A New Map of All the Particles and Forces(quantamagazine.org)
quantamagazine.org
A New Map of All the Particles and Forces
https://www.quantamagazine.org/a-new-map-of-the-standard-model-of-particle-physics-20201022/
44 comments
This is a good visualisation. It’s also a nice reminder of why the standard model feels unsatisfying. The unexplained symmetries, and the strange duplications and gaps really do strongly suggest there is something more fundamental happening behind this picture.
Strongly reminiscent of the motion of the planets under a geocentric view of the universe.
https://commons.m.wikimedia.org/wiki/File:Cassini_apparent.j...
https://commons.m.wikimedia.org/wiki/File:Cassini_apparent.j...
It would be interesting to see how this looks like for a different planet.
Always wonder how the jesuits beat the Muslim astronomer in Ming and Qing dynasty always assuming they use the geocentric one. Well unlike the dogmatic Dominican the Jesuit has its friend in the court. “In 1618, the Holy Office recommended that a modified version of Copernicus' De Revolutionibus be allowed for use in calendric calculations, though the original publication remained forbidden until 1758” (wiki) only during a few year has the catholic lost its chief astronomer in the court of emperor. (Sadly the few year gap in between Qing emperor got all the Hans Christian believer slaughtered. The notation of looking at the sky is rejected and 3 of the major crimes is the catholic astronomy dared to propose the unacceptable position of Orion component star not fit with the order of the five elements.)
As a layman in physics, whenever I look at anything quantum, I'm certain there is something fundamental that we're missing. When we've figured something out about nature for good, the explanation is usually surprisingly simple and just makes sense. You know you're most probably wrong when your model produces more questions than it answers.
That said, I like Stephen Wolfram's theory of everything. It just feels like a step in the right direction.
That said, I like Stephen Wolfram's theory of everything. It just feels like a step in the right direction.
There is no reason to think that a more fundamental theory would be simple or even tractable. We have just got lucky, so far. It is the nature of good luck to falter.
Wolfram is not doing anything original. He just doesn't tell you who he is cribbing from.
Wolfram is not doing anything original. He just doesn't tell you who he is cribbing from.
I think the history of physics does not support this view. New theories that explain a wider range of phenomena tend to be harder to understand than their predecessors that explain a narrower range of observations. For example, Newtonian mechanics is simpler than relativistic mechanics which is simpler than quantum field theories.
Also, I see nothing that would make fundamental aspects of nature comprehensible for humans. Our cognition evolved to handle classical mechanics without the relativistic or quantum effects that we find bizarre and indeed classical mechanics is roughly where average person's understanding of nature ends.
An alternative view is that there is a survivorship bias at play: we tend to understand the things about the universe that are simple enough for a human mind and remain oblivious to the ones that are too complicated for it.
Also, I see nothing that would make fundamental aspects of nature comprehensible for humans. Our cognition evolved to handle classical mechanics without the relativistic or quantum effects that we find bizarre and indeed classical mechanics is roughly where average person's understanding of nature ends.
An alternative view is that there is a survivorship bias at play: we tend to understand the things about the universe that are simple enough for a human mind and remain oblivious to the ones that are too complicated for it.
There is the argument that it might be a mistake to discard complex explanations just because they are not simple. The nature is as it is and doesn't care for our preference of simple explanations.
This new map was super informative to me, a layman. I hadn’t read about chirality in particle physics, and didn’t realize it was a key difference between the fundamental particles.
I really appreciate this new map — it makes the information much more approachable.
I really appreciate this new map — it makes the information much more approachable.
It's also interesting that so far we seem to have certain interactions happening on one side of the model but no analogous phenomena on the other side. That immediately makes me wonder whether there should be something in each "gap", even if we haven't yet encountered it experimentally or hypothesized its existence from the theory, or if not, whether that asymmetry might be a hint that we still haven't got our model quite right.
> Correction: October 23, 2020
The original version of this article stated that left-handed leptons in different generations occasionally interact via the weak force. In fact, though such interactions have been hypothesized, they have not been observed.
Those gaps immediately catch your eye, don't they? Seeing them and thinking "what if there's something we are missing" is exactly what many particle physicists also think. This is why the existence of particles and interactions addressing those gaps have been hypothesized to death and then some. Trying to compare some of these hypothesis with the experiment is a major part of fundamental physics today, second only to measuring the things we know exist more precisely. In many cases the comparison has been performed, and when it has been the conclusion was "if there is something there, then the parameters must be such that our instruments did not measure the effects yet". This is why particle physicists are pushing for better instruments.
what if the absence of the interactions on the right hand side actually contributes to the stability of the universe?
Right-handed neutrinos are a prime candidate for dark matter. The possibilities and exact contributions depend on whether neutrinos are massive or not.
The article glosses over the fact that massive neutrinos are not part of the mainstream Standard Model, but depend on semi-detached and unconfirmed extensions, such as Majorana spinors and (P)MNS mixing matrix:
https://en.wikipedia.org/wiki/Pontecorvo%E2%80%93Maki%E2%80%...
The article glosses over the fact that massive neutrinos are not part of the mainstream Standard Model, but depend on semi-detached and unconfirmed extensions, such as Majorana spinors and (P)MNS mixing matrix:
https://en.wikipedia.org/wiki/Pontecorvo%E2%80%93Maki%E2%80%...
Maybe it does. Maybe it's the key to everything existing as we know it! But it sure would be interesting to understand why, if that is the case. The most reliable models we have for how the natural world works tend to be very simple in their mathematics, as long as we're using the right mathematics to model them.
I agree. My chances of ever understanding the Standard Model are slim at best, but this representation helped to click more parts of it into place for me than any other diagram.
Which leaves, I think: dark matter and dark energy (if they exist), and gravity?
Which leaves, I think: dark matter and dark energy (if they exist), and gravity?
> and gravity?
https://xkcd.com/1489/
Note the mouse-over text :)
https://xkcd.com/1489/
Note the mouse-over text :)
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I get why particle physicists think this model is ugly, I couldn’t help but mumble “why??” to myself several times while reading it. It does seem like it’s begging to be explained in terms of more general principles.
Might be a dumb question...but what would a single hydrogen or carbon molecule look like? It was not clear, at least to me, how many of these particles make up atoms.
Please forgive me if I used the wrong terms.
Please forgive me if I used the wrong terms.
Sibling comments have described the structure of atoms already, so here is a different thing:
What you see in the article is a way to organize the types of particles and interactions that occur in the standard model according to their properties. It is not a way to visualize atoms or molecules that you might be familiar with from chemistry if this is what you meant.
The following comparison might be flawed but imagine like it an overview sheet for screws [0]. One type is listed with philips head, one with torx, one type might have a thread with this angle and that pitch, the threads being right-handed or left-handed ...
You can then look at this sheet, see the different screws and tell which one you e.g. might replace with another, depending on the tools or requirements you have. It is not blueprint for any particular object, though.
To go back to the article: because of the similarity of their properties, you could substitute an electron with a muon for example. Read more about this here: [1] [2]
[0] https://en.wikipedia.org/wiki/Screw
[1] https://en.wikipedia.org/wiki/Muon#Muonic_atoms
[2] https://en.wikipedia.org/wiki/Exotic_atom
What you see in the article is a way to organize the types of particles and interactions that occur in the standard model according to their properties. It is not a way to visualize atoms or molecules that you might be familiar with from chemistry if this is what you meant.
The following comparison might be flawed but imagine like it an overview sheet for screws [0]. One type is listed with philips head, one with torx, one type might have a thread with this angle and that pitch, the threads being right-handed or left-handed ...
You can then look at this sheet, see the different screws and tell which one you e.g. might replace with another, depending on the tools or requirements you have. It is not blueprint for any particular object, though.
To go back to the article: because of the similarity of their properties, you could substitute an electron with a muon for example. Read more about this here: [1] [2]
[0] https://en.wikipedia.org/wiki/Screw
[1] https://en.wikipedia.org/wiki/Muon#Muonic_atoms
[2] https://en.wikipedia.org/wiki/Exotic_atom
Great extra info and way to look at it, thank you.
Atoms consist of a nucleus made from protons and neutrons, and a hull made from electrons.
Protons and neutrons in turn are made from up and down quarks (uud for the proton and udd for the neutron).
Add the electron neutrino to fix up some nuclear reactions, and you're good to go as far as most things you see around you is concerned (excluding the 'force carrier' part of the particle spectrum). Hence the quip "Who ordered that?" attributed to I.I. Rabi on the discovery of the muon.
Protons and neutrons in turn are made from up and down quarks (uud for the proton and udd for the neutron).
Add the electron neutrino to fix up some nuclear reactions, and you're good to go as far as most things you see around you is concerned (excluding the 'force carrier' part of the particle spectrum). Hence the quip "Who ordered that?" attributed to I.I. Rabi on the discovery of the muon.
Thank you for the info.
A hydrogen atom is generally two up quarks and one down quark, making up a proton, and one electron. The force carriers and occasionally neutrinos show up for interactions, but most of the rest only appear on earth in particle accelerators.
Thank you. That is what I was thinking but the different sizes kind of got me.
If you don't mind watching a nearly 50 year old video then I can recommend "Powers of Ten" [0], attempting to visualize the different scales on which things are happening in the universe we know of. It is a very short video, just 9 minutes long.
[0] https://www.youtube.com/watch?v=0fKBhvDjuy0
[0] https://www.youtube.com/watch?v=0fKBhvDjuy0
Re "sizes", fwiw, you might like [1]. Something I wrote as conversation prep - loads slowwwwly. Quarks are much smaller than their proton. IIRC, >1000x smaller.
[1] http://www.clarifyscience.info/part/Atoms#view-nucleons
[1] http://www.clarifyscience.info/part/Atoms#view-nucleons
I may have to update my username
A question to physicists:
These three quark colors and the leptops are the four vertices of one of the two tetrahedra of the 3d model at the end of the article.
All three colors of quarks come with 3 generations and 2 different charges (+2/3, -1/3).
On the other hand, for the right-handed leptons, which also come in 3 generations (electron, muon, tau), this is not the case: they all have a charge of -1.
What is the reason for this difference?
These three quark colors and the leptops are the four vertices of one of the two tetrahedra of the 3d model at the end of the article.
All three colors of quarks come with 3 generations and 2 different charges (+2/3, -1/3).
On the other hand, for the right-handed leptons, which also come in 3 generations (electron, muon, tau), this is not the case: they all have a charge of -1.
What is the reason for this difference?
The answer to that question should result in a nobel prize.
They make it almost a passing comment that there are no right-handed W bosons; is there something somewhere explaining that?
The search for a right handed W boson is ongoing. As far as I’m aware there is no theoretical reason explaining why it shouldn’t exist.
This is one of those posts that burns into your mind. Totally changes how I think about the model. Kudos!
The professor I had for QMIII drew something like this on the blackboard when he was getting to SM physics.
Really good. Especially the asymmetric of the left and right spin part.
After 50 years particle physicists have finally done something of value?
Sabine Hossenfelder talks a little on graphics of the standard model here -
https://twitter.com/skdh/status/1253180545577746434
She uses this graphic visualisation - https://youtu.be/Go2TaEUQpF4?t=229
If this 3D graphic is real, it'd be nice to make 3D versions to get them into schools. We can mass produce throwout-able plastic Pokemons surely we could do a few standard models.
Sabine Hossenfelder talks a little on graphics of the standard model here -
https://twitter.com/skdh/status/1253180545577746434
She uses this graphic visualisation - https://youtu.be/Go2TaEUQpF4?t=229
If this 3D graphic is real, it'd be nice to make 3D versions to get them into schools. We can mass produce throwout-able plastic Pokemons surely we could do a few standard models.
https://youtube.com/user/peppermint78
This woman is fantastic. Its so great to hear an honest take on the particle physics field without the constant spin and angling for more funding.
Thank you for sharing!
This woman is fantastic. Its so great to hear an honest take on the particle physics field without the constant spin and angling for more funding.
Thank you for sharing!
You are quoting a rather sour person. It is not that any fact that she quotes is untrue. It is that she tends to see all of these facts in the most negative light possible. I am not entirely sure why a person would do that but there you have it.
Physics is weird in the way it attracts vocal, passionate support. People are willing to support projects for tens of billions of dollars not just with no guarantee of useful results, but with a every reason to think that the results won't be useful. The LHC is disappointing in the sense that it didn't turn up anything unexpected, but we knew that the enrgy scale required for unexpected results are much, much, much higher.
We hoped for better, and didn't get it. Billions of dollars is a lot of money to spend on hope.
We spend it because people love the hope that high-energy physics gives. Twentieth century physics had amazing benefits, both practical and intellectual. We could never have dreamed it would be so productive. We crave more.
Scientists know the limitations, but I think that people in general don't. And thats where Hossenfelder comes in, and why she always sounds so sour. She's telling people what the physicists already know and don't want to hear. She's dashing hope.
It's a hope that doesn't need to be dashed. The next LHC could produce something as important as the transistor or as philosophically edifying as the CMB. But is that "could" really worth it?
I believe that if people were really honest they'd spend the money on thousands of much smaller experiments and theoretical projects, rather than putting all of their eggs into one rather dubious basket. But people have a lot of really unjustified faith in that basket -- as jaw-dropping as "20th century physics" was, it's been the 21st century for a really long time, and we haven't gotten jaw-dropping results like that in even longer.
I feel the same way that Hossenfelder seems very sour. I, too, want her to be wrong. But she's not.
We hoped for better, and didn't get it. Billions of dollars is a lot of money to spend on hope.
We spend it because people love the hope that high-energy physics gives. Twentieth century physics had amazing benefits, both practical and intellectual. We could never have dreamed it would be so productive. We crave more.
Scientists know the limitations, but I think that people in general don't. And thats where Hossenfelder comes in, and why she always sounds so sour. She's telling people what the physicists already know and don't want to hear. She's dashing hope.
It's a hope that doesn't need to be dashed. The next LHC could produce something as important as the transistor or as philosophically edifying as the CMB. But is that "could" really worth it?
I believe that if people were really honest they'd spend the money on thousands of much smaller experiments and theoretical projects, rather than putting all of their eggs into one rather dubious basket. But people have a lot of really unjustified faith in that basket -- as jaw-dropping as "20th century physics" was, it's been the 21st century for a really long time, and we haven't gotten jaw-dropping results like that in even longer.
I feel the same way that Hossenfelder seems very sour. I, too, want her to be wrong. But she's not.
> After 50 years particle physicists have finally done something of value?
You're joking?
You're joking?
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