Are Axions Dark Matter?

PBS Space Time
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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


Feb 11, 2020




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Comments 1 493
Max Jones
Max Jones 34 minutes ago
I love your content Cosmic Jesus.
shipmaster3 Hour ago
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 ?
Cierra Mist
Cierra Mist 4 hours ago
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?
Manus Artifex
Manus Artifex 4 hours ago
Anxious dark matter
Sister of Gaia
Sister of Gaia 5 hours ago
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 📌
weylguy 10 hours ago
Wow - explaining an undetectable form of matter with another undetectable form of matter. Turtles all the way down? But I love this PBS program!
mettaur01 10 hours ago
Is this where all the perverted Globe Earthers hang out?
Scoring digits, son.
Maj kohoni? Nahe!
PouncingAnt 11 hours ago
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
Amari Reyne
Amari Reyne 11 hours ago
"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 😅
Zenothys 9 hours ago
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.
Cheasy 12 hours ago
a nerd channel and no 60 fps xD yr tittle has been revoked
Mtf 12 hours ago
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 .
Doldol D
Doldol D 14 hours ago
Really interesting episode
frysebox1 15 hours ago
Me: Officer, why am I being detained? Officer: 2:18
Lance Tschirhart
Lance Tschirhart 20 hours ago
Great apes _are_ monkeys. Jesus Christ, these cosmologists..
Manu V
Manu V 21 hour ago
Do I come here just to feel dumb!?
Art 22 hours ago
Had to downvote after the first two seconds :(
Bill McDonough
Matt, just to 'nerd all the way': the great apes (or Hominidae) are a Family within the infraorder Simiiformes... the monkeys. So strictly, all apes *are* monkeys. Catarrhini 'Old World' monkeys, in fact.
Gabriel Desmarais
I guess it is official, we can't out-nerd Matt.
Kez Day ago
Can you be straight and wear a pink shirt into a gay bar?
Jason Williams
How can observable time not affect observable mass
Nicolás Celedón
Did anyone read axioms and thought 'those damn matematicians'
Jargon that no one understands .
So I have a question... Do black holes change the topology of the fabric of space-time?
Toni Kotinurmi
Doing physics in univ, for example speed of light (yeah, 30 years ago...) tests with rather strong lasers etc it was OK if we hit within 1e10..15 - just as long as we explained where error marginals came from. That latter part is more important than hitting target. So come on... If you measure something, do it again and again in different ways until you say it's inaccurate.
Sammy Smith
Sammy Smith Day ago
You and the guy from Ancient Aliens are my heroes, so good information.
Vistico93 Day ago
An infinite universe means I would have an infinite number of tries to get my life right though only in an infinite number of them will I start off with memories of my previous attempts to do so...
Nick Moraitis
We can only need out to the fullest extent of our own universe.
Mich ael
Mich ael Day ago
Next video: Are VPN services dark matter?
C Apt
C Apt Day ago
Answer below: How many seconds before you are lost on this video?
BuhuBaha Day ago
In the Lagrangian at 5:17 in the last term one of the alphas should be a covariant index (: * Full nerd mode off * Great video though!
Ri4s co
Ri4s co Day ago
What if dark matter is just an effect of dark energy pushing on gravity
TheExpatpom Day ago
If axions, assuming they exist and are the dark matter physicists have been looking for, are produced in the core of fairly unremarkable star like our sun, is the next question why the stars in those dark matter free galaxies that have been discovered haven’t been producing axions? For that matter if loads of axions were produced during the Big Bang wouldn’t we expect them to end up in the same regions and structures as ordinary matter, and for there to be no galaxies without them? Or is there a possible answer that’s the subject of a future video?
Mainland Empire Records
AHHAHA nerd all the way. Cone'd a phrase.
Fundemort Grey Prime Defender of Truth and Justice
But Sheldon got his Nobel from Super-Asymmetry theory. (this is obv just a joke).
Mainland Empire Records
I love this show. I started watching in 2018, and I haven't stopped since. Thank for you incredibly high value content.
Tripcore Day ago
More 'infinite' nonsense
Tripcore Day ago
Physical Value zero = virtual. Value of zero in physical world = does not exist.
Tripcore Day ago
PBS: Aka 'nothing' Also pbs: 'nothing doesn't exist'.
I really don't believe in the existence of what they called axions. And even less in "WIMPS". There are better solutions to our physics problems and we will understand one day. I do think we are limited by the realist view on what we observe, it's still a too common interpretation among physicists. And the fact that they all want to invent solutions to problems between what we can verify and what we expect to verify in a way that they seem to want our universe to be a closed system that exists in itself, and is not part of anything more.
Tuco Benedicto
I understood some of these words.
Relbl Day ago
As long as you are on the "String Theory" path then we all know this leads to nothing... it's been 40yrs and no progress or discoveries. Is physics so sclerotic nowadays? or is it the sciences in general...?
Genildo Miranda
OMG I am so dumb...
Igor Tolstov
Igor Tolstov Day ago
Physicists just love to make up different constants, fields, and particles to plug in holes in what they don’t understand
Poultryphile Day ago
Would the duplicate universe have a duplicate Matt presenting another, equally awesome, Spacetime show?
Gordon Gecko
Gordon Gecko Day ago
Hey Tyrion Lannister are dragons real?
Captain Caveman
Hmmmm did I just see you on "the way the universe works" ?? Does the universe have a boundary episode.
Punk Patriot
Punk Patriot Day ago
This video, my level of understanding kept oscillating between feeling like I am starting to get it, to feeling like you are speaking Klingon.
stat a87c
stat a87c 2 days ago
I hear alot that a quantum fluctuation is suspected to have sparked the big bang...but there was no space, and therefore no time before the big bang....how tf can something fluctuate without time, and without a dimension to fluctuate in??
Faint 2 days ago
drink everytime he puts his hands back together
Supersad Cat
Supersad Cat Day ago
Okay, even chickens can join Team Cat.
Gareth Wigglesworth
do black holes contribute to the expansion of space time?
Division Zero
Division Zero 2 days ago
the frame rate was a bit of annoying ngl
Follower of Julian
16:08 Latin pronunciation changes over time and from place to place. This is a problem singers face constantly. It's sad that, for all the great work that you do, THIS is all people notice! Μὴ δῶτε τὸ ἅγιον τοῖς κυσὶν μηδὲ βάλητε τοὺς μαργαρίτας ὑμῶν ἔμπροσθεν τῶν χοίρων μήποτε καταπατήσουσιν αὐτοὺς ἐν τοῖς ποσὶν αὐτῶν καὶ στραφέντες ῥήξωσιν ὑμᾶς.
Leslie Schwartz
Leslie Schwartz 2 days ago
A complete total fantasy speculation, this isn't science.
MikeOfNotts 2 days ago
You are looking for a useless cloud of matter that is only big enough to fill the hole in your equations. Maybe it's bigger that that.
Reyna Lindström
Reyna Lindström 2 days ago
the last one was so funny!
LashknifeTalon 2 days ago
Good job guys, we made him give up on pronouncing that thing that Newton wrote.
Kazimir 2 days ago
Could someone pls make a anthropomorphized cartoon about quantum particle behavior to make this understandable? There is so much going on in nearly anything. From vacuum to simple atoms. Quarks, Leptons, Bosons and so on... I'm clearly not able to imagine what is going on anymore. Sure, I could eat some shrooms, but damn. Can anyone put this together to make a clear image to look at? Like oldschool 60's atoms, just by modern standards. I have seen so many visualizations of "this", but it is really hard to put it in some context. So how many dimensions do I need to understand gravity in its simplest form - 11?
W_Sindarius 2 days ago
Nice video, as usual, but I wish you guys would lose the music. Makes it seem less ... authentic.
Anthony Scott
Anthony Scott 2 days ago
Super nerd mode transforming that motivational learning into moral intention to direct application, while saving lives and souls. The purpose. Boundless Nampakkai
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