The discussion about Pluto and the meaning of the word planet got me to thinking about language, words, meaning, and authority. I agree with Saussure who noted that the mapping between words and meaning is an arbitrary one. (I think most of us would agree that the word dog and the meaning of the word dog and actual dogs don't have much to do with one another except by the accident that dog, in English, means 'dog', the object in the real world and the concept in our mind.) Most of us who are literate think of a dictionary as a final authority on what's a word and what's not, or what a word means, but I don't think that any of us would want to say a language without a writing system and written dictionaries and grammars is not a language or was somehow less a medium of communication than those with those things. There are many words which are not in the dictionary and many meanings which are not there, too. If you think about how a dictionary comes to be, e.g., the OED, lexicographers research how words are used and deduce what they mean in certain contexts, and then write an entry based on that research and their analysis of it. So, the real problem which lexicographers face is which meanings make it into the dictionary and which do not, i.e., which are real and which are not. That sounds too strange, but, assume that by planet, I mean those nine traditional planets in our Solar System from Mecrucy to Pluto. Is that the only meaning of planet? Is it better or worse than the definition that the IAU recently came up with which deplanetized Pluto and other trans-Neptunian objects?

I think the "planet" controversy could be viewed similar to the meaning of the word "state". There are 50 states in America, plus a handful of territories. If Puerto Rico were to suddenly become the 51st state, how would people feel? I'm certain there are probably a lot of Americans who would feel offended by this, and continue to wave flags with 50 stars for the rest of their lives.

What is the difference between "state", "territory", "province", or "protectorate"? We attach connotations to words. In America, a state is a fundamental unit of democracy, representative of life, liberty, the pursuit of happiness. For some Americans, I'm sure, there is attached this idea that a state is home to white Christians, who are the driving force behind America being the greatest country in the world. I certainly don't agree with that, but I'm sure others do.

As for planet, I'm not sure where this sentimental attachment came from. I've always thought there were 9 planets, but when the opportunity came to drop it, I was happy. Pluto has always been an outlier, and not just because of its distance. Clearly, a large number of people had an emotional attachment to the concept of Pluto as a planet. Of course, to astronomers, it was necessary to have a definition for planet which didn't have any exceptions. Given the choice between dropping Pluto as a planet, and adding a bunch of other celestial objects, the former is much more appealing.

I was recently talking to Landon Noll and his objection to the IAU definition of planet (as I recall -- it was a Christmas party) was that it doesn't allow extrasolar-planet researchers to observe an object orbiting a distant star and call it a planet. There is simply not enough information about extrasolar "planets" to determine whether they fit the new IAU definition.

I have been reading the discussion about Pluto, too, and wordnerd made me think. With other words, when the public uses them, the definitions evolve. The examples are endless. While that may not be quite as true with scientific words, it surely is true with many medical words (such as "shock lung" which became "acute respiratory distress syndrome' and even today that is evolving). I think wordnerd had a point in that Vocabulary thread.

Doesn't the USA actually have a couple of 'commonwealths'? Presumably those aren't states if you are going to be ultra-literal?

Doesn't the USA actually have a couple of 'commonwealths'?

Yes, four by this count, but it seems to be a synonym of state (at least in legal parlance). The fourth article of the US constitution simply uses the word state.

neveu: I was recently talking to Landon Noll and his objection to the IAU definition of planet ... was that it doesn't allow extrasolar-planet researchers to observe an object orbiting a distant star and call it a planet. There is simply not enough information about extrasolar "planets" ...

Your friend can rest assured. The IUD wrote its resolution to apply only within our solar system. ("The IAU therefore resolves that planets ... in our Solar System be defined ...") In other words, 'planet' for purposes of the solar system differs from 'planet' for other purposes -- according to the IAU definition.

Which should indicate to you how artificial that definition is.

Which should indicate to you how artificial that definition is.

I would amend that to "how artificial all definitions are." Way back before you or I were born, planet was defined in such a way that it included the earth's moon and the sun. Back then Pluto, Uranus, and Neptune didn't exist. Or rather we didn't know about them. Of course the objects themselves existed.

This is like the definition for element. Way back when, there were four and then five, but now there's more than a hundred. Has the world come crashing to a halt? No. When Holmes says "Elementary, my dear Watson", we still know what he's talking about. If I wrote an article I hope to have published in the New England Journal of Medicine, I'm not going to talk about humors and bleeding (unless it's an historical article). I'll use the standardized vocabulary of modern medicine. What's wrong with that? It doesn't stop me from saying, in a different context, that my heart is heavy or was broken by a certain event.

There's no special relationship between planet and any of its many definitions or meanings. It is an arbitrary one. No more, no less.

I'd disagree, z.

I'd agree that the choice to call certain objects 'planet', rather than some other name, is arbitrary (or if you like, is historical).

But the choice encompass certain objects (and not others) under a term is not arbitrary: it is a judgement that it will sometimes be useful to refer to them as a group, and therefore to have a short name for "the group" rather than naming them all every time. For instance, I could define 'shufi' to mean "Mercury, Earth, or Jupiter". But the definition would not catch on, and come into common speech, because there is no particular occassion when it's useful to refer to those bodies to the exclusion of others.

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quote: This is like the definition for element. Way back when, there were four and then five, but now there's more than a hundred.

Yes, but that's not a change in the definition of 'element'. The definition remains the same. We've simply learned of the factual matter that there are additional substances that fit that definition (and also learned that the four items thought to be elements do not in fact fit that definition).

As far as the issue on extra-solar planets, from what I remember, most of these planets are discovered through the wiggle in velocity of the parent star that is caused by the gravitational attraction to the orbiting planet. The star moves in a tiny little circle about the center of mass of the two bodies. These extrasolar planets tend to have something more on the order of a Jovian mass--huge enough to dominate its orbit and quickly clear it of any debris. The more pressing question in some of these cases is whether these entities are some star-type structure such as a brown dwarf.

That describes the first extrasolar planets found, but I think there are new methods (blink and IR) that reveal smaller planets that may or may not dominate their orbits. In any case we can't see debris so we can't determine that it has been cleared. I believe Landon also felt that the Earth and one or two other bodies didn't fit the definition of planet anymore -- I'll ask him. Finally, I think he objected to having one definition for solar planets and another much broader definition for extrasolar planets.

quote:

Originally posted by wordnerd:


Your friend can rest assured. The IUD wrote...

Intra Uterine Device? To prevent the conception of planets? Weird!

Back on the main track here, we were having a discussion of what constitutes a French word in a class I'm taking, and the instructor said of the Academie Francais, "These are not very nice people who only eat and read books!" While I'm a bit of a prescriptivist myself, I do realize that language must morph to fit changed circumstances. If an old term can't encompass a new concept, then a new word must be developed. The above mentioned A. F. decided that "telecharger" must describe downloading, and "courriel" must describe e-mail in France. I find "telecharger" on most French sites, but not "courriel." no, the public likes "email!"

quote:

not very nice people who only eat and read books

What's wrong with eating? Even Posh Beckham is rumoured to indulge in it sometimes.