3 ms·

Mercury is a very interesting case. But it is much farther from the sun than announced planets are from theirs.

defrost 4y ago
(again) Spin–orbit resonance means that "Tidally-locked" doesn't equate to "always presents the same face. which leads to: > But it is much farther from the sun than announced planets are from theirs. a) So? b) Is it really? I mean sure, in an absolute sense - but what about in an appropriately scaled sense, allowing for the 1/sixth decreased sun mass and the inverse square force relationships, etc. c) Even so, see a) - How does this alter the fact that tifally locked doesn't equate to "always presents the same face". To be clear, I'm just highlighting the fragile and dubious nature of your earlier assertion about tidal locking.
- moloch-hai 4y ago
  Literally all moons in the solar system are tidally locked, 1:1, to their parent body. That is the norm for tidal locking. Mercury, lacking ocean or even atmosphere, and mostly frozen solid, is accorded leeway a putatively-habitable planet does not get. Word games are tiresome. Mercury's 2:3 spin-orbit resonant "lock" is interesting but off topic.
  - Dylan16807 4y ago
    It's not about word games, it's about how high the prevalence of 1:1 locking is. Especially when you use words like "all" and "can't spot". Looking at the moons in our solar system is evidence but not definitive.
    - moloch-hai 4y ago
      Looking at the hundreds of moons defines "locked" without qualification to imply 1:1. Mercury is literally the only body in the whole solar system in any sort of more complicated "lock". So, no, it really is about word games.
      - marginalia_nu 4y ago
        > Mercury is literally the only body in the whole solar system in any sort of more complicated "lock". So, no, it really is about word games. How would you even begin to demonstrate this is true? There are so many bodies in the solar system, and we're still fairly frequently discovering new minor planet moon-systems..
        moloch-hai 4y ago
        Find another. It would not change anything.
        marginalia_nu 4y ago
        Dunno man. It's very hard to draw statistical inferences based on a solar stellar system. It would even require significant motivation to argue that the measurements are independent.
        moloch-hai 4y ago
        The topic here is the word game defrost and now you promote. Does "tidal lock", absent further detail, imply 1:1? Yes.
        marginalia_nu 4y ago
        The meaning of a word is conventional.
        moloch-hai 4y ago
        And of exactly zero interest. The original topic, so cleverly but pointlessly derailed, was the viability of planets we can just barely detect in extremely close orbit around a dim star, in 1:1 tidal lock, with permanently hot and a cold sides, and, likely, no magnetic field. That merited discussion.
      - 4y ago

(again) Spin–orbit resonance means that "Tidally-locked" doesn't equate to "always presents the same face. which leads to: > But it is much farther from the sun than announced planets are from theirs. a) So? b) Is it really? I mean sure, in an absolute sense - but what about in an appropriately scaled sense, allowing for the 1/sixth decreased sun mass and the inverse square force relationships, etc. c) Even so, see a) - How does this alter the fact that tifally locked doesn't equate to "always presents the same face". To be clear, I'm just highlighting the fragile and dubious nature of your earlier assertion about tidal locking.

moloch-hai 4y ago
Literally all moons in the solar system are tidally locked, 1:1, to their parent body. That is the norm for tidal locking. Mercury, lacking ocean or even atmosphere, and mostly frozen solid, is accorded leeway a putatively-habitable planet does not get. Word games are tiresome. Mercury's 2:3 spin-orbit resonant "lock" is interesting but off topic.
- Dylan16807 4y ago
  It's not about word games, it's about how high the prevalence of 1:1 locking is. Especially when you use words like "all" and "can't spot". Looking at the moons in our solar system is evidence but not definitive.
  - moloch-hai 4y ago
    Looking at the hundreds of moons defines "locked" without qualification to imply 1:1. Mercury is literally the only body in the whole solar system in any sort of more complicated "lock". So, no, it really is about word games.
    - marginalia_nu 4y ago
      > Mercury is literally the only body in the whole solar system in any sort of more complicated "lock". So, no, it really is about word games. How would you even begin to demonstrate this is true? There are so many bodies in the solar system, and we're still fairly frequently discovering new minor planet moon-systems..
      - moloch-hai 4y ago
        Find another. It would not change anything.
        marginalia_nu 4y ago
        Dunno man. It's very hard to draw statistical inferences based on a solar stellar system. It would even require significant motivation to argue that the measurements are independent.
        moloch-hai 4y ago
        The topic here is the word game defrost and now you promote. Does "tidal lock", absent further detail, imply 1:1? Yes.
        marginalia_nu 4y ago
        The meaning of a word is conventional.
        moloch-hai 4y ago
        And of exactly zero interest. The original topic, so cleverly but pointlessly derailed, was the viability of planets we can just barely detect in extremely close orbit around a dim star, in 1:1 tidal lock, with permanently hot and a cold sides, and, likely, no magnetic field. That merited discussion.
    - 4y ago