Are Axions Dark Matter?

Feb 11, 2020
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What does the strong nuclear force, the fundamental symmetries of nature, and a laundry detergent have in common? They’re all important parts of the tale of the axion - a tale whose end may take us beyond the standard model and solve one of the most vexing mysteries in astrophysics.
Hosted by Matt O'Dowd
Written by Matt O'Dowd & Graeme Gossel
Graphics by Leonardo Scholzer & Adriano Leal
Post Production: Yago Ballarini, Max Willians, Pedro Osinski
Directed by: Andrew Kornhaber
Executive Producers: Eric Brown & Andrew Kornhaber
The story of the axion is a classic physics tale: intrepid scientists delve deep into trackless mathematics in search of answers to a mystery. And there, against all expectations, they find the hint of a completely new and unexpected denizen of the natural world. In this case the mystery was a subtle inconsistency in the behavior of the fundamental forces. And the unexpected discovery? A brand new particle - the axion - which, while not proven to exist, may explain a much more famous conundrum. The axion may explain dark matter.
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  • Interesting concept for determining if the universe as we know it replicates itself somewhere, however it is based on the assumption that there are a finite number of particles that can be counted in our known universe. I suspect that may be wrong. It may be that all analogue fluctuations in space-time and fields can not be entirely quantized. That would mean that if we only considered replicating known particles, perhaps there could be a duplicate universe out there somewhere, but it would only be the same for an instant as field fluctuations would cause particles to behave differently in each replicated universe.

    Damian GreenDamian Green12 hours ago
  • "CP Violation" Why do scientists pick the worst names for things lol

    Doodle DeeDoodle Dee2 days ago
  • 4:51 Yeah, okay, physics wins, I'll admit it: I'm too stupid to even begin to make sense of that Greek alphabet soup. Anyone who sees that formula and actually understands it is essentially a wizard from my perspective and has my respect and admiration.

    David SchaftenaarDavid Schaftenaar5 days ago
  • Why don't they call it wrong until is solved? Big egoes?

    JosiffrankJosiffrank9 days ago
  • It has never occurred to a majority of people and perhaps only me that we are in a small spherical volume of space inside an atom and with the atom part of a separate reality.

    Edward GallianoEdward Galliano13 days ago
  • If axions are real and are responsible for the extra gravity, how large would the actual size of a galaxy have to be to account for the extra gravity observed? where would the axions sit in galaxy, would they be evenly distributed throughout, or would they be mostly (or perhaps all given the failure to detect them thus far) be on the outer edge of the mass we see in a galaxy because it has the least mass? lastly could the axions orbit larger masses? thank you. Lewis Shrubb.

    Lewis ShrubbLewis Shrubb15 days ago
  • This is a work of non-fiction. Any names or characters, businesses or places, events or incidents, are factual. Any resemblances to actual persons, living or dead, or actual events is purely coincidental. We do not take responsibility for decisions taken by the viewer based solely on the information provided in this video. Nor, do we take responsibility for decisions taken by the viewer based solely on the information provided in this virtual application, any dimension visited, or any dark energy attached or removed.

    Rasputin Disclaimer101Rasputin Disclaimer10118 days ago
  • I hope this video explains something.. 3rd time's a charm.

    Delta DesignDelta Design19 days ago
  • Their is no dark matter, Their is enough photon masses to equal all of the observable matter which we can see.. In the area boundary of a universe, perhaps less than two percent is composed of physical masses. The rest of the space is composed of electromagnetic waves in transit. While we do not give a value to the mass of a photon, it none the less has a mass value based on its frequency. A million cycles per second has a mass ten times less than a ten million cycle frequency per second. Photon frequencies are created from the amount of mass converted into electromagnetic waves in a given seconds worth of time as we know it to be. A Gamma Ray frequency may be carrying a million or more times the mass of our visible light spectrum frequencies.and electromagnetic waves fill every iota of space in existence in the universe, That is the so called dark matter of the universe . . .

    Norman ThorntonNorman Thornton20 days ago
    • No. That's not how it works. You need to retake all your physics courses.

      Michael SommersMichael Sommers11 days ago
  • Well actually... I wouldn't have a clue!

    JustwantahoverJustwantahover21 day ago
  • Congrats! This exceptional lecture indicates that you (unlike many others) really understand what you're talking about.

    LARTY LABLARTY LAB22 days ago
  • If you want to follow axion research in the making, right at the edge of our current knowledge, head over to our Virtual Axion Institute [ ], where early-career scientists present their recent work on axion physics in short workshop-style talks.

    Virtual Axion InstituteVirtual Axion Institute23 days ago
  • The universe is an aliens a+ project

    Kyrlics .Kyrlics .Month ago
  • This is SOOO confusing lol

    Roblox ZaaraRoblox ZaaraMonth ago
  • The DARK ENERGY curtain is opening, gentlemen. Without fear of simplicity, imagine such a blooming UNIVERSE: Quantum gravity is the vibrations of waves in a spherical quantum field. Or the wave pressure in the quantum membrane in the "rosebud", where the transfer of wave energy during the drift of the center in the "rosebud" is possible through the quantum of the string. Quantum entanglement is a mixed transmission of information without intermediaries through the quantum of strings and with intermediaries in fractals from the quantum of "rosebuds". The visible Universe is crumbling over the skeleton - Immeasurable a quantum of strings on which fractals grow, quantum "rosebuds" in the form of dark energy.

    Жан БекЖан БекMonth ago
  • Hello PBS Space Time. I'm finishing up my REU with the Axion Dark Matter eXperiment (ADMX) with the University of Washington, and I just wanted to thank you for presenting axion physics in such a clear way. I was aware of the strong CP problem during the whole internship, but since I was focused on studying microwave cavities I never got the chance to learn more about it. This video helped me sound like a boss at the end of my presentation, and of course, the video was awesome regardless of the context it has to me. Just wanted to say thanks for helping me out.

    Beta CenturionBeta CenturionMonth ago
  • No

    Musky ElonMusky ElonMonth ago
  • Apes ARE monkeys. Give it a search.

    Bill PattersonBill PattersonMonth ago
  • How could you say "inflation has started 13.5 billion years ago"? Is there any indication at all that time flows outside our bubble universe?

    saelesbon sazsesaelesbon sazseMonth ago
  • Now you’re just making stuff up.

    Ali Aseman BakhshAli Aseman BakhshMonth ago
  • Great channel

    intrepiddevildogintrepiddevildogMonth ago
  • Axions are probably something much more complex and probably comprised of something much smaller if you know physics history you know that last time we had the idea in our collective heads as physicists that we knew it all we got our heads knocked around by the next discoveries. We discovered that the universe did not rotate around the sun, that electromagnetism was a single force, that light was both a wave and a particle, radioactivity, quantum physics, and more. I doubt that axions will fully wrap up BOTH dark matter and CPT violation although it would be poetic.

    Nathan GoldbergNathan GoldbergMonth ago
  • i did some science to me portal gun morty, now its a real gun

    david nelbanddavid nelbandMonth ago
  • Totally lost me there at the end. Throw some numbers on the screen.

    NotMe,NotMe,Month ago
  • Close enough to me. I'll called dark matter are Axions. Case closed. Pack it up guys.

    R. Rod.R. Rod.Month ago
  • I used to watch Big Bang theory and think I was smart.😬

    J P JJ P JMonth ago
  • If I understood well dark matter, in this case Axions, would interact via the electromagnetic force, since it would decay into photons. So far it has been said that it was only through gravity.

    callejondoradocallejondoradoMonth ago
  • When you're really clever and then try to sell a private VPN

    Bongo BagginsBongo BagginsMonth ago
  • Can you pronounce Principia Mathematica as a superposition of all possible pronunciations?

    N MarbletoeN MarbletoeMonth ago
    • @Michael Sommers ok that's right lol

      N MarbletoeN Marbletoe11 days ago
    • No. There is no superposition in classical mechanics.

      Michael SommersMichael Sommers11 days ago
  • Longest way to say maybe axion exists or does not

    Shervin ManickamShervin ManickamMonth ago
  • The caption timing is very bad

    Shervin ManickamShervin ManickamMonth ago
  • Wow, when he suddenly pronounced ''revolver ocelot"

    Cyrill AzarkhinCyrill AzarkhinMonth ago
  • dark plasma

    isleofatoll nzisleofatoll nzMonth ago
  • Wow. So much wasted effort. I'm not saying Axeion's couldn't exist. I'm saying if they existed in such quantity as dark matter. They would have certainly been detected by now. With even the first attempt of detection. Assuming axions can actually spontaneously gain energy and release a photon. And while it is true we cannot produce the magnetic field strength of a galaxy. We don't need to. In the localized region like the space of the size of an Axion. Vastly less energy would be required. Well within our capability of producing. One of these days the scientific community will stop referring to the lowest energy State as a vacuum. As in the absence of anything. Because space itself is a form of matter. And in great enough density. Produces its own gravity. Yes. The Gravity produced by Dark matter. Is the measurement of spatial density. How about a video on that.! Although I guess it's not a complete waste. The information that you are wrong. Is still pretty important information.

    Gsup7sGsup7sMonth ago
    • I did actually notice the monkey thing. But I thought semantics. I don't want to be a d***. But next time I'll be sure to correct to you on every little thing.

      Gsup7sGsup7sMonth ago
    • Also there is no such thing as infinite inflation. And while the lowest energy state is not a vacuum. It is the lowest energy state. And through inflation all the available energy is spreading out. Which is referred to as kinetic energy. But eventually the universe will reach a lowest energy state. And cease inflation. Hope that clears up Infinit inflation for you. There is no such thing as infinite. Not in the universe in which we live. I can't say for sure about the multiverse. What is more likely. Is the existence of nothing. With no dimension. No time. No space. No energy. Nothing.! And the multiverse is just an island within it. How it got there. Or how it came to be. Is a mystery. You might assume it got there in the same way all of its constituent universes did. But no. That's where the buck stops. And while there may be an in comprehensible number of universes. It's still vastly short of Infinity. I think you will agree. So not in this universe. And very probable not even the multiverse.!

      Gsup7sGsup7sMonth ago
  • Well Tachyons are Dark Energy. The are the Anti Photons, because they travel FSOL, which would be in a inverted way is the opposite of Speed Of Light formula is SOL = -FSOL or Photon = -Tachyon. The reason for this is that neither one can cross the equal sign without no longer existing and so they become polar opposites. In other words if a photon goes faster it becomes a tachyon and if a tachyon slows down it becomes a photon. Did I just invent a teleporter? When do I get my Nobel Prize?

    BaalsguestjarBaalsguestjarMonth ago
  • It’s incredible how much his hand movement adds to the video

    Pure PressurePure Pressure2 months ago
  • Assuming there was a beginning

    Caleigh FisherCaleigh Fisher2 months ago
  • What frequency are the photons from this exchange? Are they specific? Harmonic series (quantized)? Have a distribution curve?

    Caleigh FisherCaleigh Fisher2 months ago
  • What emmits axions? How are they emmited from atoms?

    Project ManagementProject Management2 months ago
  • One way to work out how to pronounce Principia would be to find some contemporary poetry where someone rhymes it with something else.

    TT2 months ago
  • The electromagnetic force is many magnitudes stronger than gravity and reaches out to infinity in the inverse square law. I have a theory that electromagnetism is responsible for the currently unexplained attraction found between stars inside galaxies. After all, stars are giant magnets due to their flowing plasma. This seems far more likely to me, than the existence of "dark matter".

    Craig LaycockCraig Laycock2 months ago
  • excellent discussion. but your sponsor nordVPN is poor. *PROTON VPN* is the ONLY VPN you should ever use. You are an expert in physics. I am an expert in computer networking. ProtonVPN is the only good choice.

    Turin HorseTurin Horse2 months ago
  • The strong CP problem happens when mods are asleep.

    ̛̀ ̡у̶̕͝ ́͞б̷̕ ̶͝и̛͟ ̸й̵͟ ̷ц҉ ҉̸͘а̨̛́̀ ̡у̶̕͝ ́͞б̷̕ ̶͝и̛͟ ̸й̵͟ ̷ц҉ ҉̸͘а̨́2 months ago
  • Should say "sponsored by NordVPN the not so private network."

    Simon IngramSimon Ingram2 months ago
  • Excellent video. Interesting and informative. Max Tegmark has authored some relevant papers. And thanks for the reminder to head out to buy some Axion!

    Robert SchlesingerRobert Schlesinger2 months ago
  • Is there a follow up on this, citing the xenon experiment?

    Roli RivelinoRoli Rivelino2 months ago
  • If space is infinite, there are universes beyond our universe. And they are likely spewing mass outwards with infinite inflation, into our universe, which will end our infinite inflation by increasing our mass, which will increase gravity, which will cause our universe to contract. Hence ending infinite inflation and leading to another Big Bang.

    LarzLarz2 months ago
  • The axions are the strings in M Theory?

    Tim BrumaghinTim Brumaghin2 months ago
  • If Axions are dark matter and the dark matter is mostly needed inside galaxies, to explain why they don't fly apart, and these galaxies have strong magnetic fields then that dark matter should have turned into light by now providing human made CAST can turn it into light, shouldn't it? But then again i could not turn into light because it's needed for us to explain why galaxies don't fly apart.:) So i guess we need some math to explain that:)

    Jim JimmyJim Jimmy2 months ago
  • Physicist: I sense a disturbance in the forces! Axion: Come to the dark side! of physics!

    AnimeShinigami13AnimeShinigami132 months ago
  • I am so happy I found this channel! Fairly sure I've watched every video twice and some of them 10x!!! I'm constantly pausing and going on a google wormhole lathered in critical thinking lol it truly gives me so much joy that words fall short!!!! Love that I can still watch PBS just like when I was a kid!!!

    Olan DyuraiOlan Dyurai2 months ago
  • Why aren't neutrinos dark matter

    Scott WestScott West2 months ago
  • Wow. A 17 minute long video and it "only" took 11 minutes and 20 seconds to actually get to the point... which there wasn't any of anyway. Good job mate

    Magnus JuulMagnus Juul2 months ago
  • Physics abandons the ether instead calling it "the quantum field"

    p ap a2 months ago
    • Tri Biz, same experiments are well explained using pilot wave theory, and the ether. The problem isn't the experiments that are explained, it's the many that conflict.

      p ap a2 months ago
    • But experiments have demonstrated effects that are explained extremely accurately by quantum fields

      Tri BizTri Biz2 months ago
  • i just about follow along... and then i dont

    zero15388zero153882 months ago
  • I hate advertisements... Especially in science. 😑 Why Axions??? Looks like even the universe has got ads 🤣

    Thak YouThak You2 months ago
  • So Nord VPN creates Axions to populate the universe for a low monthly price. Got it.

  • Nerd all the way. Brilliant.

    Ian RogersIan Rogers2 months ago
  • "the weak force is not CP symmetric" 👁️

    impossiblemission4ceimpossiblemission4ce2 months ago
  • Brilliant using nature to explore new particles? But if!!

    Klaus ATHEIST BolvigKlaus ATHEIST Bolvig3 months ago
  • "It seems like some of you are, let's say, quite detail-oriented" That's the nicest way of calling someone autistic I've ever heard on the internet...

    Conor CorriganConor Corrigan3 months ago
  • science: we found a new particle/force/field/effect/metal genre science: is it dark matter??

    TheVergileTheVergile3 months ago
  • Your description of Axions makes them sound like Neutrinos (unviolated ones, of course!)...

    Tolen TarpayTolen Tarpay3 months ago
  • Take a shot every time Matt says "Ten to the power of"

    Anarchy AntzAnarchy Antz3 months ago
    • *dies*

      Rich MitchRich Mitch2 months ago
  • As a late 70's punk rocker I never was truly happy till "Nerd all the way"!!!!! Science is Punk!

    Christopher KinslowChristopher Kinslow3 months ago
  • What about the dendrites? little biology joke lol

    SpinnettiSpinnetti3 months ago
  • while i saw and liked this video four months ago, i was directed here once again by the wonderful person anton petrov, who reported today on a new discovery seeming to give credence to the axion's existence. it use i think a 10,000 ton tank of liquid xenon, and they had far more detections than theorized. there are several other explanations, but the axion seems to be far and above the most likely answer. i would love a followup to this video that includes these new observations. but i'm thinking you'll probably give it a few months for confirmation of the data before making a video. still, can't wait to find out if we've finally found dark matter.

    Danielle SpargoDanielle Spargo3 months ago
  • Hello, wonderful Person!

    Jens8502Jens85023 months ago
  • Dark matter are not Axions first he should prove that Axions exist before asking that question Axions are fake hypothesis partikels that nobody have found

    sgd fdgsgd fdg3 months ago
    • @Night Beard yes i have Axions are fake hypothesis partikels that nobody have found

      sgd fdgsgd fdg2 months ago
    • sgd fdg, I guess you’re not read up on current astrophysics news. 🙄

      Night BeardNight Beard3 months ago
  • Wilczek is read as "Vilczek".

    M SM S3 months ago
  • Back here from Anton Petrov. *hello wonderful person*

    Rich MitchRich Mitch3 months ago
    • @Rich Mitch Matt O'Dowd channel, let's not let channels cross. May end reality as we know it.

      Manj SherManj Sher27 days ago
    • @Manj Sher wot

      Rich MitchRich Mitch27 days ago
    • This is not the place for that kind of commentary.

      Manj SherManj Sher27 days ago
    • Me too. Now I get deeper explanation, so my un-understandig is way deeper. So I am deeply happier. I became a nerd? :-) ;-o

      tibor bogitibor bogi3 months ago
    • Rich Mitch same here, thanks to wonderful person Mr. Petrov.

      Sachin ShriyanSachin Shriyan3 months ago
  • Black Matter Lives

    Never Stop Never StoppingNever Stop Never Stopping3 months ago

    C FitzgeraldC Fitzgerald3 months ago
  • Perhaps axions are the material of Spacetime itself? We would detect them similarly to gravitons, via their waves. Given that phantom quarks pop in and out of existence, some leaving photons behind, perhaps others leave axions? If so, this explains Inflation, as well as confounding seeing axions from potential sources. Seeing them from a distant star might be akin to trying to see a ripple made by a pebble dropped in across an ocean. Thoughts?

    Herne WebberHerne Webber3 months ago
  • Is it a possibility that axions are so incredibly small, of low energy, and abundant that they create 'space' between every particle, object and ultimately; create space in the universe entirely?

    Sven VossenbergSven Vossenberg3 months ago
  • Yes i think its about vacuum

    Almir AhmedicAlmir Ahmedic3 months ago
  • Last semester I finished my first proofs class, linear algebra, and diff equ. This semester I’m starting vector analysis, the second proofs class, and a symbolic computations class I’m excited but idk anything about coding so the third class will be interesting

    rylan buckrylan buck3 months ago
  • It’s peculiar now that the Italian xenon observatory was designed to detect Dark matter and started hearing “pings”( which may be background noise or might be a newly discovered sub-atomic particle- Axions!)

    Jacob DuranJacob Duran3 months ago
  • Now, they found it !!!

    Patiparn PojanartPatiparn Pojanart3 months ago
  • "CP Problem = Bad Theory"

    John WernerJohn Werner3 months ago
  • Dark matter lives matter.

    PeriNKinGPeriNKinG3 months ago
  • Looks like we might need a new episode for this topic.

    AlosAlos3 months ago
  • We have detected axions! Only 4 months after this video was uploaded!

    SaiSai3 months ago
    • I'd advise caution, as the detection was only at 3.2 sigma confidence (5 sigma is what's required to be *really* confident in scientific circles). Still, it's encouraging.

      MarsJenkarMarsJenkarMonth ago
  • I literally had an ad of a washing-up detergent play at the beginning of the video!

    PurpleFerretPurpleFerret3 months ago
  • Dark matter is the canvas and light is the medium .

    mark banesmark banes3 months ago
  • Just answer the question. Yes or no

    DSO MoviesDSO Movies3 months ago
  • melodramatic bore

    Mario LunaMario Luna3 months ago
  • "Ten to the power of ten to the power of ten to the power..." I feel like I live in Whoville.

    Malvakai PMalvakai P3 months ago
  • Doesn't Ockham's Razor suggest Theta=0? I'm not clear on why Theta should exist, unless it is required by experiment.

    zzasdfwaszzasdfwas3 months ago
  • no [end] ----

    Casius CBUCasius CBU3 months ago
  • I'm still more partial to hexaquarks being dark matter, which have the necessary qualities to qualify as dark matter within known quantum physics and particles as explained in a recent paper. Though would be fun to have more particle discoveries like the higgs down the road, axions or not.

    ShadowTaniShadowTani3 months ago
  • Verily Verily I say that Dark Matter is a renounce of time. Used time gets dark and empty and lifeless... negative matter... overly filled with death... dead matter... drained matter that needs to be charged again, as a drained battery. This is used matter, what will be left when the light is gone. Let there be light and there was light. I divided the light into light and darkness.

    Messiah ImmanuelMessiah Immanuel3 months ago
  • Could you destroy a black hole by feeding it a large amount of antimatter?

    Kerry BegemanKerry Begeman3 months ago
  • Same is explained as

    prakash govindwarprakash govindwar3 months ago
  • Seems it has more in common with *Calgon* ......

    Robert PruittRobert Pruitt3 months ago
  • I wish this had been around when I slept through my HS physics class.

    Hound19745Hound197453 months ago
  • when would eternal inflation have begun if it had to have a beginning?

    Seth ApexSeth Apex3 months ago
  • Love your channel you have any book recommendations ?

    garrett hamiltongarrett hamilton3 months ago
  • so that's where the Half-Life 2 song comes from

    BlockistiumBlockistium3 months ago
  • All monkeys are monkeys, even humans. Humans are simians, literally, monkeys. Simiiformes includes apes (monkeys), humans (monkeys), and pretty much the rest of the monkeys currently living.

    EvilOmniscienceEvilOmniscience4 months ago