4 ms·

> ...if gravity is quantum... You don't need evidence to support a premise.

qlte 27d ago
Their point is measuring gravity's influence on a single particle is not necessarily evidence of the existence of the graviton.
- omnicognate 27d ago
  Nobody's claiming it is.
  - NuclearPM 27d ago
    “ if gravity is quantum then that means that they observed an interaction between the graviton and their rubidium atom.”
    - jacquesm 27d ago
      'if'
      - fizzbuzzbarbazz 27d ago
        That's pretty pedantic. They were simply addressing one branch of the if, so their statement was relevant.
gps372 27d ago
Actually, we do need evidence for premises which are not definitions or basic assumptions (axioms). Graviton is still a hypothetical particle and falls under neither of two categories - Definitions or axioms.
- simiones 27d ago
  The statement "if gravity is quantum, this was an interaction with a graviton" is true even if it ultimately turns out that gravity is not quantum. The statement is about the consequences of a premise, and is not falsified if that premise is false. The only way this statement could be false would be to have quantum gravity but no particle that mediates this interaction - which doesn't seem plausible almost by definition.
  - gps372 27d ago
    >> The only way this statement could be false That's quite an exotic claim! If Sound and Temperature can emerge without a sound particle or temperature particle, why is it not plausible for gravity to exists without graviton? Though, I get it that mainstream view from physicists is Graviton is the most 'likely' cause, if the gravity is proven to be quantized. But even they would have the humility to accept that this is a theory yet to be proven and observed!
    - simiones 27d ago
      Their statement has two possibilities: A: If gravity is quantum, then (B) there must be some particle-like think that we call a graviton that mediates the interactions, and then seeing a rubidium atom fall must have been an interaction with this particle. not A: If gravity is not quantum, then they are making no claims about a graviton. If you think gravity is not quantum, then you go to the "not A" branch, and they make no claims about that branch - so there is no contradiction with their IF.
      - gps372 26d ago
        Maybe I should have been clearer! There is also a possibility for Gravity to be quantum without gravitons https://arxiv.org/abs/gr-qc/0204062 https://arxiv.org/abs/gr-qc/0204062 https://en.wikipedia.org/wiki/Induced_gravity https://en.wikipedia.org/wiki/Induced_gravity https://en.wikipedia.org/wiki/Entropic_gravity https://en.wikipedia.org/wiki/Entropic_gravity However, for me to claim that quantum Gravity is only emergent without a particle like graviton's mediation, I would need to present evidence. Just like this claim - quantum gravity is only possible from gravitons.

qlte 27d ago

Their point is measuring gravity's influence on a single particle is not necessarily evidence of the existence of the graviton.

omnicognate 27d ago
Nobody's claiming it is.
- NuclearPM 27d ago
  “ if gravity is quantum then that means that they observed an interaction between the graviton and their rubidium atom.”
  - jacquesm 27d ago
    'if'
    - fizzbuzzbarbazz 27d ago
      That's pretty pedantic. They were simply addressing one branch of the if, so their statement was relevant.

gps372 27d ago

Actually, we do need evidence for premises which are not definitions or basic assumptions (axioms). Graviton is still a hypothetical particle and falls under neither of two categories - Definitions or axioms.

simiones 27d ago
The statement "if gravity is quantum, this was an interaction with a graviton" is true even if it ultimately turns out that gravity is not quantum. The statement is about the consequences of a premise, and is not falsified if that premise is false. The only way this statement could be false would be to have quantum gravity but no particle that mediates this interaction - which doesn't seem plausible almost by definition.
- gps372 27d ago
  >> The only way this statement could be false That's quite an exotic claim! If Sound and Temperature can emerge without a sound particle or temperature particle, why is it not plausible for gravity to exists without graviton? Though, I get it that mainstream view from physicists is Graviton is the most 'likely' cause, if the gravity is proven to be quantized. But even they would have the humility to accept that this is a theory yet to be proven and observed!
  - simiones 27d ago
    Their statement has two possibilities: A: If gravity is quantum, then (B) there must be some particle-like think that we call a graviton that mediates the interactions, and then seeing a rubidium atom fall must have been an interaction with this particle. not A: If gravity is not quantum, then they are making no claims about a graviton. If you think gravity is not quantum, then you go to the "not A" branch, and they make no claims about that branch - so there is no contradiction with their IF.
    - gps372 26d ago
      Maybe I should have been clearer! There is also a possibility for Gravity to be quantum without gravitons https://arxiv.org/abs/gr-qc/0204062 https://arxiv.org/abs/gr-qc/0204062 https://en.wikipedia.org/wiki/Induced_gravity https://en.wikipedia.org/wiki/Induced_gravity https://en.wikipedia.org/wiki/Entropic_gravity https://en.wikipedia.org/wiki/Entropic_gravity However, for me to claim that quantum Gravity is only emergent without a particle like graviton's mediation, I would need to present evidence. Just like this claim - quantum gravity is only possible from gravitons.