Re:Device creates negative mass and a novel way to generate ...
by hacker_9 on Friday January 12, 2018 @11:10AM
(#16133905)
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
Re:Device creates negative mass and a novel way to generate ...
by mrule_ on Friday January 12, 2018 @10:48AM
(#16133717)
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.
Re:Device creates negative mass and a novel way to generate ...
by godelski on Friday January 12, 2018 @06:20PM
(#16137163)
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:Device creates negative mass and a novel way to generate ...
by godelski on Friday January 12, 2018 @06:18PM
(#16137156)
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.
"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
It needs imaginary mass, not just negative mass.
Edit: I confused the drive's requirements with tachyons.
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.