What does the Muon g-2 experiment tell us?

The Muon g-2 experiment announced one of the most tantalizing physics measurements in over a decade. It is possible that the measurement tells us that our theoretical calculation is missing some new physical phenomena. It is also possible that a new theoretical prediction points to the possibility that measurement and prediction basically agree. In this exciting video, Fermilab’s Dr. Don Lincoln gives you an insider’s perspective.
Playlist describing the Fermilab Muon g-2 experiment
• Muon g-2
Videos about Quantum Electrodynamics
Quantum Field Theory
• Quantum Field Theory
Feynman Diagrams
• Feynman diagrams
Theoretical Physics: Insider’s Tricks
• Theoretical physics: i...
Quantum electrodynamics: Theory
• Quantum electrodynamic...
QED: experimental evidence
• QED: experimental evid...
The physics of g-2
• The physics of g-2
Nature papers on lattice QCD
Leading hadronic contribution to the muon magnetic moment from lattice QCD
www.nature.com/articles/s4158... (subscription required)
Is the standard model broken? Physicists cheer major muon result
www.nature.com/articles/d4158... (commentary, no subscription required)
Fermilab experimental paper on the muon magnetic moment
Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm
journals.aps.org/prl/abstract... (technical paper)
Muon’s Escalating Challenge to the Standard Model
physics.aps.org/articles/v14/54 (popular science article)
Fermilab press release:
news.fnal.gov/2021/04/first-r...
Fermilab physics 101:
www.fnal.gov/pub/science/part...
Fermilab home page:
fnal.gov

[@oreokid101v2]

You've been explaining the recent happenings in the world of physics to me since I was a 12 year old boy. I'm now a 23 year old man with a bachelor's in physics and I feel even further from my dreams of contributing to experimental or theoretical physics in any significant capacity. I'll see you in a few years, hopefully with a PhD. :)

[@oreokid101v2]

@@jeffallen3382 Yeah, I'm not very active in the comments section 😅

[@valentinmalinov8424]

If is too difficult to make a contribution to experimental physics, why you do not try theoretical physics? The fact is that in the last 100 years there is no significant advance in the understanding of the fundamental elements as - What Energy is; What Electromagnetism is; What Time is; What Space is...Anyway, they are looking for a new physics, which can unify QM and TOR. Why you have not read my book - "Theory of Everything in Physics and The Universe"? It is possible that there you can find an idea for your great theoretical discovery, which will make you a great scientist. You will never succeed if you never try!

[@kumar-qb2pe]

@@valentinmalinov8424 yeah I'm also fascinated to think about these fundamentals from childhood and now I'm working in that way

[@jansenart0]

Learn controls engineering. There's no money in physics.

[@valentinmalinov8424]

@@kumar-qb2pe Very good! Keep going questioning the proposed scenarios with facts and logic and one day inevitably you will succeed to produce something unique and valuable. I will suggest you tackle this problem - What is this force, which is bending Einstein's space? Where is its origin and where it is going after bending Space?

[@_vicary]

Finally, Don has spoken.

[@SlowToe]

After all the hype I was waiting for Don's take on it. I'm not disappointed. Clearly explained with a pinch of charm.

[@user-ex1fq6oz4p]

He is the best!

[@hajorm.a3474]

Charismaaa

[@franksavage1499]

Yeah, I really can't understand why there is not millions of subscribers to this channel, this is so good, fun and easy to understand content :)

[@drdon5205]

@@franksavage1499 Tell all your friends to subscribe!

[@franksavage1499]

@@drdon5205 I will, I have shared a few videos and know that some of my friends have watched them :)

[@tommylakindasorta3068]

This is masterful science communication. I don't know who at the Fermilab office asked you to do the KZbin channel, Dr. Don, but you have truly found your calling. You and everyone behind the scenes who's involved.

[@beeheart6529]

I agree! I’ve tried for years to learn about subatomic particles with no success until I found this teacher!

[@fikretonderbudakin2643]

Earth's gravitational waves contribute positively to the spin and kinetic energy of fermions. For this reason, since the muon is heavier than the electron, the muon has more magnetic power than the electron. Different laboratories around the world produce different results due to the different 'gravitational acceleration'. If the experiment were carried out in space, it would probably give the same result as the theory.

[@davio14]

The thing I love about Don's videos is how he stresses that in science, finding new questions can be as exciting as finding answers. A result which tells us "we don't know, we need to do more research" is actually a great result.

[@theeniwetoksymphonyorchest7580]

In some ways science is about finding better questions.

[@MitzvosGolem1]

Former BNL employee worked on that magnet on Long island NY . Proud 🤗

[@AnotherGlenn]

This channel is a gem. I have been repeatedly impressed by the content. It seems as though it would be digestible by a wide audience, despite the complexity of the subject matter. This video was particularly well made.

[@AmbivalentMind]

I could listen to him lecturing for hours. ☺️

[@fantasia55]

and I do!

[@sudeeptaghosh]

until my small brain overload..😥

[@chriszachtian]

Thanks Dr. Don, this was great - and long expected!

[@stephenaustin3026]

I'd been looking forward to this! Back in April, I watched the live seminar when the results were first announced. It was incredibly well put together, and was the most compelling and informative scientific presentation I'd ever seen. Truly an outstanding model for scientific communication that should be studied by others.

[@plexiglasscorn]

This is the video I have been waiting for, best PR from Fermilab

[@RME76048]

Excellent presentation, Dr. Don. Lots more info than you usually provide which is appreciated, but as always, presented in ways that allow most anybody with an interest in physics to follow along.

[@KonekoEalain]

Thank you for a digestible explanation of cutting edge science, love your videos Dr. Don!

[@TerranIV]

Wow, thank you so much for such an in-depth quality explanation of the g-2 results!!! This is very exciting. Can't wait to find out what the different groups find over the next year or two!

[@turkfiles]

Dr. Lincoln is such a great teacher. His delivery is always enjoyable and very informative. The G-2 uncertainty has been cycling through my mind since first becoming aware of it.

[@joshuaadamstithakayoutubel2490]

Thank you for explaining this

[@guilleteru]

Beautifully explained. You can sense his love for physics each team he explains something as fascinating as this. Thanks for explaining so well that even someone like me can understand

[@lk9650]

Finally, a video we've all been waiting for.

[@AnexoRialto]

Best explanation I've heard/watched on the Muon g-2 experiment. As usual, Dr. Limon knows how to cut to the chase.

[@paulmace7910]

It is amazing that there are human scientists that have the intelligence to understand stuff like this. Research like this is important, not because it has any immediate practical application, but because it furthers our understanding of our universe. Great work Femilab.

[@visavou]

Thank you for making this video. Great explanation!

[@EspritBerlin]

Thanks for the video! A very exciting experiment!

[@SuperStingray]

Professor Frink: "g is exactly 2!" Audience: *gasps* Frink: "Very sorry that it had to come to that."

[@abelgerli]

Thank you so much. For a clear explanation of the facts so far.

[@georgH]

Excellent video, it's nice to have the long format again :)

[@ericeaton2386]

This was great, easily the best explanation I've heard. And I didn't know about the lattice computations! That's really important to the story, it should be reported with this topic more widely.

[@troeteimarsch]

Thank you all at Fermilab for the great work you do for us all. I desperately hope that option 2 is the case, I really don't want to give up the sci-fi fantasies that come with it :)

[@gardenlizard1586]

Congrats to Fermi Lab on achievement

[@NalitaQubit]

Thank you for teaching us complex concepts in such a down to earth way.

[@beeheart6529]

You are such a good teacher! I am so happy to find it’s possible for me to understand what scientists say about subatomic particles, at least partially.

[@GlennElert]

Your best post ever Dr. Lincoln.

[@portuguesepossum3165]

I’m so grateful for these videos. Thank you for the work you put in for us that are of the Dummy Tribe.

[@TA-ve7ze]

What an excellent video. Thank you Dr Don

[@aportorak8575]

This is my favorite series. Love it so much

[@tj71520]

I am a big fan of the videos presented on this channel. Very cool stuff.

[@tyler1107]

I love that being wrong is the best and most exciting thing for a physicist

[@stephencorben7875]

Great to see you back Don

[@oscarmendez590]

Thanks for covering this topic.

[@redcirclesilverx4586]

Amazing, just learned about your channel from pbs space time. Excited to deep dive!

[@leshommesdupilly]

Wow, this level of precision is mind boggling !! This is remarkably amazing !! Ok, lets go back to ignore friction...

[@mattcontact1]

You're so fascinating. I don't always understand what you're saying but I'm fascinated all the same.

[@sukkrivaavijayan4493]

Incredibly clear, you have a gift

[@casandramedina6108]

Thank you very mich dr. Lincoln

[@tresajessygeorge210]

THANK YOU PROFESSOR LINCOLN...!!!

[@simian_essence]

Loved this deep dive! What better place to get this dive than right from the Fermilab's (horse's) mouth. I've got my fingers crossed for new physics!!

[@liamcjbeistle3274]

In all, I would assume Feynman would be pleased if not jealous lol. I am thankful in your approach and inspiring a new generation of brilliance.

[@Ambienfinity]

I joined the online seminar a few weeks ago -- even at 2am here in Britain, the excitement of breaking new ground was thrilling.

[@lorenzobarbano8022]

I've been waiting for this video for a few years😍

[@PMA65537]

I waited so long all my muons decayed.

[@lorenzobarbano8022]

@@PMA65537 How fast were they going???

[@PMA65537]

@@lorenzobarbano8022 You should have seen the Lorenzo transform!

[@darimshamsi2329]

Hello Sir. Hope you are well. Take care!

[@keplerthe3399]

I've been waiting for this

[@w0tch]

Best explanation so far

[@vitostan3134]

The best at explaining complex ideas.

[@jerrygundecker743]

Dr. Lincoln, if I'm hearing you right, this research is going to help us go back in time and reach the speed of light. I'd settle for fewer ads on You tube.

[@tedlis517]

Love this. So many of the early attempts to communicate the results of the BH and Fermi Lab experiments focus on “new physics” and completely ignored the lattice QCD results. Either way, bravo to all the scientists involved in the new computer calculations and in gathering the new experimental data. I can’t wait to learn how the next sets of experimental results and confirmation calculations turn out!

[@cosmosgato]

Waiting for you sir! You make advance science easily digestible for the common man.

[@itsawonderfullife4802]

Thankx Doc.

[@seangordon9164]

Can we have an updated video with the new results please!!

[@justinmoorhead2632]

Excellent explanation!

[@taknothing4896]

Best explanation yet.

[@chiseldrock]

thanks Don.

[@FobbitMike]

Good job, Doc.

[@asdfasdf71865]

Nice video. Thanks.

[@pmiecz]

Much appreciated, thx.

[@juzoli]

It reminds me to the GPS system inaccuracy. If we wouldn’t know about relativity, the GPS system clock would be off by 38 microseconds per day. It sounds to be just as small and insignificant, than the difference in this Muon experiment. But this little inaccuracy both leads to kilometers of inaccuracy in real world usage, and a whole new physics which changed how we understand the universe forever.

[@henrytjernlund]

Speaking of which, what if this tiny difference is an effect of gravity?

[@artienia7908]

@@henrytjernlund it is

[@juzoli]

@@henrytjernlund Gravity is way weaker than that. But you can believe, since gravity is the 4th fundamental force, and on the top of the lost of the biggest challenges in physics, it is always on the top of the list of ideas for explaining anything mysterious.

[@davidespano8674]

Engineers would have fixed the problem anyway empirically and have it work nevertheless. The truth is that we will never be able to know everything or know everything as our lifespans are limited and at some point the learning process as optimized as it could possibly be will reach its generational best. Problems will have to be fixed empirically and be at peace with that.

[@juzoli]

@@davidespano8674 Yeah, they would add some magical x multiplier, because that’s what they measure. Just like we add cosmological constant, and call it “dark energy”. But understanding WHY we need that correction is a whole different story.

[@jimc.goodfellas226]

This guy always explains things that I can't understand when someone else is saying it

[@hubertheiser]

The more we know, the less we know :-) Anyway, thank you very much for this clear explanation of where science stands in this particular problem.

[@alphagt62]

That’s a good version of the old Einstein quote, “The more I learn, the less I know”.

[@KaiHenningsen]

@@alphagt62 I much prefer the version "The more we know, the more we know how little we know". Which incidentally is also related to good ol' Dunning-Kruger: when you know just a little, you have no idea how little you know, so you assume you know everything there is to know.

[@OslerWannabe]

No, not quite. The more we know, the more we know about how little we know, and the more we know about where to look next.

[@TonyP9279]

That's basically how real science works: You discover new questions.

[@karaloop9544]

@@KaiHenningsen I've come to liken that effect to an expanding circle where the outside is the unknown and the inside already accrued knowledge. The larger the circle of knowledge, the longer the boundary to the unknown becomes.

[@golemtheory2218]

Congrats to Don and the Fermilab team. An fresh alternative to CERN

[@Dragon32z]

summed up, "we could be wrong, we don't know why, but we are oddly happy because of it".

[@yojiviriak675]

Awesome Don

[@Fraiser2024]

Great explanation. I wonder... in this experiment muons need to go fast so they have enough livetime due to relativistic effects. How fast? Are other relativistic effects to consider? For example in their interactions with virtual particles... thanks!

[@patrickaycock3655]

Intro music is epic. Feels like im about to meet a hero. Wait a minute.... Its dr. don lincoln.... a hero. 😯

[@teashea1]

so excellent

[@elir7184]

Cloud of particle anti particle pairs around electron. The cloud slightly enhances the magnetic effect of the electron

[@sapelesteve]

Great video Dr. Don! So, basically what you are saying is that we don't know what we think we know until we know it and even then the answer might be wrong or right depending on how you look at it. 😉😉😂😂

[@drdon5205]

Welcome to my world.

[@Galadonin]

Really great video, especially to get context about the experiments in fermilab If I may, I just have small "advice" : (Idk your budget, and I really mean well, we need more educational videos, especially on quantum mechanics. If the green screen is not used, you can maybe used a set, with half the screen for the key points. A little bit of cuts in the editing, I'm amazed that you can get a lot of these script without cuts, but it can add a bit a rhythm in the video, less breathing noises. Microphone aren't cheap, but it peaks a little bit to much, I think the clip on mic doesn't help The lightning is bright, which maybe necessary because of the green screen, but it seems that the light is not diffused, or not enough. I don't know if you'll se this comment, but please keep posting, those small notes aren't that important. I'm just nitpicking about details. A lot of science channels use green screen with a space background. Some onsite set can boost the production, especially for fermilab, it would be so great ! Btw your generic is AWESOME ! Great production, seems legit.

[@wulphstein]

In the expanding graviton model, gravitons are always coming into existence, expanding from a point, and overlapping. When large numbers of expanding gravitons overlap, they inevitably create the geometries for particle-anti-particle creation. When gravitons overlap and create the geometries for particles/antiparticles, that's the same as creating virtual particles.

[@krumplethemal8831]

Interesting, do the gravitons lose energy when the overlap produces the particle anti particle pair?

[@YaMumsSpecialFriend]

Fascinating 🖖🏼

[@bigsarge2085]

Fascinating stuff.

[@makeracistsafraidagain]

Fascinating

[@DavidKennyNZL]

thanks

[@jmcbri]

Time for an update! 😊

[@andy16666]

Need a good tailor there bud. Great video!

[@SimonSozzi7258]

FINALLY! I'm like "Where's my Fermi Dude?" I need a breakdown... in the upside, I've been briefed.

[@nikolaos9175]

I'm a simple man, I see a Fermilab video, I hit like.

[@PhilBoswell]

I haven't seen anything yet that covers the possibility that there might be something hinky with the equipment: the new experiment used a bunch of the same kit from the old experiment, what did they do to make sure that there wasn't something inherent in the hardware that might produce this discrepancy? Thanks for keeping us updated on progress: I would not be surprised if you've already talked about this but I missed it!

[@donlincoln1961]

The only thing from the old experiment was the magnet. Everything else is new. And the new measurements of the magnetic field are more precise than the old one, plus the field is more uniform.

[@DrDeuteron]

well that is a problem. I didn't work in it, but I think the uniformity of the magnetic field in which the muons both orbit and precess is the biggest (known) source of systematic error, and it's better known this time around....or something like that.

[@n1k0n_]

SCIENCE! MR DON!

[@avejst]

Impressive video 👍😀

[@seaprobecaptain]

So the QCD predictions match observations with the recent lattice QCD computation. What about other models, such as string theory? Are there predictions there that match observations?

[@TheRolemodel1337]

could you derive the relative size difference of muons and electrons using the g factor? if the muon is larger its maximum electromagnetic field strength should be smaller than that of an electron thus less matter/antimatter creation and less of a "cloud" adding to the g factor and vice versa

[@rickharold7884]

Awesome. Love it

[@TheReaverOfDarkness]

Do you think that quantum computers will eventually help calculate the lattice QCD?

[@RFC-3514]

11:49 - He launched into that sentence expecting it to be shorter than it turned out to be. It's like when you pick up speed on a bike before starting to climb a hill, and suddenly realise you're going to have to pedal if you want to actually reach the top.

[@smithanderson3511]

classic...loved it

[@KaliFissure]

When a muon decays it emits one or more (apparently) neutrinos. We know neutrinos have more mass than they should (depending on which axis you measure) so it seems like the wobble would come from singular our dual spin component of neutrinos interacting with the electron charge outflow. The spinning orbiting neutrino wobbles around charge axis. We med to understand Aharanov bohm better.

[@jimbuono2404]

The fields that make up space in the time/space continuum are only superficially understood. While we have some knowledge from experiments, our understanding is limited to the results of those experiments. It's like never having seen 4 types of fruit grown on Rigel 4, being blindfolded, and asked to identify each by touch. You know they feel different but as to understanding what they are, well, you've only scratched the surface.

[@OslerWannabe]

I gotta say, I kind of like this new, more subdued Don Lincoln. I hate to sound critical at all, because he and this channel are absolutely great. But now it's Great+.

[@rexdalit3504]

I would be most curious as to how the lattice calculations vary with "grid size". For example, if calculating on a slightly smaller grid moves the computed g-2 value away from the experimental measurements (toward zero, say), then one might reasonably surmise that calculating with a substantially larger grid would result in a g-2 value even closer to the experimental value(s). [The decades old dream of doing very accurate tau precession experiments may re-emerge, probably still remaining a dreamy dream.]

[@quantumkarthik]

It is wistful to see that this alluring experiment was left behind by the Nobel Committee

[@HackersSun]

Wow that's interesting It takes sooo long for the results but well worth the wait

[@Valdagast]

How important were the 1948 measurements of g to the formulation of QED?

[@donlincoln1961]

Very. Crucial. That and the Lamb effect.

[@johnnycash4034]

@@donlincoln1961 baaah