe Him. (Just like Zeus Himself is usually "all-seeing" or the "storm gatherer", etc.)
It means "the rich / the rich-giver", because Hades is the god of the underworld and earth itself (as opposed to Posseidon who's got the seas and Zeus who's in charge of the sky), and that's where most of mines are and on what crops grow. (Might also have been because, except for heros, most mortals - both good and bad ones - end up in Hades' realm - different sections of the underworld serve as both hell *and* heaven, unlike in christian mythology - so He ends up with the most follower).
Over time, this has shifted to his euphemistical name (the thing mortals use to name him as to not anger Him) He became known "The Rich / The Rich Giver". (Just like in christian mythology, Satan is called often "the devil" instead of by his name).
And then again, over time this became used as His official name. That's what the Romans eventually picked-up in Latin.
Fun fact, the Latin "Jupiter" (in nominative case) has a similar construction : it's the contraction of "Zeus + pater" ("the father" - obviously once you look at the genealogy of most of the Greeko-Roman pantheon). But when declined in other cases, only the name is kept, e.g.: Jovis (genetive case).
So for some period of time "Pluto" is also what the Greel go of the underworld was called,
and even for some period of time it was His actual name.
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