Live data from Hacker News

Massless particle with promise for next-generation electronics discovered

princeton.edu

21–30 of 39 posts

Re: Massless particle with promise for next-generation electronics discovered

#21

Earlier quoted context omitted.

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.

That's a really good explanation.

Re: Massless particle with promise for next-generation electronics discovered

#22
post #17
post #14

Earlier quoted context omitted.

[deleted]

I am afraid there is no nice way to say this, almost all of what you wrote there is completely wrong.

Don't be lazy. If you see errors please provide correction so the rest of us can benefit!

Re: Massless particle with promise for next-generation electronics discovered

#24
post #8
post #7

Someone 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…

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.

It is as real a particle as any other, no? If you look closely enough all particles are just waveforms in particular fields (e.g. an electron will "interfere with itself" in a double-slit experiment).

Re: Massless particle with promise for next-generation electronics discovered

#25

Earlier quoted context omitted.

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.

What about strongly interacting theories? Are quarks and gluons quasi-particles then too? They can't leave the holodeck aka. Hadron.

I think this could break your classification :)

Re: Massless particle with promise for next-generation electronics discovered

#26

Earlier quoted context omitted.

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.

Thank you for this explanation.

But hey, speaking of TNG... Can't you just stick on of those fancy crystals in your computer?

Wait, computers made out of crystals? Did that just happen? :)

Re: Massless particle with promise for next-generation electronics discovered

#27
post #24
post #8

Earlier 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.

It is as real a particle as any other, no? If you look closely enough all particles are just waveforms in particular fields (e.g. an electron will "interfere with itself" in a double-slit experiment).

I suppose the word 'real' is kinda hard here. From classical experimental point of view electron is a particle that can be observed and has an identity and existence regardless of context, whereas quasiparticles such as phonons manifest only in mathematical models that 'can be instantiated' in specific experimental setup, or describe physics only in specific limited context, such as the experiment here.

I'm of the school though that adheres to the notion that maths can be used to model the world, and while it strongly suggests 'the world is made of math' this is not conclusively the case. So, to me, mathematical equivalence does not mean 'physically equal' since physical systems can exhibit many more degrees of freedom than just those captured in a specific model. Sometimes the maths and physics match astoundingly well.

Re: Massless particle with promise for next-generation electronics discovered

#28

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.

Hmm, I think you got it in reverse. We are talking about of properties of real physical things all the time here. We just can't expect to instantiate any random piece of math in the real world - like take a specific vector subspace and try to use it as a katana, that would be silly.

We take a physical system and apply some mathematical properties to it. In the case of bullet I think what is interesting is to model it's energy, E = 1/2 mv*v. Now, if we take the kinetic energy of a bullet, and apply it to any other object, and then instantiate this object in the real world the lethality of the object depends on the nature of the object. A ball of hay of a diameter of 1 m in 1 atm 10 meters away with the kinetic energy of a bullet does not sound lethal. An object more like a bullet, like an iron nail, probably can be. Gummy bear? Who knows.

The point is, the maths here are about physical things, although it can take a lot of experimental work to manufacture a specific physical system that exhibits behaviour which is modeled with specific piece of math.

Re: Massless particle with promise for next-generation electronics discovered

#29
Neat stuff. Hopefully we get some use out of them. Meanwhile, optical computing field is coming along nicely from the time when I read press releases about it similar to this one. Maybe we'll something great (eg better CPU's) out of it if not this. :)

Re: Massless particle with promise for next-generation electronics discovered

#30

Earlier quoted context omitted.

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. :)

> just like "holes" in P-type semiconductors can be measured to behave like quasi-positrons

I'm sorry to ask because I should actually know this, isn't the remaining positive charge accounted to the protons in the core? A moving "hole" is just a figure of speech.

Post reply on HN