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MOND was there years before Batygin (co-author of planet Nine hypothesis) was born.

by Arech 3y ago

Izkata 3y ago
> co-author of planet Nine hypothesis Are you referring to what he published in 2016? Because it's much older than that, we used to call it Planet X.
- lamontcg 3y ago
  "Planet Nine" is a term of art that refers specifically to the 2016 theory. "Planet X" refers specifically to a theory proposed by Percival Lowell in 1906 about the orbit of Uranus which was disproven in 1993 by Voyager 2 flyby data. They are both more specific theories than just "a trans-Neptunian planet we haven't discovered" which is overly broad.
  - dragonwriter 3y ago
    Somewhat related are "Nemesis", the 1984 hypothesis of a distant companion red or brown dwarf to the Sun, and "Tyche", the 1999 hypothesis of a gas giant in the Oort Cloud. On "Planet X" specifically, the effect it was offered to explain was determined to have been measurement error after recalculation of Neptune's mass and consequently effect on Uranus's orbit in 1993 based on Voyager 2 data.
  - Izkata 3y ago
    The general theory was called planet X before pluto was demoted; X just means 10. https://science.nasa.gov/solar-system/planet-x/ https://science.nasa.gov/solar-system/planet-x/
    - lamontcg 3y ago
      Except you and that article are quite wrong and the naming of the "Planet X" theory happened in 1894 long before the discovery of Pluto in 1930, back when astronomers also thought there was only 8 planets: > In 1894, with the help of William Pickering, Percival Lowell (a wealthy Bostonian) founded the Lowell Observatory in Flagstaff, Arizona. In 1906, convinced he could resolve the conundrum of Uranus's orbit, he began an extensive project to search for a trans-Neptunian planet,[18] which he named Planet X, a name previously used by Gabriel Dallet.[11] The X in the name represents an unknown and is pronounced as the letter, as opposed to the Roman numeral for 10 (at the time, Planet X would have been the ninth planet). https://en.wikipedia.org/wiki/Planets_beyond_Neptune#Planet_X https://en.wikipedia.org/wiki/Planets_beyond_Neptune#Planet_...

MOND was there years before Batygin (co-author of planet Nine hypothesis) was born.

by Arech 3y ago

MOND was there years before Batygin (co-author of planet Nine hypothesis) was born.

> co-author of planet Nine hypothesis Are you referring to what he published in 2016? Because it's much older than that, we used to call it Planet X.

lamontcg 3y ago
"Planet Nine" is a term of art that refers specifically to the 2016 theory. "Planet X" refers specifically to a theory proposed by Percival Lowell in 1906 about the orbit of Uranus which was disproven in 1993 by Voyager 2 flyby data. They are both more specific theories than just "a trans-Neptunian planet we haven't discovered" which is overly broad.
- dragonwriter 3y ago
  Somewhat related are "Nemesis", the 1984 hypothesis of a distant companion red or brown dwarf to the Sun, and "Tyche", the 1999 hypothesis of a gas giant in the Oort Cloud. On "Planet X" specifically, the effect it was offered to explain was determined to have been measurement error after recalculation of Neptune's mass and consequently effect on Uranus's orbit in 1993 based on Voyager 2 data.
- Izkata 3y ago
  The general theory was called planet X before pluto was demoted; X just means 10. https://science.nasa.gov/solar-system/planet-x/ https://science.nasa.gov/solar-system/planet-x/
  - lamontcg 3y ago
    Except you and that article are quite wrong and the naming of the "Planet X" theory happened in 1894 long before the discovery of Pluto in 1930, back when astronomers also thought there was only 8 planets: > In 1894, with the help of William Pickering, Percival Lowell (a wealthy Bostonian) founded the Lowell Observatory in Flagstaff, Arizona. In 1906, convinced he could resolve the conundrum of Uranus's orbit, he began an extensive project to search for a trans-Neptunian planet,[18] which he named Planet X, a name previously used by Gabriel Dallet.[11] The X in the name represents an unknown and is pronounced as the letter, as opposed to the Roman numeral for 10 (at the time, Planet X would have been the ninth planet). https://en.wikipedia.org/wiki/Planets_beyond_Neptune#Planet_X https://en.wikipedia.org/wiki/Planets_beyond_Neptune#Planet_...