B WSU Shows Negative Mass Exists: Implications for Faster-Than-Light Travel?

[MattRob]

While the title may seem to overblow it, showing that negative mass exists may be just that big.

After all, as I understand, the primary obstacle to the reality of the Alcubierre Drive or Krasnikov Tubes is the negative energy density requirements. This of course violates certain energy conditions and allows for "ill-behaved" spacetimes.

Is that what happened?

Link to a media article on the WSU finding.

I don't have access to the actual paper, but it's here.

Does this allow for arbitrarily large negative energy densities over non-quantum volumes, or is there some kind of quantum "catch" to this that wouldn't make this suitable for breaking some of the energy conditions? Is WSU's negative-mass hydrogen that "exotic matter" that's needed, or am I missing something?

 

[Ibix]

The short version of this is "never trust a press release". See here for some discussion: https://www.physicsforums.com/threads/physicists-create-negative-mass.911744/

It's a negative effective mass. If I understood @ZapperZ right, it's just Archimedes' principle. A helium balloon in air has a negative effective mass. Put one in a car and stamp on the accelerator and it will drift to the front of the car. But it still has a positive mass - it's not exotic matter.

This is new in superfluid systems. Which is pretty cool in its own right, but not world changing to the extent the press release suggests.

 

[bitstreamout]

> I don't have access to the actual paper, but it's here.
> https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.155301

See https://arxiv.org/abs/1612.04055 ... but as already stated: it is negative effective mass, which is also stated in the article as well