Are Axions Dark Matter?

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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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    Published on 14 days ago


    1. Gregorii Katastrov

      "W" in Wilczek you should've pronounced as "V" (like in "View") and it mean puppy-wolf in Polish (don't know if Frank is Pole, but i'm pretty sure, he at least had polish ancestors). Sorry, couldn't stop myself - it was first time i felt competent enough to correct you. Great job on what you are doing.

    2. Francis

      Does this so-called dark matter even exist? Probably not

    3. The Internet Dinosaur:

      ;Love this channel so much, i am always nerding out on this! :)

    4. Ryan

      love the videos but what's with the low frame rate?

    5. Logesh K

      If axions have mass then how can they be interconverted into photons....??? Please explain (since photons have no mass)

    6. MeeK1447

      This is similar to a theory that I thought of, my theory involves 4 dimension, Dark Matter, and Electrons. My theory is that, when an entity or object is bound to a single point, there are many new possibilities being created by them simply existing. But in a 4 Dimensional universe there is no possibility because it all happens at once. there is an effect due to the 4D Universe, that I believe takes place when 3 Dimensional universes interacts between those universes. When an object or entity is in the same location at the same time, with every atom precisely in the same position. Quantum Entanglement gets involved, and they just 'Flow' through the 4 Dimensional universe, slices of the 3 Dimensional universe that are so close to one another they start to interact with each other, but at the smallest scale only. Electrons really run our universe. Even this phone I'm using. 4 dimensions to me is just the many worlds theory. Dark Matter is not known but I believe I have solved it, and a way to get small proof. So My Theory is that if Electrons are so small, they can be considered as a point. But when they are unable to interact with any matter, like say in a deep space Vacuum. Those Electrons create a 4 dimensional 'flow' through spacetimes because they are bound to a single point, which is the atom. This 'flow' of electrons is not creating new electrons, but they are existing simultaneously. What I mean is that for every possible location the electron CAN exist at one point in time, it does. Electrons becomes 'solid'. The electron has it's own state of matter, the opposite of plasma, it's a 4D object that becomes 'full' in our 3D reality when the environment of that electron is right. 4D Electrons, Exist in an Exothermic reaction, in a Vacuum at the small scale, with near absolute zero temperatures, at zero G. 4D electrons only exist when there is a lack in temperature, surrounding matter, and a lack of gravity. Basically when nothing happens, the universe loves balance, so something happens because of the lack of potential. Now take an Electrons mass multiply it by the number of points of possible locations it can exist at once. Next, 4 dimensional mass of an electron multiplied by the Mole (6.02x10/²³) now you can test this theory by comparing that to the mass effects of Dark Matter, but I ain't good at math. I can't do astrophysics but I love Science. Fun fact, if this is true, take a good look at the mandelbrot set, imagine that the edge in the black is earth. Now imagine each point being one earth, you keep zooming in you see more area it could exist, almost to infinity because of fractals. And we live in one, Beautiful. Thanks for Reading, Goodbye.

    7. Joye Colbeck

      A weakly interacting small particle - a WISP?

    8. Astromations

      Yes. Yes they are!

    9. Ricardo González

      Great video!

    10. Zepha21

      Are humans great apes?

    11. ED_DY TV

      Traduction arab plz💕

    12. M W

      Did he do a 5 minute commercial for NORD VPN?

    13. Daniel Coker

      Its data, not data.

    14. Heineken Skywalker

      I did comment that it was a chimp.

    15. So ein Spast

      I really like the Tekken 5 main menu music

    16. James Black

      Watching you move I think your camera's exposure time is too small.

    17. Verners Lejietis

      Wow! Even though, the Consiousness influencing QM video is more to my liking, I am glad I did not miss this one. I went in it without a clue what an Axion is, but your explanation with the graphics was top notch. If only i was a kid way back in school, your content is really inspirational.

    18. CleverWire

      In an infinite sized universe bag (for lack of a better sciency word) that contains infinitely sized universes where the bag's existence expanded infinite time wouldn't the probability this text message be typed already in the past by an identical me be 100%?

    19. pvc

      "CP Violation" Attention, ground units - anti-citizen reported in this community. Code: lock, cauterize, stabilize.

    20. Brenden Carr

      3:36 okay wow, the strong CP problem really sounds like the intersection in which we need to keep a very close eye on. Our error, our missing connection, lies somewhere in the maths which cause this mismatch. I absolutely love it! I almost want to go to college to learn everything about these problems, just so I can help figure it out. It's so exciting and enticing, to see things like this unsolved to this day

    21. Sazy Plew


    22. Someone

      I think a better term for "symmetric" is.. Bipolar.

    23. Vini

      Background music sounds like Twin Peaks mystery song.

    24. Vini

      The standard model / QFT is slowly reaching its limit. Extrapolating from already existing equations will eventually just make you go in circles. You need some genuinely new ideas.

    25. King Ronin

      My question is why is a chiral neutron predicted to have an electrical charge? The positive version of an electron and a negative proton should mathematically produce a neutron of the chiral constituents but of similar basic properties?

    26. civota mu az

      Would watch this whole video but goddamn it feels like Billy Mitchel is waterboarding me

    27. Binyamin Tsadik

      Check out this paper: You are saying the same thing.

    28. Dr.V

      Wonderfully informative and fantastically interesting. Thank you kindly @PBS Space Time for making this.

    29. Make Racists Afraid Again

      Please don't say "visa" versa.

    30. Michael Sander

      To me, PBS Space Time is single best physics channel for folks who studied college-level physics, but didn't quite make it to (or through) physics grad school. Agree?

    31. Inspiración Original

      so... this means the Axiom could be used to support photon decay as an explication for dark matter?

    32. Badger

      I think axions and the theory itself could for the most part be replaced with formative causation as an account for dark matter/energy or other potential issues in our simulations.

    33. Charlie Meyer

      A proton-like composite particle made of Axioms could get a lot heavier! A "Protaxion" might even move sub light speed despite its superluminal parts.

    34. Kevin Reardon

      Dark matter only exists because we are memorized by the three body problem. The Moon and Earth are gravitationally locked, which is the same effect you see with the outer stars of a galaxy. There is no dark matter, there are gravitational rings on the outer reaches of a galaxy.

    35. Exoplanet Research

      There are galaxies with barely any dark matter. They should map the total magnet fields for the galaxies, then compare the dark matter content

    36. Clickmaster5k

      Calling us out. Geez

    37. Roman Buehler

      let me nerd away in my own world: that noise... what's that noise?!?!?! in ALL your videos, it's driving me insane and i have to focus hard on what you say... there's the music in the background, and there's you speaking, but there's also a noise, probably peaking around 600-800hz all over the videos... is that intentional by the editor to avoid hearing fatigue because of too clean sound? -> better way would be to use light audio compression on the voice track... is that because your recording environment is so noisy? -> with your budget you really should get better accoustic padding and isolation... is your editor hearing impaired and he never noticed? -> run some analysis on the sound output, find it and fix it, please!!!

      1. Roman Buehler

        it appears to be the mic input... FIX PLEASE!

    38. Net Tech

      Off topic, I know it is mathematically and physically possible to add positive mass to a point of spacetime but I'm curious if it is mathematically possible to add negative mass to a point of spacetime. A blackhole adds mass to a singular point by consuming mass increasing mass and gravity bending spacetime one way but is it mathematically possible to do the opposite creating negative mass effects to bend spacetime the inverse way?

    39. Audacious Scoundrel

      17 minutes of man talking to himself in the mirror.

    40. ChefHomesteadMaker

      That Thing That Newton Wrote, is it a must read?

    41. Marcin Zieminski

      There are 4 fundamental forces, and lots of different particles. How do scientist now which particle interacts with different forces? Ex.axions interact only with gravity and weak force, my question is why they interact only with those two forces, ? What is the mechanism behind it? Are there any laws which tell us that any given particle will interact with any given fundamental force?

    42. Chrizzie 78

      Does any of this matter?! Thank you, you've been a great audience.

    43. Brad Bradson

      Maybe there is no Dark Matter, maybe there is many Dark Matters

    44. Tirlon Burke

      You recently did a show on infinite universes and possibly the infinity of our universe. If either is the case, shouldn’t there be a wormhole we could traverse somewhere accessible on planet just waiting for someone enterprising to push a monkey through into a magnitar and one for us to travel somewhere slightly more pleasant?

    45. Imgay Asheck

      This channel still believed in inflation so I'm going to guess no

    46. Frank Jaeger

      I believe that in Latin the letter "c" is always pronounced as the letter "k". So the second way you pronounced it would be the most correct.

    47. Max Jones

      I love your content Cosmic Jesus.

    48. shipmaster3

      Do you think that there is some relationship between the photon energy and the strength of a magnetic field needed to convert it? or is it just a sufficiently strong magnetic field is needed to any photon into an axion regardless of energy ?

    49. Cierra Mist

      If the spin of a black hole can rip away its event horizon revealing a "naked singularity", would all the mass that's in the singularity come exploding out? Maybe the big bang was an event like this?

    50. Manus Artifex

      Anxious dark matter

    51. Sister of Gaia

      If you take the remove the first 5 00000 from the quantum vacuum number measurment of the Universe. It would explode 💥 and we would not be here 📌

    52. weylguy

      Wow - explaining an undetectable form of matter with another undetectable form of matter. Turtles all the way down? But I love this PBS program!

      1. Gareth Dean

        Pretty sure it's been solidly disproved. But hey, flat Earth has made a comeback too.

      2. weylguy

        @Gareth Dean 130 years later, the aether theory is still awaiting confirmation.

      3. Gareth Dean

        *Currently* undetectable. The hope being of course that we CAN detect it Nobody's sitting in bed going 'Boy, I hope we find nothing tomorrow!'

    53. mettaur01

      Is this where all the perverted Globe Earthers hang out?

    54. Scoring digits, son.

      Maj kohoni? Nahe!

    55. PouncingAnt

      Excellent. Sounds like Axions are an elegant solution to at least two big physics problems. Which leaves the question, Why might they not be? Is there anything besides the lack of experimental evidence to justify the title of the video being a question rather than a statement? (Of course, experimental evidence is a requirement of the scientific method, but.. you know how when they hype a particle, then you go and see the particle, and it's not as good as you were expecting...) P.S. A lot of people thought that about the Higgs.... But I thought it was a massive success. P.P.S. Sorry

    56. Amari Reyne

      "The universe may be truly spatially infinite" Even though I already had that idea in my head, hearing the words out loud from someone else really melted my mind. There's so many things we will never even begin to understand before the heat death of our own part of the whole universe. I mean, we used to think the milky way was the whole universe. And we were calling Andromeda an "island universe" What's to make anyone think the universe we observe isn't just one of... Billions? Trillions? Infinite? Universes. Guess we will never know 🤷‍♂️ I havent slept in 27 hours, go easy on me if you reply 😅

      1. Zenothys

        Amari Reyne You have a healthy skepticism and an inspiring curiosity. No reason to worry about responses imo! To give my two cents, space is only as large as needed to contain all possibilities (which I believe isn't infinite, but does inflate fast enough to redefine infinity to some larger number the instant the previous number is defined), and once you hit the "edge" of space, space becomes _time_ and more or less travels back to the Big Bang via the "beloved" Bogoliubov transformation.

    57. Cheasy

      a nerd channel and no 60 fps xD yr tittle has been revoked

    58. Mtf

      I used to watch these videos and then, frustrated for not being able to understand, go to the pub . Now I 've thought better and I go to the pub BEFORE watching the videos and suddenly they are crystal clear .

    59. Doldol D

      Really interesting episode

    60. frysebox1

      Me: Officer, why am I being detained? Officer: 2:18