Particle that only has mass when moving in one direction observed for first time
Particle that only has mass when moving in one direction observed for first time
For the first time, scientists have observed a collection of particles, also known as a quasiparticle, that's massless when moving one direction but has mass in the other direction. The quasiparticle, called a semi-Dirac fermion, was first theorized 16 years ago, but was only recently spotted inside...
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Hmm... is this what could change space-flight? Imagine having a material that is nigh weighless when moving away from gravity but gains mass again when moving towards it. It would make it much more feasible to transport heavier stuff into space.
Misleading headline. Article goes badly wrong in its attempt to ELI5 âŚ..
Itâs not âdirectionââthatâs affected, but electron transitions to either higher or lower states âŚ.. I think. This article is horribly written if they wanted to communicate anything
Edit: the article does link to the original paper but someone else will need to translate that. It looks more like they were able to produce a formerly theoretical quantum particle (not electron) and show weird behavior. I still donât know what âdirectionâ means, because itâs relative to how its quantum state changes. I donât think direction means direction in the macro sense but I donât know what it does mean
I was misled in the posted article with hints about energy levels that reminded of electron shells. The original article makes it clear these are not electrons but talks about quantum states in a vaguely similar way (at least according to my limited understanding)
I don't think that's what they're saying. They're measuring a property that should scale linearly with Landau levels and the strength of the magnetic field by a known factor. There's one possible factor for massive particles, and another for massless ones. In this experiment they observed a third value for the factor that lies between those two, one which matches the predictions of these semi-Dirac fermions. The particles in question are electrons in a semi-metal, so I think that can mean actual movement in the sense that we usually think of the word
That said this is waaay beyond my level of physics, even with the professor attempting to dumb it down for us
For sure directions is related to different planes or lines along the crystal.
They quote in the article that when moving in certain directions, the fermion's energy is completely derived from motion. So it's essentially taking the m out of E = mc², which is still neat, but not really something you can scale up
Itâs been a while since I took a physics class, but Iâm pretty sure everything becomes more weightless as it gets farther from a gravitational pull. Things donât normally become more mass-less though.
Or, is this a âwhooshâ moment for me?
The person you replied to said "weight", but the article - including direct quotes from the professor heading the team that found it - uses "mass" consistently.
If a material made up of quasi-particles is massless when moving away from gravity at ground level, why is the distinction important?
âŚa material that is nigh weighless when moving away from gravity but gains mass again when moving towards it.
My brain hung a bit in this statement. I suppose I incorrectly interpreted ânigh weightlessâ as âlosing weightâ, which is what everything does as it leaves a gravity well.
Itâs 4am here and Iâm just browsing on my way to the airport, half asleep. So, please feel free to ignore this whole thing.
Unfortunately we can't just build something out of particles like this. Consider electrons or neutrinos, something similar is what we're dealing with here.