Pluto reclassified as a planet.

[bilby]

 

[Underseer]

The real shame of demoting Pluto is that the story of Clyde Tombaugh, the astronomer who first identified Pluto, was a standard part of US elementary school science education in the 50's and 60's. We learned how Tombaugh built his own telescope, including grinding the lens by hand. Millions of American school children were introduced to astronomy through his story. When Pluto was knocked off the list, it was like being told Benjamin Franklin did not fly a kite in a thunderstorm.

So? Tombaugh still discovered the first of the dwarf planets, and beat the other discoveries by decades. Why is that not worth telling?

Although if we're going to talk about American astronomers, Edwin Hubble was more important scientifically and makes for a more interesting story. He was a lawyer by training who decided to go into astronomy and ended up being the guy who destroyed the notion of a static universe.

 

[bilby]

So? Tombaugh still discovered the first of the dwarf planets, and beat the other discoveries by decades. Why is that not worth telling?

Nope; Ceres was discovered 130 years before Pluto, so it is the first of the Dwarf Planets; it too was originally classified as a Planet, and then downgraded.

Pluto was somewhere between the 1,100th and 1,200th dwarf planet discovered; it's official asteroid number is 134,340, meaning there are 134,339 dwarf planets officially listed ahead of Pluto by the IAU.

Officially, Pluto is a complete non-entity amongst asteroids. Not first; not biggest; not furthest away; not closest; not first to be downgraded from planetary status; not really anything-est.

Sorry.

 

[steve_bnk]

Funny how rational secular logical people can get so bent out of shape over how an object at the outer edge of the solar system is classified...

 

[Bronzeage]

So? Tombaugh still discovered the first of the dwarf planets, and beat the other discoveries by decades. Why is that not worth telling?

Although if we're going to talk about American astronomers, Edwin Hubble was more important scientifically and makes for a more interesting story. He was a lawyer by training who decided to go into astronomy and ended up being the guy who destroyed the notion of a static universe.

It's hard to beat the story of a farm boy who built his own telescope and taught himself astronomy in a cornfield. Tombaugh had to give up going to college because a hailstorm destroyed the crops the year he graduated high school.

 

[travc]

Why is everyone so upset about this?

If Pluto remained a planet, then all those other dwarf planets would also have to be considered planets, and who wants all that extra memorization?

The only upside to bumping the dwarf planets (at least the Keiper-belt ones) up to planet status would be including Eris and Orcus. I have no clue what the other one's names refer to.

 

[Bomb#20]

C'mon, Google isn't that hard to use, is it?

http://en.wikipedia.org/wiki/Dwarf_planet

Is there an argument in there somewhere, either for why the reasons for the demotion were scientific or for why all those other dwarf planets would also have to be considered planets? Or were you merely attempting proof-by-condescension? Are you under the impression that a vote of an astronomers' committee is any more capable of making a labeling convention scientifically correct than a vote of a bishops' committee is of making the doctrine of the Trinity theologically correct?

Pluto got reclassified because we found a whole bunch of other things beyond the orbit of Pluto. Heck, some of them are even bigger than Pluto. When Pluto was the only dwarf planet we knew about, it made sense to classify it as a planet, but now that we know about all those other dwarf planets, it makes more sense to put Pluto in that other category with the others.

And no doubt a committee of physicists had reasons just as persuasive to themselves for why it makes more sense to put a 0.9 mm wave in the "infrared" category with a 0.001 mm wave than in the "microwave" category with a 1.1 mm wave. That doesn't make the categories science. Astronomical taxonomy is still done the way all other taxonomy was done for most of recorded history: people make up labels for categories they feel make sense and make up definitions that ignore distinctions they choose to treat as unimportant. But a couple hundred years ago biologists started moving away from this procedure and started working out how to do taxonomy scientifically; by now they've gotten pretty good at it. Their success has given other sciences biology-envy -- the delusion that they can do categorization scientifically too.

What is interesting is that the behavior of objects in the solar system change behavior depending on how they are described by scietists.

^^^^^ This. ^^^^^

 

[travc]

Astronomical taxonomy is still done the way all other taxonomy was done for most of recorded history: people make up labels for categories they feel make sense and make up definitions that ignore distinctions they choose to treat as unimportant. But a couple hundred years ago biologists started moving away from this procedure and started working out how to do taxonomy scientifically; by now they've gotten pretty good at it. Their success has given other sciences biology-envy -- the delusion that they can do categorization scientifically too.

The idea is for the taxonomic label ("planet" in this case) to actually convey information. Including Pluto but not other dwarf planets would make the word "planet" less meaningful. Then again, it is perfectly fine for a word to have a common meaning and a scientific meaning which are a bit different.

BTW: The biological way of doing taxonomy now is really based on systematics, specifically heredity relatedness. That is cool and all, but it actually leads to some less practically useful/meaningful classifications. Monkeys would be one classic example, but there are lots of even more odd situations where rather dissimilar things are more closely related than functionally and/or morphologically similar things.

 

[Nexus]

people make up labels for categories they feel make sense and make up definitions that ignore distinctions they choose to treat as unimportant.

The reasons why pluto is best classified as a dwarf planet have been given in this thread or linked. If you have better reasons why it should be classified as a planet show us your work.

 

[Bomb#20]

The idea is for the taxonomic label ("planet" in this case) to actually convey information. Including Pluto but not other dwarf planets would make the word "planet" less meaningful. Then again, it is perfectly fine for a word to have a common meaning and a scientific meaning which are a bit different.

BTW: The biological way of doing taxonomy now is really based on systematics, specifically heredity relatedness. That is cool and all, but it actually leads to some less practically useful/meaningful classifications. Monkeys would be one classic example, but there are lots of even more odd situations where rather dissimilar things are more closely related than functionally and/or morphologically similar things.

Actually it's not based on heredity relatedness per se -- the current fashion for cladistics is an accretion. The revolution was already well underway in the early 1800s when most of the taxonomists were still creationists. (Although of course heredity gives a very tidy explanation for why the new method works as well as it does.) What biological taxonomy is based on is falsifiability. Being told a palm tree is a monocot lets you make predictions about it that being told it's a tree does not -- "tree" conveys information, yes, but only the information in its definition. But since it's a monocot, we can go learn something about grass that we didn't know before and that's different from dandelions, and it will have an elevated probability of also being true of palm trees. In contrast, if you go learn something new about Ceres that you didn't know before that's different from Mars, how does that make Pluto more likely to match Ceres?

"Monocot" is a falsifiable category. "Dwarf planet" is no more falsifiable than "tree". Including Pluto but not Ceres wouldn't make the word "planet" less meaningful; it would just mean something different.

 

[Derec]

The real shame of demoting Pluto is that the story of Clyde Tombaugh, the astronomer who first identified Pluto, was a standard part of US elementary school science education in the 50's and 60's. We learned how Tombaugh built his own telescope, including grinding the lens by hand. Millions of American school children were introduced to astronomy through his story. When Pluto was knocked off the list, it was like being told Benjamin Franklin did not fly a kite in a thunderstorm.

It's still a good story. It just changes from finding the last of the planets to finding the first Trans-Neptunian Object. If anything, that's a bigger deal.

 

[Bomb#20]

The reasons why pluto is best classified as a dwarf planet have been given in this thread or linked.

No, they haven't. The reasons why pluto is classified as a dwarf planet have been given in this thread or linked. Subtle difference.

If you have better reasons why it should be classified as a planet show us your work.

Where the bejesus did I ever suggest it should be classified as a planet? I agreed with the IAU article that the reasons for the demotion were unscientific*; and I challenged somebody's claim that if Pluto were called a planet then the other dwarf planets would also have to be. That in no way implies that it should be a planet. My point is that all claims that this categorization of solar system bodies is better than that categorization are an exercise in taste, not science.

(* They didn't mean it sincerely, but they should have.)

 

[Nexus]

I agreed with the IAU article that the reasons for the demotion were unscientific*; and I challenged somebody's claim that if Pluto were called a planet then the other dwarf planets would also have to be. That in no way implies that it should be a planet. My point is that all claims that this categorization of solar system bodies is better than that categorization are an exercise in taste, not science.

The current categorization of planets is better than the previous one when pluto was called a planet because there was no clear definition of planet back then. At least now there are some objective criteria. No shit the current criteria aren't fundamentally objective and other criteria could have been used instead. That's the nature of nomenclature. It seems you have just been engaging in semantic nonsense. That's better suited for the philosophy forum.

You appear to be operating under one definition of science which includes observation experimenting, falseability. There are also more general definitions which simply define science as a system of reliable knowledge. Having clear definitions to build upon is not unscientific even if other starting definitions could have been used instead. The question is are the categories useful.

 

[travc]

Actually it's not based on heredity relatedness per se -- the current fashion for cladistics is an accretion.

Huh? No, I really don't think it is. Every taxonomic change (and some entirely new taxonomic systems) I know of in biology has been made in an effort to reconcile with systematics based on relatedness. Molecular genetics has led to quite a bit of revision, but the 'accretion' methodology is a surprisingly good proxy which gets it right most of the time.

BTW: The main species we work on has just been split into two, mistakenly in our lab's view, since we have lots of samples of what are now 'hybrids' and sequence data clearly showing a big chunk of a chromosome introgressing between the two 'species' happening just a couple of years ago. However, we really try to stay out of that fight and just publish the evidence without comment.

What biological taxonomy is based on is falsifiability. Being told a palm tree is a monocot lets you make predictions about it that being told it's a tree does not -- "tree" conveys information, yes, but only the information in its definition. But since it's a monocot, we can go learn something about grass that we didn't know before and that's different from dandelions, and it will have an elevated probability of also being true of palm trees.

What do you mean by "falsifiability" here? I must be missing something, because any taxonomic classification based on properties instead of just an enumeration of items in each class is falsifiable. It an item does not have a proprety required by the definition of the class, it does not belong to that class.

In contrast, if you go learn something new about Ceres that you didn't know before that's different from Mars, how does that make Pluto more likely to match Ceres?

"Monocot" is a falsifiable category. "Dwarf planet" is no more falsifiable than "tree". Including Pluto but not Ceres wouldn't make the word "planet" less meaningful; it would just mean something different.

I'll agree that "dwarf planet" isn't a very good classification, but the more specific terms "asteroid" and "Kuiper belt object" are rather meaningful. If we learned something new about Pluto, it would likely apply to Eris and most other (at least large) KBOs.

 

[aeebee50]

More April Fool jokes. I am not over the finding the Jesus' drinking cup in Spain.

 

[Bomb#20]

The current categorization of planets is better than the previous one when pluto was called a planet because there was no clear definition of planet back then.

Not sure why that makes it better -- the old situation better reflected the reality that nature is a continuum and there's no more intrinsic difference between what we call an asteroid and what we call a planet than there is between what we call a hill and what we call a mountain.

At least now there are some objective criteria. ... the current criteria aren't fundamentally objective and other criteria could have been used instead. ... Having clear definitions to build upon is not unscientific

Pluto isn't no longer called a planet because it doesn't fit the chosen criteria. Rather, the chosen criteria were cobbled together in order for Pluto not to fit them. They are ad hoc, just like the old definition. And the definitions aren't even all that clear or the criteria all that objective.

"If Neptune had cleared its zone, Pluto wouldn't be there." -- Alan Stern, co-originator of the "clearing the neighborhood" concept.

It seems you have just been engaging in semantic nonsense. That's better suited for the philosophy forum.

I've just been engaging in reassuring gmbteach that there's nothing wrong with being upset about Pluto's demotion and disagreeing with the IAU on this point. If you disapprove of my efforts in this direction, think what you please.

 

[Bomb#20]

Huh? No, I really don't think it is. Every taxonomic change (and some entirely new taxonomic systems) I know of in biology has been made in an effort to reconcile with systematics based on relatedness.

But that impression comes from familiarity with recent changes. Quite a few correct taxonomic changes were made by creationists in the century before Darwin. Heck, Linnaeus himself identified the mammal category, the primate category, and a number of unobvious insect categories that are still accepted. (And he did start thinking evolutionary thoughts towards the end of his life; but improving taxonomy came earlier.)

BTW: The main species we work on has just been split into two, mistakenly in our lab's view, since we have lots of samples of what are now 'hybrids' and sequence data clearly showing a big chunk of a chromosome introgressing between the two 'species' happening just a couple of years ago. However, we really try to stay out of that fight and just publish the evidence without comment.

Wild guess: botany? Yes, stay the heck out of that fight.

What do you mean by "falsifiability" here? I must be missing something, because any taxonomic classification based on properties instead of just an enumeration of items in each class is falsifiable. It an item does not have a proprety required by the definition of the class, it does not belong to that class.

Sorry, I guess that wasn't clear. I meant the category itself being falsifiable, not the membership of a given item in it. There's a very long list of biological categories formerly accepted that have been discarded for making poor predictions. Nowadays we have an explanation for why they performed poorly -- they were polyphyletic -- but we didn't need an explanation to be busily discarding them before Darwin.

A biological taxon is a miniature scientific theory. To say "mammal" is to say "Animals come in a pre-existing tree structure that's out there waiting to be found, rather than being just an artifact of our minds; and when we distinguish between animals with and without mammary glands we are not being arbitrary; we are carving nature at its joints." That's a falsifiable hypothesis, even if we have no idea why the world laid out life in a tree structure, or even if we assume "mammal" is an idea in the mind of God, or the Platonic Form of the archetypical mammal, or what have you.

I'll agree that "dwarf planet" isn't a very good classification, but the more specific terms "asteroid" and "Kuiper belt object" are rather meaningful. If we learned something new about Pluto, it would likely apply to Eris and most other (at least large) KBOs.

But Eris isn't a Kuiper Belt Object; it's a Scattered Disk Object. Likewise, what we learn about Pluto would likely apply to Centaurs like Chariklo. The predictive power comes from the objects being nearby on a continuum of properties, not from being fellow members of a yes-no natural category. "Kuiper Belt Object" is a category like "microwave" that comes from drawing arbitrary lines through a continuum.

 

[Bronzeage]

I'm making a note to myself for next April 1st. I'm going to have the Brotherhood of Geographers United States (BOGUS) declare Australia to be a "dwarf continent," or maybe a "mega-island."

 

[The Paul]

So basically, Bomb's mad that a committee voted on a set of attributes that should qualify an object as a planet, because that's too arbitrary, and instead what we should do is have a committee vote on whether any given object is a planet (without necessarily making any attempt to group objects into "planet" or "non-planet" based on their properties.) as that would be far less arbitrary.

 

[gmbteach]

I'm making a note to myself for next April 1st. I'm going to have the Brotherhood of Geographers United States (BOGUS) declare Australia to be a "dwarf continent," or maybe a "mega-island."

We can't help being the Largest Island and the Smallest Continent.