Antimatter Reacts to Gravity in the Same Way as Ordinary Matter, Physicists Find | Hacker News Reader

Antimatter Reacts to Gravity in the Same Way as Ordinary Matter, Physicists Find

gizmodo.com

42 pointsmikece7 comments

Amazing achievement to get such a widely expected null result.

This is why I love science.

It is astonishing that ever-questing scientists are willing to dot every i and cross every t in our current theories (and also wonderful that taxpayers support them in their quest).

Damnit. There goes my last holdout hope for exotic matter capable of powering the Alcubierre drive.

Guess we're stuck here now.

A-drives require negative mass, not Antimatter. Antimatter has positive mass, so there was always good reason to believe it would react to gravity the same as normal matter.

Though, you should probably just assume it won't work given the fuel requirements even after optimization are insane for the exotic matter required. And it relies on a quirk in general relativity that may very well be plugged when we discover a unifying theory.

https://news.ycombinator.com/item?id=37227511 :

> SQG Superfluid Quantum Gravity says there needn't be antimatter; there is pressure and there are phases of matter in a varyingly Superfluidic cosmos. The Dirac wikipedia article also mentions SQG.

"Gravity as a fluid dynamic phenomenon in a superfluid quantum space. Fluid quantum gravity and relativity." (2017) https://hal.science/hal-01248015/

Fluid equations:

Bernoulli's:

Biot-Savart:

Navier-Stokes:

Anosov flows and CFD ((Quantum) Computational Fluid Dynamics) fluid predictability: https://github.com/dynamicslab/pysindy/issues/383#issuecomme...

Would negative mass imply the mass doesn’t exist yet?

Nope. If you time-reverse negative mass it doesn't act like regular mass. Time-reversed negative does fall down in a gravitational field, but it accelerates faster than positive mass does in the time-forward world. (Because positive mass slows down as it rises, while negative mass accelerates.)

>Antimatter has positive mass

Specifically we know it has positive inertial mass due to its reaction to electromagnetic fields. The paper and experiments done by the authors deal with its gravitational mass. Due to weak equivalence principle it's assumed those are the same and so far (for regular and now antimatter) experiments agree, but there's no theory unifying them. Hence GP's disappointment isn't entirely unjustified.

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