User talk:Jagun
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[edit] What's the point of this whole argument?
Why did the IAU even HAVE to reclassify what a planet is in the first place? shouldn't we (meaning the IAU, and the populace at large) be able to work with the way a planet has been defined before? I think "Spherical objects that orbit the Sun" works just fine. (Unless,of course, the IAU's planet classification binder was running out of space. --Jagun (talk) 04:47, 30 May 2008 (UTC)
- Wikipedia isn't really the place to discuss this; its primary purpose is to report, not to debate. However, I think you've slightly misunderstood the article. Until 2006, there had never been a single, fixed definition of "planet". Even dictionaries tended to define planet in a rather circular way, saying things like, "a planet is larger than an asteroid or comet" and then defining "asteroid"/"comet" as "smaller than a planet." There is no definition that cannot be picked apart for various reasons; even mandating that a planet orbit a star is a bit controversial, since it gives planetary status to boring rocks like Mercury but denies it to fascinating worlds like Titan. It also denies planethood to any potential rogue planets. The most all-inclusive definition, which is favoured by astronomers like Mark Buie, is that a planet is anything big enough to be round but not big enough to fuse hydrogen. This would basically mean that any object discovered in the universe from about a fifth the mass of our Moon to about 13 times the size of Jupiter is a planet. It would mean that kids would have to give up learning the planets in our Solar System, since the number would go from eight to about 50. And that is the main issue. The word "planet" is not a scientific term; it's a term tied to myth, history and religion. It's "special". Is it right that tiny bits of ice at the end of the Solar System should be so "honoured", or should the term "planet" be selectively bestowed only on those that "deserve it"? This isn't a scientific issue, but then "planet" has never been a scientific word. Serendipodous 07:29, 30 May 2008 (UTC)
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- That's actually a pretty good definition, but I think you should add (or at least state more explicitly) that planets have to orbit the sun directly (i.e., a planet is not a satellite). This is not about how "interesting" something is. Britney Spears is "interesting", but she does not fit the definition I have made for "music that I like to listen to". Another good addition, I believe, would be to mention that planets must be "unique", that is, there should not be an abundance of like objects (think: Kupier belt) in the immediate vicinity. And finally, if the definition of a planet is not a scientific issue, then the IAU (a scientific organization) should leave the definition to people in linguistics, like the Oxford English Dictionary. Jagun (talk) 14:24, 30 May 2008 (UTC)
- Your definition is basically the one the IAU chose to adopt. As for why they did it in the first place, they didn't have a choice. They kept under the rug for as long as they could; then Eris turned up and everything went crazy. Believe me, they didn't want to do it; Eris forced their hand. Serendipodous 16:15, 30 May 2008 (UTC)
- You're right, but I think the IAU should have worded the definition differently. "Cleared the neighborhood" is a little ambiguous. One of the articles dealing with this controversy mentions that Earth, Jupiter, etc. have not cleared their neighborhoods either, but the phrase actually refers to the original creation process. "Unique", in my opinion, is a bit less ambiguous/open for interpretation. Jagun (talk) 22:39, 30 May 2008 (UTC)
- I'm moving this here, since it really doesn't belong on the article's talk page. "Unique" isn't really any less ambiguous than "clearing the neighborhood". No planet is truly unique; each shares its orbit with dust particles, micrometeoroids, the occasional comet and many other things. If you read the clearing the neighborhood article, you'll see that Steven Soter has developed a perfectly acceptable mathematical definition for clearing the neighborhood that creates a sharp division between the large and small objects in the Solar System. Serendipodous 07:48, 31 May 2008 (UTC)
- That's what I meant. The "mathematical" definition is less easily definable in layman's terms than "unique" as in "no objects resembling it in the immediate vicinity". Jagun (talk) 20:01, 31 May 2008 (UTC)
- Resembling it how? Serendipodous 20:11, 31 May 2008 (UTC)
- In size, shape, and composition. For instance Pluto resembles Kupier belt objects, but Earth does not resemble Venus. And what I meant when I said that the IAU should have worded their definition differently was that to someone who had not heard of the mathematical formula or read the article, "Clearing the neighborhood" could have referred to the present, or the time of formation. Jagun (talk) 21:19, 31 May 2008 (UTC)
- Earth and Venus resemble each other rather closely. It's only in atmospheric composition and tectonic activity that they differ. Yes, clearing the neighborhood" was a vague term, but the conference was not long enough for the IAU to establish a fixed mathematical value for the planet-dwarf planet dividing line. Hopefully the next conference, held in Rio in 2009, will go some way to address this issue. Serendipodous 06:10, 1 June 2008 (UTC)
- But you're still mentioning a "mathematical value" which I believe is the flaw in your (and many other astronomers') definition. In my opinion, the simplest definition is usually the best one. For instance, you can define a prime number as "Any number divisible only by one and itself" or Formula for primes#Formula based on a system of Diophantine equations. A definition that is clear, concise, and easy to explain would be the optimal definition. And (unrelatedly) if you are feeling a little lighthearted, visit User:Rursus/Pluto Dont Care Dwarf Planet Not.
- Earth and Venus resemble each other rather closely. It's only in atmospheric composition and tectonic activity that they differ. Yes, clearing the neighborhood" was a vague term, but the conference was not long enough for the IAU to establish a fixed mathematical value for the planet-dwarf planet dividing line. Hopefully the next conference, held in Rio in 2009, will go some way to address this issue. Serendipodous 06:10, 1 June 2008 (UTC)
- In size, shape, and composition. For instance Pluto resembles Kupier belt objects, but Earth does not resemble Venus. And what I meant when I said that the IAU should have worded their definition differently was that to someone who had not heard of the mathematical formula or read the article, "Clearing the neighborhood" could have referred to the present, or the time of formation. Jagun (talk) 21:19, 31 May 2008 (UTC)
- Resembling it how? Serendipodous 20:11, 31 May 2008 (UTC)
- That's what I meant. The "mathematical" definition is less easily definable in layman's terms than "unique" as in "no objects resembling it in the immediate vicinity". Jagun (talk) 20:01, 31 May 2008 (UTC)
- I'm moving this here, since it really doesn't belong on the article's talk page. "Unique" isn't really any less ambiguous than "clearing the neighborhood". No planet is truly unique; each shares its orbit with dust particles, micrometeoroids, the occasional comet and many other things. If you read the clearing the neighborhood article, you'll see that Steven Soter has developed a perfectly acceptable mathematical definition for clearing the neighborhood that creates a sharp division between the large and small objects in the Solar System. Serendipodous 07:48, 31 May 2008 (UTC)
- You're right, but I think the IAU should have worded the definition differently. "Cleared the neighborhood" is a little ambiguous. One of the articles dealing with this controversy mentions that Earth, Jupiter, etc. have not cleared their neighborhoods either, but the phrase actually refers to the original creation process. "Unique", in my opinion, is a bit less ambiguous/open for interpretation. Jagun (talk) 22:39, 30 May 2008 (UTC)
- Your definition is basically the one the IAU chose to adopt. As for why they did it in the first place, they didn't have a choice. They kept under the rug for as long as they could; then Eris turned up and everything went crazy. Believe me, they didn't want to do it; Eris forced their hand. Serendipodous 16:15, 30 May 2008 (UTC)
- That's actually a pretty good definition, but I think you should add (or at least state more explicitly) that planets have to orbit the sun directly (i.e., a planet is not a satellite). This is not about how "interesting" something is. Britney Spears is "interesting", but she does not fit the definition I have made for "music that I like to listen to". Another good addition, I believe, would be to mention that planets must be "unique", that is, there should not be an abundance of like objects (think: Kupier belt) in the immediate vicinity. And finally, if the definition of a planet is not a scientific issue, then the IAU (a scientific organization) should leave the definition to people in linguistics, like the Oxford English Dictionary. Jagun (talk) 14:24, 30 May 2008 (UTC)
Be very careful when trying to explain numbers with words. Words are by nature inexact (a fact which gives us metaphor), whereas numbers are not. Linguistically speaking, one can be divided by one and itself (since it is one) but is not a prime number. A prime number is best defined, as my exasperated high school math teacher told me, as a number with only two factors. Science has it even worse, since it is trying to define the universe, which is inexact to all but the omniscient, with numbers, which don't like imprecision. In order for a definition to have any applicability whatsoever, it must have an absolute boundary. There has to be a fixed point whereat something ceases to be, say, a planet and becomes something else. Taxonomists are tearing their hair out about this right now over the precise definition of a species. Some say that it should be based on breeding capabilities, others that it should be based on phenotype (which would presumably make black people a different species of human). Steven Soter's mathematical value provides an absolute boundary to describe exactly when a planet ceases to be a planet. Serendipodous 08:32, 1 June 2008 (UTC)
- Exactly. Since the universe is indefinite, shouldn't we try to define it with (equally indefinite) words? Jagun (talk) 18:41, 1 June 2008 (UTC)
- Absolutely not. The world may be indefinite, but science cannot be. Science's job is to break the indefinite universe into ever smaller slivers of absolute certainty, each time getting closer and closer to the truth, even if it never actually reaches it. Science needs to be falsifiable, which means it needs to be capable of being proven wrong. Science needs precise definitions, because, wherever and whenever they are performed, experiments must have the same preconditions, so that they achieve the same results. These preconditions must be set to an absolute set of generally understood rules, so that scientists the world over can cross-check and verify the results of other scientists. That's why all scientists, whatever their nationality, use metric. It does no one any good when one scientist publishes a paper saying he's just discovered a new planet if no other scientists can agree what a planet is or is not. Have you ever read a scientific paper? They are not masterpieces of the written word; indeed from a literate point of view they are incomprehensible gibberish. They have to be, because science has to express its points and facts as correctly and precisely as possible, something that language is notoriously bad at. It's the same with the law. The reason law books are so convoluted is because they are, effectively, a forest of definitions upon definitions upon definitions, each one defining the absolute boundary of right and wrong for every conceivable set of circumstances. Law, like science, needs absolute boundaries; there has to be a point when a person is definitely guilty or innocent, or law cannot function. If poets, seers and magicians want to employ the term planet metaphorically, they're welcome to, but science doesn't have that luxury.Serendipodous 19:03, 1 June 2008 (UTC)
- But we don't know the boundary condition in this universe, so it's pointless trying to exactly define it when not all pieces of the puzzle are in place. It's like trying to bake a cake with only flour and water. Jagun (talk) 19:13, 1 June 2008 (UTC)
- You're right, we don't know. But science isn't about knowing, it's about evidence. For all we know, we could all be plugged into the Matrix and the world we experience might be only an illusion. Hell, I could be the only person in the universe and everything else could be a figment of my imagination. We only have this little universe to go on, and science to explain it to us. Science goes where the evidence takes it, and if the evidence tells it that the universe appears to function in a certain way, then science cobbles together as best it can a working model that explains everything we do know and, preferably, makes accurate predictions of things we don't know. For instance, Isaac Newton's theory of gravity made the prediction that another planet must exist beyond Uranus, since the motions of the outer planets were not following Newton's strictly defined rules. However, with another unseen planet added to the mix, Newton's rules worked out. Much to general relief and glee, this extra planet was eventually found. However, Newton's rules also demanded that another planet exist interior to Mercury, since Mercury's orbit was also not behaving within the strict limits set by Newtonian mechanics. In that case, no planet was found and ultimately it was Newton's rules that were at fault; Einstein's theory of general relativity was needed to fully explain the orbit of Mercury. Newton's theories explained the universe as best as Newton knew. Einstein's rules explain the universe as best as we know now. Some day, another conception of the universe may (I'd say will) come along that will make what we know now as obsolete as Aristotle. Science is always changing because our conception of the universe, with the aid of new evidence, is always changing. Serendipodous 19:29, 1 June 2008 (UTC)
- Yes, but there's simply not enough evidence to make such a strict definition of planet (and at least have it be reasonably correct). Since we know/have evidence for so little in this universe, it follows that the best definition at this point in time would be one that is rather indefinite, to avoid having it found incorrect by some small detail. Jagun (talk) 19:44, 1 June 2008 (UTC)
- Well, that was the position taken by the IAU until 2006. The only impetus for this discussion was simply that Eris was either a planet or a minor planet and, unfortunately, astronomical naming convention demands that minor planets have numbers denoting the order of their discovery placed before their names. Before Eris could be named, the IAU had to decide if it was a planet. If it wasn't, then neither was Pluto, but if it was, then where to draw the line? Basically, this whole debate revolved around whether or not Eris should have a number in front of its name or not. This is not by any means the final word on the planet definition. Even if it is precisely defined next year, future discoveries could force it to be rethought completely. Mike Brown has already started a sky survey with the expressed intention of locating an object as massive as Mercury within the outer Solar System. Such a discovery would throw a wrench into the whole dwarf planet concept, since it would technically be a dwarf planet as large as a planet. The Juno mission to Jupiter in 2011 could determine whether or not Jupiter formed as a planet or as a star; if it did, then it and perhaps even Saturn could be reclassified as low-mass stars, with their moons promoted to planets. Then the debate would shift to Uranus and Neptune, and the arguments will go on. But that is what science does. It argues. And thank God for that. Serendipodous 19:56, 1 June 2008 (UTC)
- Yes, but there's simply not enough evidence to make such a strict definition of planet (and at least have it be reasonably correct). Since we know/have evidence for so little in this universe, it follows that the best definition at this point in time would be one that is rather indefinite, to avoid having it found incorrect by some small detail. Jagun (talk) 19:44, 1 June 2008 (UTC)
- You're right, we don't know. But science isn't about knowing, it's about evidence. For all we know, we could all be plugged into the Matrix and the world we experience might be only an illusion. Hell, I could be the only person in the universe and everything else could be a figment of my imagination. We only have this little universe to go on, and science to explain it to us. Science goes where the evidence takes it, and if the evidence tells it that the universe appears to function in a certain way, then science cobbles together as best it can a working model that explains everything we do know and, preferably, makes accurate predictions of things we don't know. For instance, Isaac Newton's theory of gravity made the prediction that another planet must exist beyond Uranus, since the motions of the outer planets were not following Newton's strictly defined rules. However, with another unseen planet added to the mix, Newton's rules worked out. Much to general relief and glee, this extra planet was eventually found. However, Newton's rules also demanded that another planet exist interior to Mercury, since Mercury's orbit was also not behaving within the strict limits set by Newtonian mechanics. In that case, no planet was found and ultimately it was Newton's rules that were at fault; Einstein's theory of general relativity was needed to fully explain the orbit of Mercury. Newton's theories explained the universe as best as Newton knew. Einstein's rules explain the universe as best as we know now. Some day, another conception of the universe may (I'd say will) come along that will make what we know now as obsolete as Aristotle. Science is always changing because our conception of the universe, with the aid of new evidence, is always changing. Serendipodous 19:29, 1 June 2008 (UTC)
- But we don't know the boundary condition in this universe, so it's pointless trying to exactly define it when not all pieces of the puzzle are in place. It's like trying to bake a cake with only flour and water. Jagun (talk) 19:13, 1 June 2008 (UTC)
- Absolutely not. The world may be indefinite, but science cannot be. Science's job is to break the indefinite universe into ever smaller slivers of absolute certainty, each time getting closer and closer to the truth, even if it never actually reaches it. Science needs to be falsifiable, which means it needs to be capable of being proven wrong. Science needs precise definitions, because, wherever and whenever they are performed, experiments must have the same preconditions, so that they achieve the same results. These preconditions must be set to an absolute set of generally understood rules, so that scientists the world over can cross-check and verify the results of other scientists. That's why all scientists, whatever their nationality, use metric. It does no one any good when one scientist publishes a paper saying he's just discovered a new planet if no other scientists can agree what a planet is or is not. Have you ever read a scientific paper? They are not masterpieces of the written word; indeed from a literate point of view they are incomprehensible gibberish. They have to be, because science has to express its points and facts as correctly and precisely as possible, something that language is notoriously bad at. It's the same with the law. The reason law books are so convoluted is because they are, effectively, a forest of definitions upon definitions upon definitions, each one defining the absolute boundary of right and wrong for every conceivable set of circumstances. Law, like science, needs absolute boundaries; there has to be a point when a person is definitely guilty or innocent, or law cannot function. If poets, seers and magicians want to employ the term planet metaphorically, they're welcome to, but science doesn't have that luxury.Serendipodous 19:03, 1 June 2008 (UTC)
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All the tea in China | |
| I haven't quite got the hang of personalised barnstars yet, but I thought you might like this instead. Just don't demand a contract from the Chinese Communist Party. Serendipodous 21:11, 1 June 2008 (UTC) |
Yeah, thanks :) Just took me a while to find a suitable response. Serendipodous 05:26, 2 June 2008 (UTC)
