from the left-as-an-exercise-to-the-reader dept.
Given that everything in the universe reduces to particles, a question presents itself: What are particles?
The easy answer quickly shows itself to be unsatisfying. Namely, electrons, photons, quarks and other "fundamental" particles supposedly lack substructure or physical extent. "We basically think of a particle as a pointlike object," said Mary Gaillard, a particle theorist at the University of California, Berkeley who predicted the masses of two types of quarks in the 1970s. And yet particles have distinct traits, such as charge and mass. How can a dimensionless point bear weight?
"We say they are 'fundamental,'" said Xiao-Gang Wen, a theoretical physicist at the Massachusetts Institute of Technology. "But that's just a [way to say] to students, 'Don't ask! I don't know the answer. It's fundamental; don't ask anymore.'"
It's a good "average Joe" explanation of our current understanding of what a particle is in a non-mathematical way.
(Score: 5, Interesting) by c0lo on Wednesday November 18 2020, @02:05PM (11 children)
Interesting FA, indeed.
But... a good explanation for "average Joe"? I doubt it. Here's the list of explanations in TFA for what a particle is:
You got it, Average Joe? Come on, it's easy, you only need to know a bit of Algebra, Calculus, Statistical Mechanics, Topology, Information Theory, maybe a bit of Theory of Relativity to have a vague idea of what all above is about.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2, Interesting) by Anonymous Coward on Wednesday November 18 2020, @02:25PM (5 children)
Yeah, reading all that made me glad I decided not to go into physics as a career.
I'm still not totally convinced that modern physics isn't just a scam that all the physicists are using to avoid having to dig ditches for a living. I mean, good on them if they are because it's clearly a damn good scam. I just can't tell them apart from the theologians at this point. (which is probably just because I personally can't understand a damn thing either group says)
(Score: 5, Funny) by c0lo on Wednesday November 18 2020, @02:44PM (2 children)
On the other side, I'm convinced that those who dig trenches for a living are just slackers who found a legal loophole to eschew learning modern physics (large grin)
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @06:47PM
The laws of physics are different on the other side. For example, there are no door knobs on the other side.
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @07:26PM
very brave: they totally and fully immersed are for real digging the field ^_^
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @05:04PM
I feel the same way about patents and patent lawyers. Try reading through a bunch of patents and it all looks like nothing but confusing gibberish.
(Score: 2) by mhajicek on Wednesday November 18 2020, @06:33PM
A particle is what collects on my cpu cooler.
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @04:02PM (3 children)
The three main things to kinda look up when it comes to quantum physics that are unintuitive are
Quantum Coherence / decoherence
Quantum tunneling
Quantum Non-locality
You can find youtube videos on these.
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @05:00PM (2 children)
Also these three concepts are related to object permanence and how you lose your natural intuition of quantum physics after a certain age when you gain object permanence.
(Score: 0) by Anonymous Coward on Thursday November 19 2020, @05:13AM (1 child)
Oh, you tease! You can't come out with such a delightfully nutty comment without going the full rant. I invite you to please expound further on your ideas.
(Score: 0) by Anonymous Coward on Thursday November 19 2020, @11:09AM
I was watching this video and it kinda tries to explain it
https://www.youtube.com/watch?v=ADiql3FG5is&t=1614s [youtube.com]
(Score: 3, Informative) by Common Joe on Friday November 20 2020, @10:21AM
Ok, you got me. That was my opinion.
I still think it's a much better read than most articles which require a PhD in physics with a specialization in string theory to understand. It won't satisfy the average Joe. It won't satisfy the physicist. But it at least satisfied this Common Joe, and I thought others on here would also appreciate it.
(Score: 3, Informative) by legont on Wednesday November 18 2020, @02:20PM
"We basically think of a particle as a pointlike object,"
A "point in space" has 4 to 12 "properties" depending on whom one asks - time and coordinates. The only difference with a particle is that the relationships between those properties are somewhat more interesting than for the point or are they? After all a point in space has a Planck length. Length? How many dimensions again?
"Wealth is the relentless enemy of understanding" - John Kenneth Galbraith.
(Score: 3, Insightful) by legont on Wednesday November 18 2020, @02:25PM
A particle is something we can't split in parts; for now that is.
"Wealth is the relentless enemy of understanding" - John Kenneth Galbraith.
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @02:54PM (3 children)
The Universe just called. It wants us to know that it's very, very, very sorry that it isn't simple enough for our puny, limited, barely-out-of-the-primordial-goo intellects to even begin to understand.
(Score: 1, Insightful) by Anonymous Coward on Wednesday November 18 2020, @06:25PM (2 children)
Wait until they understand the underlying mechanics, which will be arbitrary and unsymmetrical whether the humans like it or not. Then they'll be all like "what is a $xyz?" "Fundamental! Sotp asking!" No energy beings. No warp drives. No ascension. No spirit matter. See Feynman's description of how fucking magnets work: they just do, but we can describe them! At some point it just is and we're left with the question of why there's something instead of nothing. But that's not a question physicists can help us with.
Well, maybe a Kardashev III civilization might hack the gibson. But this one isn't even fully Kardashev I.
(Score: 0) by Anonymous Coward on Thursday November 19 2020, @09:45AM (1 child)
Eh, it's been about 500 years since the Scientific Revolution. Give it another 500 and everything will be neatly described, if not flatly nuked.
(Score: 0) by Anonymous Coward on Thursday November 19 2020, @11:23AM
I think the 'scientific revolution' has left us with more unanswered questions than ever before. Give us another 500 years and we'll either nuke each other back into the stone age or destroy the environment and end up back in the stone age if we're still around to the point where we have few to no questions to answer (like animals) or advance to the point where we have even a thousand times more unanswered questions than ever before.
As far as answering all the questions, not even close. Even the ones we think we answered we haven't. How did we get here? How did life start?
Darwin got so many things wrong yet naturalists insist that evolution is still true and they try to alter their hypothesis. DNA analysis has shown that so many of our prior beliefs in what we thought different relationships should be were outright wrong yet we just say, fine, but we're still all related we'll just adjust it so that more genetically similar animals are more closely related. This doesn't answer the question of if we're related in the first place or not though (because cars share similarities with bikes, different software shares similar code and include similar libraries, doesn't mean they share a common ancestor. Maybe a common designer).
The fossil record doesn't really follow what we would expect if universal common descent is true (not at all). At first they attributed it to the incomplete nature of the fossil record but then they find that this doesn't even work because the change throughout the fossil record isn't gradual. So they make up some punctuated equilibrium garbage and say "because the evidence for gradualism is lacking this must be evidence for punctuated equilibrium because we know that universal common descent must be true no matter the evidence".
Not that theists have all the answer. The fact of the matter is that no matter what you believe you're basing much of your beliefs on faith. I doubt in a thousand years we'll have the answers. Just more questions. Maybe it was meant to be this way. Keeps us thinking. Of course the intent for it to be this way would imply a designer that intended such a thing.
(Score: 2) by PiMuNu on Wednesday November 18 2020, @03:03PM (29 children)
The question can't be answered until we know what consciousness is. Quantum mechanics, in its current form (whether classical or QFT) requires the definition of an "observation". People rattle on about "many worlds" etc, but really such a thing cannot be defined without defining the observer. Until we can define an observer we can't define quantum mechanics.
ps: I am a practicing physicist, for what it's worth, not some random hippy.
(Score: 1) by nitehawk214 on Wednesday November 18 2020, @03:07PM
Ok, Deepak Chopra, whatever you say.
"Don't you ever miss the days when you used to be nostalgic?" -Loiosh
(Score: 2) by c0lo on Wednesday November 18 2020, @03:11PM (2 children)
I'm not convinced physics need a definition of what consciousness is. Yes, among other things, I'm one of those heretics that call "The emperor's new mind" bullshit.
ps. I'm a physicist only by education, haven't engage with it seriously for the last 28 years.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 1, Touché) by Anonymous Coward on Wednesday November 18 2020, @04:25PM (1 child)
Experimental physicist here.
A particle is something that makes tracks in a cloud chamber and other such detectors. Everything else is (mental) wankers wanking.
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @06:38PM
thank you.
(Score: 2) by The Mighty Buzzard on Wednesday November 18 2020, @03:14PM (8 children)
Well, at least we know it's not a cat. That's a start anyway.
My rights don't end where your fear begins.
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @04:08PM (7 children)
Well, that depends. Is it a feral cat, a stray cat, or a domesticated cat.
Uhm ....
"A feral cat is an un-owned domestic cat (Felis catus) that lives outdoors and avoids human contact"
https://en.wikipedia.org/wiki/Feral_cat [wikipedia.org]
Wait, a feral cat is a domestic cat that avoids human contact? That's one of those quantum quirks we have where the cat is both dead and alive. I know how to resolve this. The cat is a domestic cat but it's not a domesticated cat. See, I just solved the cat in a box problem.
(Score: 3, Insightful) by The Mighty Buzzard on Wednesday November 18 2020, @04:34PM (6 children)
Word trickery on behalf of biologists there. The domestic cat is not actually any more domesticated than any ambush-style big cat. The instincts and behavior are identical for both, given the same raising. It's just thought otherwise because felis catus isn't as big, so it's not capable of maiming or killing and the intimidation factor by size difference is larger.
My rights don't end where your fear begins.
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @09:38PM (5 children)
So not all domestic cats are domesticated cats but I guess if you take a domestic domesticated cat and abandoned it in the jungle it would become a domesticated wild cat?
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @09:40PM
A non-domestic domesticated cat.
(Score: 0) by Anonymous Coward on Thursday November 19 2020, @12:36AM
"The general idea is that owned cats that wander away from their homes may become stray cats, and stray cats that have lived in the wild for some time may become feral."
(Same wikipedia article).
So a stray cat is a homeless domestic domesticated cat?
An outdoor pet cat is a cat that has an owner that takes care of it but doesn't let it inside the house but maybe lets it around the yard and feeds it and maybe gives it a small cat house? Would this cat be considered homeless since it can't go inside?
A feral cat is a homeless undomesticated domestic cat.
A non-homeless domesticated domestic cat is a pet cat or maybe an indoor cat or an indoor/outdoor cat.
A wild cat is a cat that lives in the wilderness.
(Score: 2) by The Mighty Buzzard on Thursday November 19 2020, @03:59AM (2 children)
Domesticated is applicable to the species not the individual in zoological contexts. It means instincts not suitable to living with humans have been bred out of the species, which is very much not the case with cats. The word you're looking for is tame or socialized.
My rights don't end where your fear begins.
(Score: 0) by Anonymous Coward on Thursday November 19 2020, @11:46AM (1 child)
I was trying to be funny but I guess no one really thought I was funny.
(Score: 2) by The Mighty Buzzard on Friday November 20 2020, @02:30AM
My bad then. I had an argument about this with some complete moron of a zoologist the other day. Apparently he felt it perfectly reasonable to cite research that compared the behavior of wild big cats to pet house cats. You know, instead of comparing it to feral "domesticated" cats like it should have been. Still annoys me that idiots like that are given credentials that should label them experts in a field when most laymen can easily see where they fucked up.
My rights don't end where your fear begins.
(Score: 4, Funny) by The Mighty Buzzard on Wednesday November 18 2020, @03:15PM
Wait, not some random hippie or not just some random hippie?
My rights don't end where your fear begins.
(Score: 1, Insightful) by Anonymous Coward on Wednesday November 18 2020, @04:09PM (5 children)
"observation" means interaction.
an excited atom far away from everything else can be enclosed in a sphere made out of photographic film.
we know that the atom has released a photon when the film changes, and that's when we also know that its' momentum has changed.
before that, the atom exists in a superposition of states where it's fixed with respect to the sphere (because that's how we built the sphere), or it's moving in an arbitrary direction (because the photon can go any way it wants).
"observation" of the "photon+atom" system is simply an interaction (photon-film).
(Score: 2) by choose another one on Wednesday November 18 2020, @05:04PM (4 children)
And how do we know when the film changes? - well we observe it, duh.
Without an observer, did the film change or not? Dunno, maybe ask the cat?...
(Score: 2) by PiMuNu on Wednesday November 18 2020, @05:45PM (2 children)
Right, that's the crux of my argument.
Another point
> And how do we know when the film changes? - well we observe it, duh.
What happens when two people observe the film? What happens if one person observes the film without the knowledge of the other person? What happens if the order in which the film is observed by two observers changes randomly?
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @06:53PM
about the two people question: your quantum system is "person1 + person2 + systemtomeasure". so far, it has always been the case that in such scenarios the measuerement outcome has been independent of who/when actually checks the result, as far as the "quantum" is concerned. when you consider relativity, then the discussion needs to be tweaked, but it's certainly true that each person, using the rules of relativity, can deduce what/when the other person will observe.
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @06:57PM
it changes when not observed, like misremembered quote/lyrics.
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @06:09PM
your eye is the film.
when your eye senses a photon, it means you, as a quantum system, have interacted with the "atom+photon" system, i.e. within the "exited atom + film" system any questions must be conditioned on the "photon captured by film at time t and position x" measurement, because that is reality.
there is no qualitative difference between an inert film and an active observer using eyes.
as far as we can trust experimental evidence so far, both humans and plain films follow the same laws of physics.
while humans have a significant amount of internal degrees of freedom, and are self-aware, their awareness of making measurements does not affect the outcome of measurements.
concretely: yes, whenever physicists talk about quantum entanglement and measurements etc, they use words like "when observed, the system behaves differently then when not observed". but the "observations" are actually some automated things happening unthinkably fast, and the outcome of "observed vs not-observed" takes place before any human mind can be aware of the experiment even happening. it makes no difference whether humans are watching the experiment live, or whether they read the output a week later when they come back from vacation.
to say "the tree makes no sound when there's nobody there to listen" is a philosophical statement that has no place in the lab.
you can't test it, and you can't use it to make predictions.
go ahead and play with it if you like, but stop bringing it up when we talk about physics, ok?
it's not physics.
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @05:33PM
(Score: 2) by maxwell demon on Thursday November 19 2020, @06:32AM (6 children)
Believe what you want, but there is zero evidence that observation by a conscious observer has any different effect than observation by any other macroscopic system.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by PiMuNu on Thursday November 19 2020, @09:07AM (5 children)
What do you mean by "observation by a macroscopic system?"
(Score: 3, Insightful) by maxwell demon on Thursday November 19 2020, @01:34PM (4 children)
A macroscopic system whose state after interaction depends on the state of the quantum system before the interaction. That is, basically a measurement device.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by The Mighty Buzzard on Friday November 20 2020, @02:32AM (3 children)
Depends on your definition of macroscopic. They keep pushing the bounds of how large and complex a system they can get into superposition every year or so.
My rights don't end where your fear begins.
(Score: 2) by maxwell demon on Friday November 20 2020, @03:06PM (2 children)
Basically, a system is macroscopic if it shows non-negligible decoherence in a relevant time scale.
And yes, that absolutely depends on your experimental ability. One more argument against consciousness playing a fundamental role in quantum mechanics.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by PiMuNu on Friday November 20 2020, @03:45PM (1 child)
How does one measure the effect of a non-conscious observer? Who, or what, observes the observer?
(Score: 2) by maxwell demon on Friday November 20 2020, @09:20PM
You can measure the effects the observation had on the observed system, with and without having a conscious observer looking at it. In particular, you can observe properties that are complementary to the originally measured property, and thus determine if the measurement already “collapsed” the wave function (thus destroying any previous value those complementary properties may have had).
If you want to know the observed value, you can ask the observer after examining the system (so you know that what your examination of the system told you was not affected by you getting to know the result). If it is stored in a non-conscious system, you just read it out. How to get it from a conscious observer is left as exercise to the reader. :-)
That covers anything about the measurement process that quantum mechanics is concerned with.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 0) by Anonymous Coward on Thursday November 19 2020, @02:40PM
"We need to determine when a particle stops exhibiting wave behavior and starts exhibiting particle behavior."
"The question cannot be answered without understanding the nature of consciousness!"
Doesn't make any more sense than it seems to. Even Eugene Wigner, who thought that whole madness up, eventually recanted. The measurement problem is real, because the actual collapse of the wavefunction is unobservable. But consciousness is not required.
https://en.m.wikipedia.org/wiki/Measurement_problem [wikipedia.org]
https://youtu.be/CT7SiRiqK-Q [youtu.be]
https://youtu.be/Be3HlA_9968 [youtu.be]
(Score: 4, Interesting) by bd on Wednesday November 18 2020, @03:07PM (9 children)
I think this all boils down to the fundamental limits of what physics is and isn't.
Physics is a process to better understand and model how space-time, the fundamental forces and particles interact.
What Physics fundamentally cannot do is explain how or why something works that is all the way down the rabbit hole.
Take a magnetic field line. We know exactly what it does.
But unless this force turns out to be not fundamental, Physics will never really explain why it works.
And isn't actually supposed to.
That belongs to the domain of Philosophy, rather than Physics.
TLDR: Particles? Remember it's a movie, we should really just relax and enjoy the show.
(Score: 2) by c0lo on Wednesday November 18 2020, @03:13PM (4 children)
I can't. As any field line, it's an abstraction, an intellectual construct.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @04:13PM
you're only saying that because you misplaced your superconducting lasso. maybe if you weren't so careless...
(Score: 2) by bd on Wednesday November 18 2020, @09:18PM (2 children)
You are of course correct. So... badly chosen example.
What I should have said is:
Take a common experiment: iron filings form these lines around magnets. Everyone has seen this in school.
Physics provides a model to describe how the electromagnetic force makes those filings align themselves.
But asking what a fundamental particle really is (as the article does), is the same as asking why the electromagnetic force works the way it does. Why exactly a photon does what it does.
If physics can answer this question, the particle explained is no longer fundamental, and you have simply found something else nobody will potentially ever be able to explain. Turtles all the way down.
So, I guess there will always be a set of axioms that are stuff for philosophers, not natural scientists.
(Score: 0) by Anonymous Coward on Thursday November 19 2020, @07:26PM (1 child)
Physics and science are a description of what happens when you do something. You throw a ball up and it comes back down. If you throw it up with given parameters you can use a formula to calculate the trajectory. It's a description. It simply describes nature.
(Score: 2) by maxwell demon on Friday November 20 2020, @03:11PM
It is more than merely a description. It is also a prediction. The formula is also expected to describe balls thrown in ways you never threw them before.
If your ball happens to not follow the prediction, you've possibly found new physics (or you just made an error in your experiment).
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by PiMuNu on Wednesday November 18 2020, @06:09PM (2 children)
Magnetic field lines are the trajectories of virtual photons (I might not be quite right the photon trajectory might be the magnetic potential, or something, but the gist of the statement is true, according to Quantum Field Theory).
(Score: 2) by maxwell demon on Friday November 20 2020, @03:20PM (1 child)
The virtual photon does not have a trajectory. Note that the entire Coulomb scattering process is described by the exchange of one single virtual photon (aka tree level; the many-photon processes are higher order corrections to it).
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by PiMuNu on Friday November 20 2020, @03:35PM
Thanks - a while since I did QFT...
(Score: 2) by legont on Wednesday November 18 2020, @06:42PM
Even more interesting is the question if a true math statement remains true when there is no mind to hold it. If it's not, how physics could work without us? If it does, where exactly it is stored.
I believe the answer to this question will solve the quantum observer one as well.
"Wealth is the relentless enemy of understanding" - John Kenneth Galbraith.
(Score: 3, Interesting) by oumuamua on Wednesday November 18 2020, @03:15PM (1 child)
As proposed by Wolfram:
https://writings.stephenwolfram.com/2020/04/finally-we-may-have-a-path-to-the-fundamental-theory-of-physics-and-its-beautiful/ [stephenwolfram.com]
https://www.wolframphysics.org/ [wolframphysics.org]
It is easy to dismiss as a crackpot theory but consider that Wolfram started out as a particle physicist:
https://en.wikipedia.org/wiki/Stephen_Wolfram#Particle_physics [wikipedia.org]
(Score: 2) by PiMuNu on Wednesday November 18 2020, @05:47PM
Has it ever been peer reviewed?
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @07:14PM (3 children)
i thought that was the entire point.
(Score: -1) by Azuma Hazuki 2.0 on Wednesday November 18 2020, @08:07PM (1 child)
Back to school with you! Fwapish!
(Score: 0) by Anonymous Coward on Thursday November 19 2020, @08:19AM
Hmm, a new Sequelizer [fandom.com]?
Though it seems that this sequel is only half as powerful as the original sequelizer's sequels, making you ¼ as powerful as the original.
(Score: 2) by hendrikboom on Thursday November 19 2020, @02:28AM
Exactly wrong. A particle *is* a wave, when that wave is behaving the way you'd expect a particle to.
(Score: 0) by Anonymous Coward on Wednesday November 18 2020, @07:36PM (1 child)
maybe just stretch your arm across the table and swipe everythin into the garbage bin?
then start asking which tools do i need?
maybe a straight edge?
a compass? something that gives me two point at the elevation (here we get the first few problems with tool, say a flexible pipe with water and water doesn't run uphill but if the pipe is 1/4 of earth circumvent then connecting the rwo water levels gives you a line thru the surface and not parallel).
so anyways there's gravity and it's not parallel.
so this gives us a hint that tools are embeeded too?
and maybe (to make it short here) we are reduced to gravity, electromagnetism and shit that falls apart ...
(Score: 0) by Anonymous Coward on Thursday November 19 2020, @08:21AM
Keep adding neutrons until you find an island.
(Score: 2) by RamiK on Wednesday November 18 2020, @08:37PM
1. Approximate physical reality best you can given your best available tools and math.
2. Survey the variables.
3. Make up a "thing" that associates all those variables as its properties.
4. Name it "particle".
5. Wait until you have better math and tools.
6. Repeat.
compiling...
(Score: 2) by krishnoid on Wednesday November 18 2020, @10:23PM
Medicine:
Construction: (cf. planck length) "rch". I heard it from a construction worker once, and will let you look it up on urban dictionary.