New moon discovered at Pluto
- Thread starter CaptainDonovin
- Start date
Saquist
Commodore
That's ridiculous and I don't say that often.
So I'm a planet if I've cleaned up my Room?
How do you know I did it and not someone else?
That is definitely not the definition of "non sequitur" which is a failure of logic from the premise. It seems you meant Obvious observations.
Saquist
Commodore
A non sequitur is defined the relevance of logic to it's OWN premise not by whether Topical relevance but lets not get me started on logical debate language or a mod will swoop down and take me away...
Saquist
Commodore
It's not just that, it's a form of formal fallacy...the reason it often stands in the place of "nonsense" is because in formal debate it's used when ever the premise and conclusion do not jibe. But laymen have used it for a general sense of nonsense which muddies the proper meaning.
Well think about it. We have a panel of scientist you are relying on their own comprehension or intangible understandings of what is EXCLUDED from being a drawf planet. In essense they went through all this trouble to define a planet and didn't succeed in wordage ........which.......defies the purpose of creating the definition.
I suppose, like porn, a planet is hard to define, but you can definitely recognize it when you see it. Mercury, Venus, Earth, and Mars are planets. So are Jupiter, Saturn, Uranus and Neptune. Ceres and Pluto, though...well, they're not alone and they're not much different than other bodies sharing the orbital space, so they're something else, part of a family of not-quite-planets.
If your objection is in the wording of the definition, it's possible to update it eventually.
If you're looking to retain Pluto as a planet for nostalgic reasons, though, I'm afraid you're out of luck.
If your objection is in the wording of the definition, it's possible to update it eventually.
If you're looking to retain Pluto as a planet for nostalgic reasons, though, I'm afraid you're out of luck.
You link to a press release where the IAU repeats what I just told you... why?
No, it's not. You took that part of the definition out of context. The resolution specifically says that they are defining what constitutes a planet in the Solar System, meaning that the listed points (including the one above) have no context in regards to extrasolar planets.
First of all, there's no such thing as a "debris field" in real astronomy. Objects of similar size and mass will either orbit each other and form a system (e.g. trojan asteroids, Jupiter's dozens of captured moons, Saturns rings, etc) or they clump together and form a single object (e.g. various "gravel pit" asteroids in the belt).
The reason size matter is indeed a technicality, but only because none of the possible exceptions to the rule--i.e. two major planets sharing the same orbit but on opposite sides of each other--do not exist in our solar system. So we're stuck with the working definition here such that the "planet" is THE dominant gravitational body in that particular orbit and has no other competitors along the same orbit. This cannot be said for, say, Ceres or Pluto; although they are spherical and free-floating, they exert less gravitational influence over neighboring objects than other planets in the same/adjacent orbits.
My uncle used to say that scientists can unlock the mysteries of the universe, but they cannot account for the existence of lawyers.
Yes they are. And both are subsets of "celestial objects."
And your research paper on how this is possible will be published in scientific journals... when?
Then you need to ask somebody OTHER than an astronomer.Yes planets! I want a word to describe planet-like objects such as gas giants, terrestrial planets, dwarf planets and spherical moons.
I pasted an IAU link that said exactly the opposite earlier on. Here I drew a picture of what I believe a subset is supposed to look like, and what the current definition of planet looks like:
P.S. You seem to be claiming that Pluto is actually a planet even with the new definition, that means you're on the right side of the debate.
Shh... We'll all be seeing Pluto in a little less than 4 years, and I promise you that everyone who sees it will tell you that it's a planet. Obviously
And when the Plutonians strike down our spaceship for not respecting their planet, you're all gonna admit your mistake. 
P.S. It seems like you haven't seen what my mum calls “porn”.
I do not actually care if Pluto is a planet or not really, though it makes more sense to me if it is. I think the distinction is a bit arbitrary, because I do not see why orbital characteristics (like gravitationally dominance) should be that vital for the definition. I admit that's important when you calculate planetary movements, but as far I remember we didn't include the inner planets in the calculations either when I did that myself, because their effect was supposedly already too small or something.
So why is gravitational dominance an important characteristic of a planet, and why does it make it obvious that a planet that has it is a planet when you see it?
So why is gravitational dominance an important characteristic of a planet, and why does it make it obvious that a planet that has it is a planet when you see it?
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I actually agree, personally I preferred "planetoid" as a category. Unfortunately, the IAU didn't listen to me, but it doesn't mean I should get my knickers in a twist about it. (I'm also for a narrower definition of what is a moon, formulated as "a natural satellite which is nearly spherical in shape due to self-gravity". That would make, for example, Deimos and Phobos natural satellites, but not moons. I suppose some people would be enraged at that, too.)
I don't see the problem with that. There are dwarf giant stars, giant dwarf galaxies, and all kind of arguably linguistically funny stuff out there. It doesn't matter one iota to people actually working on them.
I see no problem with that.
As for physical characteristics, you are right. But the definition focus on orbital features, not physical size or composition. It might be not your favourite definition, but it's valid nonetheless, and the one the IAU chose for itself (since, you know, they actually work on them).
But internet mooks are apparently a-ok. Funny that.
Bottom line: generally speaking, all labels are arbitrary. Nature abhors a vacuum, and except for quantum mechanics, you will find a continuum of scales from small to large. For our convenience, it's useful to set the cut off at some point, by whatever definition we find use useful. The IAU decided for a definition that made sense for the work their members. So far, all the complaints I heard from "armchair astronomers" are because they feel somehow entitled to keep the same list of planet they had on their textbook in grade school.
Except it didn't, it simply established the definitions of "planet" and "dwarf planet" and defined Pluto as the latter.
Yes and no. It's a dwarf planet, which is a new type of planet defined by the IAU as a spherical object that hasn't cleared its own orbital neighborhood.
I don't really see what the problem is. It's not like they created a new category called "Cosmic Testicle" and then came up with a definition to fit pluto. Clearly they thought--and still think--that Pluto and others like it are very similar to the other planets in the solar system. The new definition, however, is meant to take into account the ways that they are DIFFERENT, as well as the fact that is a potentially huge number of dwarf planets waiting to be discovered.
We can't call them ALL planets. That would be confusing to those poor 6th graders who have to learn this stuff in science class, which is ultimately the entire point of the redefinition.
We'll be seeing Ceres even sooner, and I can make the exact same promise in that case.
The reason the definition was changed is because the OLD definition would have inevitably applied to dozens if not hundreds of other objects within the solar system in the Kuiper belt and the main asteroid belt. This means you either accept the idea that the solar system consists of some thirty to fifty "planets" of various sizes and compositions and then make some sort of really arbitrary distinction between "major and minor planets," OR, you can come up with a decisive unambiguous definition that separates "normal" planets from the weird little ones we're bound to discover by the truckload.
The IAU chose the latter solution. And as I said, the primary reason they did this was to avoid confusing school children. And because I am serious about this, I'll say it again: they did it to avoid confusing school children. So the next time some smartass fifth grader comes up and asks you if pluto is a planet or not, you can say "It's a dwarf planet. There are LOTS of dwarf planets. Turn to Chapter 17 in your textbook for details."
Because it's easier to get sixth graders to remember "Mercury, Venus, Earth, Mars, Jupiter Saturn, Uranus and Neptune" than it is to get them to remember "Mercury, Venus, Earth, Mars, Jupiter Saturn, Uranus, Neptune, Pluto, Haumea, Makemake, Orcus, Huya, Ixion, Varuna, Quaoar, Eris, Sedna..."
At the end of the day the only MEANINGFUL difference between Pluto and, say, Triton is that Pluto was never captured by another large planet and Triton was. So they added gravitational dominance to the definition as a way of tidying up the textbooks, and the dwarf planets can be relegated to a separate chapter that mentions Pluto as the largest and most famous example.
If anything, this is a promotion for Pluto. Instead of being the smallest and least interesting of the nine major planets, it is now the largest and best known of the dwarf planets.
Saquist
Commodore
Debris:
Field:
The label is sound. Just as the term Asteroid Field is not only sound but widely accepted.
That makes no sense. Dominant merely means exerting a greater amount of control. And for it's location Pluto and Ceres do indeed do.
INDEED.
Quite right but that means the definition means nothing now. Planet isn't a word that refers specifically to our solar system we use them in reference to other systems as well. What's more, It puts even a time period on what is planet despite it's mass. The other planets all could be considered Drawf planets simply because the Kuiper belt was closer to Uranus and Neptune a couple of billion years ago The definition seems even sillier now.
This isn't so much a definition. It's a Pluto exclusion clause.
We're going to treat planets out side the solar system in an accretion disk or kuiper belt differently? Where is the size definition here? How an you keep avoiding this issues of size?
I suppose, like porn, a planet is hard to define, but you can definitely recognize it when you see it. Mercury, Venus, Earth, and Mars are planets. So are Jupiter, Saturn, Uranus and Neptune. Ceres and Pluto, though...well, they're not alone and they're not much different than other bodies sharing the orbital space, so they're something else, part of a family of not-quite-planets.
If your objection is in the wording of the definition, it's possible to update it eventually.
If you're looking to retain Pluto as a planet for nostalgic reasons, though, I'm afraid you're out of luck.
I don't think there would be this much debate on the subject if they had just give a minimum size for a planet.
This only makes matters worse then. All I can do is imagine the following conversation:
Johnnie: “Is Pluto a planet?”
Teacher: “It's a dwarf planet!”
Johnnie: “Cool!”
Two years later.
Johnnie: “My favourite planet is Pluto!”
Teacher: “Pluto is not a planet!”
Johnnie: “But you told me it is!”
Teacher: “No, I told you it is a dwarf planet!...”
Johnnie: “Isn't a dwarf planet a tiny planet?”
Teacher: “Yes.. No... Yes.. No... Um, yes... Um, no... Not really...”
It's confusing. The hyponymity issue (which exists no matter how you try to deny it) can only lead to more confusion, especially for kids, I can't possibly see it solving any. My classmates used to complain for far smaller discrepancies, and some of them simply couldn't get their head around them.
The confusion with respect to the number of objects in the Solar system has a single simple solution – create a detailed map of the Solar system and show it to the kids. A picture is worth a thousand words, and it highlights everything from the importance of the 8 major planets, to the existence of the other bodies that are similar (such as moons orbiting the planets and dwarf planets inside the belts).
You can't really spare the kids from teaching them about those numerous objects, because they need to know and feel that all terrestrial objects are alike, and that Pluto, Ceres and Calyspo as cool as Mercury (or perhaps cooler), and they could have been born on such an object if we were in another star system.
Trying to water it down to 8 planets with some moons and belts out there isn't helping.
What the fuck does that mean?
That I can't spell Calypso, eh?
No, I don't even noticed that. I meant what does "Pluto, Ceres and Calyspo as cool as Mercury (or perhaps cooler), and [kids] could have been born on such an object if we were in another star system" mean in this context?
Are you basing your argument for a scientific definition on "coolness" and irrelevant science-fiction platitudes? (beside, Jovian moons are much more likely to be habitable than asteroids and Kuiper belt objects. Are you going to call them "planets" too?)
Are you basing your argument for a scientific definition on "coolness" and irrelevant science-fiction platitudes? (beside, Jovian moons are much more likely to be habitable than asteroids and Kuiper belt objects. Are you going to call them "planets" too?)
Rocky planets, dwarf planets and big moons are the objects that appear interesting when you're discussing habitability. More massive objects would tend to lack solid surface and would suffer from extreme pressures, less massive objects would tend to be unable to keep a significant atmosphere, etc. It makes sense to present them to the kids as equally interesting and important objects. In particular, I think Ganymede should be given more time than Mercury.
But we aren't discussing habitability. We are talking about the definition of "planet".
Potential habitability of a celestial object, while interesting in itself, it's not really germane to this discussion.
Potential habitability of a celestial object, while interesting in itself, it's not really germane to this discussion.
