Are Axions Dark Matter?

  • Published on 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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Comments • 70

  • Damian Green
    Damian Green 4 hours ago

    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.

  • Doodle Dee
    Doodle Dee 2 days ago +1

    "CP Violation" Why do scientists pick the worst names for things lol

  • David Schaftenaar
    David Schaftenaar 5 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.

  • Josiffrank
    Josiffrank 9 days ago

    Why don't they call it wrong until is solved? Big egoes?

  • Edward Galliano
    Edward Galliano 12 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.

  • Lewis Shrubb
    Lewis Shrubb 14 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.

  • Rasputin Disclaimer101

    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.

  • Delta Design
    Delta Design 19 days ago

    I hope this video explains something.. 3rd time's a charm.

  • Norman Thornton
    Norman Thornton 20 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 . . .

    • Michael Sommers
      Michael Sommers 10 days ago

      No. That's not how it works. You need to retake all your physics courses.

  • Justwantahover
    Justwantahover 21 day ago

    Well actually...

    I wouldn't have a clue!

    LARTY LAB 22 days ago

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

  • Virtual Axion Institute

    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.

  • Cancel Culture Doesn't exist

    The universe is an aliens a+ project

  • Roblox Zaara
    Roblox Zaara Month ago

    This is SOOO confusing lol

  • Жан Бек
    Жан Бек Month 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.

  • Beta Centurion
    Beta Centurion Month 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.

  • Musky Elon
    Musky Elon Month ago


  • Bill Patterson
    Bill Patterson Month ago

    Apes ARE monkeys. Give it a search.

  • saelesbon sazse
    saelesbon sazse Month ago +1

    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?

  • Ali Aseman Bakhsh
    Ali Aseman Bakhsh Month ago

    Now you’re just making stuff up.

  • intrepiddevildog
    intrepiddevildog Month ago

    Great channel

  • Nathan Goldberg
    Nathan Goldberg Month 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.

  • david nelband
    david nelband Month ago

    i did some science to me portal gun morty, now its a real gun

  • NotMe,
    NotMe, Month ago

    Totally lost me there at the end. Throw some numbers on the screen.

  • R. Rod.
    R. Rod. Month ago +2

    Close enough to me. I'll called dark matter are Axions. Case closed. Pack it up guys.

  • J P J
    J P J Month ago

    I used to watch Big Bang theory and think I was smart.😬

  • callejondorado
    callejondorado Month 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.

  • Bongo Baggins
    Bongo Baggins Month ago

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

  • N Marbletoe
    N Marbletoe Month ago

    Can you pronounce Principia Mathematica as a superposition of all possible pronunciations?

    • N Marbletoe
      N Marbletoe 10 days ago

      @Michael Sommers ok that's right lol

    • Michael Sommers
      Michael Sommers 10 days ago

      No. There is no superposition in classical mechanics.

  • Shervin Manickam
    Shervin Manickam Month ago

    Longest way to say maybe axion exists or does not

  • Shervin Manickam
    Shervin Manickam Month ago

    The caption timing is very bad

  • Cyrill Azarkhin
    Cyrill Azarkhin Month ago

    Wow, when he suddenly pronounced ''revolver ocelot"

  • isleofatoll nz
    isleofatoll nz Month ago

    dark plasma

  • Gsup7s
    Gsup7s Month ago +1

    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.

    • Gsup7s
      Gsup7s Month ago +1

      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.

    • Gsup7s
      Gsup7s Month ago +1

      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.!

  • Baalsguestjar
    Baalsguestjar Month 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?

  • Pure Pressure
    Pure Pressure 2 months ago +2

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

  • Caleigh Fisher
    Caleigh Fisher 2 months ago

    Assuming there was a beginning

  • Caleigh Fisher
    Caleigh Fisher 2 months ago

    What frequency are the photons from this exchange? Are they specific? Harmonic series (quantized)? Have a distribution curve?

  • Project Management
    Project Management 2 months ago

    What emmits axions? How are they emmited from atoms?

  • T
    T 2 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.

  • Craig Laycock
    Craig Laycock 2 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".

  • Turin Horse
    Turin Horse 2 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.

  • ̛̀ ̡у̶̕͝ ́͞б̷̕ ̶͝и̛͟ ̸й̵͟ ̷ц҉ ҉̸͘а̨́

    The strong CP problem happens when mods are asleep.

  • Simon Ingram
    Simon Ingram 2 months ago

    Should say "sponsored by NordVPN the not so private network."

  • Robert Schlesinger
    Robert Schlesinger 2 months ago +1

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

  • Roli Rivelino
    Roli Rivelino 2 months ago

    Is there a follow up on this, citing the xenon experiment?

  • Larz
    Larz 2 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.

  • Tim Brumaghin
    Tim Brumaghin 2 months ago

    The axions are the strings in M Theory?

  • Jim Jimmy
    Jim Jimmy 2 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:)

  • AnimeShinigami13
    AnimeShinigami13 2 months ago +1

    Physicist: I sense a disturbance in the forces!
    Axion: Come to the dark side! of physics!

  • Olan Dyurai
    Olan Dyurai 2 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!!!

  • Scott West
    Scott West 2 months ago

    Why aren't neutrinos dark matter

  • Magnus Juul
    Magnus Juul 2 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

  • p a
    p a 2 months ago

    Physics abandons the ether instead calling it "the quantum field"

    • p a
      p a 2 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.

    • Tri Biz
      Tri Biz 2 months ago +1

      But experiments have demonstrated effects that are explained extremely accurately by quantum fields

  • zero15388
    zero15388 2 months ago

    i just about follow along... and then i dont

  • Thak You
    Thak You 2 months ago

    I hate advertisements... Especially in science. 😑

    Why Axions??? Looks like even the universe has got ads 🤣

    UNDERHILL 2 months ago

    So Nord VPN creates Axions to populate the universe for a low monthly price. Got it.

  • Ian Rogers
    Ian Rogers 2 months ago

    Nerd all the way. Brilliant.

  • impossiblemission4ce
    impossiblemission4ce 2 months ago

    "the weak force is not CP symmetric"

  • Klaus ATHEIST Bolvig
    Klaus ATHEIST Bolvig 3 months ago

    Brilliant using nature to explore new particles? But if!!

  • Conor Corrigan
    Conor Corrigan 3 months ago +1

    "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...

  • TheVergile
    TheVergile 3 months ago +6

    science: we found a new particle/force/field/effect/metal genre
    science: is it dark matter??

  • Tolen Tarpay
    Tolen Tarpay 3 months ago

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

  • Anarchy Antz
    Anarchy Antz 3 months ago +1

    Take a shot every time Matt says "Ten to the power of"

  • Christopher Kinslow
    Christopher Kinslow 3 months ago

    As a late 70's punk rocker I never was truly happy till "Nerd all the way"!!!!!
    Science is Punk!

  • Spinnetti
    Spinnetti 3 months ago

    What about the dendrites? little biology joke lol

  • Danielle Spargo
    Danielle Spargo 3 months ago +2

    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.

  • Jens8502
    Jens8502 3 months ago +1

    Hello, wonderful Person!

  • sgd fdg
    sgd fdg 3 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 fdg
      sgd fdg 2 months ago

      @Night Beard yes i have Axions are fake hypothesis partikels that nobody have found

    • Night Beard
      Night Beard 3 months ago

      sgd fdg, I guess you’re not read up on current astrophysics news. 🙄

  • M S
    M S 3 months ago

    Wilczek is read as "Vilczek".