Axions or Not. What's Hiding Behind Dark Matter? 

I mean no shade at Dr. Rogers, but this is why we need Frasier to be our energetic science communicator to help lay people, like me, to understand, cause the vocabulary and concepts that Dr. Rogers rattles off without context. Thank you, Fraser. 😊

Love the way you're able to be a conduit between scientists doing the hard work and the public understanding what that all means. You've also got a wonderful sense of how to conduct an interview, you always ask the questions I think most of us would ask were we in your shoes, which really gives the interested viewer that level of satisfaction, that our questions have been answered. Which is great! Have a nice summer!

Unraveling dark matter sounds like it would be really frustrating. I hope they figure it out some day.

Frank Wilczek got the idea for the name "axion" from a brand of laundry detergent

This was really, really good. Good guest, great questions, lots of new information.

We can’t rule out the possibility that these axions are struffled.

This was another great interview! It reminded me of that famous Sir Arthur Conan Doyle quote "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."

After Dr Keir explained the symmetry breaking with a sombrero, to my thinking, a better metaphor would be a roulette wheel. In the early universe the steel ball is rolling around the outside, not committed to any value, but as the system loses energy, the ball/axion field falls into a numbered slot, and the symmetry is broken.

I liked the question about "best possible instrument". One thing that would help to look at dark matter clumpiness would be very large aperture (perhaps 1km effective diameter) space telescopes (infrared or optical) that could be used to measure the distortions and sparkles near images of supernovae detected in distant galaxies amplified by cluster-scale gravitational lenses.

Why do I get the impression from his answers that he himself only “kinda” understands axions? …yet their relation to dark matter.

14:18 I don't think he liked the mond idea, his head stopped nodding when mond was mentioned. Quite right too. This was good

It's more topical to the previous video but Imma ask the question here anyway. What would happen to a planet or a human if they were say relatively close to a supermassive black hole merger, where gravitational waves are really concentrated? Is it gonna have some destructive effects on the matter, or is it gonna stretch/compress everything including the atomic lattices and no one would even notice anything without instruments? What could you in theory feel or see if the grav waves are strong enough?

What I hear when he talks about a solution to the limited models is much more compute power and more physicists to program out the massive new models to BE computed. Sounds like a good match with both large scale quantum compute and AI.

35:40 Hope the cute spy in the background is called Axion. 🐈

Hm, so axions got a type of "charge" that uses a circular, looped, numerical system? Is the axial charge quantized or can it have any number of decimal digits for it's "angle"? And is the axis just mathematical, or is it something with some spatial meaning sorta like the axis of spin?

This video is why we need Fraser..🤯

Fraser is excellent at interpreting "scientistese" for people that don't know the first thing about, for example, the newest axion hypotheses - or sometimes even the difference between hypotheses and theories. 😂 Even those of us that follow this stuff closer than the non-nerds can learn a whole lot more from how Frazer explains what the scientists say than what they say, themselves. 😉 Leaving this like and comment for the care and feeding of the Almighty Algorithm, in hopes it sees fit to share this great content with more interested people. 🙏🏽😊👍🏼

I think I'm going to take a break from dark matter/energy videos till there's a significant experimental result to discuss...

I waa really struggling to understand everything, but i guess i could consider it a win that i did understand most of what was said

This sombrero field potential with the ball could use some more explanation. What tips the sombrero, what keeps it tipped, what if there's a person going through that space, could that person notice or see or hear anything out of the ordinary? What happens to space when that ball goes to the tip of the sombrero or over the edge, is that basically the dreaded phase change everybody is talking about that could end the whole universe in 2.1 nanoseconds?

@12:45 And what did you find? The correct answer is: Nothing.

4:37 “ Extremely low particle masses” of the hypothesised axioms. If this is the case then the current levels of energy available in particular accelerators should be producing them. Maybe a more sensitive or different type of detector is required.

after initial kind of understanding of the matter I'm now 20 minutes into the discussion and I'm lost 🤣 Despite the great effort of Fraiser I'm not sure what to think about the topic, is the existence of those particles all speculations or is based on some ground discovery? 🤔

We know that time changes (go faster or slower) at different speeds but also when you are closer to massive objects. So isn’t dark matter just a way of telling us that we forgot to put the difference in the “clock ticks” trough the universe into our equations?

Hi Fraser, Why dont you invite Claudia De Rham in to one of your interview.She has been working on Massive Gravity for very long time. It would be very good addition to your Dark Matter series. and cool stuff man.thanks,greetings from Istanbul

Good interview. I see you are getting pulled into the rabbit hole that is the particle zoo. Have fun, many interesting things to be seen there :D . I personally suspect if we are to apply the standard model to Dark matter it is going to be found in the form of some Quasi-particle as some unexpected emergent behavior from known particles and forces acting in unison in the cold dark areas of interstellar space. Like, Bose-Einstein condensate type behaviors as particles wave properties start to reinforce each other. This would be more a question for the Dr Keir if he is available but I am curious in the case of these Axions, If abundant enough to be dark matter, why are anomalous photons not being detected around Magnetars or other magnetic fields as these axions should be converted to what I would expect to be a specific telltale photon fingerprint of somekind in such a powerful magnetic field. Shouldn't axions be rather easy to detect if they exist? Why have they gone undetected for so long?

Hi Fraser, Thanks for great videos Do you know of any theory similar my speculative idea that black holes are a Time Machine that converts matter into a previous state, recycling it into sub-particals that get spit back out into our current time and splash about with our current universe, expand it with dark matter and dark energy. Could dark matter be recycled matter from black holes or dark energy from consumed light?

"It's time for another episode of What is Dark Matter?" Pretty funny opening.

As Axions reconstitute via infrequent photon collision, the early universe will most certainly have less Dark Matter as the condensed matter makes it more frequent. No paradox there.

Thanks...

❓How would the axion fit into the standard model, or would it even fit? Would they be bosons since they have 0 spin? How could they be produced in such large numbers but still manifest as cold dark matter? If such a thing is assumed possible for axions then why are neutrinos assumed to be relativistic almost by nature? Lastly, would axions be heavier or lighter than neutrinos?

hence "dark matter" is in fact invisible non matter so it can not be a particle as it is only energy but the fields of of this energy is what makes the physical world looks flat "a field"

If in the early universe almost all of the dark matter was in a liquid form it would help explain the rapid formation of everything. Once black holes and stars form they begin to vaporize the LDM this ongoing phase transition has been lowering the ratio of LDM/GDM ever since. This ratio would also vary throughout the present universe.

I've been to that Sudbury nurtrino detector

It's once we see thru the illusion of dark matter that we will probably find out we in a matrix...not so far fetched when u realise the more knowledge we get the more things don't add up in universe...

Is it only me or do you find cosmologists who scoff at discussing distances in light years a bit pretentious? “I have trouble with light years, we only use parsecs” seems to be the mantra of every cosmologist Fraser has ever spoken with. I live in the US and to me that’s the same as me saying “Oh, I can’t understand when Fraser mentions distance in meters”. Like I can’t rapidly convert to an order of magnitude of the distance he’s mentioned. Rising to the level of PhD should not be a hindrance to discussing different units - parsecs, light years, AUs, etc.

So if there were another universe created thatis based on additional fields or anti fileds that do not have an effect in this universe but the gravity does The matter from the fields and anti field grapple with each other and have a net effect that we observe

Q: When objects or debris around the centre of a whirlpool in water are attracted to that centre, then is that attraction because of dark matter?

4:23 Okay. he says "no" there isnt an analog/proxy but then says "they're extremely light [axions]" with extremely low particle masses. 🤔 But what about neutrinos? insofar as similarity -per the question- are they that dissimilar?

Neil Turok has a compelling theory about dark matter being right handed stable neutrinos..

As much as I enjoyed this video (like all of them) I have absolutely no understanding of what was explained to me!

Dark Matter 4D particle? Would a 3D machine be able to detect something 4 dimensional?

We've spent almost a century to find Dark Matter and Dark Energy but still there's no sign of them. May be it is time to find an Alternative Way to Explain Dark Matter and Dark Energy. 4-D Hypershere model of Universe can easily explain Dark Matter, Dark Energy, Void and even the reason why the measurement values of Expansion Rate are around 70 km/sec-Mpc Dark Matter, Dark Energy, Gravity, Void and Antigravity, ... all these are same phenomena. They just look different. The problem of modern physics is they're trying to explain everything with particle physics and the physics is being cornered more and more to the dead end. To escape the dead end, they invent or design another imaginary particle in vain instead of trying to revise their way to approach to the problem. I agree to the idea that the interaction between mass and space must be explained with quantum mechanics. But that doesn't mean gravity is the QM phenomena. That's because gravity is not a force. Dark Matter, Dark Energy, Gravity, Antigravity, Void... all these are just joint effects of the expansion of the Universe and the curvature of spacetime. Details are given below. Einstein’s theory of General Relativity states that spacetime is curved by the presence of mass. This curvature influences the motion other objects with mass and gives rise to gravitation. Thus, gravity is a result of geometric features in spacetime. However, we also observe gravitational effects - curvature of spacetime - in areas without any detectable mass. This has given rise to the concept of dark matter, which is matter that does not interact in any detectable way with normal matter, except through gravity. So, there is some large quantity of dark matter scattered throughout the universe, which curves spacetime and causes gravitational effects just like normal matter, but we cannot see or detect it with any known method. An alternative theory to the identity of dark matter is proposed - it is not matter at all, but rather an intrinsic curvature of spacetime. In other words, spacetime is not naturally flat. Even in the absence of matter, we observe some inherent curvature of spacetime. So, the question is now - why is spacetime naturally curved? Why is it not flat in the absence of mass? The universe is 4-dimensional, with 3 spatial dimensions and one dimension in time. Rather than consider time as a linear dimension, we can consider it as a radial one. Therefore, rather than describing the universe with a Cartesian coordinate system, we describe it with a 4-dimensional spherical coordinate system - 3 angular coordinates, φ1, φ2, φ3, and one radial coordinate in time, t. We live on the 3-dimensional surface of a 4-dimensional bubble which is expanding radially in time. Thus, the Big Bang represents t=0, the beginning of time. The crucial point is that the expansion of the universe is not homogeneous in all directions. The expansion rate at one point on the bubble’s surface may differ slightly from another point near it. The universe is only roughly spherical in 4 dimensions, the same way that the Earth is only roughly spherical in 3 dimensions. The same way we observe local mountains and valleys on the surface of Earth, we observe local “mountains” and “valleys” on the surface of the universe bubble. The inhomogeneity of the expansion of the universe has given rise to natural curvature of spacetime. This natural curvature causes the phenomenon of “dark matter”. “Valleys” in spacetime pull matter in, similarly to the warping of spacetime of massive objects. So “dark matter” is really “valleys” in spacetime that are expanding slower than the regions surrounding it. These valleys tend to pull matter in and create planets, stars, and galaxies - regions of space with higher-than-average densities of mass. Conversely, “mountains” in spacetime will repel matter away, an “anti-gravitational” effect, which gives rise to cosmic voids in space where we observe no matter. Each point on the surface of the universe bubble traces out a time arrow in 4-dimensional space, perpendicular to the surface. These time arrows are not parallel to each other since the universe is not flat. This causes points to have nonzero relative velocity away from each other. It is generally accepted that the universe is expanding faster than observable energy can explain, and this is expansion is believe to be still accelerating. The “missing” energy required to explain these observations has given rise to the theory of dark energy. The time dilation caused by non-parallel time arrows can be proposed as an explanation for dark energy. Alternatively, dark energy is real energy coming from potential energy gradients caused by non-parallel time arrows. As a sanity check, we can calculate the expansion rate of the universe based on the universe bubble model. Since the radius of the universe bubble is expanding at the speed of light in the time direction, it increases at 1 light second per second. Therefore, the “circumference” of the 3-dimensional surface increases by 2π light seconds per second, or about 1.88*10^6 km/s. This expansion is distributed equally across the 3-dimensional surface, so the actual observed expansion rate is proportional to the distance from the observer. At present, the age of the universe is estimated to be 13.8 billion years, so the radius of the universe bubble is 13.8 billion light years, or about 4233 megaparsecs (3.26 million light years to 1 Mpc). Thus, we can calculate the expansion rate of the universe, per megaparsec from the observer, as: Expansion rate = ((d(circumference))/dt)/radiusofuniverse=(1.88*〖10〗^6 km⁄s)/(2π*4233Mpc)=(1.88*〖10〗^6 km⁄s)/26598Mpc=70.82(km⁄s)/Mpc The popularly accepted empirical expansion rate is 73.5 +/- 2.5 km/s/Mpc, so our calculated value is close. There may be some additional source of expansion (or observed red shift) to make up for the discrepancy. For example, if two adjacent points have some gravitational gradient due to non-parallel time arrows, then light passing through these points will be red-shifted. - Cited from www.academia.edu/82481487/Title_Alternative_Explanation_of_Dark_Matter_and_Dark_Energy

Axions as a window into string theory is intriguing

6:40 So axion value is a Universe-scale roulette wheel...

Q. not related to the topic How does a neutron star, all made by neutrons, produces magnetic field?

This may sounds dumb but what if dark matter is thousands of different particles we already know to science working together. How do different particles interact with matter and gravity in a vacuum? It’s like a web in a galaxy. Each massive object connects to another in a way till it gets to the most massive mass at the central point. I’m a simpleton. Sorry. I know galaxies aren’t a centrifugal clutch.

Please explain how you can map the distibution of dark matter over history, when you cannot even prove it exits. it's still only theoretical

Forest Gump: It’s time’s interaction on matter.

When he's talking about the sombreros he's talking about energy density I'm assuming in giga electron volts Imagine that as a graph Different places where different particles can be energy-wise ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-R7dsACYTTXE.html this video Help you with understanding the sombrero thing he's talking about But where the sense of freedom of not being in one of those places in the higgs field imagine the graph is a circle instead I could be wrong but seems make sense

Finally I hear someone say dark matter is all the missing stuff.

Is mass just the interaction with the higgs field ?

Axions or Not. What's Hiding Behind this Dark phraseology? Well struggled Frase...

The next thing that gets discovered is going to be called an axion, seems like.

This is the guy from SEA, right?

What is Empty Space?? Absolutely Nothing??

Hey Fraser. Do you know any youtubers who are more advanced than Paul Sutter? Paul Goes in really technical and I love it. But I need even more technical information. The kind of people who speak about things that I may need to google their words to understand them. Paul is the nxt level up from your channel but I'd like to know who is another level or two above that. Thanks #2pac4ever

Dank matter is very troublesome.

3📍22:56 4📍31:20

Parsec is simply a fail of a unit. Light year has to be the most natural unit for human comprehension, and they screw it up.

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I talked to my wife about the new Gravity Wave Background result, she said it sounded like it was Gods Heartbeat! I then calculated that at 1 billionth of a hertz, God would be 16 years old…

I Hope they Give AI control of JWST.❤ 🤓

🖤⚡🖤

Three quarters of the mass of the universe is cloaked alien battleships.

"The Dark Sector"

But, gravity, the reason why astronomers are interested in dark matter is its gravity, and as the large attracter attract me, i am also attracting the large attractor, via graviton, so, we are told there is 10 times more dark matter than undark matter, in that case, how come i do not attract dark matter?

proposed.....

I believe that dark matter is normal matter that is hidden, from an observer's perspective (in this case, us) in higher spacial dimensions. The big question is who & why would someone want to hide certain things out in space, from us? 🤔🤯 Also, In respect of the wave pattern in the double slit experiment, Photons don't experience time so, from their perspective, wouldnt all photons that go through a specific double slit setup, whether going through, from our perspective, one at a time or many at once, go through all at once, again I stress, from their perspective. Would that be why we get wave patterns when, from our perspective, when it seems they are going through one by one?

Sorry, but after listening to two very intelligent men, I'm more confused about 'Dark Matter' than ever before. I'm not even convinced that 'Dark Matter' exists outside the minds in the brains of Cosmologists!!!😇

How about you take a serious look at my theory, available here on youtube?

More than one axiom type is a frustating prospect. WIMPS, distracted us for so long

dark matter = investment scam sink

Dark matter isn't needed. It's measure of distance that is larger and the rate of time that is going faster away from the center of the galaxy in the outer spiral arms making the distance less and making things happen faster.

After watching this video, I'm absolutely now convinced that Dark Matter isn't Axions! The guest really did a really crappy job of explaining what Axions are. Despite the fact that it's somewhat difficult to explain quantum things, you should be able to explain it partially. This guy couldn't explain it at all. So I got the feeling he himself didn't understand it properly. How many of the rest of the people in this field are in a similar boat? It seems like it's just the current best employment opportunity.

Best video about it is from acollierastro. :D

Spoiler: there is no dark matter, it’s incomplete physics.

This is a simple or stupid point of view energy can't be destroyed energy changes form?

All the hype surrounding EVs and AI is delusional; the real breakthrus will come from Physics and Chemistry ... not fancy computer software or dressed up versions of old technology pretending to be innovative. EVs are nothing new, the technology isnt new or cutting edge either. You can pick up a Playboy from 1997 and see electric scooters in it. The exaggeration of the importance of so-called "AI" is also glaringly disappointing everyday, its just a meme and stock bubble. *What really matters is solving the big mysteries in particle physics so we can safely become a post resource scarcity civilization.* You cant build flying saucers or dyson swarms without first understanding how to win the battle against gravity.

Really poorly explained by this Dr. I don’t think he understands it himself. He seems to just be regurgitating information, and can’t connect it to a new person’s understanding level.