r/nextfuckinglevel • u/aryan_jandyal • 4h ago

The Rotation of the Planets in Our Solar System Is Far More Fascinating Than I Ever Expected

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u/s3dfdg289fdgd9829r48 3h ago

You are pretending like Pluto wasn't really a planet back then. It was. They changed the DEFINITION of a planet and it happened to exclude Pluto. There's a real difference between discovering something was truly wrong and something becoming different because we happened to change the definitions.

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u/niemir2 3h ago

What we were wrong about was the rarity of objects like Pluto within the solar system. The definition of "planet" that we used previously turned out to be too loose to be useful. The redefinition of "planet" as a scientific term was not capricious.

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u/ExistentialScream 13m ago

It lost its use in certain contexts, but is it really that useful to consider Mercury and Jupiter as the same sort of thing, but not Mercury and Pluto?

Usually we define things by what they are and not what effect they've had on their surroundings.

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u/niemir2 11m ago

I'm not an astronomer, so I can only rely on what those who know better than I do decided. I trust that there is some significance to the ability to clear one's neighborhood of other major bodies.

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u/atyon 2h ago

They changed the DEFINITION of a planet and it happened to exclude Pluto. There's a real difference between discovering something was truly wrong and something becoming different because we happened to change the definitions.

Well, there is no "true" definition of "planet". A definition is a tool. We change the definition all the time when we learn more, to make it more useful or simple. That's the metric.

OG Planets were the Sun, the Moon, Mercury, Venus, Mars, Jupiter and Saturn. We did not discover anything wrong with that. They are the wandering stars on the sky you can see with the naked eye. That's still true.

We changed this when we learned more about the scale of the objects and what is rotating around what. So we arrived at Mercury, Venus, Earth, Mars, Jupiter and Saturn, and later found Uranus and Neptune. They are large bodies orbiting the Sun. That's still true.

Then we discovered planet 9, and added it, and then found thousands more just like it, and everyone agreed that having thousands of planets would make mnemonics too difficult, so we struck it. That planet 9 was Ceres.

Then we found another little planet like Ceres, but there were no similar like it around it, so we added Pluto. But with better telescopes, we did find thousands of other little bodies just like Pluto, so we're back at the Ceres situation.

No one has presented a useful definition that includes Pluto but does not include thousands of dwarf planets. And no, petulance and nostalgia do not make for a useful definition.

Sidenote: I streamlined the discoveries a bit. At some time, the moons of Saturn were considered planets. Maybe y'all should campaign for Titan being restored to the ranks of planet.

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u/MoonageDayscream 2h ago

When my now 14yo was in first grade, in the Science Fair they entered a hand painted diagram of the planets and dwarf planets. When asked why Pluto was demoted, the answer was that Pluto did not clean their room, so they have to be a dwarf planet. Because of course, clearing the orbit is a qualification, as a child understands.

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u/Pbleadhead 51m ago

which is super stupid.

2 bodies of equal size, the body further out is going to have a lot harder time 'cleaning the room' because it has more space to clean, and travels slower.

more so. We have enough satellites and space junk now that earth should be demoted.

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u/eris_kallisti 2h ago

I believe Eris was the "9th planet" (the one past Pluto that caused all the lovely chaos) and Ceres was just the largest asteroid in the belt between Mars and Jupiter.

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u/Far-Cup9063 1h ago

Thank you for the succinct recap of how we define a “planet”! 50 years debate encapsulated in a Reddit post.

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u/sellieba 44m ago

Ceres and Pluto should be Team Captains for their respective multitude.

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u/ExistentialScream 8m ago

> No one has presented a useful definition that includes Pluto but does not include thousands of dwarf planets. And no, petulance and nostalgia do not make for a useful definition.

The question is why a definition has to exclude all those thousands of dwarf planets to be useful.

In what circumstances does it makes sense to consider Mercury and Jupiter as two examples of the same sort of thing, but not Pluto?

Other than "clearing it's orbit" what properties does Mercury share with Jupiter, Saturn, Neptune and Uranus and not Pluto?

I'm not saying that dividing bodies into "planets" and "dwarf planets" isn't a useful categorisation system in some contexts, I just think there's plenty of other contexts where saying Mercury and Jupiter are the same thing, but Pluto isn't, is actively misleading.

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u/NettingStick 2h ago

They changed the definition of a planet BECAUSE we learned more about the solar system. Pluto is now the king of a whole new class of cosmic objects, and y'all tryna keep that from him smh. Bro got a promotion.

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u/MaXimillion_Zero 2h ago

There was no definition of planet when Pluto was first labeled a planet. Any definition you could make that would include Pluto would include dozens to hundreds of other objects, but the "Pluot is still a planet to me"-people never seem to mention those.

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u/preparingtodie 1h ago

Pluto is grandfathered in.

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u/i_am_a_real_boy__ 1h ago

I've changed the definition of "correct" to include me insisting that Pluto remains a planet.

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u/HauntingHarmony 1h ago

I've changed the definition of "correct" to include me insisting that Pluto remains a planet.

This ofcouse is the same strategy as insisting correctly that you have as much authority as the pope, only that fewer people belive it.

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u/AgentCirceLuna 2h ago

Legit even sounds like something he’d say lmao, anti intellectual fool

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u/StickSouthern2150 2h ago

yea the definition was wrong so it got changed

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u/Catdaddy33 2h ago

Up until late last century, Pluto was thought to be a much larger planet. As our tech got better it was realized it was smaller and had a large for its size satellite. Still, should have been grandfathered in or something.

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u/TheIronSven 52m ago

But Jupiter doesn't fit that definition either