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The test confirmed GR. In particular the test results contradict theories with massive graviton and theories with "gravitational leakage" into the large extra d

by skolos 8y ago

The test confirmed GR. In particular the test results contradict theories with massive graviton and theories with "gravitational leakage" into the large extra dimensions of higher-dimensional theories of gravity.

AstralStorm 8y ago
You mean "the test did for disprove" right?
Filligree 8y ago
Annoyingly yes. We know the theory can't be exactly true, just like we know quantum mechanics can't be, but this always happens when we test them. As much as it'd be great to make a theory of everything, we need something to work off. Right now the physicists are honestly just spinning their wheels.
- pavel_lishin 8y ago
  > just like we know quantum mechanics can't be Wait, how do we know this?
  - pja 8y ago
    The standard model doesn't include gravity, for a start.
  - teekert 8y ago
    Because we can't describe gravity with it?
  - goodcanadian 8y ago
    General Relativity and Quantum Mechanics are incompatible with each other. You can't get GR out of QM or vice versa. Yet, annoyingly, the predictions of both continue to be shown to be correct. The grandparent is hoping for a discrepancy somewhere to provide a hook to base further theoretical developments on.
  - pontus 8y ago
    It's not that quantum mechanics isn't true, it's that the standard model must be incomplete (the standard model is a field theory that's built on top of the framework of quantum mechanics). In fact, one can derive Einstein's field equations from quantum mechanical arguments as a low-energy effective theory.
  - nwallin 8y ago
    Because we exist. Quantum field theory (QFT) does a great job describing the electromagnetic, strong and weak nuclear force, and has done a spectacular job describing reality in ways too numerous to count. But it has two principal failings. The first is that every time someone tries to incorporate a quantum field theory of gravity, the inevitable conclusion is "the first time a graviton interacts with a particle, the entire thing collapses into a black hole". Because we haven't collapsed into a black hole, we know our theory is incomplete. The second is the vacuum catastrophe. QFT predicts a value of the zero point vacuum energy (very closely related to dark energy, aka the cosmological constant) of roughly 10^112 ergs per cubic centimeter. With a bit of a hack, we can get this to cancel out to precisely 0. However, the observed value of the zero point vacuum energy is roughly 10^-8 ergs per cubic centimeter. Which isn't even close to 10^112, but more importantly, it is also not zero, so our hack to cancel it out doesn't work.

by skolos 8y ago

AstralStorm 8y ago

You mean "the test did for disprove" right?

Filligree 8y ago

Annoyingly yes. We know the theory can't be exactly true, just like we know quantum mechanics can't be, but this always happens when we test them. As much as it'd be great to make a theory of everything, we need something to work off. Right now the physicists are honestly just spinning their wheels.

pavel_lishin 8y ago
> just like we know quantum mechanics can't be Wait, how do we know this?
- pja 8y ago
  The standard model doesn't include gravity, for a start.
- teekert 8y ago
  Because we can't describe gravity with it?
- goodcanadian 8y ago
  General Relativity and Quantum Mechanics are incompatible with each other. You can't get GR out of QM or vice versa. Yet, annoyingly, the predictions of both continue to be shown to be correct. The grandparent is hoping for a discrepancy somewhere to provide a hook to base further theoretical developments on.
- pontus 8y ago
  It's not that quantum mechanics isn't true, it's that the standard model must be incomplete (the standard model is a field theory that's built on top of the framework of quantum mechanics). In fact, one can derive Einstein's field equations from quantum mechanical arguments as a low-energy effective theory.
- nwallin 8y ago
  Because we exist. Quantum field theory (QFT) does a great job describing the electromagnetic, strong and weak nuclear force, and has done a spectacular job describing reality in ways too numerous to count. But it has two principal failings. The first is that every time someone tries to incorporate a quantum field theory of gravity, the inevitable conclusion is "the first time a graviton interacts with a particle, the entire thing collapses into a black hole". Because we haven't collapsed into a black hole, we know our theory is incomplete. The second is the vacuum catastrophe. QFT predicts a value of the zero point vacuum energy (very closely related to dark energy, aka the cosmological constant) of roughly 10^112 ergs per cubic centimeter. With a bit of a hack, we can get this to cancel out to precisely 0. However, the observed value of the zero point vacuum energy is roughly 10^-8 ergs per cubic centimeter. Which isn't even close to 10^112, but more importantly, it is also not zero, so our hack to cancel it out doesn't work.