Earlier quoted context omitted.
But what is a "real" particle anyway?
The difference between a bullet made of real particles and one made of math is that the real one can kill you.
That's true for values of "you" reading this in 2015, at least. :)
Massless particle with promise for next-generation electronics discovered
11–20 of 39 posts
Re: Massless particle with promise for next-generation electronics discovered
#12Earlier quoted context omitted.
Thanks, great summary. To translate to non-physicists: It quacks like a particle, it walks like a particle but it's not really a particle. Like counting stones or apples, the both can be understood in terms of similar arithmetic. Same here, only more maths. And, those properties that were observed, may come in handy.
But what is a "real" particle anyway?
"real" particles are those that can leave the holodeck ([1]) "quasi-particles" vanish at the doorstep :)
[1] https://en.wikipedia.org/wiki/Holodeck
PS: replace "holodeck" with "tantalum arsenide crystal" to yield a less off-topic comment.
Re: Massless particle with promise for next-generation electronics discovered
#13Earlier quoted context omitted.
But what is a "real" particle anyway?
The difference between a bullet made of real particles and one made of math is that the real one can kill you.
Quasi-particles are not just math. They have measurable properties that are like properties of real particles (just like "holes" in P-type semiconductors can be measured to behave like quasi-positrons). Or, replying to your proposition:
"With the holodeck safeties off, even holographic bullets can kill." - Picard, First Contact.
:)
Re: Massless particle with promise for next-generation electronics discovered
#14Earlier quoted context omitted.
Thanks, great summary. To translate to non-physicists: It quacks like a particle, it walks like a particle but it's not really a particle. Like counting stones or apples, the both can be understood in terms of similar arithmetic. Same here, only more maths. And, those properties that were observed, may come in handy.
But what is a "real" particle anyway?
[deleted]
Re: Massless particle with promise for next-generation electronics discovered
#15Earlier quoted context omitted.
Thanks, great summary. To translate to non-physicists: It quacks like a particle, it walks like a particle but it's not really a particle. Like counting stones or apples, the both can be understood in terms of similar arithmetic. Same here, only more maths. And, those properties that were observed, may come in handy.
But what is a "real" particle anyway?
One example happens in semiconductors
You have n-type material, where the charge carriers are electrons. So far so good (a real particle)
In p-type material, the charge carriers are the absence of an electron (called a hole).
It is of course, not a real particle, but it carries charge as well as a real particle.
Re: Massless particle with promise for next-generation electronics discovered
#16Someone should perhaps point out, that the article talks about quasiparticles. Quasiparticles are a bit similar to the particle aspect of a quantum mechanical wave. So for example deformations of the lattice of an crystal are sound waves, but it is also possible to look at the deformations as a field and then quantize the field. Excitations of this field look suspiciously similar to a particle, as in they are produce…
To explain this using human-sized things, let's think about centrifugal force and centripetal force.
The latter is an actual force. The former is a "fictitious force" resulting from the mathematical transformation between fixed and rotating reference frames. If you are in a rotating reference frame, the force feels real, along with Coriolis and Euler fictitious forces. But to an outside observer in the fixed reference frame, there is only centripetal force.
Similarly, the article is describing a quasi-particle within a meta-material crystal that behaves similarly to a magnetic monopole. Outside the crystal, the behavior may be explainable by other means, but electrons inside the crystal can't tell the difference between the quasi-particle and the real thing, in much the same way that you can feel a centrifugal force when you spin around.
So even if Weyls do not actually exist, we now have a metamaterial that can fake it well enough to fool an electron.
Re: Massless particle with promise for next-generation electronics discovered
#17Re: Massless particle with promise for next-generation electronics discovered
#18There was some other discussion on HN about this discovery four days ago[0], based on the press release from the competing MIT team. Both papers were published in the same issue of Science[1,2] (preprints[3,4]).
[0] https://news.ycombinator.com/item?id=9899369
[1] http://www.sciencemag.org/content/early/2015/07/15/science.a...
[2] http://www.sciencemag.org/content/early/2015/07/15/science.a...
[3] http://arxiv.org/abs/1502.03438
[4] http://arxiv.org/abs/1503.02630v1 (h/t @selimthegrim)
Re: Massless particle with promise for next-generation electronics discovered
#19Re: Massless particle with promise for next-generation electronics discovered
#20Earlier quoted context omitted.
Thanks, great summary. To translate to non-physicists: It quacks like a particle, it walks like a particle but it's not really a particle. Like counting stones or apples, the both can be understood in terms of similar arithmetic. Same here, only more maths. And, those properties that were observed, may come in handy.
But what is a "real" particle anyway?
In this context, the particles that appear in the Standard Model. So a quasiparticle can be understood in terms of the underlying structure of matter ( a crystal in this case), a 'real' particle can not be understood in terms of some underlying mechanism. Granted, "can not be understood in those terms yet" is preliminary and a not really satisfying definition.