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Device creates negative mass and a novel way to generate lasers (phys.org)
37 points by dnetesn on Jan 12, 2018 | hide | past | web | favorite | 12 comments

For the confused (like I was):

"They did not create an entity that actually possesses "negative mass". They created configurations of energy states within a material that CAN BE CHARACTERIZED as a quasiparticle; there is no requirement that we think of it as a particle-like entity, it's just convenient from certain respects. In turn that quasiparticle behaves, in at least some respects, as if it were a particle with "negative mass", although from the sound of things, "negative inertia" would be a more accurate description of the phenomena they actually observed." - DarkLordKelvin

Given the need for negative mass, I ask the obligatory question as to whether or not this is even the smallest step towards the Alcubierre drive?

They examine a quasiparticle, so its "mass" is a number describing the behavior of an emergent excitation of the semiconductor. It's not actually mass in the sense of an elementary particle.

No. They didn't create a mass with a negative gravity potential. Unfortunately phys.org is increasing with its dubious reporting, using terms that are not entirely accurate. Likely from misunderstanding the science, not blatant lying.

Re: Alcubierre drive

It needs imaginary mass, not just negative mass.

Edit: I confused the drive's requirements with tachyons.

Just take the square root of the negative mass and there you are.

Also what they produced here is not the exotic matter that would be required in an Alcubierre drive.

Also, tachyons have imaginary mass. IIRC Alcubierre drive requires a negative energy density. And commonly they use a term called "exotic matter", which is an extremely vague term.

Wait, they made roton quasiparticles, not actual exotic matter, right?

Any theoretical bearing on the Alcubierre Drive or is this a different domain-specific concept of negative mass?


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