Not PARTICLES! QUANTA! Is that really all we can accurately state?
I enjoyed a recent exchange on Quora titled 'If particles are actually field excitements, should they be interpreted as a "thing" or an "event" created when different quantum fields interact?'
A physics professor called Art Hobson from the University of Arkansas stated:
Particles such as photons, electrons, protons, nuclei, and atoms are waves, or disturbances, in quantum fields. They are real things. However, the word “particle” is not appropriate because they are not tiny objects that have a definite “edge.” They are much more like clouds, and are best called “quanta.” A quantum, such as a photon or electron, is a highly-unified spatially-extended bundle of field energy. The creation of a quantum is indeed an event (i.e. it happens at a specific place and time), as is the destruction of a quantum. But quanta themselves are things. Indeed, these things are what everything in the universe is made of.
The traditional image of a quantum world of spherical structures is on a definite 'shoogly peg'(which is just scots dialect for 'insecure').
This is a 'real' image of a hydrogen atom:
If the fundamental quanta are in-fact 'field excitements' and have 'no definte edge' and are 'cloud like' etc then does this not open all sorts of other possibilities for whats really happening during experiments like the double slit? Maybe its true that if you do fire a photon, one at a time towards two slits that due to the fact that there are none of its type near it, its cloud like structure spreads out and passes through both slits. This is pure conjecture on my part and I await and expect the suggestion to be quickly dismissed but I just suggest it merely as one of those 'other possibilities' I am trying to percieve. Any others?
A physics professor called Art Hobson from the University of Arkansas stated:
Particles such as photons, electrons, protons, nuclei, and atoms are waves, or disturbances, in quantum fields. They are real things. However, the word “particle” is not appropriate because they are not tiny objects that have a definite “edge.” They are much more like clouds, and are best called “quanta.” A quantum, such as a photon or electron, is a highly-unified spatially-extended bundle of field energy. The creation of a quantum is indeed an event (i.e. it happens at a specific place and time), as is the destruction of a quantum. But quanta themselves are things. Indeed, these things are what everything in the universe is made of.
The traditional image of a quantum world of spherical structures is on a definite 'shoogly peg'(which is just scots dialect for 'insecure').
This is a 'real' image of a hydrogen atom:
If the fundamental quanta are in-fact 'field excitements' and have 'no definte edge' and are 'cloud like' etc then does this not open all sorts of other possibilities for whats really happening during experiments like the double slit? Maybe its true that if you do fire a photon, one at a time towards two slits that due to the fact that there are none of its type near it, its cloud like structure spreads out and passes through both slits. This is pure conjecture on my part and I await and expect the suggestion to be quickly dismissed but I just suggest it merely as one of those 'other possibilities' I am trying to percieve. Any others?
Comments (72)
What is an excitation? A field is just a mathematical aid which consists of distributions assigned to all points of spacetime, and these distributions have operators as "value". These operators are creation and annihilation operators. These operators create or annihilate one particle states in so-called Fock-space, a direct product of single particle Hilbert spaces. A free particle field is just a particle with a single momentum state or, when localized, a normalized superposition of a spectrum. In a Feynman diagram, there is one line only and begin and end state have the same momentum. The particle is localized if it has a spectrum of momenta. If it has a well defined position though there are infinite associated momenta, due to uncertainty.
There are no such things as pointparticles, no creation and destruction of particles (only couplings), and the virtual particle math scheme is referring to something real. One week ago I actually got suspended for a week on a physics forum because I argued against point particles, the existence preons, the existence of hidden variables, and real existence of virtual particles (which real particles are in fact too, but with related E and p). Low quality contribution. Of course. From the mainstream POV.
So, what is a particle? A particle is a tiny geometrical Planck-sized structure on which charge can safely reside, without leaking out. The extra space dimensions in which it exists are perpendicular to the 3D bulk and this ensures that the Planck length is Lorenz invariant (for which physics still has no answer...). The smallest measurable distance (the Planck length) follows naturally from the particles small extension in space. Within the bounds of the wavefunction (the temporal cross section of a field) the particle just hops around erratically if you propagate it in time. Which is to say it travels on tiny parts of all paths Feynman talks about, coupling to the timeless virtual field to reach others, and being itself a time extended virtual particle with its antiparticle component somewhere in space.
So this is one of your main divergences from the thinking of the current majority of physicists, yes?
Quoting EugeneW
But in 3D space is a 'field' not a 'volume,' in that it has 'cubic spacial-expansion?'
This is how I have always perceived the term 'field' as used in physics.
For 'excitation' I conceive the cuboid area as containing liquid like water and I see excitation as a disturbance within the water, like shaking a snow globe.
So not a mathematical aid but a real area of space. I see the 'mathematical aid' part as the conceptual breaking up of space into a 3D grid of contiguous cuboids. So all of space is in reality one big field.
What do you mean by "distributions assigned to all points of spacetime"? what specifically do you mean by 'assigned?' What/who performed such assignment? Do you use the term 'distributed,' as random or is the distribution based on a mathematical function? Are these 'operators' you mention variables/parameters/inputs for a mathematical process?
Ok, these matter/antimatter annihilations seem to me to produce a kind of 'all square' outcome.
The conservation of the total energy of the Universe seems to indicate that this creation/annihalation cycle is much less interesting than the fact that something else happened which created an imbalance within this process and that's why the Universe has galaxies, planets and us.
A free particle field is just a particle with a single momentum state or, when localized, a normalized superposition of a spectrum.
How can a particle BE a field?
The particle is localized if it has a spectrum of momenta. If it has a well defined position though there are infinite associated momenta, due to uncertainty
I think you are typing here, that a particle/quanta/disturbance which forms within a field can move in a particular direction but how fast it will move and exactly which direction it will take and the exact shape of the path (straight, curved etc) will take, is very hard to predict. Is this correct?
Quoting EugeneW
What do you mean by 'coupling' here?
Quoting EugeneW
So you are saying that the structures that you are calling particles, exist 'outside' of the known 3D of space, yes?
Do You mean 'Perpendicular' to 3D space as in 90 degrees to it? So your 4th spatial dimension is not 'wrapped around' every point of 3D space but is 'perpendicular' to every point in 3D space.
Would this be mathematically represented as a 90 degree direction away from a set of three spatial coordinates (so, dimensionless) and one instant/coordinate of time?
So a position in your space would be (x,y,z,t,90)?
the particle just hops around erratically if you propagate it in time. Which is to say it travels on tiny parts of all paths Feynman talks about,
But what makes it 'hop'? and what do you mean by 'hop'? Are you relating this to the proposed motion of an electron in orbit around a nucleus? A jump from an outer orbit to an orbit closer to the nucleus?
Does your particle jump right or left, then move forward for a time and then jump left or right again?
The particle hops around non-locally, instantaneously. The wavefunction is made of hidden variables. These surround the particle and you could even consider them space itself. These variables determine the evolution of the particle. If the overall velocity of the wavefunction is zero, the particle hops around the center of the wavefunction, like in the lowest energy orbital of hydrogen. If the electron is in a higher energy orbital the orbital has angular velocity, angular momentum. If that orbital decays to the ground state (non-instantaneous, it's no collapse) the electron couples to the virtual field. It is described as the creation of a photon, while the electron decaying to the ground state actually couples to a virtual photon, which breaks up from its circular shape to become an open stretched state which sooner or later can couple to another state and excite that state (say, another electron in hydrogen). After that the photon returns to its virtual state (so it's not absorbed by that electron, but only gave it a real kick).
We were thinking of hydrogen at the same time!
What quanta?
Ah! The photograph of hydrogen. See all the specks? The electron hops constantly between all of them. Within the bounds of the wavefunction. QFT is difficult to use for a bound state. QFT only works for particles that are initially and finally free (asymptotically free). The position and velocity are well defined at all times in this picture of QM.
Most physicists wont agree, like with Bohm. The math shows exactly the same outcomes though. You could e do an experiment though to discern. But it's a though one.
Quoting EugeneW
To me, 'non-locally' means globally, so do you mean that this particle just spontaneously appears and disappears at ransom positions in your 5D space and that no time passes between hops so time=0 during hops. Does this not suggest that the actual movement occurs within your suggested 4th spatial dimension? and this is why no relative time passes within our experiential 3D space and your particle can traverse 3D space 'instantly,' without breaking the law of c within 3D space?
Surely this makes one of your hidden variables, your 4th spatial dimension?
Again, what do you mean by 'couples to'?
Well, the hydrogen atom is in the link in the OP.
Click on the link in the OP, look at the image.
Yeah, I saw that later...
I think all of the specs together ARE THE ELECTRON. The electron is not a single sphere in orbit around the nucleus. Its a 'smear' or 'cloud' orbiting the sphere, but a cloud or smear of what?
Sorry I meant to type 'orbiting the nucleus' not orbiting the sphere.
How can it be smeared out?
It can look smeared out if it hops like mad from one place to another. Prrrrrr.... hophophophophop..... If you imagine the s orbital, it's not everywhere at once but shortly after another it's here, there, there, making up the wavefunction.
Ha ha. I was hoping YOU could help ME understand that one.
From my recent reading and from what the physics professor said on Quora, an electron is more accurately described as a cloud and not a sphere. I have also read that the electron orbits a nucleus in a 'smeared' orbit. When looking at recent images or artist impressions of an atom, it looks like there is a lot of support for this 'cloud' or 'smeared' concept. So I assumed that this 'cloud' is a diffuse mass that orbits the nucleus of an atom and its 'smeared out' throughout the expanse of the orbit.
As I think about your 'hoping' imagery and this 'cloud' or 'smear' appearance, it sounds to me more like vibrating strings! The cloud/smear/hopping appearance may be the visual consequences in 3D of vibrational strings in 10D.
Yes. The description is allright. But the electron's charge is not pulled into a spherical form. That's why the hopping image is fine. The smeared out thing is the wavefunction. Electron hops around in it. The space around the nucleus gives a potential. The electron is continuously bound to virtual photons between itself and the proton.
How does this topic and its description relate to philosophy? :chin:
Metaphysica. You can't discuss this on physics fora.
I have admitted in the past to being an interloper here Alkis. I am sure you can find a philosophical aspect, relevant to the thread and if you look at the options when choosing a category for a posted thread, one of them is 'Science and Technology,' which is the one I chose. Scientific debate often prods those more focussed on philosophical aspects to muse on their perceived metaphysical aspects of the dialogue.
Kismet!
Kis who?
Kismet is just a term that relates to 'destiny' or 'fate' or 'providence' or 'predetermination.
We both seemed to go for 'metaphysics' as an answer to Alkis's complaint.
There are still many questions I asked above you have not answered.
Why won't you tell me what you mean by 'particle coupling,' for example?
The story continues. Let me say this. In a Feynman diagram there is a virtual photon between two charged particles. A wiggly line taking care of both changes in momenta of the charged particles. The vertex is where the coupling happens. The virtual photon gives both particles a push or pull. Then it returns to its solitary timeless state, a closed wiggly line (representing a sole virtual photon, uncoupled). The charge of a particle is a measure of the coupling strength and it's a generator to induce local phase transformations of both electrons. This is how the EM field is introduced, but the electron doesn't generate an EM field, that's misleading. The EM field is always there in virtual form and charge couples to it and can even cause real photons to exist (say during the fall to a lower orbital in hydrogen; during inflation, real photons can be pulled out of their virtual state without charge).
If you think that questions like whether "the fundamental quanta are in-fact 'field excitements' and have 'no definte edge' and are 'cloud like' etc." are abstract ideas and belong to metaphysics, it's fine with me. :smile:
I couldn't agree less! That's why I find it rather strange that these concepts are seen as physical reality. :smile:
I had to look up "interloper" ... I learned a new word today. Thanks! :smile:
I really have no problem with that. If I could say I have a problem --I don't, actually-- it's only with people who do not consider themselves "interlopers", and indeed, they don't look like ones, yet I wonder what they are doing in here! :grin: ... Sometimes, I think of myself as one of them! :grin:
Quoting universeness
That could be maybe nice, but, as I often mention, I'm bad in Physics! :smile:
I didn't say that. But nice try ... Turning the negative element of my stetement to positive. You should be a journalist! :grin:
Don't muse about the physics, comment on the concept/persistence/gnawing of human imagination. When a really intelligent scientists such as Sean Carroll or Carlo Rovelli and many of their contemporaries cannot prove exactly how the Universe works, they turn to their imagination to try to make progress. As do I, even with my very limited physics. Why do I just not accept that I don't know and probably never will in my lifetime?
Why does my Cerebral Cortex pester me with, but why, why WHY?
It seems that many humans just can't accept that 'there is no answer yet,' Why will my imagination not leave me in peace and tell me to just go and have as much mindless fun as I can Alkis, help us!!
On a more serious note, I understand why philosophical purists may be unhappy that those of us who don't prioritise philosophy as 'numero uno' on TPF and we are taking up space in their playground but I hope that we can be seen as a minority who don't take up too much space and we can have our wee exchanges and still make a wee contribution to the 'heavy hitter' philosophical threads as well.
Just left some context out... :smile:
Physics, metaphysics, ontology, religion, etc, they all belonged to philosophy.
They would be out of a job!
This 'virtual photo' is emitted by one particle and absorbed by the other yes?
The process of emission changes the momentum of one particle and absorption changes the momentum of the other, yes?
Momentum is movement in a direction, yes? so the overall affect of this system is that the particles change direction and speed, yes?
This 'wiggly line' would be the new path (direction) of the particle(s), yes?
Vertex, (a joining point between two straight lines). I take this to be where the paths of the two approaching particles meet.
So the two particles don't actually touch or 'interact' as the virtual photon prevents this.
Perhaps we can accept that by 'returns to its solitary timeless state,' you mean it 'leaves our 3D space'.
I assume your closed wiggly line would just be something akin to:
Quoting EugeneW
Ok in Computing the term 'coupled' can be used as a measure of how two sub-programs or subroutines are dependant on each other. If 'Global variables' or 'the same' variables are used by two subroutines then they are 'coupled' so an error can cause both subroutines to fail. The more independent subroutines are from each other, the less chance there will be of a total program failure.
So, I take it that when two particles become coupled, they become 'interdependent.'
I take it then that 'coupling strength means the level of interdependence two particular particles might have, varies.
I am just trying to demonstrate my attempts to follow the logic of your physics but we are still quite a distance away from some of my previous questions, such as:
So are you saying that the structures that you are calling particles, exist 'outside' of the known 3D of space.
or
[b]Do You mean 'Perpendicular' to 3D space as in 90 degrees to it? So your 4th spatial dimension is not 'wrapped around' every point of 3D space but is 'perpendicular' to every point in 3D space.
Would this be mathematically represented as a 90 degree direction away from a set of three spatial coordinates (so, dimensionless) and one instant/coordinate of time?
So a position in your space would be (x,y,z,t,90)?[/b]
It could be that you think that the only reason for me asking such questions is due to my lack of knowledge of the detailed physics involved in your hypothesis and it would take too long for you to explain it to me. If that's the case then say so. I will accept that such could well be the case.
Well, I consider physics to be in the purview of science and metaphysics is 'after' physics.
Not at all, many questions are still to be answered in cosmology. Currently, all that exists are theories regarding the quantum structure and workings of the Universe.
OK, but as physicists, their imagination would still wander around protons, electrons, quanta and that sort of things. And they most probably are using their imagination --as others scientists-- with the purpose of finding solutions, explanations, etc., about the nature of these things and how they work. In the same way as I use my imagination as a computer programmer to find programming solutions to various problems ...
Exactly. This is what journalists do! :smile:
That's the popular image yes. But you can consider it like this:
Your image of the closed wiggly line is right. An uncoupled virtual photon. They are omnipresent, not moving forward or backwards in time. A real electron couples to it (also virtual electrons, also closed lines, can). This causes a potential around the electron (called a photon condensate). Another electron can couple too and this transforms the closed propagator (or in time oscillating, propagating virtual photon) into one between two interacting, say, electrons. A first order Feynman diagram. A second order diagram includes an extra virtual electron or photon (two extra verices). A third order two extra of them (four extra vertices), and so on. These are thought math tricks in qft, according to most (but not all) physicists. I consider them real. A non-zero particle size expels the need for renormalization. Indeed, by means of tiny curled up extra dimensions, like a tiny cylinder on a thin tube.
The only thing I haven't figured out is why the universe doesn't run backwards....
Quoting universeness
Einstein said that if you can't explain your physical theory to a six year old, your theory is wrong. Which is something else than Feynman said. I agree with Einstein.
Yes but I am asking you about the persistence/gnawing aspect of imagination. Philosophically, where do you think this tendency of imagination to gnaw at you, come from? Or is a gnawing imagination just my personal experience alone?
Why do humans wish to know their origin story? Why willingly submit ourselves to stressful thinking. I can understand doing so, to satisfy our basic needs, food,shelter, health etc but why give such priority to Where do we come from? and why are we here? and what is our ultimate fate?
Why are so many rich people so f*****up? Why do even they, who can take all their physical needs for granted not have more contented lives?
Just my attempt at pushing some philosophical buttons related to this thread, even though the relationship might be rather tenuous.
Well, I try my best to follow the logic of your typings as best I can but I don't blame you for my lack of physics study. I still very much enjoy our exchanges, you have been a conduit towards my improved understanding of the issues involved.
I couldn't know that. I personally use my imagination for pleasure or creative purposes ... And it doesn't gnaw at me. I'm the one who gnaws at it! :smile:
Quoting universeness
For various reasons, I guess.
Quoting universeness
I personally don't. I have control when it comes to thinking voluntarily, esp. rationally. Thinking coming from the subconscious, feelings, etc., however, can be stressful.
The exact quote is: “If you can't explain it to a six year old, you don't understand it yourself”.
It's one of my favorite quotes! I don't miss the opportunity to bring it up when the circumstances arise ...
I think you are imagining that is true!
:down: Please don't tell me what I'm imagining!
You just killed this exchange.
Well if so, then that's down to your, in my opinion, too high a setting of sensitivity.
I take a 'such is life' approach to such and move on.
A question on Quora was:
If photon and electron are point-like, how can they collide at all?
An answer was offered by: Masroor Bukhari
Ph.D. in Particle Physics, University of Houston.
[b]"Thank you for asking me this question, which is a great question indeed.
When we refer to a photon or electron as point-like, it is in fact an approximation to simplify our calculations. You have to remember that they both are in reality quantum fields, which have both particle-wave properties by the virtue of their momenta and the usual or de Broglie wavelength "[/b]
http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/debrog2.html
[b]"What is really important here are two variables, one, energy (which has in it both the rest energy and a momentum) and the wave function.
Once these or any such particles collide, what is really happening that their center of mass are colliding which is at its earnest an interaction between their probability amplitudes and energies. This is what a collision of elementary particles is and its probability is known as a cross section, unlike the macroscopic collisions, such as of a car and a van, which are deterministic and two actual bodies collide.
For instance, when an electron interacts with a positron, it seems like a collision in the lab frame, but in reality it is an electromagnetic interaction (mediated by an exchange of a virtual photon) between the two particles in their COM frame, resulting into emission of two anti-parallel (real) photons. Find appended below a figure of the interaction shown with the help of a Feynman diagram."[/b]
I used the link above provided by Mr Bukhari and this link led to other links etc which explained a little more detail about many of the physics points you were trying to make to me. Overall, I think that to fully understand the details of your hypothesis, I would need a much higher grasp of the fundamentals of Quantum physics than I currently have.
The basics is easy. Particles do not behave like macroscopic objects but they are the same nonetheless. They hop between an infinity of possible paths. That's the different behavior. But they are just like a rock, concentrated pieces of mass, which are concentrated piece of three massless pieces pure kinetic energy, loaded with three kinds of charge, which give you massive particles like quarks, leptons, and Higgs particles. The three massless preons have to be different from pointlike structures to interact. QFT can assume them pointlike and still get interaction (coupling to the virtual field, as in the Feynman diagram) but it needs renormalisation to do so. The particles themselves are assigned unobservable and unphysical infinities to accomplish this. Give them a small geometrically induced extension and they can hit one another, keep the Planck length Lorenz invariant (same in each inertial frame), and won't need renormalization. Three hits in one!
The professor in your example, gave a wrong explanation for the Feynman diagram shown. I doubt the good man is a professor! There is no virtual photon involved. Only a virtual electron. The real electron and positron turn back to a virtual electron and a virtual photon gets real (two photons,)
Look what he writes:
Not true.
At the moment, I am most attracted to the posit that it's a multidimensional string vibration.
If I was going to bet, I would bet on some future version of string theory as being the correct one for the fundamental quanta of the Universe.
The problem with string vibration is that no mechanism for the vibrating string is given. It just states the string vibrates.
He's a Ph.D. who got his doctorate from Huston Uni, not a professor!
Maybe he was just 'summarising.' According to wikipedia, a lot happens during an electron-positron 'collision':
Electron–positron annihilation occurs when an electron (e?) and a positron (e+, the electron's antiparticle) collide. At low energies, the result of the collision is the annihilation of the electron and positron, and the creation of energetic photons:
e? + e+ ? ? + ?
At high energies, other particles, such as B mesons or the W and Z bosons, can be created. All processes must satisfy a number of conservation laws, including:
Conservation of electric charge. The net charge before and after is zero.
Conservation of linear momentum and total energy. This forbids the creation of a single photon. However, in quantum field theory this process is allowed; see examples of annihilation.
Conservation of angular momentum.
Conservation of total (i.e. net) lepton number, which is the number of leptons (such as the electron) minus the number of antileptons (such as the positron); this can be described as a conservation of (net) matter law.
I thought it was the existence of the extra dimensions that caused the 'vibrations.' but if I am wrong then
my bet lies with the musings of Ed Witten, Brian Greene, Sean Carroll, Michio Kaku and Leonard Susskind to eventually figure it out before I disassemble.
But he writes:
"For instance, when an electron interacts with a positron, it seems like a collision in the lab frame, but in reality it is an electromagnetic interaction (mediated by an exchange of a virtual photon) between the two particles in their COM frame, resulting into emission of two anti-parallel (real) photons. Find appended below a figure of the interaction shown with the help of a Feynman diagram."
This is not happening.
Well, if you want, I can provide you with the link to his answer on Quora. You can respond to his answer if you wish.
I think I have figured it out already. There are no strings. Only closed geometric structures to contain the three basic charges. How does a string vibrate? It easier than they make you think universeness!
Can't you see from the diagram no virtual photon is involved? Virtual particles are the horizontal lines in the diagram, representing two time ordered states. A wiggly line is a photon (like the two externals) and a straight line an electron. In the middle, betwe4the two vertices, there is an electron. The electron goes round in a circle in spacetime.
Well done EugeneW. All you have to do now is convince the likes of Ed Witten, Brian Greene, Sean Carroll, Michio Kaku and Leonard Susskind. If you do, then when you are on TV, I will be able to say to my friends, him!, Hah! I used to chat to him on TPF when he was a nobody, just like me.
Now, he won't even answer my emails! He's just part of the cosmological elite!!! :naughty:
I'm working on it... And when I'm on TV I'll let you come with me. As the co-founder of the new physics. (I'm afraid of cameras, but we cant tellem that!). Dont worry, Ill do the physics talks! You can make jokes!
But there is only one horizontal line in the diagram.
The electron(e-) and positron (e+) are inputs. I took the wiggly lines to be the two 'real' photons emitted and I had always read that no one really knows what's happening in the middle(or horizontal line part) of a Feynman diagram.
Exactly. That's the virtual electron. There is no virtual photon (though you could see the two real photons as one long lived virtual photon). That would be the case for two electrons.
You could consider the electron and positron as one long lived virtual electron. Just connect the lines to form a closed line (which represents a vacuum bubble).
It's a deal! By that time you will be able to buy all the single malt whisky's I will need to keep the jokes flowing!
I guarantee you Ill take you with me! When the going gets tough you can joke me out!
:lol:
Can you imagine?
As I said, when I have read stuff involving Feynman diagrams. The 'horizontal line' is always referenced as 'we don't know what happens here.'
That's why it's called virtual. We obviously cant observe it. Which doesn't mean its not happening. The most important stuff happens in the dark...
If you know that the virtual can become 'real' then all those virtual bottles of single malt Scottish whisky's that I am imagining in my head right now! YOU CAN MAKE THEM REAL!
I like your Physics. String theory has never offered me such!
:rofl:
String theory, despite its 10 dimensions, offers one teeny weeny string only. I offer fully blown geometrical structures. Like Scottish malt bottles! Still virtual but if we couple to them they get very real!