What are virtual particles?
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- čas přidán 16. 04. 2024
- Virtual particles are one of those topics of modern physics that just don’t sound real. How can particles just appear and disappear without anyone seeing them. In this video, Fermilab’s Dr. Don dives into the topic, giving us an understanding of how virtual particles arise from quantum field theory.
Casimir effect and quantum foam:
• 9 Subatomic Stories: T...
• Quantum Foam
g-2 videos:
• The physics of g-2
• What does the Muon g-2...
g-2 playlist:
• Muon g-2 experiment re...
QED videos:
• Quantum electrodynamic...
• QED: experimental evid...
QCD video:
• QCD: Quantum Chromodyn...
Quantum field theory:
• Quantum Field Theory
Feynman diagrams:
• Feynman diagrams
Fermilab physics 101:
www.fnal.gov/pub/science/part...
Fermilab home page:
fnal.gov - Věda a technologie
This is the clearest explanation of virtual particles I've seen.
Me too.
Science Asylum did it first, and better. The first half of this video was just misleading.
@@MathisGries-ml5qv What's the link?
Everything happens sequentially in our universe/s and beyond. Realities can be created by consciousness because of iterative repetition of events which differentiate by small amount, thereby creating an illusion of moments in time. Now, this repetitive process is divided by destruction of all that is created before the next creation process starts again. This border line of creation and destruction is the virtual particles that physicists posit where all things are smashed (actually a grind) into the smallest parts. If you measure the frequency at which this takes place you will have the frequency of creation, in a sense. If you encase yourself with a higher frequency than the creation frequency, then you can go back in time and visit the dinosaurs, and even to our future but to a limited depth. Think about this. To really understand the above, start with a magnet not quantum whatever! (Corrected misspellings)
@@ClassicalLiberalWarrior YT won't allow links anymore, just search 'Science Asylum virtual particles' or 'PBS space time virtual particles'
I love how the more advanced physics gets, the more it sounds like you're just making stuff up. :)
It sounds like that only because the average person does not have the background to really understand. As Arthur Clarke said, any sufficiently advanced technology is indistinguishable from magic.
@@michaelsommers2356 naw, it still sounds like bs.
@@DrDeuteron it might sound that way, but only because you don't have very much familiarity or experience on the topic. This same exact thing would apply if you went back in time and tried explaining what gravity is to a medieval peasant. "Mass bends spacetime, and this results in an apparent gravity effect? Sounds crazy m'lord. Time to go back to getting killed by a drunk knight m'lord."
It makes sense to me if I consider the cosmic background radiation means there is always some energy in empty space, so that energy is pulsating through the fields making virtual particles. Kind of like if the top of the ocean has waves and every once in a while they combine to make a white cap. The white cap would be the real particles since it had sufficient energy to make them, the other waves would be the virtual particles. That makes sense in my head but I have a feeling I am wrong. What I don’t understand is when he says empty space with truly no energy could make virtual particles, that just doesn’t make sense to me. Where is the energy coming from to create the waves in the quantum fields? I understand they pop up in pairs and annihilate each other, so there would be 0 energy in the end, but where do they get the energy to make the particle anti particle pair in the first place? How does the excitation in the quantum field even exist without any energy creating it? That is really confusing to me, it is basically saying you get something from nothing but don’t worry it will go away quickly. It isn’t the going away quickly part I am confused by, it is how they even exist in the first place for this to happen. I assume it has something to do with the uncertainty principle, but even after thinking about it I am so lost. Also, for the Casimir Effect, how are they sure it is virtual particles causing the plates to be pushed together? Of the virtual particles truly don’t have energy and it is all borrowed, how could the plates get the energy to be pushed together? Man, physics fascinates me but I am a chemist and it is so much more straight forward than quantum physics (at least for the chemistry I do, I know the really smart people deal with quantum physics in chemistry)
@@ElectronFieldPulse hey there, you seem a bit confused so let me clear some things up for you.
Cosmic background radiation, or more correctly "cosmic microwave background radiation", is not some sort of energy that space has. It is merely photons from (almost) the beginning of the universe.
Meaning they are real particles, in this case photons, and thus are the specific vibrations (or excitations) in the photon field that create real particles. So CMBR has nothing to do with virtual particles.
Concerning where the energy comes from, well you are right about the uncertainty principle being used to explain it. Just think of it as the particles (and thus their energy) existing for a short enough time that the universe doesn't realize some laws are being broken.
I know it's weird but tbh I don't 100% understand it myself, and that's a simplified explanation that I think works.
And finally, the pressure difference is what creates the force pulling the plates together, not the energy of the particles. You can try and imagine a similar thing but with a vacuum instead.
Say you have a sealed container that for our example is pretty weak, like a plastic bottle. Pump all the air out and create a perfect vacuum, absolutely nothing in the bottle and thus no energy inside the bottle. It would still implode because of the pressure difference.
I hope I helped a little, physics is fascinating and I think it's a shame a lot of people don't see it because of how complex it can get at times.
Have a great day!
9:29 It’s great that Dr. Don reminds us that there’s plenty of room to understand all this better. That scientific theories are our current best understanding, not absolute facts.
Yeah I've been asked if I "believe" in the big bang to which I could only say "I believe it's our current best model".
Language is slippery and it's much easier to just talk about these things as fact rather than fill your sentences with qualifiers but I think sometimes we forget not everyone realises it's implicit.
Indeed. This aspect of scientific knowledge is critical and has implications for all aspects of knowledge. It is also much misunderstood, I think, when theists argue with naturalists.
Living with uncertainty, tentative hypotheses etc. requires a certain psychology... I might say humility!
@101Mant Unfortunately, I think most people don't realise it's implicit.
There are channels that provide pretty satisfactory explanations, but yours always shines in that regard, I'm so glad I stumbled upon it, thanks for the video!
That cover of Beach Boys “Good Vibrations” at the end is brilliant. Props to whoever made that!
you mean GOOD RATIO ?
Don must have pulled some strings 😂
@@Bjowolf2 lol
@@Bjowolf2 - Ha! Ha! You're just 'string'ing us along! Ha! Ha! Ha!
🤣
@@GaryYates-pi9gy It's just a theory 😂
More of the deep dives please, great to get to field theory which does explain this tricky subject and clears the mind.
Im just a layman but this dude makes THE best explanations I have ever heard. Are these seriously free videos? These feel like they should be behind a paywall.
He works for a national lab. Part of their remit is scientific outreach. Ultimately, taxpayers are footing the bill.
@@PlanckReliconly those that reside in the USA. So for everyone else, this is free content 🙃
Finally an explanation that is understandable and not intentionally "mysterious".
I thought that was one of your best videos, especially the bit right at the end.
I can't wait for the next string of videos. Sounds like they are going to be epic. Thanks!! 🎉
I always see scientists saying in QFT that electrons are excitations in the electric field, and so with every particle that has its field. However, shouldn't these fields all be a single, complex quantum field? This was worth a video explaining, and showing, for example, why an electron could not be an excitation in a Higgs field, for example. I'm newbie to these physics questions but I love how you explain everything in a simple way!
always a fun day when fermilab uploads!
Love this channel. Great explanation.
Banger, after banger, after banger. Thanks Don, Ian, and Fermilab once again for an excellent presentation!
So many of my questions answered in just one ten minute video. I love you
Great and straight forward explanation
Thank you, Don, you are always worth watching!
This was a really great video, thank you. Appreciate all the work you do to make advanced topics accessible to curious laymen like myself.
I find it such a wonderful *relief* to learn about Quantum Field theory in this way. I very much appreciated the assertiveness, driving home the validity of this model. I know the standard joke is that the more one learns about QM the less one understands it, but here I find it actually *quite intuitive*. I am waiting with bated breath for more videos discussing these concepts further! I'm actually enchanted. Great video.
Fermilab upload! Today is a good day :)
Much love for Dr. Don and much love for physics 😁
Great video. I've always been super fascinated with this virtual particle subject.
The mustache went virtual my friends
Informative and intriguing. Can't think of a better way to explain advance modern physics. Thank you very much.
0:42 - "I mean, just look right there. Do you see particles appearing and disappearing?"
Me: "Oh, those particles? I thought we were calling them floaters. Maybe it's time I got my eyes checked."
I saw them too, but I managed to blink them away.
@@IAmAlgoleiAfter blinking, mine just quantum tunneled to another location.
Nope mine stay in vision, being nearsighted i see them more, got a bunch too that aways stay in same spots.i can ignore them mostly unless the suns close to the horizon then the lights just right for a seconds ill confuse them for insects, then be annoyed till the sun lower or higher.
doc don lays it out again so clearly and patiently with us civilian physics phans. thank you doc!
Gotta love that Guitar Pro 6 midi outro! Good vibes are yours boy!!
Thank you as always sir.
I love these videos. I quit working on cars and I’m in college studying physics because of these. Thank you.
Great explanation of virtual particles. Thanks.
Dr Don is a hero
Lovely explanation for us mere mortals ❤
Fantastic deep dive, Don. This physics student has a better understanding of what's happening at the sub-atomic level
Good vibrations indeed :-) I hope to one day really understand particles and energy. Fascinating subject.
Dr. Don is a very good science communicator. This video clearly and concisely removes the mystery around virtual particles. He even makes clear that there is of course a lot more specifics available in other videos, AND makes clear that theories are changeable to match the experimental data.
In my opinion, a good experimental physicist usually has very solid grasp of the first principles and foundations, while many theoretical physicists seem to falter, in my opinion.
"removes the mistery"
Thank you Dr Don scientist man! I enjoy all your videos!
That was incredibly helpful and clear. Thank you.
This is a good explanation of the "pair creation" phenomenon, but from what I've heard, virtual particles are also used to mediate the interactions (for example, a static electric or magnetic force doesn't use real photons, it uses virtual ones instead). It would be nice to get an explanation how it works...
Yes, the concept that the force I feel between two magnets, or when I touch something is caused by photons - that also let me see - just seems bizarre.
Thanks, truly informative. I've wondered a long time what virtual particles were. Now I know 🙂
That is a great explanation! I have a couple of followup questions, if I may:
1. why are the fields jiggling with random energy all the time?
2. how, when a virtual particle appears, is it always particle/antiparticle? what are the mechanics that conspire to maintain that neatness?
Fascinating!
What he said at the end there is so important! These are models. We don't necessarily know what is actual
Ok. It's time to catch up with several months of "farming chapters" from Fermilab =)
Cheers Dr. Don!
With all of space being full of virtual particles, how do things move through space without any drag/friction?
They probably don't? Not even the best vacum is perfect. And even if I assume a perfect vacum, there are these particles with some mass in the way. Their mass and the friction/drag they cause must be negligible, I think.
and maybe the boiling bubbling animation is just an illustration. Maybe 1 pair happens a second in 1 cubic m?
(yes, I am guessing)
Yes, but it both directions. Drag in front but a boost from behind. It's the same as the Casimir effect he talked about.
Didn't learn anything new, just was reassured that my view is in line with modern physics view. Anyways good value video!
Love your channel and this video in particular. Congrats to you and your team. One criticism: near the end, you said, ‘just a theory’. We all know what you mean, but some people might hear that and say evolution is just theory. Maybe, ‘not a highly Confirmed theory’?
Excellent video, as always. I watch it, rest my head in the pillow, close my eyes and rest in peace as your class reverberates inside my brain. And no, I do not fall asleep or else I would waste that moment of truly peace. 🙂
9:24 And that's just a theory. A Field Theory!!!!
I would love to see a video about the spin of quantum particles and the Pauli exclusion principle, I think it is fascinating but really hard to understand 🔬😇
It seems to not correspond to anything classical at all, which is why it is so strange.
@@jameshart2622 There are good visualisations of spin on YT.
@@jameshart2622 No. Example, spin as a crystal deformation: czcams.com/video/1KXpkUYvbGo/video.htmlm20s
More explanation, please ! Do the virtual particles originate at the same point? What determines their velocities? Do their velocities have equal magnitude but opposite directions? What causes them to disappear? If their masses are positive, how does Hawking radiation reduce the mass of a black hole?
Bring on the deep dives
That idea of virtual particles being like, "imperfect"/"partial" manifestations of particles - rather than complete individual particles we usually think of - makes so much sense, I think the lightbulb that appeared above my head was brighter than the sun.
'Virtual Particles' Is that like a 'Virtual Magical Sky Daddy' that many people also believe in to be really true?
Thank you, Don Lincoln, that video has got real substance.
I propose to delete all those recent Shorts about The World Quantum Day, which have zero content.
I second this proposal.
Me too
Agree. Many of the questions were not answered or need more content to do so. Not great, not even good, answers to good questions, from those who may have given a reasonable answer if not being asked to do in less than 2 minutes or in a sound bite. Poor content.
Everything happens sequentially in our universe/s and beyond. Realities can be created by consciousness because of iterative repetition of events which differentiate by small amount, thereby creating an illusion of moments in time. Now, this repetitive process is divided by destruction of all that is created before the next creation process starts again. This border line of creation and destruction is the virtual particles that physicists posit where all things are smashed (actually a grind) into the smallest parts. If you measure the frequency at which this takes place you will have the frequency of creation, in a sense. If you encase yourself with a higher frequency than the creation frequency, then you can go back in time and visit the dinosaurs, and even to our future but to a limited depth. Think about this. To really understand the above, start with a magnet not quantum whatever! (Corrected misspellings)
Notification squad!
Thanks again dear professor. Another easy class for people like me, basic Physics apprentice.
I only have a question, an eternal question: Where does Energy come from? the Energy that keeps fields and particles in constant activity.
It feels like there is a lot missing here. Is there a difference between the vacuum energy churning which produce virtual pair particles, and the virtual particles, say photons, that exist between two electrons, a la the basic Feynman diagram?
Good point.
A physicist finally said something I've always wondered about, i.e that an anti-particle is a different vibration of the particle field.
Plus something that I never even considered, i.e that virtual particles are also vibrations of the particle field.
THANK YOU... PROFESSOR DR.LINCOLN...!!!
EXCELLENT 😅
Excellent....❤ thanks 🙏.
There is a school of thought that says the casimir effect is similar to the Van der Waals force, caused by polarization of the surface atoms.
It isn't. It's caused by the boundary conditions of the vacuum. In practice the ontological difference is negligible, I suppose... atoms are "the vacuum". ;-)
This is so great.
I usually come back to this channel to get reliable info about what the real status is in astrophysics in contrast to hollywood physics like the string theory.
Speaking of the crazier corners of physics... I've heard that there's a hypothesis that all electrons (and, presumably, all of each other distinct type of lepton or quark) are the same particle traveling through spacetime. A video exploring this idea would be very interesting.
IIRC, this theory was debunked when the very first electron was smashed in a particle accelerator. If the theory were true, the entire universe would have ceased to exist (at least, as we know it) at that instant.
@@rajesh_shenoy I think "disproven" would be better than "debunked." Nobody was trying to sell you on it, so it wasn't bunk to start with. :-)
Actually, the hypothesis is that a positron is an electron traveling backward in time, and the single electron bounces back & forth in time again & again, so that it looks like many electrons exist at any particular moment. It's debunked by the imbalance of antimatter & matter, because it predicts an equal number of electrons and positrons should appear to exist, but they don't.
Everything happens sequentially in our universe/s and beyond. Realities can be created by consciousness because of iterative repetition of events which differentiate by small amount, thereby creating an illusion of moments in time. Now, this repetitive process is divided by destruction of all that is created before the next creation process starts again. This border line of creation and destruction is the virtual particles that physicists posit where all things are smashed (actually a grind) into the smallest parts. If you measure the frequency at which this takes place you will have the frequency of creation, in a sense. If you encase yourself with a higher frequency than the creation frequency, then you can go back in time and visit the dinosaurs, and even to our future but to a limited depth. Think about this. To really understand the above, start with a magnet not quantum whatever! (Corrected misspellings)
@@JerryMlinarevic LOL... who has visited the dinosaurs??
are you saying that somebody can predict an as-yet untapped archaelogical dig site?
by visiting a specific place that hasn't yet been explored to see what persistent structures got buried at that location?
I’m a scholar that’s been fascinated with muons as well as non hermitian morphological topology for a very long time now and I wish I knew about this video earlier on
🎸🎶✨🎸 Thanks a lot, Don! I have a few questions and a comment:
- Do virtual particles interact with the Higgs field, or does the way they "vibrate" make it impossible to interact with the Higgs field? If so, what about virtual particles that "normally" have no mass (photon, gluon)? Or is interaction with the Higgs field another story altogether?
- Is there, then, only ONE way for particles to vibrate that allows them to become "real" but, perhaps, a multitude of ways to vibrate that allows them to remain virtual?
- And why do you speak about the "uncertainty principle" and not the "indeterminacy principle" ? Knowing that the 1st way of naming it can be misleading. 🎸🎶✨
It is interesting that these particles give such excellent answers to physics systems in QM but terrible for space in general. Turns out that this issue can be solved.
Dr. Don, why do you need so many fields, it's sounding like a Field Zoo, why not just a single field, the spacetime field, that behaves/vibrates as needed? Great video.
So, how much mass does empty space have? (And how much zero state energy?) Also can light scatter off of virtual particles? And if we look across the universe would things look blurry and dim?
I think it still a question physics looking for the answer.
For your 1st question, our 2 best theory (General Relativity & Quantum Field Theory) gave very different answer about the amount of energy in empty space. You can look in previous Fermilab video called "The Worst Prediction in Physics".
As a matter of fact... Light _can_ scatter off virtual particles! Specifically, very high energy gamma rays (more then a GeV) can scatter off the QED vacuum by , essentially, creating an electron-positron pair, which immediately annihilate into a pair of 500MeV gamma rays. It's the Breit-Wheeler Process.
Don rocks!
Casimir effect in a nutshell. Also, the ultimate opening titles!
Consider the phase conjugation of waves in fields and how it seems to mask the presence of real particles as quantum potentials with no vector components. For example, 2 photons which conjugate perfectly in space and time are everywhere zero amplitude in E and B field, but they cant annihilate because of energy conservation, they must deposit all their energy in the region of constructive interference on the surface of particles or other boundary conditions. You can only ever see such waves under relativistic transformations or with very non-linear boundary conditions. An example of tricky hidden quantum potentials is the electron phase shift caused by the magnetic vector potential around an infinite solenoid. The casimir effect is another. The Stark shift is yet another effect attributed to virtual positrons caused by vacuum polarization around electrons in atomic nuclei.
Anapole antenna also does something weird. Anapoles are known as zero pole antenna, they emit radio waves together in pairs in order suppress the far field radiation completely and become perfect absorbers. The pairs of photons cancel the E and B fields but this creates non-zero vacuum expactation value for the
propogating quantum potentials (Phi the electric scalar potential and A the magnetic vector potential). The 2 photons are copropogating but in perfect destructive interference, so all the photon energy is deposited in the anapole antenna near field where constructive interference occurs. But this implies that quantum potentials can be used to beam power in ways that mask the power flux by phase conjugation. 4-wave mixing and 8-wave mixing are the basis for many futuristic technologies that manipulate the light-matter interaction.
Please do a video on how the different quantum fields interact
Deeply fascinating, and excellent explanations. More questions, we can say - What is a field? And, What is a vibration? (Really, what causes it, and what is a field in reality outside of our mathematics?)
Classically we have real empty space, quantum we have fields - where is the merging of these realities?
The field that strikes me is the photon field. Light is endlessly mysterious.
That's my question. "vibrations in a field" really don't say anything except what the math says. There's no underlying explanation. You're talking about the way you calculate the theory as being the thing that is out there causing that. Maybe Tegmark is right, though.
@@darrennew8211 The job of physics is to make mathematical models of the physical world, and to test those models with experiments. It is not to find out what is "really" out there. That question makes no sense, if you think about it. Trying to figure out what is "really" going on is a sure route to confusion, because such an explanation would have to be in terms of things we are already familiar with, and the quantum world is fundamentally unlike our macroscopic world.
@@michaelsommers2356 Right. That's the "shut up and calculate" school of thought. At every point in science before that, we were trying to figure out what was *really* going on. We didn't stop at the formulae for thermodynamics, or chemistry. We worked our way down to the atomic motions, then the quantum formulae.
My point is more that everyone talks about the "fields" and "vibrations" as if they're what's actually out there. Popular videos don't say "we measure a field of measurements, and when we measure something that looks like a wave in the field, we find something that behaves like an electron." They say "the electron is a vibration in the field." It's misleading, like the field is actually a thing there.
Great question! From Dr. Don: Precisely what a field is is a tricky thing to imagine. It’s a uniform and pervasive energy. Because it is uniform, it cannot do anything. It’s like an infinite plane of the same altitude. If you put a ball on that plane, it won’t move, so whether it’s there or not is irrelevant. Vibrations are local variations in the field strength, likes bumps and valleys in that uniform plane.
@@fermilab I would disagree that fields are energy, and that they are necessarily uniform.
Excellent video!
I have heard that the fundamental forces are “communicated” through virtual particles. Are these the same kind of virtual particle? Because I don’t see how something that only exists for an instant could, for example, cause one macroscopic magnet to be attracted to another. It seems to me like that would imply a constant stream of these particles being emitted by the magnet and travelling macroscopic distances, which seems implausible.
sometimes I speculate on a version of kaluza klein theory where instead of an extra compactified dimension its actually an extra scalar field with its own 1D hamiltonian metric. And that the dirac field is actually this field, which is what gives particles spin. Spin is basically a quantized motion in 1 dimension and the dirac field is a zero spin scalar field with imaginary mass. It has translational symmetry with the higgs field in the same way that real numbers and imaginary numbers have translational symmetry on a number line, and due to this it is a slower than light version of imaginary mass which does not violate causality. Basically from the perspective of an imaginary mass field our real mass field would appear to have imaginary mass and vice versa. Which implies that black holes, the universe, and even particles all have complex mass. (solving the large electron problem for kaluza klein theory and the gap problem for yang mills theory) But dirac field interactions are interesting as they behave in a soliton like manner and that not only is electromagnetism and gravity unified under this model (meaning that all electroweak symmetry interactions are just products of gravity and the topology of space) but that magnetism is basically the warping of the dirac field itself and behaves in a way that we can attribute to current virtual particle speculation. These 1D interactions are why magnetic field lines appear to expend no energy until they make contact, and why virtual particles can seemingly be emitted from a source with no loss in energy until they make contact. Because there are no virtual particles at all. This is just electromagnetism behaving in 1D where it can't spread out over an area and does not obey the inverse square law. Instead it creates these soliton like feedback loops that appear to lose no energy.
As described, there is an obvious problem with virtual particles.
If a particle spontaneously appears with an energy E, it cannot disappear with the same energy E. Those must be separate events occurring at different times and locations. Therefore, the Heisenberg uncertainty principle does not allow this to happen. Other particles with smaller energies must be involved. Then, those particles would still have additional particles to reappear and disappear. So, this process never ends, but the energy is decreasing.
So, where does the energy go?
Hi Dr. Don! Another mind bending hypothesis is that gravity is an entropic force. Would you like to make a video about that? I'd be very interested in your take.
I would love to see a video about ghost particles and gauge fixing 😉
I have a hypothesis that virtual particles' behavior is part of the explanation for gravity. I won't spell it out here, but the keywords are compressed energy, equilibrium, entropy, and how matter travels across "empty" space. It does not involve gravitons but is somewhat analogous to magnetism.
matter doesn't travel across empty space--relativity says moving wrt to space is a meaningless concept.
Even if their existence is fleeting, special relativity tells us time can appear slowed down when there is high enough relative velocity. Can we "catch" these particles before they disappear if we move fast enough?
Check out the Unruh Effect
If you try to directly detect a virtual particle with a photon of sufficiently high energy to see it, you will have added enough energy to the system to make the particle real, and it won’t be clear to you if the particle was real or you jist created it and its antiparticle, if I understand correctly.
I’ve heard the story that the Casimir effect was originally computed using van der Waals forces and only later someone pointed out that you get the same result using virtual particle hypothesis. Also afaict the virtual particles arise mostly only in the pertubative calculations from qft, which at least for me, cannot be considered a fundamental aspect of the theory (as they completely break down for strong coupling). The field itself can be measured, which means that in some sense you are measuring virtual particles. Also the fact that you can find weird things inside a proton or neutron speaks in favor of “virtual particles”, but I think in those cases we are actually colliding against on-shell particles.
Another outstanding video. Please include more math in these videos
Everybody can make the noise of virtual particles audible. The only thing it takes is an operational amplifier (OPAMP), connected to a positive/negative power supply, (e.g. two 9V-Batteries in series) connect the positive input to GND, solder a resistor of about 470kOhm to 1MOhm between the output and the negative input and place a low voltage (6.3…10VDC, 10…100µF) tantal-, or MLCC-capacitor between GND and the negative input. Connect the output and GND to the line-input of a computer. You will hear a 1/f-noise in the speaker as the result of virtual charged particles banging the capacitor's dielectric causing tiny electrical charge changes. The spectrum strictly follows the Heisenberg inequation, as shown in the video. And no, this is not kB·T·R-noise, because neither the amplitude, nor the frequency distribution changes when the capacitor is placed within liquid nitrogen or even liquid helium, because this *is* the noise of quantum vacuum fluctuactions.
Wow this indeed makes a lot of sense! We get the normal particles from specific vibrations on each separate field, but we also get all the other vibrations too... And we call these virtual particles; If that is what this video is suggesting, then it makes a lot of sense to me...
Now, would that make the particle real? Or each specific field real?
Sadly - no. What is real is a philosophical question. Not just a physics question. (Philosophy includes all Human intelect to ponder about reality, not just physics). Meaning that this question: "what is real" is a question that physics doesn't address, doesn't care and doesn't lose time pondering about;
So by definition we can't use physics alone to debate about what is real and subsequently - if a particle is real... Or if a chair is real for that matter...
Word salad.
If you are one of those solipsists who claim we can’t know if anything is real I have a foolproof method to find out. Step in front of a bus and then you can verify if solid things like a chair or a bus are real.
@@pansepot1490 Can you define what is real?
Im not a solipsist or do I abide by any philosophical dogma or whatever... I just know enough to know that I don't know enough.
So go ahead, define what is real to me. And try not to use "real" or its derivatives inside the very definition of what is real.
The real question, I think, is "are particles real?". The more I learn about QFT, the more convinced I become that particles are just an emergent phenomenon at macroscopic scales. Virtual particles aren't any less real than particles on the mass shell, but that doesn't actually make them real.
Yeah, according to QFT, the fields are more fundamental than particles. So in that sense, “real” and “virtual” particles are really just the fields vibrating in different ways. But, we don’t know a deeper theory at this point in time, and it’s very possible (and likely) that the fields themselves are emergent phenomena from something we haven’t discovered yet.
Everything is “real” which has measurable effect. So yes they are real.
But it might be “real” in a different way than what we might think.
As far as we know, virtual particles are just a figment that appears in the math of QFT due to the perturbative approach.
Emergent does not mean nonexistant. Possibly even space is emergent.
Particles are real in that they have conserved properties such as 'quarkness' or 'electronness' (baryon and lepton number), spin, charge, mass etc, and they cannot just 'disappear' into the vacuum. These strongly conserved properties ensure that the real particles hang around for a very long time unless they interact in a certain way, and that their properties are conserved if they become other particles.
the important thing about virtual particles is that, while, yes, mathematically they are "particles", that doesn't mean much for physical reality. for instance, they can't be measured individually, they can't be separated by any means, and they can't exist for very long. so yes, they "exist" in some sense, but not really in others. they are at the boundary of language.
The most mind boggling thing is the quantum entanglement. Not the idea of it, but the proof of it. The thing about particles appearing for a moment is due to our shortcomings. There could be many things happening that we can't yet conceive let alone measure and prove. And we can't measure anything moving faster than the speed of light. Which brings me back to the quantum entanglement.
What do we know about the energies and masses of virtual particles ? Those with mass must interact gravitationally (obviously very weakly, but there are a lot of them) with other particles. If only measurements are real, what have we measured about virtual particles ?
i NEED that video on how quantum fields interact
Don Lincoln, you noted at 4:04 in your Fermilab video [1] on virtual particles that _“… even with virtual particles, some of the usual rules apply. In this case, matter and antimatter particles appear in pairs.”_ My apologies for violating the usual CZcams physics etiquette of never asking serious questions. My three questions are so simple that I hoped you might make an exception for a poor, bewildered computer scientist.
Producing a pair of virtual particles requires them, however briefly, to have equal and opposite momentums to achieve separation. That, in turn, requires them to originate at a point in space where their total momentum is zero.
*Question #1:* In what inertial frame is the virtual-pair origin point motionless?
*Question #2:* Since special relativity requires empty space to be identical from in frame of motion, won’t every moving observer, regardless of speed, see pairs of virtual particles that are motionless in their frame and thus moving relative to any other frame?
*Question #3:* Since observers moving at close to lightspeed must observe virtual pairs similarly moving at close to lightspeed from any other viewpoint, how do you keep the indefinitely increasing relativistic energy of these fast-moving virtual particle pairs from forming an infinitely energetic gas that instantly incinerates the universe (Fig. 1)?
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*References*
[1] D. Lincoln, What are virtual particles? Fermilab (CZcams) *2024,* 0417 (2024). czcams.com/video/ayQhNLqbTFk/video.html
Not a physicist, but I can say that the pairs *don't* appear to behave the same from two reference points. In fact, one peculiar aspect of hawking radiation, which is what happens when examining these fluctuations at the event horizon of a black hole, is that if you accelerate towards and/or freefall into the event horizon it appears to radiate less (or not at all). If you accelerate away, it appears to radiate more.
So in one frame there are real particles - as one half of the pair tumbles into the event horizon, now making the other "real" with no virtual partner - that appear to be virtual particles in another frame.
Why are these uploads times so perfectly on what I’m asking myself? Idk but thanks anyway. Maybe my brain sends waves to make the action field fluctuate which makes you guys upload exactly what I think about, or something like that 😅
Do you have videos on gauge theory gravity? I can't seem to find any and I think that would be a good topic. Geometric Algebra I think is the tool we need to solve quantum gravity
Nice video.
Dr. Lincoln, great video, how is the qft photon field different from the theoretical "aether" field that was theorized in the late 1800s that was tested by the Michelson Morley experiment?
They have nothing to do with each other. The ether was hypothesized to be the medium through which light waves traveled.
There is a relationship to the aether idea. See the introductory paragraphs of the Wikipedia article on Zero Point Energy.
@@brothermine2292 Did you read the last sentence of that paragraph?
>michaelsommers2356 : Yes I did, and hopefully the OP will too. The last few sentences of that paragraph seem like a good place to start diving deeper.
I do see particles popping in and out of existence, but it's more a problem with my eyes than actual particles.
I think another problem with understanding virtual particles is that the term is used for two things, both the subject of this video and particles that really don't exist but are useful to pretend exist in order to simplify mathematical models, like electron holes or particles exchanging forces can be (but not necessarily are) in Feynman diagrams.
I was so prepared to dismiss the Heisenberg explanation and than you did it anyway! Good video. It may be a philosophical "beauty" argument, but I can't really accept 17 or so fields to be the "basic". But i leaves the question, how could one determine if muon are their own field or say (due to symmetry) muons are a in fact higher state or just different vibration of the electron field? BTW: there is IMO a simpler effect than casimir for virtual particles: the dielectric constant of vacuum (or whatever it is called nowadays) without virtual particles it should be zero.. and it in reality it is not.
How do the QED field(s) relate to the classical electromagnetic field ?
QFT is so cool, imo. Particles being concentrated perturbations in an expansive field just clicks.
Interesting explanation. Virtual particles as normally talked about are very confusing to the lay person, because when asked, many physicists say they are real (but don't get into what Don said) while just as many say they're not real, they just help the math work. Thanks, Don! So then my question is, if non-standard vibrations make virtual electrons, are two virtual electrons the same? Or is one pair compatible to annihilate, while a different pair is not the same as those but are compatible with each other? It's reasonable that the one vibration that is responsible for both members of a pair would make a compatible pair.
First paragraph, because physicists don't really know, combined with the philosphical question if something is useful and in all matters and effects real, is it "real"? Second.. interesting question. AFAIK from Feynman diagrams .. yes they are all the same, with the same basic properties, but thinking about it as QF flucations I do see why they might not.
almost figured it out I need a couple more Up Quart's