
Why do matter particles come in threes? - theafh
https://www.quantamagazine.org/why-do-matter-particles-come-in-threes-a-physics-titan-weighs-in-20200330/
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GuB-42
Unlike what the title lead me to believe, it is not the number 3 that is
special. It could have been 2 or 42, the question would have remained the
same.

The real question is "why are there N copies of each fundamental matter
particles?", where N is a seemingly arbitrary number that happens to be 3.

~~~
RangerScience
Hmm. I dunno, I think there's something to three specifically. One is
singular; AFAIK two (and any even number) has a symmetry; so three is the
smallest number of things you can have in a set and have it be a set, instead
of a unity or symmetry.

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asdfasgasdgasdg
> so three is the smallest number of things you can have in a set and have it
> be a set, instead of a unity or symmetry.

Three is the smallest number of things you can have in a [non-empty] set and
have it not be a set of one or a set of two? You don't say. :)

~~~
RangerScience
Okay, I'll try again.

AFAIK, the number 1 shows up in nature, it actually represents either an
everything (this entire atom) or a 0-1 continuum.

When the number 2 shows up in nature, it's always balanced opposing
somethings. Newton's third law, matter / antimatter, negative/positive
electric charge, n/s on a magnet.

When the number 3 shows up in nature, you actually get a set of things.
Proton, neutrons, electrons; and perhaps this theory now runs into a problem
because I'm not thinking of another trinity.

So, if you have two things, and they're not opposites, they imply more things
in the category. If you have one thing in a category, and it's not an
everything or a spectrum (of the everything), it implies more things in the
category. If you have three things in a category, they only imply more things
if two of them have a symmetrical relationship (resistors, inductors,
capacitors). The category may still have more things. but it's not otherwise
implied.

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jordanpg
It's unfathomable to me that anything about the universe would be pinned at
some integer value.

My intuition is that particles come in infinite numbers of "generations" and
we just so happen to be only able to measure three of them right now.

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lisper
_Everything_ in the universe is pinned at integer values. That's the reason
quantum mechanics is called what it is.

~~~
dhimes
_Our model_ for everything in the universe is pinned at integer values. I
think that's gp's point.

~~~
lisper
No, the _physical evidence_ shows that everything in the universe is pinned at
integer values in point of actual physical fact. It's not just our models. It
goes all the way back to blackbody radiation and the ultraviolet catastrophe
of the late 19th century. The evidence for QM is overwhelming. It's not just
an artifact of our modeling.

~~~
bananabreakfast
The ultraviolet catastrophe is for sure a good example of this phenomenon.

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dchyrdvh
There is common trick in designing reliable systems out of unreliable
components: replicating the unreliable component 3 times. When one of the
three behaves differently from the other two, it's declared faulty and
replaced. This wouldn't work with 2 copies as it wouldn't be possible to say
which copy is faulty. So roughly speaking, for an outsider, the HN website
appears as a single entity, but under the hood it's 3 replicas. This is an
analogy to a proton that consist of 3 quarks.

~~~
drlobster
But not a good analogy.

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hateful
Could it be that just like having extra neutrons in an atom make it more
massive, but still have nearly the same reactive properties - that the
particles themselves are made up of something else that can have extra "higgs"
that make them more massive?

~~~
ars
If that were the case you would expect there to be some change in how upper
particles behave compared to lower ones, but as best as anyone can tell they
act identical other than being heavier.

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beervirus
Well, identical except for weak force interactions.

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toddh
The rule of three is also a decorating rule. You should always clump picture,
vases, etc. in clumps of three. The reason always given is balance. Three
esthetically produces the best visual balance. Maybe the universe has an
esthetic sense?

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atombender
I question the universality of this rule. What makes two vases on a table less
"balanced" than three? What about a single vase? Four? Five? Symmetry in
physics isn't really about aesthetics.

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airstrike
> What makes two vases on a table less "balanced" than three?

Perhaps two points create an implied line that cuts across the table, where as
three or more create a polygon that fits -within- the table with some balanced
amount of space between the polygon sides and the table sides.

Alternatively (but perhaps similarly), it's the same reason why two-legged
tables don't really exist.

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abiogenesis
Two-legged tables don't exist because the minimum number of points to define a
plane is 3.

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bmn__
An entertaining introduction into the zoo of subatomic particles:
[http://enwp.org/Atom_%28Asimov_book%29](http://enwp.org/Atom_%28Asimov_book%29)

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MR4D
It's because of the 3 Fates.

j/k

More seriously, this is an interesting coincidence.

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stallmanite
Perhaps we are on track to implementing the three seashells.

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JohnBerea
In related news, the existence of biscuits and triscuits hints at a third food
known as monosquits.

~~~
philsnow
I read somewhere that the origin of the name 'triscuit' is because they were
originally baked "with electricity" from turbines in/near Niagara Falls.

They had a picture of some period promotional material with the "baked with
electricity" line, but who knows, in this era of deepfakes it easily could
have been just a photoshop job done for fun amidst pandemic boredom.

Snopes [0], which is for the most part what passes for fact these days, says
it's legit.

[0] [https://www.snopes.com/fact-check/triscuits-electric-
biscuit...](https://www.snopes.com/fact-check/triscuits-electric-biscuits/)

~~~
cestith
[https://twitter.com/sageboggs/status/1242968530250870786](https://twitter.com/sageboggs/status/1242968530250870786)
is a Twitter timeline thread of an investigation into this.

[https://twitter.com/TheRealTriscuit/status/12431774024921620...](https://twitter.com/TheRealTriscuit/status/1243177402492162049?s=20)
is Nabisco's response through the brand account.

[https://twitter.com/TheRealTriscuit](https://twitter.com/TheRealTriscuit)
currently says "elecTRIcity biSCUIT…but you can just call us Triscuit #ifykyk
High voltage sign" in the bio field.

Other theories have been that the original recipe has only three ingredients,
but Nabisco quashed that, and that it's named for triticum since it's a wheat
snack.

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earthboundkid
As though a) we actually know that particle flavors come in threes and b) any
human being's opinion on this is worth more than that of the schizophrenic on
the corner who at least believes he is talking to God.

~~~
dang
" _Please don 't post shallow dismissals, especially of other people's work. A
good critical comment teaches us something._"

[https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html)

~~~
earthboundkid
Yes, I think I was in a particularly bad mood when I wrote this.

But I also stand by the sentiment that a schizophrenic is in a better position
than Weinberg because the schizophrenic hears God directly and so has reason
for believing what he hears. Weinberg doesn't believe in God but somehow has
convinced himself that his aesthetic preferences have something to do with the
intrinsic nature of the universe.

Weinberg has been out of the physics game in and in the world of letters for
my entire lifetime. He won a Nobel Prize (which is generally a tombstone for
careers) before I was born. I don't want to say that his insights are
completely worthless, but they're already conventional wisdom (so they don't
add much to what we already commonly think) and he's just gotten so used to
talking about the nature of the universe that he isn't trouble by the fact
that he has nothing more than a hunch to back him up.

In this case, I have to be _ad hominem_ because there's nothing but the man to
discuss. He has a hunch. His hunch is worth printing because he's a Great
Physicist (or whatever the original title was). To point out that the hunch is
just a hunch, I have to point out that the Great Physicist is just a person
and the hunch has no grounding whatsoever.

~~~
dang
This includes much more information and so is less shallow, and therefore much
a much better post than upthread. There's an interesting phenomenon where
people often reply to moderation comments with a post that says what they
meant in the first place.

The personal aspect is arguably still a problem. But it's also true that
critiquing celebrities isn't the same thing as garden-variety personal attack,
since they represent more than just themselves individually, and you make it
clear that the intention isn't personal.

There's at least one revision a comment like this could go through to get
better: a little more information about what the specific ideas are. For
example, which insights are already conventional wisdom? Readers who are not
steeped in the field could learn something from that.

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amai
three-dimensional space => three particle families ;-)

