Talk:Geophysical definition of planet/Archive 2

Self-Citation
User:MarkVSykes had added a reference which pointed to an online interview in which he was the interviewee. It was deleted by another user on the basis that it was "self-citation". Note that in general self-citation is not forbidden according to No original research, so it this not generally an adequate reason for deletion without more explanation. In this case I agree it was a questionable reference because it was an interview rather than a peer-reviewed article, so it might be interpreted as a primary source. However, I am adding the interview back as a reference because I can see that Mark Sykes, as president of the Planetary Science Institute, is a relevant source to state what the definition means, so this makes it a secondary source, as well as reliable and published. It is important to show that numerous planetary scientists have been defining this definition of a planet, not just the two sources that were already in the article.107.77.221.185 (talk) 13:29, 8 October 2019 (UTC)

Good call, 107. Rule-mongering for the sake of rule-mongering is jejune. What's important is substance. One should never lose sight of that. Sowff (talk) 17:19, 8 October 2019 (UTC)


 * I'll let other people decide, but I didn't remove that reference over "no original research" issues. It was about self-promotion and advocacy. I don't think Wikipedia should be a place for someone to advertise their own work or a platform to argue for their personal opinions. If you think the Sykes reference is purely informational, or if it is presented as one of several, differing opinions, then I don't have a problem. Fcrary (talk) 21:12, 8 October 2019 (UTC)


 * Since Sykes is a bona-fide scientist if he provides a reference to his own work, I don't see that as purely a vain act. Sowff (talk) 21:32, 8 October 2019 (UTC)


 * I guess if you are a scientist, you need a posse who can post your scientific stuff? Sowff (talk) 21:35, 8 October 2019 (UTC)


 * Yes and no. Yes, you should rely on someone else referencing your own work. No, that doesn't just apply to scientists. A fair amount of the content on United Launch Alliance came from one of their media relations people. She posts suggested drafts to the talk page and lets other people decide whether or not to add them to the article. And, even among scientists, people who cite their own work too much are often criticized. So it isn't just Wikipedia. Why should Wikipedia be a forum for advertisements? (By the way, could use one or more colons at the start of paragraphs? It's a wiki markup thing which causes the paragraph to be indented, and it really helps people see which comments are new and which are replies.) Fcrary (talk) 21:46, 8 October 2019 (UTC)


 * But there is no rule in Wikipedia against self-citation. Each individual case has to be judged like every other edit regardless who made it. Is it a high quality reference? Is it encyclopedic? Does it contribute to the article in an important way? Etc. In this case I think it does, since this is an article about the geophysical planet definition on a statement that says there are planetary scientists arguing for it and it is a citation showing exactly that. It couldn't be any more relevant. And it is just a reference (a very relevant one), not a self-promoting advertising piece.Sanddune777 (talk) 05:29, 9 October 2019 (UTC)


 * I see both sides on this issue. Thanks for clarifying, F.


 * Sowff (talk) 13:04, 9 October 2019 (UTC)


 * Sanddune,


 * I agree. I like the idea of looking at everything on an individualized basis. They say every snowflake is different. I disagree that there's nothing new under the Sun. As an artist, I don't like people saying I can't create a new work of art. I think that adage is not true at all. The GPD is a beautiful snowflake, a definition that encompasses and accounts for more planets in our Universe in a very scientific, neutral way, including lots a exoplanets, even Solar System round moons; in fact, Titan and Ganymede are both larger than Mercury, and even those reprobate rogue planets. Sowff (talk) 13:11, 9 October 2019 (UTC)


 * We know Pluto, Titan, Io, and Enceladus have active geology, too. It's pretty obvious a better definition than the Prague plop is necessary. That one is an utter dud.
 * Sowff (talk) 13:15, 9 October 2019 (UTC)

Fcary I see you just commented on an edit that the author of the published work should not edit Wikipedia on that topic. That is not a rule in Wikipedia and we already hashed that out, above. Please see the discussion above. Please do not take us down that argument again. Your other comment on that edit was an adequate reason for the edit by itself. — Preceding unsigned comment added by Sanddune777 (talk • contribs) 04:06, 24 August 2020 (UTC)

Moved and reduced article
I gutted parts of the article as OR and POV-pushing. I agree, actually, that amorphous scientific terms like 'planet' should in general be defined by use rather than by vote. But much of this article was more bullshit than theory. For one thing, any moonlet made round by scree falls is a "planet" (I added a comment to the lead that this should not count, but that's OR and I should probably take it out), contrary to the definition, in actual use 'round' does not mean an ellipsoid (e.g. Proteus, Pallas are counted), and the published definition is so sloppy that it contradicts itself (e.g. Iapetus and Haumea are not geophysical planets because they are not spheroids, but they are because they're ellipsoids -- perhaps the authors don't know what 'spheroid' means?). If the publishers of the article can't be bothered to do better than that, the whole concept becomes a joke: which definition of 'planet' is the most ridiculous? How about someone come up with a definition of 'planet' that isn't ridiculous, or have the honesty to say that a 'planet' is anything that someone calls a 'planet'?

I also moved the article. If we move it back to 'definition', then we should concentrate on the definition as used by the proposers, how they contradict themselves, and how the objects they accept as planets do not fit their definition. How they came up with a count of round objects when we don't know that the objects are round is beyond me.

And finally, is their any indication that the published article is NOTABLE? I agree that the widespread dissatisfaction of the IAU definition of 'planet' needs to be covered, but this isn't making it look like an intelligent alternative. — kwami (talk) 10:29, 18 August 2020 (UTC)

Also, Stern's summary of what a geophysical planet is contradicts the definition that we had used. Stern makes more sense, as he doesn't try so hard to fudge a definition to justify the answer he's already decided on. (A sin of the IAU 'definition' as well.) I wish he'd stuck with his actual definition, which was perfectly reasonable (if it looks like a world, it's a planet) rather than this fake definition that supposed to look sciency even though it's not, but it appears that ship's sailed. — kwami (talk) 11:14, 18 August 2020 (UTC)


 * I don't disagree with the changes you have made, but this article has been debated at painfully great length on its talk page. I really don't want this change to provoke an edit war, so it might have been better to start a discussion on the talk page before making such massive changes. Fcrary (talk) 03:08, 19 August 2020 (UTC)


 * Why do I feel like Casandra? It isn't fun when I get to say, "I told you so." (talk) 04:09, 24 August 2020 (UTC)

Well, there's a larger issue, which is that the geophysical definition is not just the 2017 proposal and not adhered to by just the mission team of New Horizons. It's been long held by planetary geologists. Some of their definitions make sense, too, if you disregard the nonsense inherent in trying to force-fit a subjective distinction into purportedly objective criteria. I've rearranged the article so the 'background' is now the lead, and the lead is now a section dedicated to the 2017 proposal. Ideally, we should have much broader coverage of the history of the idea. There are plenty of RS publications that we can draw on, including multiple statements by Stern, Buie et al, but hopefully also by people who are not direct colleagues of them, and not just reactions to the IAU decision. That is, IMO we shouldn't present this as a tantrum by poor losers whining that they didn't get their way, but as a legitimate position held by the majority of astronomers in their (sub)field that's simply at odds with the priorities of other subfields (such as people working on the Nice Model, who don't care whether a body is round or in HE). — kwami (talk) 02:41, 22 August 2020 (UTC)

→To kwami: It was inappropriate to gut and move the article without discussing here, first. Hard disagree about a couple things you wrote. Example, moonlets rounded by crustal motion is not gravitationally rounded as discussed in the literature. There are papers in the published literature discussing gravitational rounding, and it goes back in history at least to Gerard Kuiper as the difference between planets and sub-planets, as well as recently. According to Kuiper, the few largest asteroids were gravitationally round and that made them planets, whereas the many smaller asteroids that weren't large enough to be round via gravitaty are not planets. Leading up to the 2006 vote the committees recommended gravitational rounding as a criterion for planet status, and the IAU included it in their definition. Since this is an encyclopedia, its job is to report facts, not for editors to make up personal arguments why they do or do not like the historical facts. The gravitational rounding concept is a reportable fact, and your argument about round moonlets is OR and not relevant. Why not add to the article by citing papers that provide different views on gravitational rounding? I am sure there are variations. Analogously, there are several definitions for clearing an orbital neighborhood, and they are all covered in an article on that topic. That doesn't undermine the concept of clearing a neighborhood, but it shows that there are some variations within the concept. Why not add the details on different variations of gravitational rounding? -- only the variations that are actually published of course. You also mention that the article should be expanded to add other perspectives about the GPD, and I agree with that. A version of the GPD was the definition favored by Galileo and Kepler and almost all astronomers until the 20th century, since moons were counted as planets by them and all astronomers until about the 20th century, so it would be useful to expand the article to give more perspective on the history of the GPD. Sanddune777 (talk) 01:03, 24 August 2020 (UTC)


 * That isn't really correct. The primary criteria, according the the geophysical planet definition is that the body is round, i.e. in hydrostatic due to self gravity. Galileo, Kepler and pre-20th century astronomers had little idea about the shape of these objects, and definitely knew nothing about whether that was a result of hydrostatic equilibrium. It is true to say that the GPD is not inconsistent with historical usage. It is incorrect to say that this definition was "favored by Galileo and Kepler and almost all astronomers until the 20th century", since the definition involves things they did not know about or consider. Fcrary (talk) 04:09, 24 August 2020 (UTC)


 * Roundness is not the distinctive aspect of the definition, since the IAU definition also includes that aspect. The distinctive aspect is the fact that it does NOT include the orbital dynamics. It doesn't make sense to nit-pick this definition over something that all definitions include. The distinctive part -- omitting dynamics -- is the view of the early Copernicans, etc.


 * Also, you are wrong saying that the earlier scientists had little idea of the shape of these objects. They most certainly DID call them round and spheres and globes over and over and over. This is beyond question. They saw the Moon, the phases of Venus, the Earth's shadow on the Moon, and by induction they concluded they are all likewise spheres. In the 1700s, Laplace supplied an argument why they are round through the formation process with gravity. I can't remember for sure but Newton might have said something about that, too. Kirkwood in the mid 1800s argued that all the planets are round because they went through a liquid state prior to cooling and gravity pulled them into round. It was not until the 1950s/60s that papers began to argue that the smaller asteroids are not round, which was a novel thought because prior to that everybody assumed all the bodies were round. The understanding of accretion coupled with interpretation of light curves is what led to that development. Based on that, Kuiper argued that only the ones that accreted to sufficient size to induce a gravitational growth stage and hence were round by gravity should be considered planets, while the sub-round ones should not be planets. That was in 1953. That essentially restored the concept of planet that Galileo and other had earlier held, removing the non-round asteroids, since the earlier scientists had all assumed they are round and didn't think to question it. Roundness was always a part of the concept of planet, although it had not been identified as a key definitional part until the IAU's committees suggested it, and the IAU wrote it into their definition. Sanddune777 (talk) 04:25, 24 August 2020 (UTC)


 * Nonsense. The whole point of the geophysical definition of a planet is that it based on geophysics. The idea that "planets" are in hydrostatic equilibrium is fundamental to the idea that this definition is "geophysical". You are claiming geophysics (and hydrostatic equilibrium) is an irrelevant detail, since it's part of the IAU definition as well. If so, why is "geophysical" part of the name? Why isn't it the "non-orbital dynamics based" definition of a planet?


 * As far as historical words about solar system bodies being round, well, you're correct to say that early astronomers had reasons to think that the Earth, the Moon and Venus were round (as well as Mars, Jupiter and Saturn) and "by induction they concluded they are all likewise spheres". But that's something they assumed. Not something they measured. They assumed, based on their orbits, that these objects were similar. Based on that assumption, they often added the second assumption, that they were round. It is misleading to say, as you do, that "roundness was always a part of the concept of planet". It is correct to say that things they had already assumed to be a planet, on the basis of their orbits, were also assumed to be round, based on no evidence and lots of speculation. That's a very different logical proposition. You can't say, for example, note that college students are generally assumed to be young, and then turn that into a statement that most people think all young people are college students. "It's round because it's a planet" (which early astronomers assumed) is not the same thing as them saying "It's a planet because it's round." Fcrary (talk) 04:54, 24 August 2020 (UTC)


 * A concept is different than a definition. I said "concept" to avoid saying "definition" since no definition existed prior to 2006. Anyhow, it isn't clear to me what your argument is trying to accomplish. Two parts of the IAU planet definition need more work to be precise -- and a third, unwritten part does, too. These three things are: what exactly is gravitational roundness? what exactly is clearing a neighborhood? and what exactly is being substellar (never initiating fusion)? Just because they need work by scientists doesn't mean they aren't valid concepts for people in the science community to propose for a planet definition, and it is the job of an encyclopedia to report this is happening and tell what the issues are, not to do the science of evaluating the definition and deciding if roundness is good or not. Sanddune777 (talk) 05:15, 24 August 2020 (UTC)

It might help if I support what I just wrote by giving a few examples, since most people have not read the history of the planet concept and are unaware what it really meant from the Copernican Revolution until recent times, that it was always the geophysical idea that orbits are irrelevant, contrary to the IAU defintion. So here are just a few examples drawn from the countless evidence in the literature:

From Galileo, 1610:


 * There remains the matter, which seems to me to deserve to be considered the most important in this work, namely, that I should disclose and publish to the world the occasion of discovering and observing four PLANETS, never seen from the very beginning of the world up to our own times... ...These are my observations upon the four Medicean planets, recently discovered for the first time by me...

From Kepler, 1620:


 * How are the planets divided among themselves? Into the primary and the secondary. The primary planets are those whose bodies are borne around the sun…; the secondary planets are those whose own circles are arranged not around the sun but around one of the primary planets and who also share in the movement of the primary planet around the sun….Jupiter has four such planets around itself...

From Bernard le Bovier de Fontenelle (French Royal Academy), Entretiens sur la pluralité des mondes, 1686 (transl by Gunning in 1803):


 * But what a beautiful object is Jupiter, surrounded by his four little moons, or satellites! These moons are four little planets which, whilst Jupiter revolves in twelve years round the sun, constantly go round him as the moon does round the earth.

From the letters of Isaac Newton to Richard Bently, Dec. 10, 1692 to Feb. 25, 1693:


 * “...the several Distances of the primary Planets from the Sun, and of the secondary ones from Saturn, Jupiter, and the Earth ; and the Velocities with which these Planets could revolve about those Quantities of Matter in the central Bodies;...

From John Vose, A System of Astronomy: On the Principles of Copernicus. JB Moore, 1827, p. 31:


 * The word Planet, is derived from the Latin Planeta....Eleven primary planets have been discovered, Mercury, Venus, the Earth, Mars, Vesta, Juno, Ceres, Pallas, Jupiter, Saturn, and Herschel...There are eighteen secondary planets. The earth has one, Jupiter four, Saturn seven, and Herschel six.-- The discoveries of the last half century warrant that expectation, that the number of planets, both primary and secondary, may yet be greatly increased.

From James M'Intire, A new treatise on astronomy, and the use of the globes, in two parts... AS Barnes & Company, 1850 (a textbook for high schools and academies):


 * The Planets are opaque bodies like our earth, moving round the sun, and shining by the reflection of his light. They are distinguished into primary and secondary. The Primary Planets move round the sun as their centre of motion. There are seventeen primary planets known, namely, eight large planets, and nine small ones, called asteroids...The Secondary Planets, Satellites, or Moons, move round the primary planets as their centre of motion. There are eighteen secondary planets or satellites known. The Earth has one, Jupiter four, Saturn seven, and Uranus six.

From Henry Kiddle. A New Manual of the Elements of Astronomy: Descriptive and Mathematical... Ivison, Blakeman, Taylor, & Company, 1873.


 * 7. There are two kinds of planets; Primary and Secondary Planets.
 * 8. PRIMARY PLANETS are those which revolve around the sun only.
 * 9. SECONDARY PLANETS, generally called SATELLITES, are those that revolve around their primaries, and, with them, around the sun.

Fro William Thynne Lynn. Celestial motions: A handy book of astronomy. Edward Stanford, 1891.


 * In its annual journey round the Sun, the Earth is accompanied by a smaller planet called the Moon, the movement of which relatively to the Earth being in the nature of a motion in an elliptic orbit round the latter, she is considered as a satellite or secondary planet thereto.

From George Frederick Chambers. The story of the solar system. University society, Incorporated, 1909.


 * The planets are divided into “primary” and “secondary.” By a “primary” planet we mean one which directly circulates round the Sun ; by a “secondary” planet we mean one which in the first instance circulates round a primary planet, and therefore only in a secondary sense circulates round the Sun. The planets are also “major” or “minor” ; this, however, is only a distinction of size.

It goes on and on. At first astronomers assumed a "clean" solar system with no small bodies. Eventually they started realizing there are bodies of all sizes. In the 1950s/1960s a sea-change occurred and they stopped calling the smaller ones "planets" following a paper by Kuiper that argued for roundedness by gravitational influence to be the dividing line. When the IAU tried to write its definition, it included gravitational rounding as part of the definition. The difference between the GPD and the IAU definitions is NOT the rounding, but whether or not to include the orbital state. The historic view from the Copernican Revolution is that the orbital state is only a secondary division among the planets, so both primaries and satellites are all true planets. The idea that only the primary (direct-Sun-orbiting) bodies are planets was a recent change that came from culture, not from scientists. The GPD is an attempt to retain the scientific concept from the Copernican Revolution because it is scientifically useful, rather than bow to a cultural one so that planets will be countable by school children. This is significant and should be reported in an encyclopedia because there have been numerous press reports, numerous public debates, and numerous publications in science papers, and there is the deep historical and modern literature including the common usage by planetary scientists.Sanddune777 (talk) 01:54, 24 August 2020 (UTC)


 * We all know that satellites and asteroids were first conceived of as planets, though it's interesting that such conceptions went on for so long. They were hardly universal, however -- simultaneously with the later quotes of yours, there were common presentations of much more limited sets of planets, where orbital considerations dominated.
 * Pace your other claim, Stern says at one point that he doesn't want a hard rule for the lower bound of planet, just as we have no hard rule for the upper bound. So that is indeed a distinction from the IAU, which pretends to have a lower bound even if it's completely impractical. — kwami (talk) 05:50, 24 August 2020 (UTC)


 * You raise interesting thoughts that probe the difference between a concept and a definition, and honestly I don't have an opinion how to parse this in wikipedia. I want to think about this for a few days. You know of course there is also the article on Planet, which is supposed to describe the concept of a planet distinct from any particular definition. In general though, I think it is proper to have a separate article about the IAU definition, and the same for the GPD definition, because both are events in the community trying to define the concept. The focus is on the event of trying to write the definitions. Sanddune777 (talk) 07:27, 24 August 2020 (UTC)

I gutted the article again as bullshit, and now it turns out COI as well. Even more this time. This is entirely appropriate -- on WP, anyone can delete unsupported claims at any time. It's not a democracy, and it's guilty until proven innocent.

I sympathize with Stern's position. For a planetary geologist, Pluto is obviously a planet. Privileging the IAU position on WP is inappropriate IMO -- we should reflect both, just as we don't try to decide whether the chemical or agricultural definition of 'organic' is correct. But this article was such blatant nonsense that it was practically astrology.

To start with, it claims that Runyon's definition is "the" definition, which is stupid. Not least because Runyon contradicts himself so often that the result is gibberish. Get something where the first author is Stern, or Buie, or Grundy, or someone else capable of making a cogent argument.

I may have been wrong to add the bit about round moonlets, though a naive reading of Runyon's def will lead one to conclude that they are planets. But the way to deal with that is to remove my comments as unsupported by the lit, not by restoring a bunch of other bullshit that's not supported by the lit. — kwami (talk) 05:31, 24 August 2020 (UTC)

Request for disclosure of conflicts of interest
Now that we are back to debating this article (again)... I would like the editors with a conflict of interest to openly declare that fact, in accordance to Wikipedia policy. We know or strongly suspect that the editor, Nasaman58, is Kirby Runyon, the first author on the paper which first described this Geophysical Planet Definition. At least, Dr. Runyon uses Nasaman58 for things like his Twitter account name. Since this makes him inherently partial, his editing of an article about his own work is highly questionable and subject to unconscious or inherent bias. I am also concerned that other editors may be professionally involved in the debate about the definition of a planet and therefore also biased. Could we at least have all editors with some personal or professional involvement in the debate openly and publicly admit it? Fcrary (talk) 04:19, 24 August 2020 (UTC)


 * This does not exist as a policy in Wikipedia. I just read the article on addressing bias. Nowhere does it say editors must discuss their backgrounds, discuss their day jobs, reveal who they are, or anything like that. Nowhere does it connect the idea of bias to the professional expertise or outside work of the editor. In fact, it says the opposite. It says this: ::"Discuss content, not other editors. While personal talk pages and administrator noticeboards may be used to discuss behavioral issues, article talk pages should discuss the content of articles. Avoid personal attacks and focus on content."
 * The rest of the article can be read here: Guide to addressing bias
 * I have seen JL Margot editing the article on Clearing the Neighborhood and/or the IAU's planet definition (his user name is his real name), even though he wrote a key paper defining how to clear the neighborhood and argued it should be the basis of the planet definition. He did not need to reveal his name if he did not want to. I did not see any editors claiming he was biased. Everybody focused on content. It is common for experts in a field to edit the wiki article. As the article on "addressing bias" says, we are supposed to focus on the content, not the editors.
 * Please, just find sources that support the views that you think have been omitted and use them as the basis to improve the article. If you can find experts who say the GPD is bad for reason X, then include it. If the sources cited in this article don't support what the article says, then make that case. Sanddune777 (talk) 04:45, 24 August 2020 (UTC)
 * I think you are very much mistaken about how Wikipedia works. You are correct about the formal policies, but not about the rules, guidelines and consensus views of editors, which are more than 90% of how things are done. If someone has a personal bias or is personally involved in a subject, they are expected by other editors to state that fact. Not to hide it behind a pseudonym or alias. That is not a policy, in the sense of something which will get you kicked off for legal reasons. But it is something honest editors do and which many (most?) editors expect from each other. It is not a "personal attack" to ask someone to admit they have an axe to grind when it comes to the article's subject. And if Margot is editing articles concerning his own work, well, I think that's annoying but acceptable if the other editors know that and can take it into consideration. If he's hiding his personal involvement in the subject behind a pseudonym, that's a very different matter. It amounts to intentionally misleading other editors, and that is not something I consider acceptable.
 * In the case of this article, I suggest you consult the edit logs for an example of bias. Someone had put in a quote about roundness (hydrostatic equilibrium) being a threshold for objects becoming geologically active. Fine, but I felt it important to add that there are some bodies which are geologically active due to tidal forces rather than self-gravity, and that there were round and apparently hydrostatic bodies which show no signs of every having been geologically active. I thought it was worth mentioning because there exemptions to the idea that shape and geological activity go hand in hand. Kirby deleted that because he considered it an irrelevant detail. We went back and forth on it a bit, but that's the point about bias when it comes to one's own work. People will, even if it's unconscious, consider issues which support their own idea to be more important and issues which disagree with their own proposal to be less important. To keep an encyclopedia like Wikipedia honest and useful, the other editors have to be aware of other editors biases. So I think it's critical for everyone with a bias to admit it. Fcrary (talk) 05:19, 24 August 2020 (UTC)


 * Your comment about tidal heating is interesting science and I think that sort of thing should be used to revise a definition. For example, someone might have argued mammals give live birth, but then we discover the branch of mammals that lay eggs so that requires revision of the concept of mammals. Likewise, someone would need to publish a paper arguing that the GPD needs to be revised because it failed to take into account tidal heating. But this is an encyclopedia, not a journal, and it is supposed to have no OR. Your comment on tidal heating is OR and should be published outside Wikipedia before putting it here. You note I said a lot in the talk page that I have never tried to put into the article. That is because it would be OR. Sanddune777 (talk) 05:32, 24 August 2020 (UTC)
 * No, I was not debating the definition, nor was what I added original research. I simply added text saying the preceding statement was not categorically true with links to the related Wikipedia articles which that qualification was based on. And I was not bringing it up to restart that discussion about geological activity. It is an example of how Wikipedia editors always have to use judgement about what information is, or is not, relevant. And how someone who has a personal involvement (i.e. a conflict of interest) will have opinions about relevance which are not impartial. Even if that is unconscious and not intentional. Which is why the other editors need to know when someone has a conflict of interest, so they can take that into consideration when making their own judgements. Fcrary (talk) 05:50, 24 August 2020 (UTC)
 * I still think it is OR, and maybe the statement you were responding to, before the statement about tidal heating, was OR, too. The question is this: are there are any published papers or news reports or any other external sources showing that planetary scientists are criticizing the GPD on the basis of tidal heating? Or are there any that make the point about active geology? Etc. If not, then putting it here to evaluate the GPD is OR. If the GPD is notable then have to report what is being said about it as an encyclopedia, not create our own statements about it, either pro or con, here within Wiki.Sanddune777 (talk) 06:06, 24 August 2020 (UTC)
 * The earlier statement about roundness and geological activity was from a statement by Mark Sykes, published in a reliable source. So that's not original research. The qualification I added was a statement that his statement was inconsistent with information on other Wikipedia articles, which described objects which did not match Dr. Sykes' statement, and which cited equally reliable sources. Comparing and contrasting information in different Wikipedia articles is not original research. I was pointing out existing facts from other Wikipedia articles. That's not creating my own statements about the subject. And, by the way, you dodged the question about Dr. Runyon's apparent conflict of interest. Did, in initially deleting that qualification on the grounds that it wasn't significant, was his judgement biased by the fact that it points to a potential weakness in his own definition? Was he even slightly and unconsciously biased in that judgement? If so, would it have been better if other editors had actually known he was the editor involved as opposed to appearing to be some unbiased person using the account name "Nasaman58"? Would it have been more honest and better for Wikipedia if he announced his potential conflict of interest, according to Wikipedia guidelines? Those are the questions I'm asking about, not whether or not an inactive but round moon is a problem for the GPD. Fcrary (talk) 06:37, 24 August 2020 (UTC)


 * Just to clarify, I put conflict of interest into the section title and then used the word "bias". I am talking about a conflict of interest. That guideline states, "Any external relationship—personal, religious, political, academic, legal, or financial (including holding a cryptocurrency)—can trigger a COI. How close the relationship needs to be before it becomes a concern on Wikipedia is governed by common sense. For example, an article about a band should not be written by the band's manager" I think being the lead author on the paper which introduced the whole subject of this article fits that description. Fcrary (talk) 05:41, 24 August 2020 (UTC)


 * I agree that is a much more relevant policy. Thank you for pointing it out. I think the example of a band manager is not a good analogy since that involves financial COI. A more relevant part of the article is "Subject Matter Experts", and it says:
 * "Subject-matter experts (SMEs) are welcome on Wikipedia within their areas of expertise, subject to the guidance below on financial conflict of interest and on citing your work. SMEs are expected to make sure that their external roles and relationships in their field of expertise do not interfere with their primary role on Wikipedia."
 * I doubt there is any way to get a financial COI out of this, so it is primarily about citing your own work. That paragraph says,
 * "Using material you have written or published is allowed within reason, but only if it is relevant, conforms to the content policies, including WP:SELFPUB, and is not excessive. Citations should be in the third person and should not place undue emphasis on your work. You will be permanently identified in the page history as the person who added the citation to your own work. When in doubt, defer to the community's opinion: propose the edit on the article's talk page and allow others to review it. However, adding numerous references to work published by yourself and none by other researchers is considered to be a form of spamming."
 * On that basis, I will divulge that I'm writing a paper that, if published, will be relevant to this article. If it gets published or released in the arXiv and I wish to edit this article on that basis, I will discuss it on this Talk page first. This, by the way, is exactly why I have refrained from putting anything about the history of the GPD (Galileo and all that) into the article. When you and I had this discussion last October 2019 (see history), I promised to add material to fix the article to avoid deletion. You might remember that. I also discussed that I was trying to avoid OR and I discussed that I would try to publish an article in a journal first to make sure it is not OR. I have been working on it this entire time. It is now close to submission, and if it is published or released on the arXiv I will come back here and disclose it at that time. — Preceding unsigned comment added by Sanddune777 (talk • contribs) 06:29, 24 August 2020 (UTC)
 * I think we both know there is some potential, financial conflict of interest. Getting good press or public recognition of your work helps you get your grant proposals selected, even if it isn't supposed to happen that way. And it also helps your career. So a scientist using Wikipedia to promote his own work is a potential, financial conflict. In any case, the guideline says that, if you cite your own work, you should disclose that fact. Which is, after all, all I have requested. If Kirby wants to edit this article and cite his own work, I wouldn't wouldn't complain (well, I might grumble.) But when he edits and cites his own work as "Nasaman58" and doesn't admit that that's him, I consider that unethical. In the same way, It's nice to know you've got a relevant paper on the subject in the works, but when it's published and should you cite it to this article, I would expect you to say so. As in telling us that "Sanddune777" was the first author of that paper. If you don't, then you are not disclosing the fact that you cited your own work. Fcrary (talk) 06:49, 24 August 2020 (UTC)


 * I am really sure you are interpreting the policy contrary to its intent. If an academic citing their own paper were what the policy had in mind as an automatic COI, either financial or otherwise, then it would have simply said "SMEs must self-disclose every time they self-cite." There are grotesquely obvious places in this policy where it would have said that, but it did not, so clearly it is not the policy. Instead, it gave other rules that allow for not self-identifying in most cases. Also, the examples about financial COI are far more direct cases than that of an academic SME self-citing and getting reputation by that, so the examples themselves define something very different than what you are saying. Also, this same policy about COI gives rules to prevent outing people who do not want to be outed, so this is not a one-sided consideration. Sanddune777 (talk) 22:36, 25 August 2020 (UTC)


 * It does seem that we disagree. First, COI is a guideline not a policy. Guidelines on Wikipedia are simply a statement of the usual consensus editors have come to, stated to prevent the whole thing from coming up again and again on multiple articles. They are not hard and fast laws intended to be followed to the letter. As I understand this guideline, it is that people should not be using Wikipedia to promote themselves or their own ideas or opinions. They can edit articles involving themselves or their own ideas, but they should openly state that they are doing so. That allows other editors to take that into consideration when differences between editors come up (i.e. taking the views of someone with an interest in the matter with a grain of salt.) Second, the COI guideline is not limited to financial conflicts. It also includes personal or professional conflicts of interest. I think that applies in this case. Third, in terms of self-identification, how exactly could someone say they are citing their own work, as the guideline says they should do, while editing under a pseudonym? If Kirby Runyon is expected to tell us he's citing his own work, how could he do so without stating that he is editoring under the name of Nasaman58? By making self-citations, I think he's expected to give up that level of anonymity. Fourth, I don't think the policy of not outing people applied in this case. Kirby Runyon openly uses Nasaman58 as his Twitter account name, and has publicly said so in things like in several public contexts. You can't out people by associating their real names with the pseudonyms they, themselves, have publicly connected to their own real names. Fcrary (talk) 07:07, 26 August 2020 (UTC)


 * You wrote: "in terms of self-identification, how exactly could someone say they are citing their own work, as the guideline says they should do, while editing under a pseudonym?" But that is a circular argument. We are debating whether or not the guideline actually says you must do that, and I claim it does not say that. (It is actually completely clear that the guideline does not say that.) The policy only says "when in doubt" then you need to discuss the self-citation on the talk page. You are arguing that there is never any doubt, and thus we are always supposed to identify our self-citations as SMEs. But if that were true, then the guideline would not have said to do it "when in doubt". The point is that there can be times of doubt, and there can be times when you have not doubt that adding a single reference to your own work (or other cases of self-citation within reason) do not require disclosure. Yes, Kirby apparently did not try to protect his identity, but that wasn't my point. My point was that the guideline gives consideration that sometimes some people have a reason to not be outed, so the guideline does not give a hard-and-fast rule about always disclosing. I'm going to stop responding on this because the guideline is clear and there's no point in debating this. It seems like you keep trying to make up rules that don't exist because you want to make this about the editors rather than focusing on the content, as the guideline about bias says you are supposed to do. Sanddune777 (talk) 16:37, 26 August 2020 (UTC)

What should be the topic of this article?
Do we really want an article about this one series of published articles? Are they really that notable? Or should this article be about geophysical / non-orbital definition(s) of 'planet' in general, reflecting the historical quotes above? (Though IMO anything predating the demotion of the asteroids isn't really relevant to the current dispute.)

IMO this article should cover the concept of 'planet' held by planetary geologists. And fairly universally held, AFAICT, though the details are often rather murky. As noted above, the primary distinction from the IAU conception is the lack of an orbital qualifier, but of course there can be other differences as well, such as all minor planets being 'planets' in some of the historical positions quoted above. (Not a position held by any modern astronomer that I'm aware of.) As Stern notes, neither the IAU nor planetary geologists concern themselves much with the upper bound, since it's not relevant for the Solar system, so perhaps we can skip over that and just refer the reader to brown dwarf or something. But there are differences in the lower bound, in how we define 'round'. E.g., why does Runyon consider Pallas, Proteus and non-solid TNOs to be 'planets', but not, say, Phoebe, which is a differentiated body? Stern seems to include over a hundred known TNOs as established planets, whereas Grundy would accept only a dozen as even likely to be. I'd like to hear where Buie stands. All of that should be reflected in this article, without us pushing one conception (Runyon) as "the" definition or even as the primary definition. That would be good form even if Runyon were coherent.

Re. COI, I personally know a couple astronomers, but if anything that connection would bias me toward accepting Runyon et al., not against it, since they're mostly on the planetary side of things. I'm opposed to Runyon et al. because it's badly written gibberish, not because of the POV that it advocates. I would love to create a good article here based on credible sources. Not pushing for either definition to be the default on WP, though that would mean removing the IAU def from its current default position. — kwami (talk) 06:19, 24 August 2020 (UTC)
 * Personally, I'd support merging all of the articles on what a planet is or how it is defined. That would allow the reader to easily see that there are multiple definitions and let the reader easily compare and contrast their differences. But the last time we debated this, no one liked that idea. In terms of COI, I guess I should also say that I'm a planetary scientist, but my work concerns the magnetospheres of outer planets. So I don't really have any axe to grind on this subject. (That is on my Wikipedia talk page, but I guess it couldn't hurt to repeat it.) I should also mention that I know many of the scientists involved in this debate about the definition of a planet. They are nice people to have dinner with at conferences. I have no strong personal likes or dislikes for them, other than considering them friends and colleagues. (I.e. it's not like I've got a grudge against one or a close personal relationship with another...) — Preceding unsigned comment added by Fcrary (talk • contribs)

Yes, I would also support a merger into a single definition of planet article, though perhaps best to settle the issues here first rather than export an edit-war to another and better-established article.

Besides the really early stuff, there's the historical conception of minor planets, but not moons, as planets. There's the demotion of MP's to asteroids ca. 1850, resulting in 8 planets before Pluto, and 9 after (with persistent by minority doubt about Pluto). Currently there would appear to be three major conceptions of what a planet is:
 * (1) the formal IAU definition, or perhaps something similar that's a bit more practical (e.g. the IAU definition is useless when discussing the Nice model)
 * (2) the traditional definition that IAU planets and DPs are planets (voted down at the IAU that year), and
 * (3) Stern et al.'s definition that all
 * (a) 'round' or
 * (b) equilibrium
 * bodies are planets. (3a and 3b may produce very different counts.)

I don't think these ideas should be scattered into different articles. — kwami (talk) 07:25, 24 August 2020 (UTC)

I do not support merging them. For one thing, I think a lot of astronomers became emotional because of the 2006 events before & after (because that's what forcing an issue and voting on it does to groups of people), so now they want to defend the IAU as for its professional stature, which creates bias because anybody who holds the geophysical view is perceived as attacking the IAU and is an enemy to be defeated. Therefore, many astronomers are biased to label the geophysical planet concept as fringe (even though it is a mainstream view and has always been the mainstream view since Galileo until at least the 1920s, with resurgence again starting in the 1960s). There is a bias to minimize it and keep it out of Wikipedia in order to defend the IAU's stature. If it is put inside the article where the IAU defenders are trying to fight it, then it will not be represented, and it deserves to be represented. But if it is a fringe view then it is quite right to make it a separate article, so both sides can be happy having it separate. IMO, the emotional bias needs to calm down a few more decades before it is discussable without bias.

For the other thing, the basis of dividing planets from non-planets is completely different in the IAU versus the geophysical concept. Thomas Kuhn would have called them incommensurable, and this is exactly the type of example he had in mind when he discussed the concept of incommensurability in scientific concepts. Even though both the IAU defenders and the Geophysical planet users both use the same word planet, and even though the membership of bodies in the planet category overlaps between the two concepts, and even though there is some common overlap in the evolution of how we got to where we are today, NEVERTHELESS the word planet is really a fundamentally different concept in each case, so we are using one word for two different things. Since they are fundamentally different things, they should be different articles. The fact they happen to use the same word planet is not enough reason to force them into the same article. For an example, cereal can mean a type of grain or a breakfast food, and there are separate wikipedia articles on each, even though the cereal grains can be breakfast cereals and that is exactly why breakfast cereal ended up with that name. (Eat your cereal originally meant eat your grain, but now it can mean eat your colored sugar puffs so it is a different concept). The fact that they derived from the same origin and have the same name and have overlap doesn't mean they have to stay the same article. The issue is the fundamentum divisionis, the basis of division separating one class from another classes. If the bases of division are incommensurable, then they are fundamentally not the same type of thing despite the fact that they have the same name and some overlap in membership.

This is not the same as having different definitions for two things that are fundamentally the same concept:

The geophysical planet concept originates from Galileo and other early Copernicans and refers to a body big enough to be "like Earth" in some way (which needed better definition, which "gravitationally rounded" tries to provide), regardless its current orbital status (in fact they can change orbital status). This was the predominant view since Aristotelianism was rejected during the 1600s.

The IAU embraced a planet concept (I will call it "Cultural Heliocentrism") that originated from the general public (actually from heliocentric astrology in the early 1800s, when this concept first appears in print) and it means a world that is big enough to be "rounded" and that (through the random history of our solar system) has survived to continue to dominate its orbit around the sun at the present time, where we mean "dominate" in some ill-defined way that has the goal of ensuring they are monocentric, orderly, and easily counted, with the purpose of retaining their cultural significance from astrology and geocentrism (but in this heliocentric form since the early 1800s).

These are not the same two concepts, obviously, even though they have some overlap in the membership. There can be variations in the definition of the Geophysical planet concept ("What is 'round'?"), and there can be variations in the definition of the Cultural Heliocentrism planet concept ("what is round?" and "what is dominating an orbit?"). The definitions within either concept are not incommensurable with other definitions within the same concept, but the definitions from either concepts are incommensurable with the definitions from the other concept. This is why they aren't the same thing.

More to come when my paper is published. It shows clearly from the literature how, when, and why the Cultural Heliocentrism concept (embraced by the IAU's definition) emerged, and how, when, and why the Geophysical concept of Galileo, et al., emerged. As I promised a year ago the last time we had this argument, I think this paper will make it clear that this needs to stay as an article. Sanddune777 (talk) 01:06, 26 August 2020 (UTC)


 * I think that merging the articles would be a good idea. I also think that Sanddune777 and others are getting too close to this. The debate should not be about the facts (as strange as that sounds coming from a scientist and expecting other scientists to read this.) The debate is about how to present the subject to members of the general public who are not previously familiar with it. Putting everything about what a planet is into one article, perhaps with links to other articles giving a more technical description of each definition, is what would be most accessible to the general audience. The average reader would not know to look up an article on the IAU definition and another article on the geophysical definition.


 * I do appreciate the fact that, on a single article about the definition of a planet, fans of the IAU definition would debate the text describing the geophysical definition. But they are going to (and have) also done so on an article exclusively about the geophysical definition. So, separate or merged, that debate and possible edit war is going to happen. It's just a question of where it will happen.


 * Finally, these talk pages are supposed to be about how the material is presented, editors debating and trying to convince each other that their own views are the true ones. Could we keep it to the clear presentation of information from reliable sources? Fcrary (talk) 07:24, 26 August 2020 (UTC)


 * Fcrary, to the contrary I would argue that you are getting too close to this. I have done nothing but produce sources from the literature that support what I am saying, and you have done nothing but try to make it about the editors, trying to carve out a position that certain editors should be disallowed from editing this article. You want to win the debate by making other voices go away rather than arguing facts. That is way out of bounds. Let's focus on the content, not the editors, which is what I have been doing.


 * About your proposal to have one central article then have it point to other articles that give more detail, that is an excellent proposal and I agree. The existing IAU definition article is one of the detailed articles it can point to. This article on the Geophysical Planet Definition/Concept (with the title restored, and variations on the concept added to make it rounded) can be another one that it points to. We only need to add the new article that is the top-level. I don't have time to fight the editorial war that will erupt, but I am full agreement with your proposal, which means we keep this article separate. Yes? Sanddune777 (talk) 16:52, 26 August 2020 (UTC)

To kwami: You are really, really wrong when you wrote, "Besides the really early stuff, there's the historical conception of minor planets, but not moons, as planets." The published record shows that astronomy books were teaching that moons are planets into the 1920s, and it was always the majority view from Galileo until about that time. This can't be questioned. Do a google scholar search on "secondary planet" and see all the textbooks and papers explaining that planets are both "primary planets" and "secondary planets" and that moons (secondary planets) are planets. You are also really, really wrong when you wrote that asteroids (or minor planets) were demoted to non-planets in the 1850s. That is an example of the "presentism" fallacy, interpreting past events from the bias of modern perspectives. The published record shows without any doubt that all, or almost all, astronomers considered asteroids (minor planets) to be actual planets until the 1950s/1960s. Textbooks explained that planets exist as both "primary planets" and "secondary planets", and that the primary planets exist in three groups: "inner planets" (or terrestrial planets), "minor planets" (or small planets or asteroids), and "giant planets". Yes, this was a different concept of planet than we have today, but it was a different concept back then. That's the whole point. When they meant that they are all planets, they really meant it, because that fit the concept they had. The concept they had changed in the 1950s/60s, and now people use the presentist bias to say "well, the asteroids weren't really planets, so they didn't really mean it when they said they are planets." People try to create an event in the 1800s when they were "demoted" from planets, and they put it after the first four or the first 15, before they got really small, because our concept of planet would not include the really small ones. But the historic record shows that they actually were part of the concept that all astronomers (or almost all) were using. But a few writers in recent times have latched onto the idea that when astronomers stopped inventing new astrological symbols for them and started numbering them instead, that meant they no longer counted them as planets. Of course that is pure rubbish. They stopped creating astrological symbols because there were too many to keep creating symbols, and numbering them was a practical necessity. There is zero support in the historic record for saying astronomers had a concept of planet that did not include the asteroids until during the 1900s, and it is pretty clear it happened in the 1950s and 1960s. This is part of the reason we need separate articles, to tell the true history of these things. As I said in October 2019, I am avoiding OR so I am going to publish first and then will bring it to this talk page to put into the article. But you can do the literature search for yourself to see. And there already are some published papers star gin to talk about this. The IAU vote in 2006 woke people up to realize we need to recapture the true history and teach it because a bunch of presentist, historic revisionism is being used to support a concept that ultimately came from astrology rather than from the Copernican Revolution and science. Sanddune777 (talk) 01:23, 26 August 2020 (UTC)


 * You're presenting your claim as awfully certain for not providing any evidence.
 * I probably haven't read a much as you on the topic, but from what I have read, things are not as straightforward as you present them to be. Certainly even in the late 19th century asteroids were still counted as planets, but why, since 46 'planets' were discovered in the year 1930, was there such hoopla about Pluto? IMO this argument of Stern's undermines his case. In any case, Tombaugh in his autobiography depicts a younger man in 1930 who did not consider asteroids to be planets, nor did his fellow astronomers:
 * p. 13 This book tells the story of the discovery of the ninth planet, Pluto, from my own personal experience.
 * p. 14 ... the discoveries of the planets Uranus and Neptune. Pluto is the only planet discovered to date in America. The few planet discoveries were accomplished over a span of 150 years and were rare events.
 * p. 15 A new planet, if there was one, could be anywhere in the Zodiac belt, or even outside it.
 * p. 29 Of the nine known planets ... Between these two groups there is a wide gap, in which move thousands of dwarf worlds known variously as the asteroids, planetoids or minor planets.
 * p. 85 The more powerful the search telescope, the more hundreds of asteroids are recorded and the greater the number of deceptive planet suspects.
 * p. 121 Slipher would come down to the room where I was blinking. "Are you finding anything [planets]?" "Not yet," I said, "but finding lots of asteroids and variable stars, also some interesting groups of nebulae [now called galaxies]." (brackets in the original)
 * p. 136 If Minerva, the goddess of wisdom, had not already been given to one of the asteroids, the name of the new planet would have been Minerva.
 * p. 172-174 In this extensive search, the following discoveries were made in order of importance: one trans-Neptunian planet, one globular star cluster, one cloud (or super-cluster) of galaxies, several lesser clusters of galaxies, five "open" galactic star clusters, one comet, and about 775 asteroids.
 * p. 191 Since the discovery of Pluto in 1930, there were at least three reports of the discovery of a tenth planet, but none of them materialized.
 * And if 'planets' were numbered at the time, why was Pluto not numbered in 1930?
 * Also, relevant to current 'is-Pluto-a-planet' debate, on p. 145, he speaks of early (1930s) debates that 'because of [its] orbit, should Pluto be regarded as a super asteroid?'
 * — kwami (talk) 04:27, 26 August 2020 (UTC)


 * I'm looking through general-audience astronomy books from 1880 to 1920, and indeed the status of the asteroids is ambiguous. Sometimes they're counted as planets, even if only 40km across, sometimes not. But the moons are moons -- I'll keep looking, but so far it seems to be universal that moons were not classified as planets at the time. — kwami (talk) 04:50, 26 August 2020 (UTC)


 * It is confusing for a couple of reasons (and I have spent probably two or three years focused on reading the literature in-depth to understand this). The first reason is because the general public's concept of "planet" diverged from the scientists' concept. (This explanation is Euro-centric, for which I apologize. I am language-limited.) Textbooks usually fail to mention this: the public continued believing geocentrism until the late 1700s/early 1800s.  Scientists developed a different concept than the public beginning with the Copernican Revolution, really accelerating after Galileo and Kepler in the early 1600s. That concept included moons as planets. Every early Copernican was clear about this. However, the vast majority of the public never learned about astronomy in their primary education (which was all that most people ever received). I searched a repository of textbooks for primary education and found not a single astronomy book, and not a single line teaching planets in any book. The only references to planets were literary allusions. Historians discussing the 1600s and 1700s are in complete agreement that the public learned about astronomy only the the astrology almanacs, which were extremely popular -- so popular that in England and North America there were so many printed that every household could buy one every year. Historians point out that the almanacs switched from geocentrism to heliocentrism only in the 1700s, but many stayed geocentric, and even in the heliocentric almanacs the list of "planets" used for astrology and in the tabulations was the exact same list from geocentrism. The Moon and Sun were still being called planets into the 1800s. After about 1820 or 1830 the first four asteroids were added to these almanac lists, and astrological interpretations were invented for them. Historians point out that all the other asteroids were never added to the almanacs because there were simply too many for use in astrology. It would be impossible to invent good and bad influences over each part of the body and each part of life for each asteroid in each part of the zodiac. It would be impossible for them to claim that meaning could be interpreted from all this. Also, it makes sense that of all the secondary planets, only Earth's Moon stayed in the planet lists because it is the only moon that we can be seen traveling the zodiac separately from its primary. All the other moons are in the exact same part of the zodiac as their primary, so there cannot be any distinct astrological "signal" from those secondaries other then the "signal" of the primary. (They travel together.) As a result, the public never learned that the secondary planets are "planets" because they were never included in the lists of planets in the almanacs (even though they were listed as planets in every scientific textbook for advanced education and treated as planets by scientists). The public quickly lost interest in the discovery of more asteroids, so while scientists were still finding them and calling them planets (sometimes "small planets" and sometimes "minor planets") the public no longer cared. In reading everything I could find that shows the attitude of the public (and scientists) toward planets, what I see is that there was confusion in the public's concept of planets in the 1820s - 1830s, with lists that included various hybrids between geocentrism and heliocentrism, with and without moons, with and without asteroids, sometimes with the Sun, sometimes with the Earth but sometimes not, etc. Finally by the mid 1800s and especially by the 1870s the public's lists settle down and start to look like the ones we see today with just the major, primary planets included.


 * So the public would get excited about discovering Pluto, because to them this was a real planet that matters, and because the story of discovery was like the story of finding Neptune (they thought). But to scientists, it was another "major" planet, very different than the swarms of minor planets they were discovering, so it would be interesting for scientists, too. Scientists were fully aware that the public used simpler terminology and only counted the major primaries as planets, so nobody was confused about saying Pluto was the 9th planet. The scientists simply knew that other types of planets exist, too. Their concept of planet was different than ours is, today. It is the presentism fallacy for us to impose on scientists of that era a view that they did not have.


 * The second reason it is confusing is because scientists used somewhat confusing terminology. In textbooks with formal definitions they stated that moons are planets (secondary planets) and asteroids are planets (minor planets) -- that there are four types of planets (terrestrial, minor, major and secondary). But scientists didn't always overtly say that they are planets. They usually used the simpler terms "asteroid" or "moon" because it was simpler. This is in no way an indicator that they did not consider them to be planets. Here are a few examples:


 * From a 1767 English edition of de Fontanelle's book:


 * "The other sixteen are called Planets.
 * “These are divided into two classes; six are called the Primary Planets; ten are called the Secondary Planets. When we speak of the Planets without any distinction, we always understand the primary ones.
 * “The Primary Planets move round the Sun, and are carried at different distances from it, in curves that return into themselves.
 * “A Secondary Planet revolves round a primary one, and accompanies it in its motion round the Sun.”


 * He acknowledges that sometimes they said simply "planets" when they meant only the primary ones. Here's another example from a 1911 book (Chambers, George Frederick. The story of the solar system simply told for general readers. D. Appleton & Company, 1911):


 * "The planets are divided into “primary” and “secondary.” By a “primary” planet we mean one which directly circulates round the Sun ; by a “secondary” planet we mean one which in the first instance circulates round a primary planet, and therefore only in a secondary sense circulates round the Sun. The planets are also “major” or “minor” ; this, however, is only a distinction of size.
 * "The secondary planets are usually termed “satellites,” or, very often, in popular language, “moons,” because they owe allegiance to their respective primaries just as our Moon—the Moon—does to the Earth. But the use of the term “moon” is inconvenient, and it is better to stick to “satellite.”


 * He acknowledges that popular language uses the simpler terms. Here's another example from an 1897 book (Thornton, John. Advanced physiography. Longmans, Green and Company, 1897):


 * Classification of the Planets.---The planets have been divided into primary, minor primary (called also planetoids or asteroids), and secondary.


 * From an 1893 book that defines astronomical terms (Gore, John Ellard. An Astronomical Glossary. Crosby Lockwood and Son, 1893):


 * Planets, Minor or Asteroids. The group of small planets which revolves round the sun in orbits lying between those of Mars and Jupiter. They are very small bodies. The diameter of the largest, Vesta, probably does not exceed 200 miles. The number now know (1893) amounts to over 300.
 * Planets, Primary. The planets which revolve round the sun as a centre. These are in order of distance from the sun: (1) Mercury, (2) Venus, (3) the Earth, (4) Mars, (5) the Group of Minor Planets, (6) Jupiter, (7) Saturn, (8) Uranus, (9) Neptune.
 * Planets, Secondary. The satellites which revolve round the primary planets as a centre. Our moon is a secondary planet, or satellite of the earth, but from its relatively large size and other reasons, it may almost be considered a primary planet. Mars has 2 satellites, Jupiter 5, Saturn 8, Uranus 4, and Neptune 2 : a total of 22 secondary planets.


 * So they were being clear that minor planets are actual planets, and secondary planets (moons) are actual planets, but commonly they used simpler terminology.


 * I think this simplified terminology also confused the public, which already didn't understand that dynamical state is not what defines a planet, ever since Galileo. They got the idea from geocentrism and astrology that planets are important because how they impact the world of humanity, and that they impact us through their orderly dynamics. I could give many examples of authors in the 1800s arguing that the reason planets were created is to teach us about the orderliness of the heavens, because they thought planets needed a purposed related to humans, and that was what they came up with. To the public it was all about orderliness and human-centrism (very un-Copnernican).


 * The records show that astronomers finally gave up Galileo's geophysical planet concept in the 1920s to 1960s because of something that occurred during that period, which I explain in the manuscript that I am getting ready to release. But then in the 1960s the planetary science community was born, and they immediately started calling moons "planets" again. Sanddune777 (talk) 06:53, 26 August 2020 (UTC)

I wasn't aware the concept of 'satellite planet' was significant that late. — kwami (talk) 10:55, 27 August 2020 (UTC)

Runyon et al. (2017)
Can we get rid of this ref? It's my principal problem with the article as I found it. It defines a planet as a non-spheroidal spheroid, and provides as examples of round bodies a number that are not round. We're better off pretending it doesn't exist.

Runyon and Stern (2018) is much better, though they do count a lot of bodies as being 'planets' even though they're not in HE and therefore don't qualify as planets by their definition. But at least the definition itself is coherent (apart from their editor not knowing how to punctuate):

A substellar mass [sic] body that has never undergone nuclear fusion and has enough gravitation to be round due to hydrostatic equilibrium, regardless of its orbital parameters.

Note that Io and Europa quality under this definition, whereas they would not under the IAU criterion for HE, since it doesn't require the body to be massive enough to be plastic as a solid body. As I read it, whether the body is in HE due to tidal heating is no more relevant than whether it's in HE because it's composed of ice rather than rock.

Unlike Stern's more agnostic definitions elsewhere, where 'round' is intentionally left vague, only 6 moons are likely to qualify under this definition, not the 19 that he routinely counts. (That's assuming that the present tense in the definition indicates present time for the definition, as that bodies that used to be in HE but are no longer are not planets. Otherwise you get Phoebe and Vesta, which Stern does not accept because they're not currently round.)

I was tempted to advocate for the Planetary Society's definition, the word "planet" as used in planetary geology implies: a planet is a world too small to be a star (meaning it never produced nuclear fusion) and is big enough to be round due to its self-gravity. The transition from not-round to round is gradual, unlike the sharp transition from planet to star.

But with 'by its self-gravity' we're back to Io and Europa not being planets, and they go on to say that Pluto, Charon, Eris, Makemake and Haumea are 'empirically proven to be round', which is categorical bullshit. AFAICT, Pluto is (disregarding the quibble that nothing is 'empirically proven' in science), and while Charon is round, we don't know if it's in HE. For the others, we simply don't know. (And as for the transition from planet to star being 'sharp', Stern wanted to sidestep the issue because he deemed it to be a can of worms best left alone.) So the Planetary Society's article is unfortunately rather bad once we get into the details. But perhaps we can give both definitions, especially if we have sources that discuss the consequences of the differences between them?

Note also that the IAU's and Stern's are not the only definitions of 'planet'. A very common one, in fact the one used almost universally until 2006, is summarized in Grinspoon (2015) and includes orbital characteristics. In the common non-IAU definition, DPs are planets, but moons are not. It would be interesting to know what the relative popularity of the two conceptions is among astronomers who reject the IAU definition.

I suspect that the claim that asteroids were 'planets' until 1950 depends on careful cherry-picking of the sources, and is an unfortunate attempt to 'win' this argument by deception rather than by debate or common usage (which are plenty good enough!). When Neptune was discovered, there was a lot of hoopla, and similarly with Pluto. Why would people care about Pluto if new planets were discovered every year? Why was Pluto not given a 'planet' number like all the other 'planets' that were discovered that year? Obviously, asteroids were not generally considered planets. To now twist history and claim that they were, simply to push a partisan POV, is dishonest. But that's another debate, not particularly relevant here. — kwami (talk) 07:10, 24 August 2020 (UTC)
 * I'd rather keep all of those references, but add text comparing and contrasting their differences. None of them are entirely rigorous or and there are internal inconsistencies. But no one is saying one is correct and another is wrong. They are just different ways of describing the same basic idea. Putting the common elements in the lead and compare/contrast in later text would be informative to the readers. Also, the whole hydrostatic equilibrium thing is a can of worms. The whole point of including roundness in the definition of a planet is that it says something about its internal structure, and (to me) that doesn't make sense unless they are actually talking about hydrostatic equilibrium and its implications for geological activity. But hydrostatic equilibrium is basically impossible to measure without gravity data from multiple spacecraft flybys. Which we don't have for most of these bodies. So the whole thing strikes me as a mess. It might be best served by adding a section on what round versus hydrostatic means, and letting the readers decide for themselves. Fcrary (talk) 07:23, 24 August 2020 (UTC)

Yes, a nice, easily justifiable idea, but completely impractical for most bodies. That's why I like Stern's earlier definition, which was basically (if I'm remembering right) "if it looks like a world, then it's a planet". That is, a planet is defined as a planetoid (in the literal sense of the word). That still is his definition, it would seem, since he repeatedly claims objects are planets even though he must know they're not in HE, or even solid bodies and so cannot have ever been in HE. So, at some level, both the IAU and Stern definitions are bullshit, fudging words to justify a decision that they've already made, rather than because there's any scientific merit to them.

We don't even know yet whether Ceres is in HE, do we? And Rhea -- all we know is that its shape is consistent with being in HE, but all that might mean is that it froze out after it despun, which is reasonable since it's a bit more massive and substantially closer to Saturn than Iapetus is. So, yeah, all the spuriously precise definitions are nonsense. — kwami (talk) 07:53, 24 August 2020 (UTC)
 * After Dawn spent so much time in orbit around Ceres, I really hope we know if it's in hydrostatic equilibrium. But that depends on whether you mean in equilibrium on global scales or local scales. It does look like there are some local or regional parts of Ceres which are not in equilibrium. But since we're talking about bodies as a whole, local departures from hydrostatic equilibrium don't strike me as relevant. The Earth has some local departures from equilibrium as well, and no one questions whether the Earth is a planet. At level of detail, it would just confuse readers and it might make my head explode. The same thing is true of a definitions which involve saying something used to be a planet but isn't one anymore, or bodies which aren't a planet but might be one in the future. One old, proposed and defunct definition for a "double planet" depended on tidal evolution, and technically would have meant the Earth's Moon could, at some point, become a planet for half of its orbit and then become a moon for the other half of its orbit. I really hope we don't need to go into things like that to put together a good, comprehensible Wikipedia article. Fcrary (talk) 08:18, 24 August 2020 (UTC)

My major problem with Runyon (2017) was that we were saying it was "the" geophysical definition of a planet. If we presented it as an early version of their definition, perhaps defunct now even for them, and don't try to claim that it ever was "the" definition, I don't have such a problem with it.

I don't know about Ceres. Last thing I read was that there were anomalies that couldn't be explained, and it sounded like this was relevant to it being in HE on a global scale, but I don't know if that's really what they intended or if they were right in saying it if it was.

You're right, the real criterion is either (a) is the body geologically active, or (b) is the body geologically interesting. Perhaps geologically interesting but no-longer-active objects like Vesta could be categorized as 'dead' planets? Or geologically dead planets? Or just avoid the whole issue with the word 'planetoid'. Because you're right, calling them 'ex-planets' would be weird.

Yeah, by one definition of 'double planet' intended for the Earth-Moon system, Uranus is a triple planet, because the outermost two of its tiny little irregular moons are far enough away and thus move slow enough for their orbits to qualify. Like 'planet', I think, "Hey, that looks like a double planet" is probably a better definition than some fake-sciencey fudge designed to justify an already-decided conclusion. — kwami (talk) 08:54, 24 August 2020 (UTC)


 * If it makes anybody feel better about this, biologists have argued over the definition of species since Linnaeus, even before Darwin, and they still have not resolved it. Someone listed about 50 different definitions. The arguments often get into minutia, but many think it is worthwhile because it drives out specificity that helps the science. Sanddune777 (talk) 01:56, 26 August 2020 (UTC)
 * Yeah, that's a good parallel. Or what a 'continent' is -- I asked a geologist once, and he said there was no definition that would tell you which landmasses were continents. Another would be 'organic', which has fairly clear definitions, though ones that are completely at odds between agronomy and chemistry. I don't see why planetary geologists and people working on the Nice Model can't have different conceptions of what a 'planet' is. — kwami (talk) 03:13, 26 August 2020 (UTC)


 * I think the article should include multiple variations of the definition. For comparison, the article Clearing the neighborhood contains three versions. I agree with kwami that this article can be about the broader Geophysical concept. However, IMO the article should retain the title "Geophysical Planet Definition" since the public probably doesn't appreciate the abstract difference between a "concept" and a "definition". The "IAU definition" is also somewhat of a concept rather than a definition, since they did not define either Clearing the neighborhood or gravitational rounding. I would be happy if this article discusses how the concept (or "the definition") has evolved since Galileo. Adding asteroids was one major change, since the concept de facto drifted to include ever smaller bodies from the 1850s through 1950s, until they were no longer anything like Galileo had in mind. Galileo had defined planets as "other Earths". The inclusion of asteroids shifted the concept to become almost "anything in space that is substellar". (The literature shows this, clearly.) Then, removing the asteroids shifted the concept back closer to the idea that Galileo had. There have been multiple attempts to define the current version of the concept more precisely, as you stated above, and those should be included, too. IMO these kinds of details don't matter that much, and arguing the details can actually help science, and they don't need to be resolved for science to function. A major part of the purpose of science is to evolve the concepts. Sanddune777 (talk) 01:56, 26 August 2020 (UTC)


 * Agreed. I think that's the way to go. Though this argument by Runyon et al. that asteroids were 'planets' until 1957 or so would seem to be exaggerated. They may have been counted as planets by some people under loose usage of the term, but they were not counted among "the planets" in common usage.
 * I disagree that the geophysical def is more traditional, though, and pushing that goes beyond what the definition is and would seem to be unjustified. I don't see any early distinction between "Earthlike" asteroids and "non-Earthlike" asteroids that parallels Stern's concept of a DP. Rather, if asteroids are planets then all asteroids are planets, no matter how small. Several of the ca. 1900 books on astronomy comment on this -- that you could bike around one of these 'planets' in an afternoon. There is no conception of some being more planetlike and some less planetlike, apart from the distinction into major and minor planets. Both the IAU and Stern divide the traditional planets into real planets and not-planets. The difference is only in where they draw the line. The IAU follows the traditional major/minor divide, whereas Stern uses a novel divide that, AFAICT, has no parallel prior to perhaps the mid 20th century. A novel definition is not unreasonable -- Stern is addressing the interests of a field that did not exist prior to the era of space exploration -- but it's not traditional. — kwami (talk) 03:13, 26 August 2020 (UTC)


 * I agree that the idea of making the small planet into non-planets, and coming up with some reason to do that, did not emerge until a later time. Check out figures 4 and 5 in this paper: https://arxiv.org/pdf/1805.04115.pdf (The journal version is here: Metzger, Philip T., Mark V. Sykes, Alan Stern, and Kirby Runyon. "The reclassification of asteroids from planets to non-planets." Icarus 319 (2019): 21-32.) The change in attitudes about minor planets was in the 1950s/60s, following a paper by Kuiper where he argued that only the larger, round ones are true planets. But that is because earlier scientists had no clue that space is filled with small junk. They didn't realize that until they started finding smaller and smaller asteroids. As they did, they originally didn't have any good reason to make them non-planets (and there are no arguments anywhere in the literature until very late to say they aren't planets). Finally, Kuiper came up with a reason. He argued that protoplanets that became big enough to grow by gravitational instability will be round (and they are true planets), while smaller asteroids that grew by accretion without gravitational instability will be lumpy and they are not planets. That triggered the change. (I suspect the change was super rapid in part because the public already did not consider asteroids to be planets, so scientists were moving more toward the common view.) Now, we are arguing over possibly better ways to define it than Kuiper's proposal. But whatever exact definition we use, it is basically putting the planet concept back closer to what Galileo had. Galileo's argument was that the Moon has mountains and therefore it is another Earth, and the Moon is a planet, and therefore all the planets are "other Earths". So his entire concept was that planets are "other Earths". By removing asteroids (by whatever definition) we are moving back closer to Galileo's concept. Sanddune777 (talk) 07:10, 26 August 2020 (UTC)

"Other worlds", really, rather than "other Earths". Which is Stern's de facto definition today. But this still is a problem for Stern's thesis -- the IAU definition is the common conception of 'planet' since the 1850s or so, whereas Stern's conception only dates to the 1950s or so, and so is less traditional in its definition. Also, if you're working on the Nice Model, then all the DP's and moons are "small junk". What is junk depends on what is of value for your field.

But Stern's stated definition violates his de facto definition. He claims 147 TNO planets "and counting", when hardly any of those bodies are known to fit the versions of his definition that speak of HE. So Stern's def is just as much BS as the IAU's. — kwami (talk) 11:04, 27 August 2020 (UTC)


 * Well, Galileo was actually using "another Earth", and it was quickly after him that other Copernican astronomers began arguing for a "plurality of worlds". Back then, the idea of a "world" was different. A world was not a geological or physical object. A world was a center of God's creation, or a center of civilization, or a center of teleological importance. They used "world" to mean the entire cosmos including all the planets and stars. It was revolutionary to say the Earth is not at the center of the world, and then they had to ask, "if the planets are their own centers with their own moons going around them, then why do they exit? Why would God create multiple centers?" The Copernicans concluded, almost universally, that all these planets must contain their own worlds. They must have their own purpose for existing separate from Earth's purpose. It was only later, starting in they 1700s with Laplace, where they had a planet formation theory, so they no longer needed to invent a purpose for things to exist. But in the 1600s they argued that it is crucial to Copernicanism to believe in a "plurality of worlds". Galileo never made those arguments. He focused on the geology of the Moon and he argued it is another Earth, which was contrary to Aristotelian philosophy that said everything in the heavens is made of quintessence (the fifth essence) and is perfect and unchanging, following celestial physics, while Earth is changing and delaying and following earth physics (geophysics). (That is where the name of the geophysical planet definition comes from.) Galileo pointed to the mountains and claimed the Moon doesn't have celestial physics, but instead it, too, follows geophysics. He argued there is only one physics. So then the other Copernicans after Galileo made the argument about a plurality of worlds, that all the planets contain "other worlds".


 * In the 1800s, scientists started realizing that the planets don't all contain civilizations and life. It was William Whewell who made the habitability argument that really got that line of thinking started. But we continued saying they are "worlds" because they could have life on them, for example if we went there and visited. The idea of a "world" evolved to mean something like "an immersive environment on the surface of a planet". The word "world" still carries the idea of the interaction of intelligent beings on the surface of a planet. We call a large asteroid like Bennu a "world" because it is a fascinating place where we could go (perhaps virtually by robotics) and immerse ourselves in the study of its processes and history. We don't call a meteorite a "world" because it is not an immersive environment. The line between a "world" and a "sub-world" is not defined, but it has something to do with how humans mentally feel about the object. For sure, we see scientists calling things "world" when they are far too small to be called "planet".


 * Also, I want to clarify that there has been a split between the public's terminology & concepts versus scientists' terminology and concepts ever since the 1600s with the Copernican Revolution. That split did not heal when the public finally switched to heliocentrism in the 1800s. Instead, they developed a quasi-astrological concept of planets, in which moons are not planets, and in which small asteroids were not planets. At that time, scientists had a different concept. That accounts for the differences in terminology we see in the literature. Scientists later rejected the small asteroids as planets, and then in the 1920s to 1950s (somewhere in there) embraced the culture's concept of planet, saying moons are not planets. So when we look at older literature we see a split between the public's and the scientists' terms. This is crucial, because the GPD is not trying to be a popular culture definition. It is trying to be a scientific, taxonomical definition. — Preceding unsigned comment added by Sanddune777 (talk • contribs) 14:00, 27 August 2020 (UTC)

That all seems reasonable.

I've been reverted in the past in some of my changes to the lead, so, though they now seem to be sticking, I thought I should clarify (though hopefully the changes are pretty obvious). "Our" Solar system to "the" -- it's not like there are others. "Many more" DPs and satellite planets than "terrestrial and gas" planets --> "More" than "classical" planets. Assuming Ceres truly is a DP, there are at least 3 DPs and 6 satellite planets vs 6 terrestrial and 4 gas planets (because Io and Europa are terrestrial planets), so with the original wording it could actually be *fewer*. With my wording, then assuming Ceres it's at least 9 to 8. Could be many more, we just don't know yet.

Of course, if you accept Stern's count, there indeed are many more. But Stern's count doesn't follow from the geophysical definition. I wish he would address the discrepancy. — kwami (talk) 05:16, 29 August 2020 (UTC)

The whole exoplanet section is OR, since no-one uses a geophysical def for exoplanets. But I think I've cleaned up the article enough that it's no longer just about Runyon et al. No-one's been reverting me, so I've moved the article back to a generic title. — kwami (talk) 07:34, 20 September 2020 (UTC)