Comment on Sad Ganymede noises
yetAnotherUser@discuss.tchncs.de 1 day agoDo you mean the asteroids at the Lagrangian points? Every single planet has asteroids there because math/physics dictates those points to be stable. Jupiter has the most at its points because it’s the largest planet.
Same with Neptune cleaning its orbit: It has collided with every single thing in its orbit EXCEPT those that synced their orbits to Neptune. An object that is gravitationally dominated by a single planet should not be a planet under any definition.
Sources because I had to read into your claims and I’m no astrophysicist:
nexguy@lemmy.world 1 day ago
Yes, that’s the made up exception. And for neptune not clearing its orbit due to pluto crossing that orbit? Well we have to make an exception for that so…um…the resonance between neptune and pluto. Exception achieved!
The rules are so contrived that it would not make sense for almost any other system except exactly ours. Whatever it takes to keep Earth’s category of “planet” important… you know… for reasons.
Very unscientific but very human.
Live_your_lives@lemmy.world 1 day ago
What rules do you believe make for a definition that isn’t contrived? How do you exclude asteroids from your definition or reject other dwarf planets like Ceres without making up contrived exceptions of your own?
mech@feddit.org 1 day ago
Planets are round objects orbiting a star.
Cethin@lemmy.zip 13 hours ago
Many asteroids are round. The list of planets, under your definition, would be so large it isn’t useful anymore. Even when Ceres, Pluto, and Eris were called planets the list was getting too long, and there are several larger than Ceres. Including every nominally round object would be insane.
yetAnotherUser@discuss.tchncs.de 1 day ago
I propose a better definition:
Planets are very large objects orbitting a star that dwarf everything nearby
I’m pretty sure this is the intent of the IAU’s definition. It’s just more specific.
sp3ctr4l@lemmy.dbzer0.com 21 hours ago
No.
Lets try a more simple metaphor.
One person is navigating through a crowd, occasionally bumping into other people, having to juke and dodge their way around.
Another person has an entourage or body guards to their front, and two gaggles of papparazzi following behind them, at each 45 degree angle to their rear, as they walk through an entire empty street 4 lane street, with some occsional people walking past the whole scene on the sidewalk.
Pluto and Charon are basically an awkward, clumsy couple trying to get through a densely packed mall or convention.
Neptune is Taylor Swift, as an entire parade float, just, herself, body guards, papparazzi. And I guess she also can have some literal ingroup orbiters who manage to stick around, their lives revolve around her the same way their walking patterns do.
And then maybe, by chance, that awkward couple leaves the convention, gets lost, walks the wrong way to a restaurant, and end up just directly crossing the street that Swift walked down, 6 hours ago.
There, is that a sufficiently relatable visual metaphor to illustrate the difference between the two situations?
nexguy@lemmy.world 21 hours ago
It’s a fine metaphor but it doesn’t work for scientific definitions which are exact. The IAU came up with the rule then had to make an exception to their own brand new rule in order to have Neptune remain a planet but not pluto even though both fail the rule. The exception is real and written down, not assumed.
Yet again another of the IAU rules is the body has to be assume hydrostatic equilibrium (nearly round). Mercury is NOT in hydrostatic equilibrium and they knew this. So they just…decided… that Mercury is a planet anyway and does not have to follow that rule.
So two planets don’t even follow the rules they made yet were unscientifically decided to be planets. Why? What was the point of it? Certainly wasn’t done for any scientific reason.
sp3ctr4l@lemmy.dbzer0.com 20 hours ago
Ok, so, Pluto is more spherical than Mercury, but the most important criteria is local gravitational dominance.
Which Mercury has, but Pluto does not.
I do not see how this is a difficult concept to grasp.
Yeah, sometimes you can make a hasty definition, and then refine it to a level of consistent clarity, after it is justly critiqued, though it may be multi tiered and somewhat complex.
Thats… thats how science works, thats like the entire fundamental concept of it, right there, improving the level of detail to which you understand reality, via empiricism, logic, participatory debate.
The primary purpose of the planet defition refinenment is to emphasize the importance of relative local gravitational dominance.
I’m trying to imagine you using this kind of logic with like, biological taxonomy.
mnemonicmonkeys@sh.itjust.works 22 hours ago
Ah, yes. This is clearly justification for Pluto to become a planet! /s
nexguy@lemmy.world 22 hours ago
If the definition of a planet is that it has cleared is orbit then how is Neptune a planet? It shares its orbit with the dwarf planet pluto therefore they should both be dwarf planets correct?
sp3ctr4l@lemmy.dbzer0.com 21 hours ago
You could just look up the actual astronomical or mathematical definition of a ‘cleared orbit’ if you wanted to, you know that right?
en.wikipedia.org/wiki/Clearing_the_neighbourhood
Pluto and other plutinos are bodies whose orbits are significantly governed by Neptune.
Go look at all the numerical values provided by various algorithms that measure essentially the extent to which a celestial body is locally gravitationally dominant, the extent to which it has ‘cleared its orbit’.
You may notice that everything considered a dwarft planet scores orders of magnitude less, by literally all the metrics.