Talk:Definition of planet/Archive 5

message: The whole “Pluto is not a planet” idea comes from reports on the IAU (International Astronomical Union) which got together and decided on a new definition of a planet ["a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet”].
From this, it’s been everywhere that Pluto is not a planet.  BUT on the IAU’s website, it says that Pluto IS a planet (http://www.iau.org/iau0601_Q_A.435.0.html).  Even more, it says there are 12 planets in the solar system, not 9: "Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Charon and 2003 UB313 (provisional name)".  The last one is “popularly called Xena,” but the official name has not been chosen yet.
Pluto and Charon are classified as “Plutons,” which is a subcategory of planet, not a separate category.  Plus, “Perhaps as many as a dozen or two new planets in the IAU category called “plutons” remain to be discovered” and are just waiting on reports from committees formed to study them.
The whole “Pluto isn’t a planet” might come from the IAU’s attempt to rename everything.  They’ve decide that Mercury through Neptune are the first nine planets (planet 1, planet 2, etc), but Pluto is not “planet 9.” Rather, it is “Pluton 1.”  —Preceding unsigned comment added by 216.138.96.227 (talk) 18:56, 26 October 2007 (UTC)
replies: text: That is an old website referring to an earlier proposed definition that did not pass the conference; for the whole bloody story of the different proposals at the time, see 2006 definition of planet.--Pharos 19:06, 26 October 2007 (UTC)

text: That's the draft resolution. The final resolution excluded pluto. Serendipodous 19:09, 26 October 2007 (UTC)

text: The final definition makes no reference to "Classical" at all. Resolution 5b was proposed, but it failed at the vote. Only 5a and 6a made it through. (see here) If you read the "Semantics" section, not to mention the IAU quote I added two days ago, you can see that the IAU makes perfectly clear that dwarf planets are not planets. I just added the results of the final vote to 2006 definition of planet, so hopefully that should clear the matter up.Serendipodous 16:20, 2 January 2008 (UTC)

text: I wouldn't mind, but it probably would violate Wikipedia linking guidelines, since it states a very strong point of view. Serendipodous 23:19, 7 January 2008 (UTC)

text: Unlike all other large moons, Charon and Pluto orbit a common centre of mass outside themselves. In essence, they both orbit each other, so either could be described as the other's moon. Because of this, the initial proposal suggested that Charon be considered one part of a "double planet". However, that proposal was dropped and the final proposal left Charon a moon. Serendipodous 15:59, 23 February 2008 (UTC)
thread_title:  Pluto IS a planet, according to the International Astoronomical Union 

message: This is a great article, but the lead doesn't do it justice. The current lead reads more like the lead for 2006 definition of planet, and that was what I was expecting to find in the rest of the article. I was (pleasantly) surprised: this article contains a treasure-trove of historical information. However, such surprise runs contrary to WP:LEAD, so I think the lead needs a complete rewrite. Geometry guy 18:50, 1 November 2007 (UTC)
replies: text: I had a go at editing the lead; I didn't really want to rewrite too much because otherwise I would be in danger of repeating information already in the article. Let me know what you think. Serendipodous 07:43, 2 November 2007 (UTC)
replies: text: It is definitely an improvement, but I don't understand why you are concened about "repeating information already in the article": that is exactly what the lead is supposed to do! It should "briefly summarize the most important points covered in an article in such a way that it can stand on its own as a concise version of the article". This means not only that the most important points in the body of the article should be summarized in the lead, but also that "Significant information should not appear in the lead if it is not covered in the remainder of the article". So actually, all the information is repeated! Geometry guy 17:43, 2 November 2007 (UTC)
replies: text: I just don't see the point of going into too much detail. As long as all the salient points are mentioned, what else needs to be said? Serendipodous 17:48, 2 November 2007 (UTC)
replies: text: I agree, and the lead is probably a bit long now: it could surely be made more concise without loss of significant information. To me, it still does read a bit like the lead for 2006 definition of planet, and it repeats itself a few times: for instance the 2005 debate is discussed twice, as is the ambiguity in the meaning of planet historically. Geometry guy 18:35, 2 November 2007 (UTC)
replies: text: OK; how's that? Serendipodous 19:01, 2 November 2007 (UTC)
replies: text: Nice one! Well, I like it, anyway, and hope you haven't found this exchange completely pointless :-) Geometry guy 19:47, 2 November 2007 (UTC)
replies: text: Nope. Any excuse to edit this article really. I like tending it; it's the only featured article I created, so I like to see it at its best. You know, like a prize winning pet. Serendipodous 19:55, 2 November 2007 (UTC)
thread_title:  Nice article, inadequate lead 

message: WP:NOTDICDEF Can somebody explain the significance of this article within the scope of this rule? WP:NOTDICDEF 67.137.0.28 (talk) 04:09, 5 May 2008 (UTC)
replies: text: This article isn't a definition of planet. It's about the definition of planet. Serendipodous 05:33, 5 May 2008 (UTC)

text: I agree. This article provides a good concise history of planetary astronomy from ancient times to the most modern discoveries, all centered around the central objects of planetary astronomy for over two millennia. This is a good article. And the introduction is excellent. —MiguelMunoz (talk) 23:05, 27 November 2008 (UTC)
thread_title:  Wikipedia is NOT a dictionary 

message: I am moving this comment to the talk page in case I want to figure out a way to reinsert it later. -- Kheider (talk) 15:00, 24 July 2008 (UTC)
replies: text: It could probably go into the double planets section. Serendipodous 15:13, 24 July 2008 (UTC)
thread_title: Galilean moons

message: The lead for this article is beautiful. I don't know if I have ever seen prose that great on Wikipedia. Wow. Phenomenal. Matt Yeager ♫ (Talk?) 22:51, 7 November 2008 (UTC)
replies: text: Thank you :-) Serendipodous 10:30, 8 November 2008 (UTC)
thread_title: Holy cow

message: I changed a description of pluto from "one sixth the size of the Earth's Moon" to "one sixth as massive as the Earth's Moon. The word "size" is tricky, since it can refer to several different properties. We should be careful to use the word "mass" when that's what we're actually talking about. In general, I avoid the word "size" in astronomy, in favor of more specific words like "radius," "diameter," "mass," "length," and so on. This article uses the word "size" a lot, and most of the uses are perfectly legitimate, since it's often making vague (but accurate) claims like "most of these objects were similar in size to Pluto." But for more specific claims, "size" should be avoided. Pluto's diameter is 70% of the Earth's Moon, but it's mass is roughly one sixth.   —MiguelMunoz (talk) 22:59, 27 November 2008 (UTC)
thread_title:  Use of the word "size" 

message: The intro claims that by the end of the 19th century, the working definition "only applied to objects in the Solar System." Strictly speaking, this isn't true. While the known planets were only our solar system, the term was often used when speculating about planets orbiting other stars. In that sense, it applied to undiscovered objects orbiting star. I'm giving some thought to how we might reword that sentence without making it clumsy. —MiguelMunoz (talk) 09:14, 28 November 2008 (UTC)
thread_title:  Only in our Solar System? 

message: Serendipodous: I have two questions:
1) Can you show me the "decree" where this definition applies only to our solar system? The cited reference is vague.
To state that the definition applies here "by decree" misses an important scientific point. If this "decree" exists and if you understood it properly, it exists only because it reflects the state of the current science. It's more important to describe the scientific reasons for the limitation, than to specify the limitation. As it stands, the current definition distinguishes planets from smaller bodies, because that's the only distinction that matters in our solar system. To state that it doesn't apply outside the solar system suggests that other definitions might rival this one, when in fact they complement this one, by distinguishing planets from larger bodies. That's the point I want to get across in this article. —MiguelMunoz (talk) 21:37, 28 November 2008 (UTC)
replies: text: What you say is your opinion. It is not based on fact or sources. You have not cited any IAU source claiming that your rationale is the one behind the decision. If you're willing to watch the entire 2006 session, you'll see that Owen Gingerich specifically excluded extrasolar planets as too complex to be dealt with then. Serendipodous 11:40, 29 November 2008 (UTC)
replies: text: You'll also see that the reason it was too complex was that extra solar planets require that planets be distinguished from larger bodies, which is a very difficult question, whereas the solar system only requires a definition that distinguishes planets from smaller bodies. Owen Gingerich is very clear about this when he is asked why they're not including exoplanets. He answers the question by talking about why they're not addressing the question of "upper limits" of the planet's mass. My source is the same as yours. My point still stands. (Granted, for extrasolar planets, there is the additional question of defining planets in young stellar systems where they haven't had the time to clear their neighborhood, although the science behind the definition may still work, since it could be used to predict which protoplanets have enough mass to do so. But the IAU didn't really go into this, and I didn't want to get into the question of young stellar systems.) —MiguelMunoz (talk) 21:18, 29 November 2008 (UTC)
replies: text:  Serendipodous: I appreciate that you made changes to address the issues I raised here, but you completely removed the point that the new definition is only used in our solar system. I feel that's an important point that should be a part of this article. If you're looking for documentation, check out this clip from the 2006 session. About 60% of the way through, a bearded astronomer (with a thick accent) asks about extrasolar planets, and specifically states that he doesn't want clashing definitions. This is where they clarify that they are only concerned with the lower mass limit, to avoid clashing with the extrasolar astronomers. —MiguelMunoz (talk) 04:39, 30 November 2008 (UTC)
replies: text: I didn't remove it, I moved it a few paragraphs down. Serendipodous 21:57, 3 December 2008 (UTC)

text: I fixed the mass statement about Pluto since that is more accurate and not misleading.  the comment "and with similar orbits" implies that most TNO's have orbits like Pluto, which is not a good general statement.  Pluto is a plutino, most TNOs are not.  The comment "tend to be much larger than Jupiter" seems to imply that most exo-planets will be larger than Jupiter when the truth is that it is simply easier to detect large bodies.  Dwarf planets and asteroids will likely be far more numerous. -- Kheider (talk) 22:12, 28 November 2008 (UTC)
replies: text: Here's what I meant by "similar orbits," and I think this is an important point that should be in the article in some form. The eight planets all orbit in planes close to the ecliptic, with nearly circular orbits. The NGOs tend to have highly inclined orbits with larger eccentricities. My point was that Pluto's orbit resembles the other NGO orbits. Granted the phrase "similar orbits" is a bit vague. I originally had "similar key orbital characteristics," which was both vague and wordy, and I was reluctant to use terms like eccentricity, since that might go into more detail than the paragraph needs. But my point remains. Pluto's orbit doesn't resemble those of the eight planets, but it does resemble those of most NGOs, and the reasons come directly out of what distinguishes the NGOs from the planets. If you have a better way to put this, then please do so, but it should be in the article. —MiguelMunoz (talk) 23:17, 28 November 2008 (UTC)
replies: text: Your addition isn't relevant to the definition. The definition distinguishes Pluto purely on the grounds of clearing the neighborhood. That's it. Everything else is just personal opinion. And anyway, not all TNOs have orbits like Pluto (Quaoar has a very circular and flat orbit) and many extrasolar planets have very eccentric and inclined orbits. However, since in that context it doesn't do any harm, I'm willing to keep it. Serendipodous 11:25, 29 November 2008 (UTC)

text: As for TNOs tending to be much larger than Jupiter, that sentence was clearly talking about those that have been discovered. Your point about exoplanet detection is well taken, but I feel Serendipodous would have better served our readers by clarifying my point rather than removing it. The reasons I added that phrase come from the points I first raised in this section: The complementary definition's purpose is to distinguish planets from stars.—MiguelMunoz (talk) 23:17, 28 November 2008 (UTC)
replies: text: Your point, despite being misstated, was out of context in that sentence. That paragraph was about why the IAU had decided not to cover the issue at the 2006 conference. The fact that exoplanets can be larger than Jupiter had nothing to do with it. Serendipodous 11:18, 29 November 2008 (UTC)
replies: text: Again, your sources clearly state that the reason this was too complex was that they didn't want to consider the complex question of the upper limit of a planet's mass. So the point wasn't out of context at all. And I don't see how it was "misstated." The fact that exoplanets can be nearly larger enough to be stars had everything to do with it. I put in the size comparison with Jupiter to put the issue in a context that people will be more familiar with. —MiguelMunoz (talk) 21:26, 29 November 2008 (UTC)

text: I think your problem is not in intention, but in execution. You obviously have problems fully expressing your points on the page, so perhaps it would be best if you kept your ideas on the talkpage. Serendipodous 21:32, 29 November 2008 (UTC)
replies: text: And you tell us you're not being territorial? —MiguelMunoz (talk) 01:25, 30 November 2008 (UTC)
replies: text: This article requires very precise wording, because it must make very fine distinctions. Your additions so far have been vague and unclear, but based on your discussions here you obviously know what you're talking about. So; if you have an addition you think the article needs, offer it up here and, if I think it's valid, I'll try and work it into the article, just as I did for your other two additions. Serendipodous 01:30, 30 November 2008 (UTC)
replies: text:  "This article requires very precise wording." This is from the one who changed "mass" back to "size." Your suggestion here is hardly within the spirit of Wikipedia. I have no problem with collaboration, and I'm happy to work with you, but your tone here is hardly conducive to a good working relationship. I am not your student, and you are not my supervisor. I will continue to make small changes as I see fit, and if you have a problem with them, please feel free to say so on this page. (Although the article is pretty satisfactory as it stands now.) —MiguelMunoz (talk) 01:57, 30 November 2008 (UTC)
replies: text: Point taken, though that reversion was accidental. However, I still reserve the right to revert any changes that don't make any sense, unless they are explained on the talk page first. Serendipodous 10:46, 30 November 2008 (UTC)
replies: text:  Let me reassure you that I have no intention of gutting this article. You and I share the goal of a clear, concise, and accurate article according to the standards of Wikipedia. This is a very good article, and mostly handles the scientific points very well. I wouldn't dream of making any major changes without first getting a consensus of other editors, especially you. There were a few points that I felt weren't as clear as they could be, and I just wanted to clarify them. —MiguelMunoz (talk) 11:26, 30 November 2008 (UTC)
thread_title:  Definition applies only to our Solar System 

message: You've added that line about Herschel before, and it's been removed, so I don't know why this has come up again. It is inappropriate on several counts. First of all, it is unsourced; second, it uses colloquial emphasis- you make it seem like the narrator is saying, "Aww jeez! It's always a friggin comet!" Finally, it's wrong. The reason Herschel did not suspect that his object could have been another planet was simply because no one had ever found another planet before. It was as alien a concept to him as finding a second Sun would be for us. Other astronomers were actually far more eager to call it a planet than he was. Serendipodous 11:18, 29 November 2008 (UTC)
replies: text: It came up again because you removed it with no discussion. And it's not wrong. The statement is factually accurate, which I'm sure you already know, although if you can come up with a counter example, I'm all ears. I wasn't claiming this was a documented part of his thinking, I was putting his discovery in historical context, to clarify his hesitation. His reluctance to call Uranus a planet seems strange to modern readers, so improving the context makes things clearer.  —Preceding unsigned comment added by MiguelMunoz (talk • contribs) 19:40, 29 November 2008 (UTC)

text: OK. I think I understand what you were trying to say, but it was unclear. I can rephrase it, and, more importantly, reference it to make it clearer. Serendipodous 21:31, 29 November 2008 (UTC)
replies: text:  Your latest addition works pretty well, but I feel it could be strengthened. It's fine to say that "comets were the only moving objects one expected to find in a telescope," but my original point wasn't about expectations, it was about experience. It's a subtle difference, but I feel it's an important one. —MiguelMunoz (talk) 01:45, 30 November 2008 (UTC)
replies: text: I don't think Herschel's personal experience is relevant. No one had ever observed a planet before, so the fact that Herschel had never observed a planet before is a given. If we were talking about the discovery of Neptune or Pluto, then maybe personal experience would be relevant, but not here.Serendipodous 10:43, 30 November 2008 (UTC)
replies: text: I wasn't referring to Herschel's personal experience. I was referring to the experience of all astronomers since antiquity. The preceding sentence described how the notion of the planets had been around since antiquity, which is fine, but it sounds like Herschel was simply treating the prior paradigm with reverence (which he probably was). I felt that it was more important to give the reasons for that reverence, by describing the experience of astronomers since antiquity. —MiguelMunoz (talk) 11:11, 30 November 2008 (UTC)
replies: text: I don't understand what the difference is. Uranus was spotted through a telescope many times before Herschel identified it, but no one recognised it. The reason experience told people that there was no sixth planet was because no one even considered that one could exist. Serendipodous 12:26, 30 November 2008 (UTC)
replies: text: Good question. When I've described Herschel's hesitation to other people, the most common response was incredulity that he called it a comet. It's that misidentification that's so puzzling to people of today. So that's what I wanted to put into historical context. I've tried a few different explanations, but the one that seems to work the best is to point out that, for at least 2000 years before Herschel's discovery, anything new that was ever spotted moving against the stellar background was always a comet. When I put it that way, people seem to have the least trouble understanding it.—MiguelMunoz (talk) 11:48, 1 December 2008 (UTC)
replies: text: Is that not what the article says now? Serendipodous 12:06, 1 December 2008 (UTC)
replies: text: No, it's a bit more vague. It says comets were the only thing "one expected to find." It doesn't say they were the only things that had ever been found. It's close, but it's not as clear. That can be extrapolated from what it says, if you know astronomy. But a beginner wouldn't know enough to make that extrapolation. And we're not writing for the informed reader.—MiguelMunoz (talk) 18:59, 1 December 2008 (UTC)
replies: text: This is where you and I differ big time. Comets were certainly not the only things that were found through a telescope before Uranus was discovered. Uranus itself was found several times, but was recorded as a star. Galileo even found Neptune once. Its not that these things weren't found; it's that they weren't recognised for what they were. Serendipodous 19:20, 1 December 2008 (UTC)
replies: text: Let us not forget the List of Messier objects published in 1771.  They merely looked like comets. M1 was first observed in the western world in 1731.  Uranus was a 1781 Nebulae/comet. -- Kheider (talk) 19:40, 1 December 2008 (UTC)

text: I was talking about objects found to be moving, not found through a telescope. It doesn't matter how they were found. And you missed my point about beginners vs. informed readers.—MiguelMunoz (talk) 05:04, 2 December 2008 (UTC)
replies: text: Well, given the fact that you've had to expend thousands of words explaining what you meant, I don't think your initial addition would have been any help to the novice reader. I couldn't make head or tail of it and I know I'm not alone (when you first posted that line, months ago, someone else reverted it claiming it was incomprehensible). I think the article is fine the way it is; any attempt to say that comets were the only moving objects found before Uranus is just begging to be revised by better-informed historians than either you or me. I've gone out of my way to accomodate your concerns. I would appreciate some reciprocation on your part. Serendipodous 12:02, 2 December 2008 (UTC)
replies: text: 1) You're hardly an unbiased judge of my communication skills. I was very clear from the beginning that I was talking about objects found "to be moving" and you suddenly started talking about objects found "in a telescope," words I had never used, so it sure looks like you were trying very hard to misunderstand me. This is one of the most territorial remarks you've made here, which is hardly in keeping with Wikipedia's standards. You have also not even answered other questions I've posted on this page, which again isn't in the spirit of Wikipedia. —MiguelMunoz (talk) 22:11, 2 December 2008 (UTC)

text: 2) You say "I've gone out of my way to accomodate your concerns," but you once again didn't address my concern about beginning vs informed readers, even though I've mentioned it twice. Instead you went off on a tangent about objects found through a telescope. You also haven't addressed my objection to your removal of the point that the new definition applies only to our solar system. (see my third comment under "Definition applies only to our Solar System") —MiguelMunoz (talk) 22:11, 2 December 2008 (UTC)
replies: text: I did address it. I rewrote the entire dwarf planet section to accommodate your issues. Serendipodous 22:49, 2 December 2008 (UTC)
replies: text: I posted that comment after you rewrote it. It was a response to your rewrite. —MiguelMunoz (talk) 08:49, 3 December 2008 (UTC)
replies: text: So I'm assuming that wasn't enough for you. You really aren't keen on meeting people half way, are you? Serendipodous 11:23, 3 December 2008 (UTC)
replies: text: I raised a valid point about your change, in the spirit of Wikipedia. You haven't answered my point, so don't tell me that I'm the one that's not cooperating. —MiguelMunoz (talk) 20:55, 3 December 2008 (UTC)

text: 3) You also say ...any attempt to say that comets were the only moving objects found before Uranus is just begging to be revised by better-informed historians than either you or me. If you're questioning my facts, go back and reread your sources. Or give me a counter example. Maybe you're having trouble understanding me because you're not as familiar with the science as I thought. —MiguelMunoz (talk) 22:11, 2 December 2008 (UTC)
replies: text: What you're asking simply cannot be backed up, because you can't show that NO observer ever saw anything other than a comet when they looked up in the sky. That's proving a negative, which is impossible. How are you going to cite it? Serendipodous 22:49, 2 December 2008 (UTC)
replies: text: Well then we don't have to worry about, as you put it, some better-informed historians than either you or me. My point is that, once the seven planets of antiquity were identified, the only new things ever found (and documented) to be moving against the background was always a comet, before Uranus. To this day, the only things that move against the stars are the moon, planets (major and minor), comets, and artificial satellites. If you don't know that to be true, you shouldn't be writing astronomy articles. —MiguelMunoz (talk) 08:49, 3 December 2008 (UTC)
replies: text:  If you don't know that to be true, you shouldn't be writing astronomy articles this is a borderline incivility. To this day, the only things that move against the stars are the moon, planets (major and minor), comets, and artificial satellites—How about natural satellites and Sun? In addition, starts and galaxies also move relative each other. As to you assertion that comets were only moving objects known in the past (except planets, Moon and Sun)), I would say you are wrong here. Meteors had been known for many thousands years before Uranus was discovered. Ruslik (talk) 10:12, 3 December 2008 (UTC)
replies: text: Meteors were only discovered to be astronomical phenomena in the 19th century by Denison Olmstead. In Herschel's time, they were thought to be an atmospheric phenomenon. (Hence the name "meteor" from the greek for the atmosphere, as in meteorology.) The Sun was one of the original seven planets, and I include satellites with the planets they orbit. Also, I'm talking about movements against the stellar background, not within it. If you'll read my comment in the context of this thread, you'll see that I'm talking about planetary astronomy and 18th century discoveries. The "moving" objects I'm talking about are objects in our solar system. Herschel wasn't going to suspect that Uranus was a meteor or a stellar parallax. As for your allegations of incivility, my point was that Serindipodous knows the astronomy well enough to know that his claim here about counter examples is silly. He knows the astronomy very well. —MiguelMunoz (talk) 20:55, 3 December 2008 (UTC)

text: One could say that a telescope was inferred since Uranus is at the limit of naked eye visibility and was discovered using a telescope. -- Kheider (talk) 22:43, 2 December 2008 (UTC)
replies: text: I was referring to anything found before Uranus. For centuries, comets had been found by the naked eye. In Herschel's time, they were also found by telescope. —MiguelMunoz (talk) 08:49, 3 December 2008 (UTC)

text: Well, Herschel didn't figure out it was a planet, so I doubt that story is entirely true. I'll look into it. Serendipodous 12:04, 1 December 2008 (UTC)
replies: text: Well, I was being brief. He figured out that it had a planetary orbit, and he reported it, which is why he got the credit, according to the story I heard. I wish I knew where I read it. Thanks for checking. —MiguelMunoz (talk) 18:59, 1 December 2008 (UTC)
thread_title: Herschel

message: I am sorry if I am coming across as territorial. But this is a very difficult article to maintain, because in a topic like this the difference between fact and opinion is often blurred. However, for this article to be of encyclopedic value it must remain absolutely factual. No unsourced information can be added. No opinions can be stated unless they are the opinions of notable third parties. All facts must be backed up. And I will maintain this standard ruthlessly. Serendipodous 11:45, 29 November 2008 (UTC)
replies: text: Your devotion to the facts is admirable, but you don't really need to remove clarifications that come from the same sources you've already cited. I'm very familiar with the issues in the article, having poured over many of the same sources as you. —MiguelMunoz (talk) 21:33, 29 November 2008 (UTC)
thread_title: As a general note