[Nevermark]

It does seem pointless to avoid naming a new era for dramatic irreversible changes that would have defined a new era if they happened millions of years ago.

How many common assumptions about the Holocene are already broken?

--

With much less at stake, I think it was out of touch and impractical to choose scientific terminology at odds with existing common language, when "dwarf planet" was defined as not a subcategory of "planet".

It defies common usage, and also common language forms. Prefixed nouns usually refer to subcategories, not excluded categories.

What science fiction story is going to carefully distinguish "dwarf planets" as being a completely separate category from "planets" because one didn't completely clear its orbit of debris?

A better (equivalent, and just as useful) nomenclature would have left the common definition of "planet" alone: i.e. a body circling a star, too small to be a star or brown dwarf (no continuous or aborted fusion), but large enough to form a near sphere based on its own gravitational field.

THEN, subdivide "planets" into "major planets" and "minor planets". We have 8 major planets, and it turns out, many many dwarf planets.

Pluto is a "planet", specifically a "dwarf planet". Earth and Jupiter are "planets", specifically "major planets".

"Rogue planets" are "planets" that left their systems. Some were originally major, some dwarf. "Protoplanets" are new "planets" actively accumulating mass by clearing their orbital field. They may stabilize as "major" or "dwarf" planets.

The new exlusionary definition of "planet" also opens the doors to inevitable conundrums:

Some day a huge planetary type body will be discovered in the outreaches of a solar system where it has not cleared its area of debris. So not a "planet"?

Some day a small planetary body with a cleared orbital field will be found between the orbits of larger planetary bodies that haven't cleared their fields. So it is a planet, but the larger bodies surrounding it are not?

[kadoban]

That doesn't really fix anything, because no matter what you call Pluto, it has to get demoted from the list of planet-like-things-whatever-we-call-them that school children learn.

The issue is that there's hundreds of objects at least as planet-y as Pluto is, and nobody is going to remember all of those. So either we demote Pluto somehow, or we have to have some reason that it's more important than the rest.

So, Pluto is just historically interesting but inherently just one of many rocks. And science tries not to categorize things based on "oh that one somebody noticed first".

[Nevermark]

I agree, distinguishing between the importance of things is helpful.

But changing “planet” to not include Pluto just created unending inconsistency.

There is nothing that screamed “not planet” about Pluto until some scientists preconceptions and emotional investment about the numbers of planets got challenged.

People now have to learn by rote that Pluto is not a planet. Because “scientists say so”, not because they are actually becoming sensitive to debris fields.

The link between orbital debris and planetary size isn’t even going to hold with future discoveries. So the new restrictive regular language-unfriendly definition isn’t even going to be stable.

Ridiculous.

[kadoban]

> There is nothing that screamed “not planet” about Pluto until some scientists preconceptions and emotional investment about the numbers of planets got challenged.

> People now have to learn by rote that Pluto is not a planet. Because “scientists say so”, not because they are actually becoming sensitive to debris fields.

Even the other dwarfs we know of so far seem to make it a different category to me. Pluto is a lot more like them than it's like even Mercury.

https://planetseducation.com/dwarf-planets/

> The link between orbital debris and planetary size isn’t even going to hold with future discoveries. So the new restrictive regular language-unfriendly definition isn’t even going to be stable.

Are you saying that we're going to find huge planets that haven't cleared their neighborhoods? That sounds unlikely.

[derbOac]

I guess I never understood the problem with saying we have hundreds of planets, and then to classify them.

[kadoban]

The main issue is just that you have a limited number of rocks that normal people are going to care about. Mercury, Venus, Earth, etc.

Should Pluto be in this list? If so, why? It's a boring tiny rock way the hell out, one of hundreds. Making this list hundreds long is not feasible, nobody will remember them.

[runeofdoom]

We already had 'minor planets' (asteroids). Planets are a continuum, from small rocky or icy ones the size of large moons, to "terrestrial" ones, to ice giants and gas giants.

[Nevermark]

Yes, that is how I think "planets" should be used. A root category over any number of subcategories defined over continuums and combinations of other features.

As it is used in common langauge.

[FrustratedMonky]

Yes. The entire Pluto thing seemed like a pedantic waste of time. Or, at least grandfather it in. Now everyone still thinks of it as a planet, but we have to qualify it when talking : "Oh hey I read an interesting story about the 9th planet Pluto, ooops, sorry, I mean 'dwarf', don't crucify me".

[masklinn]

The only waste of time is from emotionally charged reactions like yours. The IAU vote happened 18 years ago, yet you can’t let it go.

The grandfathering idea makes a negative amount of sense. These are technical classifications on objective criteria.

[Nevermark]

> The IAU vote happened 18 years ago, yet you can’t let it go.

The IAU happened 18 years ago but the vast public hasn’t cottened on to the whole new “cleared orbital debris” concept tacked on to a word that already has widespread use and understanding.

Mistakes don’t become not mistakes because of 18 years. The mistake was that it’s predictable that two definitions for “planet” will still be jostling each other 50 years from now - for no good reason when distinctions could be made without attempts at universal redefinition by a minority of people who use the word for highly specialized reasons.

Instead of just coining a new phrase such as “major planets” for their brand new definition.

What are regular people supposed to say now when they want to say what planet meant which includes Mercury and Pluto? “Planetary like things?”??? It’s a completely avoidable mess.

[masklinn]

> The IAU happened 18 years ago but the vast public hasn’t cottened on to the whole new “cleared orbital debris” concept

The vast public doesn't generally cotton to anything. People don't routinely specify that they're talking about non-avian dinosaurs, or non-tetrapod fishes.

Which doesn't matter, because nobody expects the general public to actually be precise, so nobody gives a shit.

> a word that already has widespread use and understanding.

An enumeration is not an understanding. There is no understanding where Pluto is a planet and Eris is not.

> without attempts at universal redefinition by a minority of people who use the word for highly specialized reasons.

You mean the people who actually use the words as if they meant something?

> What are regular people supposed to say now when they want to say what planet meant which includes Mercury and Pluto? “Planetary like things?”???

That scenario occurs about as often as regular people wanting to say planet excluding pluto before the vote: they're never precise enough that it matters, and in the zero cases where it happens, they can just specify "incuding pluto" or "excluding pluto".

[FrustratedMonky]

Sometimes when forming standards, it is worthwhile to grandfather something in, just for the pure logistical effort needed to change.

Consider that every single book, textbook, poster, pamphlet in the entire world has to be edited and re-printed. Just so we don't have the numbers go to 9.

Every kid for decades was taught about the 9th planet Pluto. 18 years later, and a lot of people still refer to it as a Planet.

And. Now we can't refer to the search for Planet 10 with the much cooler name of Planet X. "Searching for Planet X" sounds cooler. Now every conversation has to be "Searching for Planet X, oh, I mean 9, because of those guys that renumbered them, why did they do that again? Was there a point."

"emotionally charged reactions like yours"

Someone needs to look in the mirror.

[masklinn]

> Someone needs to look in the mirror.

Your entire comment is a weak attempt to justify an emotional response on non-existent grounds and making shit up (wow, people have to update their understanding of classifications, such hard, so never happens), and you waste more time on a subject you complain is a waste of time.

You really should talk to your therapist about your unhealthy relationship with pluto.

[FrustratedMonky]

Do you hear yourself?

Pluto was big enough for your mom.

[arduanika]

"Planet" derives from the Greek word for "wanderer", so it's totally on brand if the category keeps moving around.