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How the Higgs field gives mass to elementary particles

quantamagazine.org

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Re: How the Higgs field gives mass to elementary particles

#71

Post by Maxatar »

simpaticoder wrote: post #68
Maxatar wrote: post #48

Earlier quoted context omitted.

That hardly constitutes a precise definition, but at any rate the lecture I linked to goes over the history and I quote, once again from Einstein himself: >The next position which it was possible to take up in face of this state of things appeared to be the following. The ether does not exist at all... >More careful reflection teaches us however, that the special theory of relativity does not compel us to deny ether.…

That hardly constitutes a precise definition It is precise enough for our purpose: ether is a hypothetical medium for light waves to propagate. Moreover it would need to have no interaction with ordinary matter, or else it would cause planets' orbits to decay. only we must give up ascribing a definite state of motion to it - Einstein This is a "No True Scotsman" fallacy wherein one redefines the assertion to deal wit…

> ether is a hypothetical medium for light waves to propagate.

If that's the extent of your definition then it is not at all inconsistent with Einstein's definition of the ether in the lecture I linked to.

>This is a "No True Scotsman" fallacy wherein one redefines the assertion to deal with specific objections.

Imagine using your argument to claim that atoms don't exist because atoms were by definition indivisible structures, and so anyone who argues that atoms are made up of protons, neutrons and electrons is just engaged in a "No true Scotsman" fallacy.

This might be how people on the Internet argue, but it's not how curious people make genuine advances in science.

Note that your definition of ether never said anything about having a definite state of motion so it's not at all clear what exactly you're looking to criticize to begin with. Einstein isn't claiming that the ether has no motion, just that it's motion adheres to Lorenz invariance.

>One can be generous and say he had an intuition about fields

Claiming that it's generous that Einstein had some kind of intuition about fields is so absurdly laughable that I'm not sure there is much more to even discuss on this matter. How generous you must be to recognize that Albert Einstein had some kind of intuition about fields.

It certainly makes me wonder if people read what they write sometimes before hitting the reply button.

Re: How the Higgs field gives mass to elementary particles

#72

Post by calf »

emrah wrote: post #32
hinkley wrote: post #23

Imagine some preindustrial scientist being awakened in the modern era to find that the aether has been first debunked for more than a century and then rediscovered, but with different rules.

Aether has a specific definition and it still does not exist. It was not rediscovered. QFT is not aether-like. Aether was a substance filling all space, while QFT fields like higgs are not physical at all (but rather give rise to physical properties)

How does something not physical give rise to physical properties? Saying that way makes it sounds like a logical conceit is being used.

Re: How the Higgs field gives mass to elementary particles

#73

Post by cryptonector »

tines wrote: post #14
wyager wrote: post #11

Earlier quoted context omitted.

First, worth noting that "the EM field" (the thing that shows up in the wave equation) in this case is specifically the EM 4-potential. This doesn't work if you try to treat "the EM field" as the strength of the E and B fields or something - it has to be the 4-potential. I got tripped up by this at one point Second, this isn't pinning the field in space , it's pinning the magnitude of the field to be close to some va…

What trips me up is that we don't think of the field being a real physical thing. But isn't the field really the _true_ physical thing, and the wave is just a concept we overlay on it? Like, water is the real physical thing, and the wave is just an arrangement of the water that we recognize as humans. Isn't it the same with the EM and electron fields etc?

Think of a field as a set of scalar field strength values, one value at every point in space. It's not a "thing" you can grab or see. The field strength values are based on the distances to and the magnitudes of the "particles" have have {charge, mass, color, whatever} (with the complexity that the particles themselves are really just standing waves, thus the scare quotes).

Re: How the Higgs field gives mass to elementary particles

#74

Post by cryptonector »

wyager wrote: post #5

I studied wave mechanics in college, but the origin of mass didn't click for me until several years later (and in fact I don't believe it was every brought up in the context of wave mechanics, which seems like a problem in retrospect). The conceptualization that worked for me is this: The normal wave equation is (ignoring constant factors like mass and propagation velocity): d^2/dt^2 f(x,t) = d^2/dx^2 f(x,t) = This s…

This is beautiful. Thanks for this. Is the choice of `M` for "the strength of the restoring force" intended to resemble `m` for mass?

Re: How the Higgs field gives mass to elementary particles

#75

Post by simpaticoder »

Maxatar wrote: post #71
simpaticoder wrote: post #68

Earlier quoted context omitted.

That hardly constitutes a precise definition It is precise enough for our purpose: ether is a hypothetical medium for light waves to propagate. Moreover it would need to have no interaction with ordinary matter, or else it would cause planets' orbits to decay. only we must give up ascribing a definite state of motion to it - Einstein This is a "No True Scotsman" fallacy wherein one redefines the assertion to deal wit…

> ether is a hypothetical medium for light waves to propagate. If that's the extent of your definition then it is not at all inconsistent with Einstein's definition of the ether in the lecture I linked to. >This is a "No True Scotsman" fallacy wherein one redefines the assertion to deal with specific objections. Imagine using your argument to claim that atoms don't exist because atoms were by definition indivisible s…

I think you need to review the site guidelines about tone and purpose. Moreover, I'd suggest you review the history of quantum mechanics, because Einstein did not invent field theory, just as Newton did not invent or understand the Lagrange or Hamiltonian formulations, nor statistical mechanics, even though his theory provided the foundation of them all. I'm not a historian of physics, or a psychologist, so I will bow out of the conversation. May your clear passion for science continue without making you hostile.

Re: How the Higgs field gives mass to elementary particles

#76

Post by pb1729 »

throw0101d wrote: post #19

> Once upon a time, there came into being a universe. Searingly hot, it swarmed with elementary particles. Among its fields was a Higgs field, initially switched off. But as the universe expanded and cooled, the Higgs field suddenly switched on, developing a nonzero strength. Any particular reason/mechanism why the Higgs field suddenly (gradually?) switched on?

tldr is that it happened because the universe cooled down from a stupendously insanely high temperature to a merely insanely high temperature shortly after the big bang.

First look at this picture [0]: https://en.wikipedia.org/wiki/Higgs_mechanism#/media/File:Me...

The Higgs field is a complex number Φ (this number can vary at different points in space, we'll come back to this, so don't worry about it for now). You can imagine it as a ball bouncing around on the landscape shown in the image. The higher the altitude of the ball, the more energy it has (just like a ball in real life). Φ = 0 corresponds to the center of the image, the point right at the top of the little hill.

At a high temperature, the ball is jostling and moving around like crazy. You can imagine constantly pelting the ball with marbles from all directions, causing it to dance eratically around the landscape. (Further, the ball doesn't experience any friction. It slows down when it happens to get hit by a marble that's heading in the opposite direction to it.) In reality, there are no marbles, of course, the jostling comes from the interactions of the Higgs field with other fields, all of which are also stupendously insanely hot.

The landscape in the picture has a rotational symmetry. You can rotate it by any angle, and it will still look the same. When the temperature is very high, the ball dances across the whole landscape. It slows down as it climbs up a slope, so it does spend less time at the bits that are at a higher altitude. But if we consider a thin ring around the center that's all at about the same altitude, the ball is equally likely to be anywhere along the ring. The average value of Φ is 0.

As the temperature decreases, the ball's motion calms down, and it spends more and more of its time in the deepest valley of the landscape. It rarely has the energy to climb high up the slopes anymore. Eventually, the ball will start to live on just the narrow ring around the center where the altitude is lowest.

Now we come back to the fact that the Higgs field is a field, which means it has a value at every point in space, and these values can differ from each other. It turns out that all fields in physics "prefer" to have similar values at nearby points in space. There is an energy penalty for fields that change rapidly in space. At high temperature, this didn't matter too much. The Higgs field had lots of energy to pay this penalty, just like it had lots of energy to climb up the slopes of the landscape. So the field here and the field 1nm to the left could have wildly different values. At cold temperatures, it matters a lot. So the Higgs field has the lowest energy if it has the same value everywhere in space. Anything else comes with an energy penalty. If we pick a point in space, and try to move the field clockwise or counterclockwise around the center, the neighbouring points in space pull the field back towards the average of the surrounding values.

So at any point in space, Φ is just equal it its average value, which is not 0. It's not zero because we have to randomly pick a point somewhere along the ring of lowest altitude, which is some distance from the central 0. The universe has randomly selected a direction in this landscape to be "special".

This is the situation from when the universe was insanely hot all the way up until the present. Incidentally, if you vibrate the ball radially, towards and away from the center of the landscape, this vibration corresponds to the Higgs boson.

If we could somehow heat the universe up to a stupendously insanely high temperature again, then the special direction would disappear, and the average of Φ would be 0 again. This is kind of similar to how magnets lose their magnetization if heated past a certain critical temperature, the Curie point. [1] If we let it cool down again, it would choose a different random special direction.

[0] https://en.wikipedia.org/wiki/Higgs_mechanism [1] https://en.wikipedia.org/wiki/Curie_temperature

Re: How the Higgs field gives mass to elementary particles

#77

Post by Maxatar »

simpaticoder wrote: post #75
Maxatar wrote: post #71

Earlier quoted context omitted.

> ether is a hypothetical medium for light waves to propagate. If that's the extent of your definition then it is not at all inconsistent with Einstein's definition of the ether in the lecture I linked to. >This is a "No True Scotsman" fallacy wherein one redefines the assertion to deal with specific objections. Imagine using your argument to claim that atoms don't exist because atoms were by definition indivisible s…

I think you need to review the site guidelines about tone and purpose. Moreover, I'd suggest you review the history of quantum mechanics, because Einstein did not invent field theory, just as Newton did not invent or understand the Lagrange or Hamiltonian formulations, nor statistical mechanics, even though his theory provided the foundation of them all. I'm not a historian of physics, or a psychologist, so I will bo…

You're bringing in a bunch of entirely irrelevant topics into this instead of actually addressing the points.

My apologies if pointing that out in clear language goes against site guidelines, it might be rude to point it out but this site does have a problem with people who think they know it all and blurting out something as laughable as it's "generous to say Einstein had an intuition about fields" is in my opinion a prime example of it.

All the best to you.

Re: How the Higgs field gives mass to elementary particles

#78

Post by calf »

oezi wrote: post #59
halyconWays wrote: post #41

Earlier quoted context omitted.

Particles don't actually exist, however. They're excitations in various fields. A proton, for example, is actually a sea of three quarks of different "colors" that continually exchange energy (and only have potential positions) via gluons, and those quarks and gluons themselves aren't particles, but excitations in fields

So we have a duality of fields and particles. Likely it doesn't make sense to give one representation precedence over the other.

Yeah did everything forget about the double slit experiment? Why are fields any more real than particles? Is the updated science now resolved on wave particle duality then?

Re: How the Higgs field gives mass to elementary particles

#79

Post by halyconWays »

criddell wrote: post #58
halyconWays wrote: post #40

Earlier quoted context omitted.

> while QFT fields like higgs are not physical at all Phew, I feel better now. Non-physical scalar and tensor fields permeating all of expanding spacetime in a non-physical manner give rise to physical behavior via local nonphysical wavefunction collapse that we call excitations.

That's why the mathematical universe hypothesis (everything is built from mathematical structures) seems likely to me.

It's sort of unsatisfying to say that math has the ability to experience itself, though

Re: How the Higgs field gives mass to elementary particles

#80

Post by halyconWays »

oezi wrote: post #59
halyconWays wrote: post #41

Earlier quoted context omitted.

Particles don't actually exist, however. They're excitations in various fields. A proton, for example, is actually a sea of three quarks of different "colors" that continually exchange energy (and only have potential positions) via gluons, and those quarks and gluons themselves aren't particles, but excitations in fields

So we have a duality of fields and particles. Likely it doesn't make sense to give one representation precedence over the other.

QFT doesn't have a duality of particles and waves, it explains both as excitations in underlying fields. So even the particle in a double slit experiment is just the collapsed wave function, but we experience it as a particle. So precedence in this case is that QFT is the underlying explanation.
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