What are virtual particles?

[@ColinJonesPonder]

This is the clearest explanation of virtual particles I've seen.

[@ClassicalLiberalWarrior]

Me too.

[@MathisGries]

Science Asylum did it first, and better. The first half of this video was just misleading.

[@ClassicalLiberalWarrior]

@@MathisGries What's the link?

[@JerryMlinarevic]

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)

[@tribute2aname450]

@@ClassicalLiberalWarrior YT won't allow links anymore, just search 'Science Asylum virtual particles' or 'PBS space time virtual particles'

[@wbgookin]

I love how the more advanced physics gets, the more it sounds like you're just making stuff up. :)

[@michaelsommers2356]

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.

[@DrDeuteron]

@@michaelsommers2356 naw, it still sounds like bs.

[@Philitron128]

​@@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."

[@ElectronFieldPulse]

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)

[@amit2smadar]

​@@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!

[@Schulstand]

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!

[@DCDevTanelorn]

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.

[@101Mant]

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.

[@martifingers]

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!

[@caseyshearer9519]

​@101Mant Unfortunately, I think most people don't realise it's implicit.

[@PaulBrassington_flutter_expert]

More of the deep dives please, great to get to field theory which does explain this tricky subject and clears the mind.

[@okiesam]

Finally an explanation that is understandable and not intentionally "mysterious".

[@kiefnebula3464]

I can't wait for the next string of videos. Sounds like they are going to be epic. Thanks!! 🎉

[@Turnoutburndown]

That cover of Beach Boys “Good Vibrations” at the end is brilliant. Props to whoever made that!

[@benjaminfrank9294]

you mean GOOD RATIO ?

[@Bjowolf2]

Don must have pulled some strings 😂

[@moegreen3870]

@@Bjowolf2 lol

[@GaryYates-pi9gy]

@@Bjowolf2 - Ha! Ha! You're just 'string'ing us along! Ha! Ha! Ha! 🤣

[@Bjowolf2]

@@GaryYates-pi9gy It's just a theory 😂

[@jackielinde7568]

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."

[@IAmAlgolei]

I saw them too, but I managed to blink them away.

[@jaybingham3711]

​@@IAmAlgoleiAfter blinking, mine just quantum tunneled to another location.

[@orionx79]

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.

[@TedToal_TedToal]

I thought that was one of your best videos, especially the bit right at the end.

[@richard84738]

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.

[@PlanckRelic]

He works for a national lab. Part of their remit is scientific outreach. Ultimately, taxpayers are footing the bill.

[@inverse_of_zero]

​@@PlanckReliconly those that reside in the USA. So for everyone else, this is free content 🙃

[@jeffhaugaard6740]

I have been watching these for years and appreciate all the work you put into them. I also appreciate that fermilab sees what you do as part of its mission. I struggle to understand most of your videos, but this I understand. Horray.

[@scotthammond3230]

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?

[@toastyburger]

Good point.

[@DarkBraveStuff]

always a fun day when fermilab uploads!

[@luiscaldera1295]

The mustache went virtual my friends

[@jamesedward9306]

Love this channel. Great explanation.

[@vick229]

Great and straight forward explanation

[@davidetomsu]

Appreciate this more than can be said. Thank you. Please make a video on how the different fields are known to interact with one another.

[@GeoffryGifari]

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?

[@Deutschebahn]

Check out the Unruh Effect

[@enterprisesoftwarearchitect]

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.

[@rc5989]

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.

[@jareknowak8712]

"removes the mistery"

[@Bakasan16]

What's the difference between the Casimir effect and Van der Waals force

[@bytefu]

The latter is simply electrostatic attraction.

[@Bakasan16]

@@bytefu Yeah but how could you tell them apart experimentally? They both come from putting 2 electrically neutral surfaces near each other.

[@aether_]

So many of my questions answered in just one ten minute video. I love you

[@Breakfast_of_Champions]

I still miss the mustache😋

[@Ri-ver]

It's still there, it's just a virtual mustache

[@canis2020]

He's been replaced by an AI. Welcome to the future.

[@MrElvis1971]

It annihilated with his anti- moustache

[@VarroTigurius-u1f]

Mustacheless Dr Don does not exist.

[@danieloberhofer9035]

Funny, I was just thinking the same thing. Then I got really distracted by that outro music. Horrible tune.

[@meesalikeu]

doc don lays it out again so clearly and patiently with us civilian physics phans. thank you doc!

[@JonBrase]

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.

[@i_booba]

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.

[@juzoli]

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.

[@zray2937]

As far as we know, virtual particles are just a figment that appears in the math of QFT due to the perturbative approach.

[@arctic_haze]

Emergent does not mean nonexistant. Possibly even space is emergent.

[@tonywells6990]

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.

[@luudest]

8:29 What is a virtual photon with mass? Do virtual particles only appear to us through the vibrations of the fields? Or do they also show up in particle collisions?

[@DrDeuteron]

imagine electron + position -> virtual photon -> q+qbar... something that happened at SLAC's collider regularly. The two 45 GeV beams collide with opposite momentum, so the virtual photon [note: there is no borrowing energy, like Don said, that is old, like pre 1948 old] has zero momentum and an energy of 92 GeV..so like a niobium nucleus. Kind of a heavy photon, aka "highly virtual". At this mass, it's much more likely that the virtual particle is near real, so a Z0 (mass=91.2 GeV) ...which is my SLAC had that beam energy in the first place. Now in positronium binding, around 1/2 a Rydberg...(or is it two?), Z0's are much less probable...but there are atomic physicists who can see them in atoms.

[@luudest]

@@DrDeuteron ?

[@DrDeuteron]

@@luudest do the kinematics yourself: E1 + E2 = E3 + E4 p1 + p2 = p3 + p4 if's it's ee->ee at 180 degrees: E1 = E2 = E3 =E4 = E p1 = -p2 = -p3 = p4 = p then the virtual photon energy & momentum are E1 + E2 & p1 + p2 2E & 0 In an exchanged photon that's: E3 - E1 & p3 - p1 is 0 & 2E

[@Blackacreonfire]

With all of space being full of virtual particles, how do things move through space without any drag/friction?

[@istvansipos9940]

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)

[@adama7752]

Yes, but it both directions. Drag in front but a boost from behind. It's the same as the Casimir effect he talked about.

[@YatrikShahisAwesome]

This was a really great video, thank you. Appreciate all the work you do to make advanced topics accessible to curious laymen like myself.

[@praveenb9048]

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.

[@lepidoptera9337]

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". ;-)

[@KrudlerTheHorse]

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.

[@PawelS_77]

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...

[@neilhubbard6461]

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.

[@DrFrank-xj9bc]

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.

[@0neIntangible]

I second this proposal.

[@Jetstream__]

Me too

[@jballenger9240]

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.

[@JerryMlinarevic]

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)

[@dunnokki]

Banger, after banger, after banger. Thanks Don, Ian, and Fermilab once again for an excellent presentation!

[@JustaReadingguy]

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?

[@haikalmiftah2529]

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".

[@juliavixen176]

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.

[@x19man1]

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 ?

[@LynxUrbain]

🎸🎶✨🎸 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. 🎸🎶✨

[@WestOfEarth]

Fantastic deep dive, Don. This physics student has a better understanding of what's happening at the sub-atomic level

[@kylebowles9820]

Notification squad!

[@paulneeds]

Why do atoms represent as circles or spheres under electron microscopes? Are we ‘seeing’ the entire ‘orbit’ of electrons as a solid structure? Why is this not transparent?

[@kimpettersson6605]

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 🔬😇

[@jameshart2622]

It seems to not correspond to anything classical at all, which is why it is so strange.

[@frun]

@@jameshart2622 There are good visualisations of spin on YT.

[@frun]

@@jameshart2622 No. Example, spin as a crystal deformation: kzbin.info/www/bejne/Z3y7oZ6LjtuVfdEm20s

[@lettuceman306]

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.

[@charlesbrightman4237]

'Virtual Particles' Is that like a 'Virtual Magical Sky Daddy' that many people also believe in to be really true?

[@bigsarge2085]

Fascinating!

[@Dhoulmegus]

1:45 how are we sure their attraction is not from gravity and are from virtual particles creating a sorta 'quantum pressure' effect on the plates? I'll go watch your other video on this topic to see if the answer lies there. Edit: I also recall someone claiming this experiment was proof of dark matter.

[@JimmyCerra]

9:24 And that's just a theory. A Field Theory!!!!

[@ahmedrafea8542]

Informative and intriguing. Can't think of a better way to explain advance modern physics. Thank you very much.

[@agharohailmehmood4224]

EXCELLENT 😅

[@Rationalific]

I'm not really a slouch when it comes to learning about virtual particles for fun through online videos. However, in this video, I definitely learned a number of new things, such a each particle having a field (I would have thought that electrons, muons, and tau particles would have been different vibrations of the same field). I also had no idea that virtual photons had mass. And I learned other things as well. Your video was straight to the point and fascinating!

[@Markoul11]

Finally done justice to the virtual particles and that they really exist. I was sick and tired reading opinions of experts that are insisting that VPs were only mathematical non physical constructs to describe the model. Fermilab Muon g-2 5σ second run 2023 results validated the existence of virtual particles. VPs confirmation should really make anyone excited again since it indicates new physics.

[@markfernee3842]

No it doesn't. As I mentioned in a comment, virtual particles are placeholders for forces. Forces are empirical. Virtual particles are used in calculations of such forces. The Casimir effect is a force. The muon corrections are associated with the random forces associated with the Heisenberg uncertainty principle. Forces are empirical. Virtual particle exchange is just a way to describe such forces in terms of quantum field operators.

[@cedricpod]

❤❤❤❤❤❤❤❤❤❤ I am so tired of being told you exist

[@DavidBenney-rr2wk]

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?

[@michaelsommers2356]

They have nothing to do with each other. The ether was hypothesized to be the medium through which light waves traveled.

[@brothermine2292]

There is a relationship to the aether idea. See the introductory paragraphs of the Wikipedia article on Zero Point Energy.

[@michaelsommers2356]

@@brothermine2292 Did you read the last sentence of that paragraph?

[@brothermine2292]

>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.

[@nguttam1982]

8:48 If a wrong vibration of a field creates a virtual particle, then the should infinite types of each virtual particle, for example each wrong type if vibration in electron field should result in a different virtual election taking the count to infinity.

[@lepidoptera9337]

These fields don't vibrate. You simply don't understand physics sufficiently, yet. The "vibrations" are caused entirely by the boundary conditions.

[@kkgt6591]

What if we start capturing those particles before they dissappear?? And since the pair of particles cancel each other, why we don't observe radiation?

[@TheKrimzonGuard]

Should the Heisenberg equation at 5:25 say "≤" a very small number? "≥" suggest that both ∆E and ∆t can be arbitrarily large, which doesn't match the subsequent explanation? An inequality defines a region of the graph plane, not a single line; should the upper right or lower left of the graph be shaded? If it's "≥", isn't any point to the upper right of the line permitted?

[@thedeemon]

exactly, that particular inequality isn't really explaining anything.

[@markdelag]

Thank you, Don, you are always worth watching!

[@TerryBollinger]

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 KZbin 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)? ---------- *References* [1] D. Lincoln, What are virtual particles? Fermilab (KZbin) *2024,* 0417 (2024). kzbin.info/www/bejne/l6q0mYGCpseHfM0

[@etaaramin9361]

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.

[@Sumaleth]

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?

[@waclawkoscielniak9291]

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?

[@LgbtqiapnDudu]

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!

[@tellesu]

They don't know

[@LgbtqiapnDudu]

@@tellesu Oh!

[@kadourimdou43]

Where do they come go from? What does it mean for a point in space to have the fields value at zero. Does it mean even though it’s zero there’s still “something” there, from which a particle pair to come from?

[@michaelsommers2356]

Zero is not the same as nothing. It's just a value. The electric field, for instance, is measured in volts per meter. At some point at some time it may have a value of zero. The field is still there.

[@antoniovega1544]

Fermilab upload! Today is a good day :) Much love for Dr. Don and much love for physics 😁

[@esalehtismaki]

Good vibrations indeed :-) I hope to one day really understand particles and energy. Fascinating subject.

[@debrainwasher]

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.

[@somedude4805]

I love these videos. I quit working on cars and I’m in college studying physics because of these. Thank you.

[@DD-ze7qm]

Is there only one unifying field with different types of vibrations accounting for the many types of particles and interactions? To extend the metaphor- the guitar string induces different and varied notes in the air that are travel differently at different pressures and temperatures in the air in a room through the breeze from a window from a storm brewing outside to a tornado down the street to a hurricane seen from above to a thin skin of air enveloping out planet. The effects of the elastic medium of air, from cavitation bubble to supersonic heating, from music to thunder are related by medium. Is there a common medium at quantum scales that relates all things?

[@theultimatereductionist7592]

5:50 Could somebody PLEASE answer my question: EVERY time I see or hear applications of HUP (Heisenberg's Uncertainty Principle) INCLUDING this video, it seems to ME that the lecturer conflates the UNCERTAINTY in a value with the VALUE ITSELF. So, why couldn't a particle whose energy we know lies somewhere between SUPER BIG value minus delta-E and SUPER BIG value plus delta-E for a VERY LONG TIME whose value we know to be SUPER BIG value minus delta-t and SUPER BIG value plus delta-t pop into existence, as long as delta-E*delta-t > small number>0, and not violate HUP?

[@JoelFeila]

question, how do we know the kasamir effect is not just the plates own gravitational pulls?

[@fixminer9797]

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.

[@piercebros]

Dr Don is a hero

[@DH-bf9xb]

Great video. I've always been super fascinated with this virtual particle subject.

[@chrisarmstrong8198]

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?

[@ZetaFuzzMachine]

Gotta love that Guitar Pro 6 midi outro! Good vibes are yours boy!!

[@johnbaker9120]

Dr. Don, you are a national treasure

[@samikatto2851]

when talking about experimental proof, what is important to know is, what was directly measured, and what was used to make the measurement.

[@cabanford]

Lovely explanation for us mere mortals ❤

[@taylorwestmore4664]

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.

[@constpegasus]

Thank you as always sir.

[@betaneptune]

Can you tell us more about just what a field is? I take it that it's basically a number assigned to each point in space, and a vibration is those numbers oscillating in certain spots, which gives a particle. Is that right? And then the vector fields, perhaps for particles with finite spin?

[@xaviermartinezalvarez6332]

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.

[@drdca8263]

1:34 : no doubt? Really? I’ve heard that the Casimir effect can be given an alternative explanation in which the virtual particles aren’t interpreted as physically real?

[@maxp3141]

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.

[@ManyHeavens42]

Still looking for the how to be free principle,and live forever principle, search So Three universes share the same gravity .I never heard nobody say that

[@BlueArcStreaming]

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.

[@darrennew8211]

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.

[@michaelsommers2356]

@@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.

[@darrennew8211]

@@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.

[@fermilab]

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.

[@michaelsommers2356]

@@fermilab I would disagree that fields are energy, and that they are necessarily uniform.

[@kenjinks5465]

So, let me get this straight, the fields can vibrate however, if they don't vibrate in a specific way the particle is virtual, otherwise if it does vibrate in a specific way it becomes real. So is each universe in the multiverse a radio, and this universe is tuned into these particles that we experience? If so, would there be any way to selectively listen in on other radio bands, and study the other universes?

[@joshuadiliberto1103]

Can a pair virtual particles get separated? If so, what would cause that? What is vibrating the fields?

[@thedeemon]

Strong electric field is expected to produce particles this way, for example. en.wikipedia.org/wiki/Schwinger_effect

[@fermilab]

Great question! From Dr. Don: Yes, this is how Hawking radiation is explained (I explain Hawking radiation briefly in this video: kzbin.info/www/bejne/rpC7oaamo8x1jqs). However, it requires external energy/input to do so.

[@ajisaka3108]

Hi Don, i just ordinary person who doesn't actively study physics, yet very interested in content about fundamental nature like this. Some clarification needed: 1. Is virtual particle excitation of QF below rest mass of the corresponding particles? 2. Can QF excitation of virtual particle take any continuous value? Hence QF is not quantum? 3. If not the elementary particle, what virtual particle manifest? Like what is Hawking radiation actually?

[@thedeemon]

1. Can be below, can be above. Like, many virtual W and Z bosons have mass below rest mass of those real bosons, while virtual photons may have positive mass while rest mass of a real photon is zero. 2. Yes, position, momentum, energy and maybe some other parameters of virtual particles take all possible values from a continuous spectrum. Same with real free particles. Both are quantized in the number of particles, not in their frequencies/amplitudes. 3. Real particles are the ones we observe, virtual are the "intermediate" ones we employ when computing how a quantum state evolves, they are not observable/detectable directly by definition. Hawking radiation consists of real particles. Formation of a black hole changes geometry of spacetime such that the state that was previously vacuum, is not a true vacuum state in the new geometry, hence it contains some particles (see "Bogoliubov transformation").

[@Jamex07]

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.

[@larrywebber2971]

Great explanation of virtual particles. Thanks.

[@kidamkolkoznam]

When e- and e+ pop up, and then they annihilate each other, doesn't that make a photon? So we have nothing, then e+ and e-, and then we have a photon? So we had nothing and now we have a photon?

[@glynnec2008]

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.

[@bumpedhishead636]

What makes the specific frequency of the field vibration that results in a real particle special? Are these "special" frequencies related or correlated to anything else in quantum physics? Are the "special" field frequencies of real particles related or correlated to each other? (eg is the field freq of a real electron related in some way to the field freq of a real muon?)

[@thedeemon]

Frequencies in time and space directly correspond to energy and momentum. For "good" particles they relate as energy and momentum must relate in relativity: E^2 = (mc^2)^2 + (pc)^2. Such "good" particles are called being "on shell" and probabilities for them get high values (see "Propagator"). Meanwhile waves where frequencies don't correspond this way, are called "off shell", and get probability amplitudes close to zero. Most virtual particles are like that. See wikipedia pages: On_shell_and_off_shell , Propagator , Klein-Gordon_equation .

[@ManyHeavens42]

almost figured it out I need a couple more Up Quart's

[@LaboriousCretin]

Could a virtual particle be formed at the center of a black hole? Time dilation, keeping it alive longer. Also, how close is the vanderwall effect to the Casimir effect?

[@YellowPenetrator]

Could these be behind dark energy? Over long distances, millions of particles must "squished between" two places, and pop out again. Would that increase long distances?

[@michaelsommers2356]

No.

[@MrZooBreak]

It would be beneficial to me to understand how these virtual particles make up magnetic flux. I have heard that between the poles of a magnet, the magnetic field is carried (or consists of) virtual particles. Can you specifically explain this? And what happens, for instance, as the poles of a magnet are brought together and then farther apart? Thanks.

[@rajesh_shenoy]

Doesn't the fact that space itself is quantized work against the idea of a "field" (which I think assumes space is uniform)?

[@michaelsommers2356]

The quantization is not known to be a fact.

[@rajesh_shenoy]

@@michaelsommers2356 Isn't planck's length a unit of quantized space?

[@thedeemon]

@@rajesh_shenoy no, not in QFT. Space is continuous there. Once we add gravity, we think a particle shouldn't have wavelength less than Planck length, otherwise its energy is high enough to turn it into a black hole, but the position of a particle can take any value, Planck length doesn't affect possible positions, only sizes of objects.

[@Mr.Not_Sure]

Didn't learn anything new, just was reassured that my view is in line with modern physics view. Anyways good value video!

[@joyl7842]

2:00 couldn't this be interpreted as quantum-gravity?

[@michaelsommers2356]

Np.

[@vladnurk4710]

This was described to as Foam Does the density of virtual particles vary between space voids and concentrations of matter like galaxy clusters Is this a possible clue for dark energy and or dark matter?

[@WildBillCox13]

How does this all affect the energy budget of the universe? Do microtime quantum field fluctuations randomize any of the energy involved? Is the universe steadily losing potential energy at the quantum level due to these interactions?

[@lucofparis4819]

Hmm 🤔 Could virtual particles be said to be unstable version of real particles then? Also, what about the 'severed pair' explanation for hawking radiation? Does it make sense? Could it be the case? If so, how 'real' is that lonely virtual particle suddenly separated from its counterpart over the event horizon of a black hole?

[@jeffreymartin8448]

What causes the quantum fields to vibrate when creating either a virtual or real particle?