Very interesting. I love how Hooper was able to construct a new example on the spot. This guy knows his stuff, since he is able to craft new examples and not just repeat the examples others have already thought out.

Thanks Dan, 5 years on, and this is STILL the most understandable conception & explanation of Dark Matter that I've seen.

Love how approachable he makes this. Well done and tysm for making this content available for the masses

Well done. Including the slides and the video editing and formatting. Very enjoyable.

Thanks for uploading - interesting lecture and very well presented!

Dan Hooper is very engaging and makes this already interesting subject even more engaging. Well done!

Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but accounts for most of the matter in the universe. The existence and properties of dark matter are inferred from its gravitational effects on visible matter, radiation, and the large-scale structure of the universe. It has not been detected directly, making it one of the greatest mysteries in modern astrophysics

A great talk, probably the best I've seen on Dark Matter. I also loved how intelligent the questions afterward were.

15:50 "If anyone can convince you of something that complicated in 5 minutes, then you're too gullible" Good one.

Thank you Dr Hooper.

Fascinating, thanks!

Amazing lecture !

Such wonderful lecture!!😄😃

I love nature, keep it rolling!

The hype man should be a Fermilab legend. I was love to find out that introduction is remembered among Fermilab insiders.

The downside for when we understand Dark Matter is that it won't be so mysterious anyone. The upside is also that it won't be mysterious anymore.

This came out on my birthday!!

So much better than the brain dead "Hollywoodized" docu-tainment garbage on television.

Wonderful lecture. Dr. Hooper made it clear and easy to understand. Thank you!

Great lecture!

Man I really love how that dude just popped out stage right and yelled "GOOD EVE TO YOU M'LADIES ET GENTLESOULS" with a tip of the fedora and a twinkle in his eye.

27:41 I think, this gamma ray shows us the rotation axis of universe. And this image pretty nicely fit a "torus universe" model.

on this day Monday 12th of February I unified QUANTUM MECHANICS AND GENERAL RELATIVITY! now can someone please tell me who requires the answer and how do i get it to them.

Excellent lecture! One question: Based on the energies of the observed gamma rays, what is the mass of the corresponding dark matter particles?

Really nice and informative lecture.

awesome!

Great explanations. I cannot wait to see the results of the next 30 years. Hopefully a result is forthcoming. I’m no particle physicist, but I can say that anything is nature is very natural and we see that, once we are aware how any given system works. The spin of the galaxies is very curious indeed. Black holes have more to them then just existing and creating gravitation waves. Scientists do not attempt to understand their inner structure, and I think this is a major mistake. While past the event horizon lays “elsewhere” it still represents volume within our universe. What is their function......

Shouldn't planets also move faster than expected? That can be easy calculated and dark matter density around star can produce some sun effects

DM is an elegant explanation - best fit. But we don't know what we don't know and a better understanding of quantum mechanics may bring other explanations. Particles with no locality or time signature, entanglement, and virtual particles may offer an alternative to explain the phenomena responsible for accelerated expansion.

So this is how so many physicists keep food on the table?

wow what we don't know is far more interesting than what we do know. Very good video!

43:12 The pulsar is pulling matter from its companion star, I guess that's why it's called a pullsar :D

Anyone knows if some sort of "Light bulb" that Darkens a room instead of lighting it exists? if you do please let me know!

12:23 We are In!

How about trying to use the lightest Solid because itgood insulator to hot and cold substance ? On the LZ dark matter experiment.

Dark matter is just a placeholder name for something we don't know. However it does qualify as being matter in the same way as atoms do, it has mass.

Don't believe Dan answered Troy's question: "What were you smoking when you wrote the paper?" Think it was lead-up to the follow-up question:"Where can I get some of that?" Great imaginative work on DM annihilation. Good job, now get back to work!

What is more likely? That 96% of the Universe is invisible, or there is some fundamental flaw in our scientific understanding of gravitational effects? Really now, grumpkins and snarks?

Great presentation. But I really want to go to the reception with punch and cookies. That makes me hungry!

I have some questions: Since we don't know what exactly DM is, how do we know they can annihilate and create Gamma rays? Also If the most of DM within the galaxy is contained at the center, doesn't that mean that the Galaxy should still move like it doesn't have any dark matter? (like the left Galaxy at 7:50) I thought the dark matter has a different distribution than the light matter and that's what is causing the Galaxy to move Faster on the outer radii than it should.

I think that more needs to be known about the area in space you are observing the density of gamma radiation in. You mention it, but it is worth restating that a feeding black hole (or anything else either massive enough or intense enough - e.g. particle collision at speed in the Hadron Collider) can or does create gamma rays which are also a byproduct of E=MC squared. Great presentation, is there a rationale behind why you are finding a density of gamma rays in the data rather than finding a spread of gamma rays? I guess what I'm not following is - if we are assuming Dark Matter to be non-EMI based and ruling out the EMI forms of matter and that Dark Matter doesn't interact with normal matter (as explained as passing through our hand) I don't entirely follow how the presence of an electromagnetic wave such as a Gamma ray indicates a density of Dark Matter. In the initial description Dark Matter sounds like it's proposed to be some form of a non-conductor which doesn't interact with the electromagnetic spectrum. It would almost seem that absence of gamma rays in an area could be more an indication of dark matter - supposing that as a non-conductor it block or somehow deflects the path of the gamma ray - which also sounds improbable if the description that it does not interact with EMI and there by shouldn't reflect, change the course, or absorb something based in the EMI.

So a black hole do emit: (1)Gamma rays from it's poles, (2)Hawking radiation, (3)Gravity waves when two BH collide and (4)Explode upon shrinking to the smallest size. Can black holes radiate dark energy too? (Since stars emit light) Just seems like there is more going on here...

I recently spilled about 5 liters of dark matter in my basement. It seems like everything that's not tied down gets attracted to it. Clean up is going to be impossible.

I downloaded this

I like in every model of the singularity it is surrounded by a dark space. In the model too it has to be surrounded by dark space before light can travel. That a magical area helped to cool down the infant universe and it physically did it all on its own with nothing to radiate that kind of heat. Found it kind of interesting that they thought of interactions with antimatter. That ultimately dark matter is interacting with particles if it is primed down to size.

If the observation holds up: what parts of the theory-"playground" are excluded? I mean in order for the models to be distinctive, they have to make different predictions... (- aside from the problems DM was invented to solve: mass distribution / structure formation).

This public lecture is even better than Feynman's

What is dark matter? Physics don't hurt me, don't hurt me, no more.

So while there's clumping, groups of galaxies passing through each other he's not showing that all of this is expanding at the same time? Is that taken into account and it's just too slow to show up? I don't think these examples are correct if not. Are they? I'm just a high school graduate, help me here.

How about pass around it the other neutrino ?

Could the beam from a pulsar reflect off of a planet and be reflected back to earth? It would give a 3d version of a part of the universe and that might help with the hunt for dark matter

Always enjoy a dark matter lecture.

What if we tried looking in instead of outward? If DM interacts with gravity but not matter then Earths gravity should attract it? yes/no? If it does not interact with matter then any DM attracted over the past 4.5by should collect near the earths centre? yes /no? Creating a pool/layer of unexplainable "mass" that may already be detectable by standard seismic readings but appear to be an error?

Like explaining looking for intelligent messages from space in high energy wave lengths while ignoring crop circles around the globe. Fermilabs telling us that Dark Matter exists while ignoring the massive amounts of Blackholes in the Universe .... remember, when going the speed of light, drive around the black holes - black holes are black, nothing escapes their grasp, not even light

Here is an idea... I wonder if light (EM radiation) from stars can somehow increase the production rate of virtual electron-positron pairs in free space due to ever-present quantum vacuum fluctuations. And these virtual electron-positron pairs are interacting gravitationally (no outside EM interaction) before popping out of existence again. Maybe dark-matter isn't permanent, but more a property of how space behaves when the quantum fields are excited by passing bosons. Virtual particle production and destruction rates are able to reach different equilibrium pair concentrations (more-or-less gravity), depending on the concentration of bosons flying through a volume of space. That's why you would find "dark-matter" clustered around normal matter. It's because that's where the highest radiation concentrations are. I think we will need to understand gravity a lot better (quantum theory) before we will be able to determine what dark matter is.

I like watching scientists trying to explain what they do to a general audience - some do so extremely fluently and others struggle tremendously but either way it's a break from all those samey TV drama shows they encourage you to buy twice. SLAC have got the right idea with the catchy thumbnails and I know you could probably get in touch and they would sell you a hard copy of your preferred presentation but how about releasing an entire series? I know your teenagers would be pleased you stopped off after work on Monday for the latest box set even if you could have downloaded it on cable.,..

I thought that DM was introduced to explain gravitation in places other than where ordinary matter is. Why do they look at the center of the milkyway then? That is counter-intuitive. Shouldn't they look at the supposed DM-Halos etc.?

What if the fundamental forces act different in the large scale? Or maybe dark matter is small particles smaller than quarks.

what a privilege, to have Dr. Hooper for a lecturer..... even moreso, for those he has mentored !!!! the planet needs more Scientists/Researchers like Dr. Hooper, who arent so biased and convinced of their own god-like superiority......! this guy is a Model Human, curious, clever and humble.

Sooo are we gonna talk about how we are basically claiming the ether to exist by another name? :x

The dismissal of neutrinos as was very fast. I think it would have deserved some more atttention because that's the first idea an amateur student would usually think of. Because, obviously, they have been getting produced alot, even at the beginning at the universe - and have we got estimates how many ?

Listening to lectures in my socks and underpants, reminds me of Art college. Fascinating, thank you.

why is gravity still considered a force??

My hypothesis that Dark Matter is not a weakly interactive massive particle (WIMP), but maybe is a deformation of space-time by which the curvature of space-time itself is the cause of the gravitational effect. Gravity is the consequence of the curvature of space-time when mass is present. It may be possible that the structure of space-time itself could be warped without the presence of mass. So, how did this warping occur? We believe this warping of space-time occurred during the extreme conditions present during inflation. Space-time has been shown to react like a fabric by warping, twisting, and propagating independent of mass. These properties have been proven with observations of gravitational lensing, frame dragging, and now gravitational waves. Fabrics can be stretched, pressured, and/or heated to the point of deformation. Such extreme conditions were all present during inflation, so it is plausible that space-time’s elastic nature could have hit its yield point and permanently deformed. Therefore, if gravity is the consequence of the warping of space-time, and fabrics can be permanently deformed, then a deformation could create a gravitational effect independent of mass. Thus, the unidentified dark "matter" that seems to be so elusive to modern science may not be matter at all but merely warped deformities causing gravitational effects. We have a prediction using gravitational lens mapping to prove Dark Matter isn’t a weakly interacting massive particle, but instead is a floating fixed pocket of warped geodesics in space-time geometry causing gravity wells.

i love how we rewrite an entire universe to make it fit our minuscule minds when we should be rethinking our minuscule minds to fit our virtually endless universe

We keep saying we know less and less about what the universe is made up of. It's now down to about 4 percent known substance, and 96 percent absolutely unknown. I encourage you to really look at galaxies. It looks like many of them are expelling matter and generating stars from the middle and hurling them outward, expanding rather than collapsing.

A better analogy for the last question would be a wheel.. same reason smaller wheels have to rotate faster to go the same speed as bigger wheels

If his assertion is correct that there may be represented a new sub-particle then there also may be a way to make stable elements previously found impossible within the periodic table. An entirely new understanding of physical dynamics may actually exist. If the sub-particle is a stable version of the Higgs Boson, or even a transient manifestation of it, other worlds unimagined might still be in the offing!

If black holes 🕳️ keep are imperative for the galaxy to form and dark matter keeps our galaxy from falling apart and the universe is expanding then how is it that the Andromeda galaxy will one collide with the Milkyway?

So it must be likely that dark matter is a lot of different things just as visible matter is?

Most awesome discovery would be to find out that universe is an enormous brain, and everything is a manifestation of computation happening in that system...

In *1967* the first gamma-ray emissions were discovered in our galaxy from satellite Orbiting Solar Observatory. *1969* OSO3 detected from the galactic center gamma rays with energies > *1 MeV.* What is now so new here?

extra dimensions good candidate because it help the String Theory

I watched Dr Dan's video & i read the comments & i would like to give an aether perspective (ie a non-Einsteinian perspective). Ranzan says that a neutrino is made of two helical photons sharing the same axis (the fields negate). Hencely a neutrino has a mass of twice the mass of a single photon (the standard model says that photons dont have mass). Anyhow the destruction of a neutrino must produce two photons. Elementary particles are made of confined-photons, made when a free-photon bites its own tail & forms a loop (Williamson). If free-neutrinos (dark photons) likewise form loops then perhaps this gives dark elementary particles (possible i think), which form dark sub-atomic particles (impossible i think), which form dark atoms (impossible), giving us a class of dark matter (yes & no), & a class of blackhole (possible i think). I reckon that dark elementary particles (having no charge & no electro magnetic field), would not be able to form nuclear atoms (ie dark atoms), but would be able to directly form the equivalent of a neutron star, but made of dark quarks & dark electrons packed tightly together (due to gravity). These dark-stars need not be very massive, in which case they could be called dark-planets, & dark-moons, & dark-asteroids, & dark-dust. They need not be very massive, but all of them would be as dense as any neutron star. This type ofdark-mass might be as black as the mythical Einsteinian BlackHole, perhaps blacker. Dark-mass would gravitationally attract ordinary (visible) mass, & this might create very visible bursts of ordinary photons. A dark-star colliding or merging with another dark-star (or other dark-mass) might also create bursts of ordinary photons, giving visibility for a while (including gamma rays etc). Dr Dan might be measuring these gamma rays. Dark-quarks & dark-electrons would have no charge or emf (the opposite of what Dr Dan says-expects). Very massive ordinary stars (ie neutron stars) if having a plasma atmosphere must be blueholes due to Cherenkov (blue) light, hencely these are not blackholes (they are blueholes). Einsteinian BlackHoles (where the mass can become a singularity & where the escape velocity equals or exceeds c) are impossible. Anyhow blueholes can be much less massive than BlackHoles, & there might be a great number of blueholes distributed throo all of the Milky Way. I haven’t done the math but i think that unless a dark-star or a neutron-star can shrink to form a singularity (or very nearly) then the escape velocity can never reach c. Ranzan has a theory where mass disappears out of existence inside a super-massive star. Regarding dark-mass, neutrinos have mass & hencely are themselves dark-mass. Ordinary photons have half the mass of neutrinos & hencely can be classed as dark-mass, not because they are dark, but because Einsteinians are blind to them.

As reference, the paper where is described a solution of the rotational velocities observed in spiral galaxies, without using dark matter, is the following (from 2020): article.sapub.org/10.5923.j.astronomy.20200902.01.html

Dark matter is obviously just a variation of matter that's not bound to this exact position in the 4th dimension but is close enough that we can see its interactions with the matter that is in our position in the fourth dimension. You can email me for details on how to send me the nobel prize, you're welcome.

My theory is :- dark energy are waves of extremely low frequencies and long wavelengths. Dark matters are waves of ultra low frequencies and long wavelengths( but higher in frequencies and shorter in wavelengths than dark energy). Visible matters are waves of frequencies higher and wavelengths shorter than dark matter. Apart from frequencies and wavelengths, there are no other difference between visible matter, dark matter, and dark energy. E = Mc^2.

Is it possible that dark matter are the constituent of quark and lepton? Maybe during the big bang some dark matter became charge and transform into quark and lepton that formed atoms.

It just really blows my mind how this was all created randomly...

Video starts at 3:28

If we are in Euclidean space inside an elliptic plane and light is just red-shifted by elliptic gravity it's apparent that the universe is far older.

start here 2:50 if you would like to keep your sanity

I almost thought that i heard Bob Odenkirk's voice :-o

Oscar nominated film?!?! What the?!-- no doubt she was looking for something like "Titanic". Being old-school myself, it's obviously a classic (mystery) like "The Maltese Falcon"

p.s it will add an awesome intersection for the really inquisitive if you are super aware

if the universe was tilted 90 degrees ,we would see a 10 node universe contained in a magnetic bubble, created by the galactic center object

Good lecture but he didn't really answer most of the audience's questions. If one doesn't know the energy of the dark particle, how can you run the gravitational lensing or matter consolidation models? Without those numbers, what led him to conclude that particle annihilation could be detected by the gamma ray telescope? He mentions that there may not even be a dark matter anti particle to annihilate. So what interaction would be giving off the GR signal? Guess we need to read the papers.

I truly hope there does turn out to be dark matter... shame to be so long, and yet empty, a rabbit hole.

Wonder if an advanced species in the universe, is watching this like we would watch a comedy show. Thinking WOW this is so dumb it's funny. Basically we have no idea what Dark Matter, or Dark Energy is, or how to detect it. We are still babe's in the woods trying to make sense of the forest. I hope they keep trying and learning so maybe one day we will know. Also he's a very informative and engaging speaker, and seems to really care about discovery. Which is rare when most only care about ten-year. Go Dude.

In fact, it seems more and more..that Milky Ways and Galaxy's (and every other item in the universe) are not orbiting just around gravity. It's a lot more to do with Electromagnetic Fields than you and I think. Check 'Primer fields' and you will have some more clues and answers. (and a lot more questions!)

"Dark matter" is the flow of electrons into galaxies. The galaxies have B-fields and when electron flows into gives a force f=eVxB=mv^2/r. The result rotation v=(e/m)(z/c)I=220km/s. The electrons come from escaped hot bodies. See my book The Universe is Electric.

Scalable Aether, Casimir Effect Universe. "The smaller the spacial footprint, the higher the capacitance". Space and Counterspace are the plates and the infinite capacitance, Inertial plane attracts and repels the plates. Dark matter is in Counterspace. The Universe is a negative hologram. Inertial plane(0D, "Condensate of Universe")~Dielectric energy(longitudinal pulses)~Dielectric voidence field/Magnetism = transverse waves, EM waves path, needs both paths. Aether = e- ~ Inertial plane ~ p+. >~< Aether's hyperboloid rotates in one direction. Oscillating Inertial plane = neutrino. Absolute zero is in the Inertial plane/Counterspace. That's why absolute zero can not be reached from above or below.

I wish my last name was "Goodenough"

What's bothering me is that bullet like picture of collision of two galaxies when two globes of dark matter fly thru each other with no collision. okay, dark matter does not interract with regular matter - thats okay for me. But dark matter is gravitationally involved , that means dark matter particles should stick to each other gravitationally and if they not interract there should be ultimate mass concentrated in singular point after a while! Shouldn't be a somewhat like Lennard-Jones potential for dark matter?

More accurate to call it .

Love to hear and learn from these lectures. Anyone who refutes the conclusions here is an idiot unless they understand the science as well as this gentleman and has data to back up their refutation. Scientists say what they think and they reveal the data that causes them to think as they do. I love hearing scientists explain things in reference to what is known and what is not yet known. My only issue is the amount of money we spend and the value the common man gets from that expense. What is the point of science if we refuse to learn from it?

Why the big bang hapned?

Why exactly can't dark matter be made out of neutrinos tho?

So how come we call the 4% ordinary?

Maybe there is a world of invisible planets and galaxies around us, only 'visible' by its gravity