Is Dark Matter Real? - with Sabine Hossenfelder

What is the evidence for and against dark matter? Sabine argues for the superfluidity of dark matter that allows for a suitable combination of dark matter and a modification of general relativity.
Watch the Q&A: • Q&A: Is Dark Matter Re...
Explore more of Sabine's ideas via her book: geni.us/HfbLg
Or KZbin channel: / sabinehossenfelder
For more than 80 years, astrophysicists have collected data that suggests 80% of matter in the universe is 'dark'. These observations have led them to believe that it is made up of an as yet unknown substance.
Sabine Hossenfelder is a physicist and science writer. She is currently a research fellow at the Frankfurt Institute for Advanced Studies. Sabine's research focuses on the foundations of physics. But her interests extend to the philosophy and sociology of science. Sabine partly works as science writer. Her writing has been published, among others, in Scientific American, New Scientist, Nautilus, Aeon, and the New York Times. Sabine has an active KZbin Channel dedicated to communicating current science news and scientific methods in general.
This talk was recorded on 10 June 2021.
Image credit: Illustris Collaboration
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[@TheRoyalInstitution]

Can it be? It can indeed, she's here! We're so happy that Sabine Hossenfelder accepted our invitation to speak at the Ri about all things dark matter. If you haven't checked out her KZbin channel, you really should - kzbin.info

[@SynKronos]

Conceptual fallacies abundant

[@janwaska4081]

This insightful video presentation is another indication confirming that Biology is the new Queen of science, while Math and Physics are the efficient servants of the new queen. Biology has more ongoing research producing real results that can lead to new medical treatments and even ecological improvements. But most importantly, Biology research is increasingly showing complex functionally specified information processing systems that according to our accumulated empirical observations can only be the product of purposeful conception.

[@twt1524]

@@janwaska4081 It took a while to get from Schrödinger to 5G and iPhones but no one cancelled physics funding b/c it didn’t create a profitable commodity every year. But yes, thank you biologist for all you do, from evolutionary biology to medical sciences. I wouldn’t want cancer treatments from the math or physics department. But you can’t hav chemistry without physics, and you can’t have biology without chemistry.

[@dxhelios7902]

This is confusing for a science. We observe curvature of spacetime, ok. Then we say ok, this could be cause by matter. Can we find the matter? No. So, then, first assumption should be, that probably curvature may be caused not just by matter. But instead of that, we make assumption that it is matter, even we cannot detect it and then go further and say it is dark matter. Pseudoscience? Confusing.

[@trollking202]

@@BeckyYork good one👍☺️

[@Siderite]

I like how she paused after saying Einstein, probably considering whether to say "yes! that guy again"

[@bjs301]

You watch her videos!

[@PetraKann]

That’s what you liked from this presentation?

[@owlredshift]

@@PetraKann It's an inside joke, don't let it upset you

[@tarmaque]

Only true Sabiniacs get that joke.

[@mesokosmos2212]

Even without saying it, she communicates her point.

[@eljcd]

It's great to see Dr. Hossenfelder in the RI channel. I hope that someday we can see her lecturing in the hall!

[@trespire]

Watching Sabine blow up stuff in a RI Christmass Special would be fun !!

[@onionknight2239]

I thought I was watching her channel till I read this comment. Couldn't agree more 👍

[@leematthews6812]

I would totally love to see one of her lectures in real life, rather than on screen.

[@greghansen38]

Interesting how her presentation and speaking are different on her channel and in a (Zoomed) lecture hall. I kind of like Sabine die Professorin.

[@claytoncostello6583]

Agreed

[@illogicmath]

This is absolutely the best public lecture on dark matter I've ever seen on KZbin

[@gerardvila4685]

I agree. Sabine is a fantastic teacher. ❤☺👍

[@annaclarafenyo8185]

I'm surprised, because she had a close to unscientific position on this in the past.MoND doesn't work, unfortunately, it's a lousy theory. The superfluid idea is good though.

[@illogicmath]

@@annaclarafenyo8185 a good scientists has an open mind

[@annaclarafenyo8185]

@@illogicmath What? Absolutely not. A good scientist has a mind that closes once the evidence is evaluated. No scientist must ever have an open mind, ever, at any point.

[@illogicmath]

@@annaclarafenyo8185 That's the weirdest thing I've ever heard.

[@alexanderstainton3199]

What a great overview. Most dark matter content normally focuses on one possible theory without giving context on the extent of problems that need to be solved.

[@ShauriePvs]

I guess Sabine would have loved giving lecture in the actual royal institution stage offline.. But still happy to see her in this channel

[@TheRoyalInstitution]

We are absolutely inviting her back to give a talk in the theatre! But in the meantime, she was actually in the building very recently with another of our good friends Rohin Francis - kzbin.info/www/bejne/mHq3aZKiiJmpiLs - keep your eyes peeled for our video with them both that is coming out soon!

[@LeoStaley]

@@TheRoyalInstitution Thanks for reminding me of that! I would love to see more of that kind of format, "expert in one field asks their personal questions to expert in a totally different field"

[@rubiks6]

@@TheRoyalInstitution - This is why it pays to read comments! Looking forward.

[@trucid2]

It was an unexpected surprise to see this video in my feed. Go Sabine!

[@hannessell7883]

Are there expected surprises?

[@user-wu8yq1rb9t]

*SABINE??!!* *REALLY?* *I LOVE Sabine Hossenfelder, she's great.* Thank you so much *RI* .

[@effiebriest1278]

Sabine allways gives me the feeling, I could maybe understand physics. Also, in addition to all the great content we get from RI, finally this is one with good audio. Danke Sabine!

[@JimGobetz]

Just joining with many who have posted before me, it's great to see Sabine at the RI. It's great to hear her anywhere but especially nice at RI. Thanks for this great content.

[@TheRoyalInstitution]

That's really lovely to hear, thank you!

[@deltalima6703]

I appreciate that Sabine added in some speculative stuff about superfluids, it was pretty clear that it is speculative too. A very nice talk from Sabine and RI. :)

[@nurk_barry]

Tried to watch this last jogger before bed after a long day at work, was exhausted but still kept trying to stay awake and take in the lecture, this morning I’m watching it again. Love Sabine!

[@davewalker8850]

Shes so so cool, wish id stayed in school, 6th grade educarion and im getting the concepts. Which for me not bad, just never learned the tools.

[@malcolmtent]

Just in case you didn’t know, Sabine has a superb KZbin channel.

[@bjs301]

It's one of my favorites. She's not only brilliant, she's very modest, scientifically. She never loses sight of the fact that what we know is vastly outweighed by what we don't.

[@urfinjuice1437]

Yes, there you can learn that two plus two is not really four and other interesting things. She debunks these falsehoods that many of us have been taught in school. I totally recommend this.

[@urfinjuice1437]

@@bjs301 Indeed. I admire her modesty as well. Especially when she talks about how most physicists are wrong and that she knows what is actually true. This demonstrates her modesty and her brilliance at the same time.

[@ElectronFieldPulse]

@@urfinjuice1437 - What specifically has she been so wrong about?

[@urfinjuice1437]

@@ElectronFieldPulse What do you mean? I never said she is wrong. Most physicists are wrong, e.g. about dark matter currently being the best model to explain the observed phenomena. But about other things as well. They are just not smart enough to see what she can see. But I am most impressed by her understanding of math. Like when you put two cups of water of 20 degrees together, you do not get water of 40 degrees. This proves that two plus two it not necessarily four. Many people to not get this.

[@baoboumusic]

This is pretty awesome. I like that it starts from the question pretty much everyone has, and doesn't evade any of the other questions either. Well done Professor Hossenfelder and RI.

[@rbewoor]

Brilliant! Simply brilliant video and explanation. Sabine i have been a fan of your channel. Your ability to convey dense subject matter in a clear, concise, and still keeping it so interesting is par excellence. Thank you to you and RI for making this video available to us all.

[@georganatoly6646]

you know the channel cares about scientific validity and integrity when the first noun in their video's description is 'evidence' -- a refreshing change in priorities compared to some other pop-sci youtubers

[@Lolwutdesu9000]

I don't think there are any science channels that hold a candle to Sabine. Rather disappointingly, there are many terrible pop sci channels. I remember cringing at minute physics many times, and now Science Asylum is probably going to take that spot for worst channel.

[@georganatoly6646]

@@Lolwutdesu9000 I would also add Anton Petrov's channel to that list with Sabine's, from what I've seen his content tends to focus on discussing published research papers, which tends to help keep his discussions of topics grounded

[@Lolwutdesu9000]

@@georganatoly6646 totally agree. There's also Astrum (brilliant for astrophysics) and Physics Explained (describing well in detail different physics principles).

[@axeman3d]

Sabine on RI. I'm a bit disappointed she never got the chance to present in person at the hall.

[@dorgarm]

Doctor Hossenfelder is truly one of the greatest physics educators! So happy to see her work with the RI!

[@AlphasysNl]

34:15 on the subject of a0 being related to the cosmological constant in MOND. I have a serious problem with that. That a0 is about the square root of a third of lambda is fine and all, but we're comparing constants. Singular values. Specially when saying "No one has any idea why", these singular values might not have ANY relation to each other, but it is asserted that they do; for which reason? Relative magnitude is nothing to go on. If we had similar curves, or an algebraic relation between two curves, now that could be indicative. "Inventing" some relationship between two constants is too far a stretch, so I'd love to hear more about this assertion.

[@Chris.Davies]

Specially when saying "No one has any idea why"! This, and the preceding statement of relation stopped me in my tracks. I clicked pause and tried to do some sort of mental experiment, or creative imagination on the subject... and totally failed. Perhaps space itself is a superfluid of sub-Planck length particles with their own set of 3-dimensions of sub-space, and another dimension of time. If the observed redshift is attributable to tiny amounts of drag through this superfluid, and our picture of the universe is not correct, having interactions between baryonic matter and superfluids in our four-D spacetime, and superfluids lurking in subspace dimensions might explain a few things? My feeling is that Dark Matter IS another superfluid. and that phase changes in, and relative densities of them, and their interactions might help explain a few fundamental things. Perhaps gravity is simply the local density of the space-time superfluid, and it is attracted to mass? And maybe there is no curvature of spacetime at all? Maybe it'll end up in human sacrifice! Cats and dogs living together! Mass hysteria! Run for the hills! Get batteries on the way!!

[@raffaeledivora9517]

It is not in any way implied that they are related. It simply comes out that the most likely value is close to that, and so you write it like that for simplicity's sake. It's a bit like when we use 1/137 as an approximation for alpha_em, without any implication that the electromagnetic coupling constant is actually equal to 1/137 [and in that case, it's known that it isn't]. Of course, that the transition scale would be close to that particular number is very curious, so some people will (and should! You discover new things by trying and most likely being wrong, not by doing nothing!) try to work and build a model in which the two are actually related... but even if a theory like that was made to work, in no way it would become a fact. It would be just an hypotesis, as long as there is absence of experimental evidence

[@lucemiserlohn]

I really like Sabine's content and approach to science. Skepticism that is grounded in scientific observation instead of opinion or make-belief, and a principled rejection of conjectures that cannot be proven or have not been proven as of yet (proven in the physics sense of: so far it has turned out to make correct predictions and we have not found a wrong prediction YET) and instead rigorous application of Occam's razor. Also, very thoughtful deliberations and jokes about "that guy again", what is there not to like? Thank you for all the amazing contributions to science education, Dr. Hossenfelder, and if I may make a wish, please do a joint discussion with Dr. Carroll one day, that would be very entertaining :)

[@hi2ravi]

Can you do a video how exactly they estimated matter and energy that is "visible"?

[@terrywbreedlove]

I suppose Dark Matter is real in the sense that we can see something is effecting surrounding matter and light. What that something is we still have zero understanding of.

[@Apocalymon]

It's probably a mixture of several phenomenas & dark matter is just the mathematical physics' place holder - til we parse it

[@ElectronFieldPulse]

@@Apocalymon - I am very interested in the resolution of dark matter and dark energy. I tend to agree with your putative analysis, although it would be cool to find out there was some radical new force that could explain it all, such as the inflation of the universe.

[@davidbroadfoot4214]

yes, Sabine, I feel you are on the right track with the super fluid dark matter idea,.. its density varies because it interacts,, it is the stuff of regular matter (which are much denser geometries) but at a much lower density and perhaps different geometric configurations thereby increasing or decreasing its density and it's interactive force on regular matter. the interaction of the superfluid with regular matter, as you have postulated, is the gravitational force we observe. imo as an amateur theorist :) As a test for its existence; if intense em radiation could be made to modify it (since light uses it for propagation and lensing effect) from its gravitational geometries perhaps it could be tested for?

[@KaliFissure]

Mond at the galactic scale as additional binding component. When Friedman is modified it makes low density regions more viscous

[@NathanOkun]

Max Plank, if I remember correctly, had the idea that the gravitational and angular momentum forces that we observe are based on these factors relative to the "fixed stars" or, essentially, an average of all external mass and energy of the universe forming a baseline coordinate system that we have to measure this stuff against, at least its strength, if not its direction. MOND seems in some ways to show that some of its parameters may be based on such things, like the "Cosmological Constant" and so forth. This would mean that the universe as a whole is interacting on ALL levels in its causing the various forces and laws to be what they are and not so3eemthing else. Those graphs that show relationships that do not seem to have any known cause, but work, show that we have to be able to figure them out before we can determine what is really going on. Throwing out data that does not fit would have caused General Relativity to be ignored, would it not?

[@DWeirich76]

Brilliant topics... I am glad there are physicists who can break this stuff down for us regular folk.

[@RT-kh4ck]

Beautifully explained. Thank you!

[@timveseli]

This was a great lecture. Thank you.

[@arkansasorigami83]

Sabine @ RI... love it!

[@mrfranksan]

Um I was going to raise some potential challenges to the superfluid speculation, but I should have known Sabine was about to do just that and a thousand times more coherently than I ever could have done. Is there a more capable physics communicator out there? Wow. Brilliant talk.

[@jonb4020]

Very neatly and clearly stated, and lots of interesting hypotheses - but in reality the only honest answer to the question in the video title has to be a very simple one, namely: "we don't know".

[@rauladdams5709]

These lectures enrich me to no end. Thank you so much ❤

[@lanimulrepus]

Excellent review of the current status of the dark matter conundrum...

[@themelleryeller]

Idk if anyone else can hear them, but the birds in the background are lovely.

[@deltalima6703]

Sounded like toilets flushing. Maybe she is by a runway and its airplanes, i dunno.

[@edsmith9846]

Regression analysis in action. I have seen this many times in solving complex engineering problems. Sabine is fun to watch!❤❤❤

[@flyfree78644]

I’ve enjoyed Sabine’s video presentations for a while. Then I saw her conversation with Roger Penrose. Watching her deliver remarkable content on her feet demonstrated real depth and command of physics. Brilliant!

[@kefhomepage]

I couldn’t of thought of anyone better to do this lecture .😊

[@mahfoudseraf5995]

What about me?

[@carloscartaya26]

If dark matter makes up so much of the universe, why does the lens effect bend light around a regular old object? If there's so much dark matter, wouldn't light be bent more this-way-and-that? If it is "transparent" and doesn't interact with anything else, why does it interact with light? And, if it interacts with light, why doesn't it interact with anything else?

[@murraymadness4674]

dark matter is just gravity particles essentially, so it effects light just like normal mass gravity does, but no other effect.

[@WaffleSSSSSPLUS]

wasnt there something about the speed on the outerdisk being faster than expected because of how populated a local group was? i remember seeing an article with something along those lines, or was it retracted

[@stephencktsang]

When the universe expands into the void, it maybe "spreading out" in an "uneven" pattern, forming patches or spots of "imperfections" in the time-space continuum that have different so-called "density" of space (for space is actually something when one compares it to the absolute nothingness of the void), each of them having a different "X" extra to the equation. After all, we, as laymen, "need not" be living in a perfect universe with an evenly distributed or diffused expansion (of the space-time continuum). When you break a glass of water on the floor, the water doesn't need to spread out evenly. Instead, it leaves puddles of water on some part of the floor. I don't know about physicists' need though. But the human "need" for the universe to be perfect and explainable doesn't mean the universe need be.

[@angrymokyuu1951]

If spacetime itself isn't expanding evenly, there needs to be a mechanism: with water, that's hydrostatic bonds and interactions of the many moving pieces involved in dropping water on the floor(especially if the glass breaks). As far we know, the only such mechanism for spacetime is gravity, which our understanding of states there's not enough visible mass to explain. If you mean instead that the universe might not be homogenous in its mass-energy distribution on a grand scale, then what you're dealing with is dark energy(which is only necessary to explain observations in a homogenous universe).

[@stephencktsang]

@@angrymokyuu1951 Well, then I would guess the universe might not be as "homogenous" as you think by the way it expands. And instead of labelling these patches of anomalies prematurely as dark "energy" or dark "matter", why not simply give them a more neutral name like "missing factor" or "strange pockets" to avoid being fixated on the conventional paradigm. By this I mean it might not be what "matter" or "energy" is missing in that space-time, but the very nature of space-time itself in the process of its expansion. The water from the broken glass analogy might not be appropriate, but what if space-time has a "density" of its own that varies across the universe? Space-time is what "matter" and "energy" are embedded in, and gravity is its manifestation we know so far. But space-time in its pure form, devoid of the "matter" or "energy" it carries, might have a nature of its own that might change.

[@angrymokyuu1951]

@@stephencktsang I had an aside about people getting caught up in the idea of dark matter as a particle, but it got lost in one of my rewrites of the post(I tend to overthink things). That said, my main point was that you were replacing a known mechanism(gravity) with an unknown one. My point about dark energy was that it was hard to tell if you were talking about the galactic scale dark matter is talked about at(where the necessary level of "bunching" seems like it should be readily visible) or the cosmological scale where dark energy becomes a thing, since the latter is out of the video's scope. (For what it's worth, I don't buy dark energy either, especially since the accelerating expansion neatly fill the hole in the homogenous universe hypothesis and is unnecessary if you forego that assumption.)

[@stephencktsang]

@@angrymokyuu1951 Umm, yes. I am postulating some wild guess. That's because what is known doesn't fit. Space-time is the simplest form of existence we know so far. It's one hierarchical level above the theoretical void of absolute nothingness. There might be much more to it apart from the physical property of gravity. And I am just a "pedestrian" that happens to came across this video on youtube, not a physicist. So please don't take my words too seriously.

[@AerialTheShamen]

​@@stephencktsang Does the universe expand at all is the question. All we have is redshift, but that can be explained as well with a property of space that consumes energy from traveling electromagnetic waves by increasing their wavelength.

[@brothermine2292]

When Sabine says at around 39:00 that dark matter theory has become "hideously complicated" it sounds like she's applying a beauty standard that she wrote a book to argue against.

[@tim40gabby25]

Good point.

[@forthrightgambitia1032]

There is a difference between Occam's razor and beauty though. Demands for theoretical beauty insist that the explanation is more simple than nature presents itself. Occam's razor merely forces the simplest (least parameters) explanation consistent WITH nature.

[@brothermine2292]

@@forthrightgambitia1032 : I agree with you about Occam's Razor, which is why I was surprised that Sabine's book barely mentions it. Regarding the definition of "beauty," I don't recall an attempt in Sabine's book to define it... my vague recollection is that she wrote that she didn't know what it means. You may be wrong about its definition, because I don't recall anyone ever insisting simplicity trumps empirical evidence. Dark Matter theorists, for example, have made their theories more complex to avoid being contradicted by experimental evidence. String theorists aren't running around insisting that the LHC's failure to detect supersymmetric particles means the LHC is broken.

[@tim40gabby25]

@@forthrightgambitia1032 Better point :)

[@tim40gabby25]

@@brothermine2292 Did not Chandresekhar (apologies if misspelt) refer to beauty as a desirable close association of good physics?

[@Brattoes]

@Sabine, in case you pay us commenters a visit, is the superfluid state theory related, and aligns with, the observations of S. Gillessen et al, in The Astroph. J. in 2019 in which they observed a drag force in G2, around Sgr A (the milkyway’s primary black hole) and E.A. Becerra-Vergara et al, 2020 in A&A who hypothesize that its dark matter that causes the drag? (for us layman: youtuber Anton Petrov does a nice explanation in the first ten minutes of his 4th October 2021 compilation of Black hole discoveries)

[@johannestiefenbrunner]

Excellent talk. Quite dense, but that‘s what the pause button is for, right? :) Sabine‘s videos to me always bear the danger of provoking the feeling that I actually understand all that stuff. I then have to remind myself that while she thankfully has the gift of presenting it in a way that gives laymans like me a vague glimpse on how it all works, I of course still know nothing and am far from really understanding any of it.

[@PurnamadaPurnamidam]

Thanks Sabine you've been always great in explaining and teaching.

[@MyMy-tv7fd]

my sense of history leads me to this instinctual response: 'dark matter', aether, phlogiston, caloric, élan vital, Einstein's (fudge factor) gravitational constant, etc.

[@jonathonjubb6626]

So what's your theory then? God?

[@MyMy-tv7fd]

@@jonathonjubb6626 I do not need a theory, wrong is wrong with or without alternatives

[@andycordy5190]

Wow! I was totally hooked after the pie chart that showed the observable mass in the universe. I've never really understood the scale of the problem facing theoretical physics. I also loved the puddle imagery but I immediately questioned the two phases idea considering we already know 4 phases of matter. I am sorry to say that the Doctor exposed a dreadful prejudice in me, for which I'm truly sorry. The presentations I've seen online, on KZbin, I've ignored because of the images posted with the KZbin links, the wide eyes, the contact lenses, they struck me as goofy and trivialising. I follow Ri and am here because of the seriousness of the science promoted here. My bad. Mia culpa.

[@stanleydodds9]

I don't think you should read too much into the analogy between the 4 phases of atomic (baryonic) matter and the 2 phases of this fluid dark matter. In any case, we already know dark matter is almost certainly not atoms, because we would see them (the compact, dark objects being the only way it could happen, and these are certainly not in multiple states like solid, liquid gas). More to the point, phases don't just mean the 4 normal states of matter. As an example, look at liquid helium; above roughly 2K, it has a normal fluid phase, and below 2K, it is in a superfluid phase, but these 2 phases aren't 2 of solid, liquid, gas, or plasma; the helium is liquid the whole time. But in general, many things in mathematics have phases; in some region of a phase space, something has one property, and in another region, it has another property, but this doesn't have to have anything to do with reality.

[@AerialTheShamen]

Likely dark matter is only an illusion produced by the blurred gravitational force of regular matter in state of quantum uncertainty, that makes the sum of their gravity crosstalk from parallel universes.

[@kimcosmos]

Ghaffarnejad, Hossein; Dehghani, Razieh, Galaxy rotation curves and preferred reference frame effects DOI: 10.1140/epjc/s10052-019-6985-z are claiming similar effects from changing the way we calculate reference frames. But I suspect its effects on gravitational lensing would be less

[@arieloxford6790]

Wonderful. Learned a lot here.

[@undertow2142]

Do we know that all the gravity waves propagating around are not producing some effect on spacetime that changes how mass behaves? How has the gravity wave content of the universe changed over time and how does that compare to the expansion rate of the universe?

[@AerialTheShamen]

Likely dark matter is an illusion produced by the blurred gravitational force of regular matter in state of quantum uncertainty, making the sum of their gravity crosstalk from parallel universes.

[@lmahesh26]

To those who don't know Sabine's KZbin channel is a treasure

[@NathanOkun]

Would the two-phase super-fluid adjustments cause a change in any other fundamental constants, such as the speed of light and so forth? Why do these values have the numbers that they have if the basic structure of gravity that deforms space itself can be changed in such a fundamental manner?

[@_SPKer]

Great talk! Be really awesome if you uploaded your playlist to Apple Podcast or Spotify so I can continue when working 👌

[@TheRoyalInstitution]

We do actually have a podcast that's available on Spotify - open.spotify.com/show/3zfY0yzdW6UUfNmV4S4DjU - it's based on our talks and we choose a variety of topics and speakers.

[@sanny27]

What a great talk. So well expained that even someone like me with no science background could follow. Thanks.

[@mediaaccount8390]

Hi. I would like to ask you about what seems like a slight paradox to me (which means I'm not thinking clearly enough): How did you get to this video and choose to sit through it if you have no science background? ( I don't mean to sound snarky.) There are many possibilities, but I prefer not to speculate, so I'm asking politely. Thanks.

[@sanny27]

​@@mediaaccount8390 People might have broad interests even if they studied something else (social sciences and humanities in my case). Yet, I have always been interested in science, especially astronomy and astrophysics. It is quite exciting. Of course, I don't understand the underlying mathematics of it, but when it is explained so well like in this video, I think I get quite a lot out of it.

[@mediaaccount8390]

@@sanny27 Thanks for explaining. That's basically what I thought, but I decided too ask too. Have a great day. If you're interested in a bit more technicals, Don Lincoln of Fermilab also does a good job.

[@iaov]

Thank you Sabine and thank you RI!!

[@thebrothersdude]

Yesssss! more Sabine!

[@physisyst]

I agree that increased effort in this area is a good trend. Maybe it can have a similar effect for grav. theory as quantum information and computing science is having on QM fundamentals.

[@charliemeyer6475]

When dark matter falls into a black hole does it get darker?

[@nias2631]

Huh, I've watched a lot of dark matter talks on YT but this one stands out for explaining the evidence at a high level. Nice work Professor!

[@zhiqiangyan1554]

Being stubborn and not making the best choices is not always a bad thing for humans (or astrophysics) compared to AI. It allows us to explore more possibilities and is sometimes called "romanticism".

[@michaelpettersson4919]

The scientists need to find a way to make dark matter less dark because just claiming that it have to exist without having anything tangible to point at are not going to hold up in the longrun. What is needed are essentially a lump of the stuff on the table. A lot of effort are put into detecting neutrinos after all. Eventually it will be this dark matter's turn.

[@ChewyBacAaaah]

These UAP phenomena. Possibly the mysterious propulsion system burns DM? Then for theorists it becomes a quest to determine whether; 1. Dark Matter is buried deep in quantum fields (like antimatter) but can be invoked into participating in our experiments. 2. We need to physically venture out & harvest DM & bring it back as fuel. Ideal test for this: attempt to create an apparatus that allows to utter energy into existence & cause it to condense into a copy of Atom number one. Namely: precise arrangement of quarks/gluons to arrest that carefully-prepared energy into that supposed arrangement. Useful anti-gravity effects will be apparent if DM is indeed willing to logically participate in this process, emerging from QF.

[@AerialTheShamen]

Dark matter is likely just the sum of gravity crosstalk from normal matter in state of quantum uncertainty from parallel universes.

[@soumyaprakash3569]

Sabine ... Wow ! I love her ...

[@Brattoes]

@the royal Institute: very nice you guys have managed to get one of my favorite KZbin-scientists on the show. Keep up the good work and looking forward to your future shows, both in theatre and livestream. Also, I wish you guys might do a bit more with my personal love, tumor immunology. Since 2013 we have gone through a major revolution in understanding/applying the immune system against cancer since (but also prior to) the breakthrough studies of Nobel laureates James Alison and Honjo Tasuku, this is certainly awaiting a series that I haven’t seen anywhere yet, especially since one of our major anti-cancer vaccine platform from the last decade has become the standard Corona vaccine (mRNA). And there are just so many options open for future therapies: oncolytic viruses, genetic modification of the patients’ immune cells.

[@williambunting803]

This was really good. I share your excitement.

[@daisverrisson7167]

Wow, she´s so good at explaining these mind boggling phenomena, many thanks!

[@JPColter]

Every day dark matter seems to be less popular amongst scientists . That's what I've been seeing lately .

[@MyMy-tv7fd]

my sense of history leads me to this instinctual response: 'dark matter', aether, phlogiston, caloric, élan vital, etc.

[@alnilam2151]

Now if only I'd paid attention in maths class? Professor; if I may, in Einsteins's equation of ten, would that incl, a estimated weight&mass factor for elements\metals or are they as such muons baryons and the like? Pleaze&Thankz!

[@RaphaelBraun]

Watch "The Math of General Relaticvity" by ScienceClic. I think it is the best explanation for Einsteins field equations that you can get without visiting University. Afterwards you'll know precisely what those equations are about and equally important, you know what they are not about.

[@alnilam2151]

@@RaphaelBraun Indeed thank you I'm sure they would if I had figures that for what is sought but kno equation can replicate complex biologic regeneration: Ah ah A tissue... Gesundheit! Sneeze Snooze just like the cold? Fires Some up + others it Shutsdown & Einstein called it {Spooky} I think he saw while Fermat, well we could go round+round with this 1 ❎ Go figure❣

[@frankfrances3893]

Sabine Hossenfelder is on one hot topic that truly needs to be unraveled. Just the lecture alone of particle dark matter and the square root of a cosmological constant divided by three equals color code frequencies and is between a shadow and its highlight (black/white). While the color wheel or red; yellow density waves and blue of its gravity counterpart try to unmask the cosmological constant with specific gravity and density in tow.. And in terms that state 26% of dark matter aligned with red and yellow while blue is of 68% in dark energy; with 5% element gaseous matter that seems to be floating around in the void of space outside of the super fluid condensed galaxies. Trying to define the terms of infinite energy needed to addressed semiconductant delta/wye differentials of one wave or color source grounded while the other two are entangled electromagnetically and then again differentiated in that two waves grounded PnP of all reactant mosfet junctions in accord to all frequencies of light in its color code of d(phi) RO D(Iota) in accordance of and gating a control of receptive light source. This then projects light dependent on the ideals of torus or chopper eye squared with a delta offset. as receptive flow toward condensed matter resultants. A warp field geometrically aligned toward maximum gain of receptiveness of most every frequency of light toward a 5th dimensional infinite light source while condensing toward finite matter density output. This differentials of 3 phase graphic design converts energy into matter.

[@eugenechun4140]

Is the physical geometric world we experience an 'expression' of the subatomic world or quantum mechanics? Is it possible that spatial geometry applies to both quantum mechanics and the macro physics world?

[@Amethyst_Friend]

Sabine H! Yes! Thnk you R.I.

[@rylian21]

Man, I wish I had Sabine for a physics teacher!

[@mediaaccount8390]

You do, sort of.

[@electrospank]

37:26 I think this image is well placed because we see pavement with water falling into the minor variations in elevation of the concrete. In a similar idea as MOND, has anyone looked at the potential for the universe to be slightly uneven at large scales? Just like how this concrete slab in the photo will look essentially flat from a distance, but does contain some slight variation that water will fall into. If that concrete was flexible the water would push itself down further. So essentially you can use regular gravity, but place that matter into a slightly uneven field of spacetime. We know there are places with dark matter and no regular matter, also places with regular matter and no dark matter. Sometimes due to momentum regular matter will get flung over to a "high spot" but will ultimately drain down into the areas of lower elevation. Maybe I'm crazy but it seems like this would provide a pretty elegant description without requiring the need for WIMPs.

[@zhiqiangyan1554]

What is the unique prediction of the superfluid dark matter theory compared to LCDM and MOND theory? Does it introduce new parameters?

[@subhanusaxena7199]

Fascinating lecture, though it sounds like even the SFDM theory still requires a particle that behaves this way, so we are still looking for a particle? Is there any theory that postulates a Higg's like field and associated particle that behaves in this SFDM way? Danke Sabine wie immer

[@jessstuart7495]

I have discovered how dark matter is created; It's made by an overconfidence in our physical theories.

[@tarmaque]

Have you published?

[@mediaaccount8390]

@@tarmaque I have published (in applied optics), and I don't think it's an appropriate bar to require a publication in order to comment on KZbin. I thought @JessStuart's comment was a clever pun, since in a literal sense, (the idea of) dark matter really was created by confidence that that theories are correct. (I wouldn't call it overconfidence, but that works better for comedic effect).

[@tarmaque]

@@mediaaccount8390 Oh my sweet summer child; as if you were actually capable of recognizing humor.

[@mediaaccount8390]

@@tarmaque Hu? Can you help me? Did O miss a joke? Was your comment intended comedically? Sorry if I missed that.

[@murraymadness4674]

I point out that we have an abundance of irrefutable evidence that every theory in the past has been proven wrong, e.g. the earth is flat, god of thunder creates weather, sun rotates around it, ether exists, time is constant, etc, etc. To think our current theories are not wrong is insanity...but of course the scientists goal is to prove things wrong, so they need to carry on

[@malectric]

Question: do the velocities of satellite galaxies as they rotate around the main galaxy exhibit a similar correspondence to that of stars moving in the outer arms of the main galaxy? The picture I get of a large galaxy from the descriptions I've heard is that their components exhibit motions somewhere between that of a wheel rim held together by spokes and a collection of disjointed orbiting parts. ? I wonder whether gravitational measurements made well within the galaxy are essentially being made within the confines of a large mass which may be different to those which might be measured at the outer edges and indeed, well beyond the galaxy in relatively empty space. I suppose this has all been thought of by people smarter than me and anyway doesn't fit with observations made so far. The modified gravity model/s might be unappealing in some sense but surely the point is to make the model fit the observations?

[@ellenbryn]

Impressively, she managed to explain all that to a humanities major who's never made it past basic organic chemistry and who crashed and burned on the rocks of integration in differential calculus a quarter century ago. (My grandmother was a planetarium director, and my father worked in aerospace, but solar system exploration consists mostly of geology and stories, not equations and theory). Thank you very much. I've been trying to wrap my head around the concept of dark matter for years.

[@franciscooyarzun2637]

How come dark matter does not accumulate in the center of massive, detectable, objects; more so, the more massive the object?   🧐

[@JC-zw9vs]

What an excellent question!

[@franciscooyarzun2637]

​ @J C Thank you. My point, of course, is that if dark matter were to get sucked into big stars and massive black holes, then pretty soon it would clump together with all the matter that we see, and it would cease to have this odd “shepherding” distribution that purportedly acts as a scaffolding. How does the scaffolding maintain its structure ?? 😐

[@deltalima6703]

To accumulate you need friction, which us related to electromagnetic force, which dark matter avoids.

[@JC-zw9vs]

@@deltalima6703 That doesn't seem to hang true surely gravity accumulates without friction?

[@franciscooyarzun2637]

@@deltalima6703 Friction. Good point. But what about galactic black holes??   😲 Then again, Sabine talks about superfluid and “regular” fluid versions of dark matter ...

[@derekfrost8991]

So dark matter is a fluid? Isn't that brewed in Dublin?? :)

[@FlockOfHawks]

Guinness is good for you ( -niverse :o)

[@physicsprof.9639]

Note that the apparent resolution of the Hubble tension means the cmb value is correct. And it's based on dm among other things.

[@michaelogden5958]

Very nice presentation!

[@reculture]

Wow, i finally understand dark matter problematics in a understandable and concise way without excessive mystification. Very interesting stuff!

[@Games_and_Music]

Hah, nice "Crossover", didn't expect to see you here, nice video though. I have to say, my gut feeling doesn't really side with superfluids, but it might explain the weird "bubbling" at the edge of the Solar System? Does it specifically have to be between young galaxies, is the distance too short between solar systems? It could also explain the expansion, since water surfaces can spread substances out, like when you throw fish food flakes in water, they often drift apart. But yeah, fluids, be it super, would be detectable, or they'd have to be super-duper fluids. It also doesn't really explain why sound doesn't travel through space as it does within the atmosphere, because either sound or light would have something to reflect off of, how super are those fluids?

[@deltalima6703]

Just upvoting for the part before the fish flakes, because it sounds like BS to me too. These rotation curves are mostly a mess from making too many simplifications to make it easy for computers to crunch numbers, not actually using GR. Its a smoking gun that modified super newtonian fluid phase transition dynamics whatever doesnt explain the CMB data.

[@Games_and_Music]

@@deltalima6703 Hah yeah, i know the flakes were flakey, it's a simple way to say "surface tension", but yeah, i figured, surface tension can bring heavy things together, and spread out any lighter material, which could simulate the way cosmic matter moves, but yeah, that analogy is nothing new. I feel that the vacuum of space is enough to create that effect, i don't see the point of adding a superfluid to it, other than to include the stuff we can't explain yet. But i agree, sometimes calculations and simplifications will overlook certain things and they end up revising them, so at this point i am not feeling convinced at all, it just doesn't click with me.

[@GhostEmblem]

First you seem to be treating superfluids as though they are a type of liquid when superfluids are a state of matter as different from liquids as gases are different to liquids. Sorry if I'm wrong. Second I think she said it wouldn't act as a superfluid in the solar system because of too much gravity so you wouldn't expect our experiences of space to be any different until we leave our solar system and only for things outside solar systems. If the super fluid was actually dense enough for sound and you spoke your voice would in theory continue until it hit the vacuum bubble of the solar system. Third they are not replacing dark matter only saying it has multiple states, so it still would still not interact with light for unknown reasons.

[@deltalima6703]

@@GhostEmblem your voice could not convince the dark matter to form any sort of wave, even if they got the dark matter wave started somehow, the dark matter cant convince more dark matter to move, so there would still be no soundwave. Quantum mechanical waves propogate differently, im not referring to those.

[@haroldnowak2042]

Thank you so much Dr Hossenfelder, both very informative and entertaining. Predicting what AI would do, well, that's brave.

[@hopefultoo]

MOND appeals to me as being the simplest explanation. To me it seems to imply two variations in space time. In the one we are familiar with mass depresses the structure of space time deeply and its effect dissipates over distance. The second space time is also depressed by mass and the effect is shallow but dissipates much more slowly over distance. In fact we could go further and imagine multiple space times ringing like bells over the whole universe.

[@KaliFissure]

Neutron decay cosmology. You heard it here first. Help me do the math Sabine

[@nulfire]

What about using Drake's equation to investigate dark matter?

[@KaliFissure]

@@nulfire how so?

[@nulfire]

@@KaliFissure was just doing my version of you heard it here first.. Arrived there as a little tangent to investigating gravity and time.. Best way to generally describes what I meant is to ask the question. Do calculations of astronomical mass take into account the possible mass of life as we (think think we do)know it? But of course we can't measure something we cannot perceive. Unless indirectly through its effect. Anyhoo. It is a fun little tangent and may appear more fanciful than serous. Hmmm (edit: that is if DM/DR do exist that is. 😂) Regards G

[@douggale5962]

It would be so funny if dark everything were just billions of Dyson spheres, with cloaking fields showing an illusion of the energy and particles arriving from the other side.

[@Alkis05]

Then it would, with the same stone, solve the fermi paradox XD. Than again, they would still have gravity, and we would have the same problem as dark matter being black holes and feint stars: namely, there would be to much of it and we should be able to see their gravitational lensing.

[@nosuchthing8]

@@Alkis05 Why is there too much of it? From the first chart there appears to be more dark matter than visible matter. Could there be that many Dyson spheres?

[@Alkis05]

@@nosuchthing8 That couldn't be it. If dark matter was from stars that we can't see the light, there would have to be so many of them that we could look for them by gravitational lensing. That was one of the early candidates for black matter, but the hypotesis was discarted, because there was no amount of gravitational lensing observed that would explain even a fraction of the dark matter that is out there. Besides, Dyson spheres wouldn't explain the dark matter evidence from the Cosmic Background Microwave, which was there before stars even formed. So no, Dyson spheres are not a good candidate, as I understand it.

[@nosuchthing8]

@@Alkis05 Dyson spheres and primordial black holes then.

[@Alkis05]

@@nosuchthing8 Primordial black holes are a possibility, but I don't think it can explain the majority of dark matter mass. Same for invisible stars, which definitely can't. Problem is, we are not even sure if primordial black holes are a thing. That is one thing that the JWT is going to search for. If such blackholes existed when stars started forming for the first time, we will be able to see if galaxies were already forming around them. Or we may find that galaxies only start forming further down the line, when the first stars started dying and formed black holes. We will find out soon. Personally, I think it is the Force: "It permeates all of us, and binds the universe together" -- Obi-wan =D

[@jabowery]

It's interesting that the dark dwarf galaxies around our galaxy have the opposite characteristic of the high correlation between light emission and dark matter shown in the scatter graph.

[@mark9118]

Question: If Dark Matter exists as a way to explain that all stars in a spiral galaxy are spinning around the center of the galaxy together, regardless of the mass of each rotating star (unlike our solar system where planets orbit around the sun at different speeds based on the mass of the planet and distance from the sun), wouldn't Dark Mater have to exist inversely proportional (more or less) to the mass of the stars in the spiral galaxy to make all the stars in those galaxies rotate together. I assume that Dark Matter would also have to be more dense in stars farther away from the center of the spiral galaxy, as that also would account for the speed of those stars since they actually have to rotate around the center at a faster speed since they are further away form the center. If so, exactly where would the Dark Matter exist (in the stars, around the stars, etc), and and doesn't that all seem unlikely?

[@ElectronFieldPulse]

I am fairly sure they have thought about the obvious problems with the ideas, and given the consensus, I assume they have dismissed them with good reason.

[@mark9118]

@@ElectronFieldPulse I don't agree that there is complete consensus about Dark Matter these days, except perhaps by those who have invested their entire careers into its supposed existence. Additionally, I don't find your answer to be a satisfactory scientific explanation.

[@ElectronFieldPulse]

@@mark9118 - By all means, delve into the actual literature. You aren't going to find a proper scientific explanation in KZbin comments, so I suggest you put some actual work into it instead of demanding others spoon feed you the info. There is a broad consensus on the effects of dark matter and dark energy. There is a consensus that something is there that must explain the observations. Agree or don't agree, it doesn't change the material reality.

[@mark9118]

@@ElectronFieldPulse My question was really for Sabine, who has not 100% accepted many of the current explanations of Dark Mater, as explained in this video and videos on her own KZbin channel. Plus, I disagree about "broad consensus," especially among younger physicists who don't have any intellectual baggage on this issue.

[@mark9118]

Perhaps you should look at Sabine's video on her own channel, where she outlines some of the problems with the theory of Dark Matter that needs to be taken into account. kzbin.info/www/bejne/apDUe6OqrM6eiMU Here is another Sabine video you may interested in: kzbin.info/www/bejne/nGOWloqFptp5h5I I personally have only a slight interest in what the "consensus" is on Dark Mater, and I only watched this video because Sabine was featured in it.

[@TheBRUCELM]

Sabine, why does the cosmic microwave background seem static? We measure it as it passes by...from where to where? Is it static in an expanding universe much as we are static in such? Hmm

[@Blowfeld20k]

If CMB is "static" please explain why when observed it is red shifted in all directions? I advise actually finding out the basics of a topic prior to challenging working experts in the field. Doing otherwise is the province of flat earthers and other anti science ignorance cultists.

[@cgibbard]

My understanding is that the CMB is essentially an image of the compact early universe, at the moment that it had spread out and cooled just enough to become mostly transparent to light. Might that snapshot of the big bang look any different from an extremely different vantage point though is a good question.

[@MrAlRats]

Check out this video for a partial explanation: kzbin.info/www/bejne/rHqthaqPhL-lfbc

[@TheRogueRockhound]

Wish I was smart enough to understand half of this...Guess I'll just stick to my pebbles.

[@deltalima6703]

Do you use a rock tumbler? Do they work? Lots of nice pebbles here, but I dont know much about them.

[@TheRogueRockhound]

​@@deltalima6703 Tumblers work great but take a long time (roughly 4 weeks) to finish. They are very affordable compared to other lapidary equipment and require almost no skill. Once the weather changes here, I will be making shop videos that will cover different types of lapidary equipment and how to use them so stop by if you feel compelled and I'll do my best to show you what I know. Look forward to chatting with you in future and hope you find some great treasures ^^

[@deltalima6703]

@@TheRogueRockhound Very interesting, I live on a beach with lots of interesting rocks, I will probably give it a shot actually. :)

[@TheRogueRockhound]

@@deltalima6703 Awesome! It's a great hobby and super affordable. If you ever need any tips, let me know and I'll do my best to help.

[@smith5796]

I really want to believe also. No brain. Or pebbles.

[@sociallyinept5430]

That's interesting, becasue I was thinking, if you were going to shoot fire into and liquid/gas, you should make it a liquid that turns to a gas at a certain temp. Keep your "nothing" you put the gas in that temp. Then just find something really dense, so the "something" particles aren't able to pass through it, thus creating enough gravity to throw some fusion reaction in the mix and yeet.

[@samposyreeni]

Density waves in colliding superfluids... Speaking as a rank amateur, that immediately brings to mind the arms of spiral galaxies...and only spiral or bar galaxies, not the elliptical kind. Could there be a connection? I mean sure, Sabine says those newer density waves would be predicted to be too small to currently detect. But if there was some resonant, nonlinear amplification mechanism present, they might still over long spans of time coalesce into the discrete, curly arms we see. But only if there's other evidence of an earlier galactic collision. That sort of reasoning can be made precise and testable. For example, you'd see arms develop over time, the number of arms would probably have some sort of quantized relationship with the excentricity of impact, and there would be some extra evidence in the vorticity of the arms around the center of a galaxy as well, against the visible revolution curve. Be as it may, a stellar performance from Dr. Hossenfelder. I'd go to argue it's even more physicky than most of the stuff on her own channel. That already being pretty good; I'm an ardent follower.

[@brucesuchman1253]

Space-time is relative, the curvature of the space-time field is not a constant smooth, but more like a globe with mountains and valleys raised or lowered. Causing the curve to be relative, affecting time flow and gravity effects. I'm my uneducated understanding. This seems to account for much of the dark matter and dark energy

[@watcherofwatchers]

Please demonstrate how it accounts for dark matter and dark energy. I have seen literally nothing from the science to support this bold statement.

[@deltalima6703]

Your uneducated understanding is fairly good. It might be a very large globe or it might be overall flat we arent sure. Some of those mountains are vertical cliffs, and time and space flow are related to the slope. Dark matter and dark energy are not completely accounted for by these curves and slopes though. Dark matter has numerous effects, a few of which Sabine mentioned, although she focused on galaxy rotation curves, a common mistake made by science communicators.

[@brucesuchman1253]

@@deltalima6703 thank you. I know this doesn't completely account for dark matter and energy. It does seem to my ignorant self as a step in the right direction to better understanding.

[@brucesuchman1253]

@@watcherofwatchers Delta Lima better explains what I was trying to articulate

[@watcherofwatchers]

@@brucesuchman1253 This is not an idea supported by observation, evidence, or math in a meaningful way. It doesn't have the force of scientific theory behind it. I have my doubts about dark matter and energy, but mountains of evidence have at least led to those conclusions.

[@shawns0762]

There is an "elephant in the room" explanation for these higher than expected rotation rates. Einstein explained it in the 1939 journal "Annals of mathematics". Wherever you have an astronomical quantity of mass "dilation" will occur. There is no place in the universe where mass is more concentrated than at the center of a high mass spiral galaxy. Low mass galaxies have been shown to have predictable star rotation rates (some galaxies can appear to be low mass but can have high mass at the center). This is exactly what relativity would predict. According to Einstein and to Einstein's math singularities can not exist. Nobody believed in singularities when Einstein was alive because he would promptly explain that you have to factor in dilation. The mass that we think of as being at the center of our own galaxy is dilated throughout spacetime, it is all around us, there is no direction you can point your finger in thats not pointed to it, it is the cosmic back round radiation. If you pose the question "why can't we see light from the galactic center?" the modern answer would be because gravitational forces there are so strong that light cannot escape. Einstein's answer would be because the mass there is partially or completely dilated through spacetime relative to an Earth bound observer.

[@erikjohansson4275]

That sounds absolutely ridicolous, but also perfectly sensible, at the same time.

[@shawns0762]

@@erikjohansson4275 You can read Einstein's article on the JSTOR website if your interested, on the last few pages he talks about high mass scenarios.

[@murraymadness4674]

I have not heard of 'dilation', but that is akin to my theory that black holes are effecting gravity in ways we don't currently understand, as we don't really understand what matter makes up a black hole. I would like to see more options/theories put forward, most of these videos are rather limited, i'm sure someone has thought of these ideas and shown why they don't work, that is true of almost everything I come up with, eventually the more I look I find the reason they don't work...

[@p39483]

Are you saying that time dialation in high gravity near the center makes close-in stars orbit slowly? I immediately thought the same thing. It seems like the first thing one might want to rule out. So if time dialation in terms of Schwartzchild radius units from the center is t'/t=√((r-1)/r) then it's pretty obvious from looking at that curve that it can't explain the huge speed increase in the outer arms since most of the slowdown occurs with r

[@shawns0762]

@@p39483 Not orbit slowly, orbit at speeds approaching the speed of light. Not time dilation, spacetime dilation. If a bullet is approaching you near the velocity of light than you would have nothing to worry about because every aspect of it's existence would be smeared through spacetime relative to you.

[@gbye007]

So Pavel Kroupa lists more than ten large stellar research efforts which rule out CDM by between 5 and 8 sigma. He also describes the current 'belief' in CDM by the bulk of physicists and cosmologists as one of the biggest crises in science history. How do I reconcile this view with the LCDM model proponents?

[@malectric]

I find the concept of dark matter rarely interacting with anything being able to have such a huge effect on the motion of stars in a galaxy fascinating. If that isn't an interaction with ordinary matter I don't know what is.

[@jorgis123]

I stopped watching this channel, because I just can't be engaged by some person on a screen. The recorded lectures in the hall with a public were much better at conveying knowledge. But for Sabine, I'll make an exception.

[@watcherofwatchers]

SameSame.

[@TheRoyalInstitution]

While we completely agree that there is no competition for our theatre (we love it to a ridiculous degree), we're very glad that we were able to continue our events programme throughout the pandemic thanks to the wonders of livestreaming. Now that the world is opening up again, we have been able to get back into the theatre to do some more filming there, and you'll start seeing those videos very soon. We are however probably going to continue with these long distance events to at least some degree, because it has been wonderful being able to get scientists from across the globe to speak about their work. We are a small independent charity (royal only in name, and not in our treasury contents) so flying scientists over is sadly not in our budget.

[@jorgis123]

@@TheRoyalInstitution I understand, I am happy you were able to continue sharing all this knowledge. I'm looking forward to the recorded live lectures again!

[@Chris.Davies]

Holy sub-Planck scale quantised superfluid particles in 11-dimensions, Batman! O_O 🦇🔦Are you out there? @ThadRoberts What's up next, TRI? Bowl-shaped magnetic fields?

[@bonescheffel7795]

Love how she says "hypothethith".

[@edwardlee2794]

Thanks Dr. Hossenfelder I was attracted to dark matter for no reason, so much that I attended a lecture recently at the perimeter institute in Canada. Now, after Dr Hossenfellders lecture, I founded my reasons to follow what's the matter with dark matter. .Thanks you for the effort and keep up the good work . From Hker worldwide