111–120 of 255 posts
In case anyone was curious, the Moon is bigger than Pluto. Pluto's 2/3 the size of the Moon. If any dwarf planet should be upgraded to a planet, it's Eris. Eris's diameter is over 600km bigger than Pluto's.
Earlier quoted context omitted.
Planets predate modern astronomy. You have to negotiate with the public if you want to change what “planet” means. To most people, in most contexts, it means 8 or 9 specific things that they have specific ideas about, not a theoretical category of infinite objects.
> Planets predate modern astronomy. If we're segmenting off "modern astronomy" then Pluto wasn't even discovered yet. And we discovered Ceres long before Pluto. It would be pretty rude to keep excluding Ceres just because we knew about the asteroid belt before we knew about the Kuiper belt.
I’m not a member of the IAU. I don’t adhere to their linguistic prescriptivism, and nobody should expect that I will. Some of their own members do not — the article here explains.
Are you a member of the IAU?
The obvious solution to this issue is to destroy Pluto.(*) Many problems can be solved by application of sufficiently powerful explosives. (*) Or, possibly, eject it from the Solar System.
Earlier quoted context omitted.
> Planets predate modern astronomy. If we're segmenting off "modern astronomy" then Pluto wasn't even discovered yet. And we discovered Ceres long before Pluto. It would be pretty rude to keep excluding Ceres just because we knew about the asteroid belt before we knew about the Kuiper belt.
It’s not about being rude to Pluto so much as about being rude to me. I’m not a member of the IAU. I don’t adhere to their linguistic prescriptivism, and nobody should expect that I will. Some of their own members do not — the article here explains. Are you a member of the IAU?
Earlier quoted context omitted.
It’s not about being rude to Pluto so much as about being rude to me. I’m not a member of the IAU. I don’t adhere to their linguistic prescriptivism, and nobody should expect that I will. Some of their own members do not — the article here explains. Are you a member of the IAU?
I didn't say anything about rudeness to Pluto, I was talking about Ceres. I like Ceres. I think it deserves some recognition for being known before even Neptune.
I’m not the IAU, and I have no interest whatsoever in emboldening thousands of people to smugly harass you or anybody else about it.
> “One of the biggest flaws with the IAU definition is that you can have the same object in two different orbits,” says Kornfeld. “In one, it’s considered a planet, and in the other, it’s not considered a planet.” No, there is no flaw in this, and moreover there is nothing new in this. This is how it has always been, it is not something invented recently. In the Solar System, there are 3 Mercury-sized satellites and…
Since the Moon's orbit is always concave towards the Sun, one could even argue that the Moon is a planet, not a satellite, it just happens to have an orbit that is closely coupled to that of another planet, Earth. As I understand it, in fact, there was discussion about defining systems like Earth-Moon as double planets, but that didn't make it into the final definition.
Pluto was only discovered in the 1930s. The only cultural heritage of Pluto as a ‘planet’ is a few decades of science schoolbooks, but going by these comments you'd think it's been in the same list as Jupiter since the Babylonians.
Could someone explain what the IAU means by "clearing its orbit". For example, could we consider the Earth having not "cleared its orbit" because of the Moon? The Sun attracts the Moon more strongly that Earth does, so does that mean that the Earth doesn't fit the criteria? Or does the IAU have some sort exception for moons which they've defined some place else? I'd really appreciate if someone with more knowledge co…
To use a different phrase from wikipedia, "orbital dominance".
Other objects that stick around are either captured as satellites or forced into resonant orbits.
> The Sun attracts the Moon more strongly that Earth does, so does that mean that the Earth doesn't fit the criteria?
The Earth's sphere of influence goes out to about a million km, 2.5x the moon's orbit.
The problem is that the word “planet” refers both to cultural symbols — mythology, gods, archetypes, and the heavens — and to objects of scientific study. Those are different domains, and one of them is cultural heritage, and the other is irritating when it tries to infringe on the first one. There’s no need for a god complex. Stop picking and choosing which planets are real. Scientists can create their own, more pre…
The actual problem here is weirdly aggressive nerds who are incapable of nuance, and insist that an astronomical classification (Pluto is not a planet by the IAU definition) should be used in non-astronomical contexts. Historically and culturally, Pluto is considered a planet. An IAU classification shouldn't be used to try and retroactively change that, because the IAU does not have control over history and culture.…
It gets worse. Whales and dolphins are more closely related to certain fish than those fish are related to some other fish. (As are we by the way.) There are also some fish, such as lungfish or certain eels which can spend more time out of water than whales and dolphins can. Some fish can even breathe air, which undermines another assumption about whales etc.
For some reason, I rarely hear fewer people objecting to jellyfish or shellfish being referred to as fish, even though these are more distantly related to fish than mammals are.
So biologically, the term "fish" doesn't make much sense.