Arizona announces its official state planet, but it isn't actually a planet

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No, that’s just Goofy.


Arizona is not actually a state.


I still say the IAU’s definition of “planet” feels pretty arbitrary and the organization doesn’t have any legal authority anyway so it’s not surprising that there are Pluto fans who choose to ignore it.


Won’t somebody think of the Arizona Verde Rim Spring Snail? Small outliers get no respect.


… since Pluto’s orbit includes Neptune, that’s quite a bit of clearing left to go :thinking:


Science is all about categorizations that are useful. Including Pluto in the category just for sentimental reasons wasn’t useful.

If we included it, we’d have to include at minimum Ceres, Haines, Makemake and Eris, and most likely Sedna, Orcus, Quaoar, and Varnuna. But then it would almost certainly blow up to many dozens more, as it’s so hard to spot these little guys that we’ve almost certainly seen less than half of them.

But you’re right, IAU’s definition isn’t a legal one, and Arizona is more than welcome to have Pluto be its planet.

They’re also more than welcome to follow Indiana’s lead and have 3 be their official state value of pi.

Just a few billion years more of tiny nudges and Neptune is suddenly going to get slingshotted out of the solar system!


Wait, I am pretty sure this was already an episode of Rick and Morty?

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So? How is “there are more planetary bodies than we once realized” an argument for changing the definition of the world “planet”?

I’m all for useful definitions, but I don’t see how the new definition is inherently more useful than the old one. We could just as easily say that a “dwarf planet” is a subcategory of “planet,” just as “gas giant” is a subcategory of “planet.”


Pretty song about a couple of snowballs

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At some point you have to draw the line between planet and pebble. The line they drew seemed to be a reasonable one.

The argument that we should draw it somewhere else just because some scientists named something that way for a few decades doesn’t hold water. We don’t redraw the line of “fish” to include whales just because people once thought they were fish.


I really don’t understand this criticism. The IAU’s definition is the least arbitrary one I’ve heard, since it gives an extremely well-defined cut off that just happens to coincide with the eight most massive objects aside from the sun, where most of the other proposals don’t bother giving any sharp cut offs at all.

“Spherical” for instance doesn’t mean anything – real objects are more or less spherical, and right now it’s impossible to be sure if things like Hygiea actually count as dwarf planets or not. It’s a very poor definition that only works because the category isn’t really used for much.

The IAU doesn’t have any legal authority but they are the ones who keep track of the thousands of objects in our solar system, and so need good criteria for how to categorize them. They put a lot more thought into it than detractors seem to give credit.


2 Skinnee J’s wrote a song about immigration rights through a Pluto metaphor way the hell back in 2000 and I can’t believe how relevant this song remains.

Lend me all your ears and let me state my case
About all the types of satellites we must embrace
Cause like parents’ great-grandparents
This planet was an immigrant; to deport it’s an offense
It’s an upstanding member of the solar system
Apply the laws of Earth and make it a victim
Of Proposition 187
When Pluto spawns a moon it will apply to the heavens

If Arizona wants Pluto, it damn well better take immigrants, too.


The IAU started the ‘Dwarf Planet’ conversation because they felt left out and wanted some attention.
I still don’t care, Pluto is a planet (and Mickey’s dog). Good boy Pluto, nice tat.

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On the other hand, there’s no such thing as “a fish” scientifically speaking. The category of “fish” is basically meaningless as it’s a traditional catch-all term for “things that were traditionally identified as animals, that live in water.” Even excluding aquatic mammals, it encompasses a bunch of unrelated animals - warm blooded, cold blooded, vertebrates, non-vertebrates, so you might as well call whales “fish” because it makes about as much sense.


Next thing ya know, you’re going to start insisting that gender is an unrealistically reductive categorization that has never managed to accurately reflect the complex spectrum it claims to represent!


That seems unlikely. It may have a broad definition with fuzzy edges, but I’m pretty sure it has a scientific definition. I’m also not aware of any fish that are invertebrates.

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This isn’t actually true. Fish are vertebrates that are not tetrapods. That’s not a clade so it’s not something modern taxonomists would put in a classification, but that’s very different from being scientifically meaningless. Other scientists like ecologists or developmental biologists will routinely speak about fish, because they share various characteristics in common, just some of them are ancestral characters (gills, fins instead of limbs).


Yeah, there’s no “actually” here. There’s just multiple different attempts to carve firm boundaries to define words to achieve various goals when the real world is unavoidably fuzzy.

Meanwhile Oklahoma’s state vegetable is watermelon, and New Hampshire’s state fruit is pumpkin (yes, technically correct, but still).