Never thought I would ever hear somebody say "one of the lesser known facts about me is that I am one of the few world experts on anti-gravity". Sabine, you're a legend! Thank you so much for sharing all your knowledge with such a broad audience.
no doubt you have in mind Feynman's example of an antigravity device: a chair. Feynman was one of the few dreaming followers of the religion scientism, that had the wits to recognise that it is no more than a religion. 'Anti-gravity ' my arse!
Knowing that Sabine herself developed a theory based on beauty really changes how her "lost in math" thesis comes across. Definitely makes her seem more humble.
Fascinating to hear an expert talk about the experience of being wrong. We don't hear enough about this in pop-sci media, but it's critical to the scientific process that we understand when we're wrong and how to handle being wrong. Because even wrong answers can give interesting and useful insights. Thank you!
I was reflecting on my own science education as a kid and how my science fair project one year didn't produce the results I wanted, and I was so conditioned that wrong=bad that I faked the results and still passed. I think it could have changed a lot about how I approached science if things has been otherwise and I was more comfortable examining why I was wrong rather than just "getting the right answer"
A negative result is always a positive thing, not for the people hoping(thinking) that it would yield a positive result, for the scientific field it is part of. Knowing what something is not slims down the possibilities what it can be and therefore avoid scientific research furthering going down paths that are incorrect.
I learned more from failed theories than from successful theories. Understanding why they are wrong is valuable knowledge. I often participate in “pointless” online arguments just because often they have arguments which seems to be wrong (and they ARE wrong), but I can’t clearly explain why they are wrong. An argument with a flat-Earth theorist will never persuade them that the Earth is round, but I learn a lot about geometry, light refraction and gravity.
Thomas Huxley said (in various ways): “The saddest day in my life was to see a beautiful theory destroyed by an ugly fact.“ This presentation is beautiful on many levels. Thanks again, Sabine!
Actually, the real quote from Huxley is "...the great tragedy of Science-the slaying of a beautiful hypothesis by an ugly fact..." From a speech to fellow scientists in Liverpool England in 1870. The text of his speech was reproduced in _Nature_ magazine, and went down in history. The quote has variously been falsely attributed to Charles Darwin, Benjamin Franklin, and John Tyndall, among others. It is often rearranged or phrased differently, even by Huxley himself. None of this makes it any less poignant and relatable to scientific thinkers.
Aldous Huxley experienced a conscious state of binary superposition in his 1950s "Doors of Perception" where a conscious singular observer sees the beauty of its own existence. He recognized this could be seen as both a blissful revelation of one's conscious existence or a horrifying realisation of singular but isolated loneliness, very eloquently. Depending on ones viewpoint and situation, the observation problem, there's a binary superposition of positive and negative, so to speak.
My boss used to say "if the experiment always turns out the expected way, it wasn't an experiment". You are the sort of scientist that can make fundamental contributions since you can see when your ideas need to change, and learn along on the journey. Thank you for sharing your experience.
Love this video. I disagree that your work was wasted, negatives are as important as positives and no one knows whether your negative result may become crucial to some later endeavour. I would also support 'guessing' (at least informed guessing), one ever knows. Keep up the excellent work and keep guessing.
Her point is part of a long standing argument she's been making: informed guessing is fine so long as it is warranted and driven by real inconsistencies/problems to be resolved. It's not okay when it's just driven by aesthetics. That is, beauty in a theory is no indication of truthfulness. So she's demonstrating this applies to her own work, too. And more, she's revealing a bit about why, on a personal and not merely professional level, this is important to her.
@@GulfsideMinistries yes 100% agree with you. The OP has validity too though because her own growth (and now ability to help others investigate more fruitfully) was attained in large part due to learning from that "waste" thereby not truly being a waste. Just absolutely a worthwhile and valuable lesson to empart on others 👍
Physicists should proud themselves for having a great criticizer like Sabine who never shy to criticize herself. Thanks for this beautiful and great confession.
"The theory of negative masses would therefore predict that the universe doesn't exist, which is in conflict with evidence." You are such a joy to listen to! I'm adding this to my quote collection. Also, the apple was clever. Also also, how cool would it be in a few billion years if the Andromeda galaxy turns out to be anti-gravitating? Finally also, I'm really enjoying Lost in Math.
At the stake, dear Michael Piz (I swear you aren't myself) is if geometry might give birth to anything, or either gravitation comes from a Higgs- like mechanics.
@@micaelapizza510 Geometry is a human invention designed to describe the universe, i.e. that which existed prior to geometry. So geometry doesn't "give birth" to anything but more ideas in the human mind. Nice name. 😁
I think we are all attracted to intelligence. Ms Sabine is like the super massive black hole of intelligence. Even though I only understand less than 50% of her videos because of my lack of knowledge, I still learn and love every video. So much free knowledge and honest insight. Amazing amazing teacher.
This is such a great post on so many levels. First, taking a logical idea - that anti-gravitating matter may finally explain dark matter - and showing how it doesn't hold up to observation helps all future students and researchers in the area. Proving why something is wrong in science is just like "negative space" in art... the positive space couldn't exist without it. Second, this post was personal to me because I fervently believe that the field of anti-gravity will become an enormous area of innovation, and I believe (hope) it will provide tremendous fodder for science fiction between now and then. Thank you again for all your tremendous work!
I think it's an area where Edison's quote applies - it's not a failure, it's successfully identifying one approach that doesn't work so that people can move on to the next.
If 'gravity' is due to spacetime distortions, what would 'anti-gravity' be due to? It takes 'energy' to distort spacetime in order to produce gravity so if it is the case that 'negative energy' is required to produce 'anti-gravity' then that would mean that 'negative energy' would be subject to a different Second Law of Thermodynamics than the one that governs 'positive energy'. And there is one more confusing issue I have: if a particle annihilates with its anti-particle counterpart, is it 'energy' or 'anti-energy' that is released? I mean, we can account for the masses of the original particles in terms of the debris and energy released and there is nothing left unaccounted for that would require the need to consider that some of the mass had been converted into a form of energy, 'anti-energy', that cannot be detected by our equipment except by deduction. Right? Surely 'anti-gravity' is a scientific cul-de-sac?
I hear too often those in the applied sciences claiming their research was a "waste of time" when information (through scientific means) indicates that the outcomes are not what they or their institution had hoped for. Part of learning is through experience, and experience can teach us not only what to do, but most importantly what NOT to do. Please be supportive when someone shares wisdom of what NOT to do; it's a difficult pill to swallow but also very valuable information.
Heck. Finding a dead end and a wrong answer in science is discovery in itself. Being wrong is pure discovery. The real answer remains unknown. As much as we crave being right: We love a mystery.
Sabine!!! This is so close to what I'm working on, but instead of tying RG to a form of mass, it's an inherent property of spacetime, just like quantum gravity!
Sabine acts the part of Einstein's granddaughter - she's already got that lovely accent - she's inherited Einstein's last lost secret papers on antigrav technology that he kept secret for fear of what the military would do with it. But now the technology is needed to save Earth.
@@DavidOfWhitehills Considering Einstein's attitude to the US military after WW2, I have watched many a hollywood movie that started with a far, far weaker premise. I have read Sci-Fi books that were far weaker too. Maybe you should expand that into at least a short story?
I love this video. I believe every road should be explored even when it gets us no where. Yes, it may have been a mistake and a waste of time. However, the effort can still have good value. It can serve as a guide to those of us that may have wanted to take the same path late on. Thereby saving others from making the same mistake. Thank you Sabine!
We can’t know for sure that it doesn’t work, until we prove beyond the shadow of a doubt that it doesn’t work, and eliminates that possibility from our reasoning. So yes, it’s important to prove what is and what isn’t. Deductive reasoning. Some things we’ve recently discovered about quantum physics doesn’t make a lot of sense, a good thing someone did pursue those avenues of thought and not just assumed it was too crazy to work.
The phrase "waste of time" makes me wonder out loud: Could "time" not be a field that is ever present in physics as well as natural languages? If time indeed might be a field, what does it imply? that it might not be emergent, virtual or non-existent?
Indeed, but also her follow up point is a good one touched in philosophy of science. Much, much, much of the effort has been done on how one can determine if a hypothesis is a true one or wrong one. There is actually little to no work one how you can get good hypothesis. In classical PoS they just come from nowhere.
You must have seen another video. Sabine said exactly the opposite, it was a pure waste of time. I wonder if this misunderstanding is intended by her to reach antiscientiest crackpot but also science fans. Of course any scientist knows that you learn most from your failing ideas and experiments. Understanding why it fails is usually a big step forward. But this is clearly not said in the video and also not in her anti scientist book.
Every road? I'm not sure if I agree. I guess explore sufficiently to know the road is a cul de sac - it would then not be logical to continue further down that path. Just saying.
Sometimes it feels good to stretch the brain towards something I really don't understand. I do enjoy Sabine's calm presentations of hard to grasp theories, it's almost like meditation.
Wonderful video Sabine. I didn't understand much of what you were talking about other than on a cursory level, but your method of presentation makes for an engaging and incredibly interesting viewing experience. Even if much of it was outside my sphere of knowledge the information was presented in such a way as to make it enjoyable and informative to watch. Thanks, and do keep making these videos!
Read it last year, it´s an eye opener for me. The talk with Steven Weinberg belongs to the best I´ve ever read. Just read her new book "Exitential Physics", which I recommend too, hopeful and entertaining.
I am so into your communications, elegant , confident and courageously communicated. Thanks for being a hero to my curiosity. I’m able to develop on my own ideas from a solid angle 🙏🏼💯♥️
Excellent presentation with lots of “gems!” I’ve watched it twice and may do a third after I’ve had a chance to process the information. I admire your tenacity exploring the possibility of anti-gravity. Great video!!!!!
This is extremely cool! I had no idea you'd toyed with the idea of antigravity and it being what dark energy might be! And explaining why you had to abandon the hypothesis was quite clear, which helped me to understand it! Thank you! Here's a comment for the Almighty Algorithm! 👋 😊
I like the honesty in this one. It's hard when time we spent on stuff appears to be wasted. But if you're positive then there's always something to take away from it. A deeper learning, a new understanding and perhaps a step to the next successful theory! All the best Sabine!
Mad respects for you. Its not everyday you see someone talking about how they were wrong on a theory. And please do not think of it as wasted time, your time has provided us with invaluable information of what darkmatter isnt, and the more and more we look into it, and rule out alternatives, the closer we are to the thruth.
I believe she referring to spending tons of time ignoring the fact that facts were not going to let her beautiful math ever work out. In other words she could have found out she was wrong way faster without her bias preventing accepting she was wrong. So her being wrong on theory helpful, spending way to much time before accepting wrongness only helpful if others heed the warning that there a time to accept your wrong and to always watch if your own bias is preventing you from knowing your wrong. Bias actually warps reality is been shown to have people unable to recall reading facts opposing their view and in other cases warping recall of the facts to support your idea so much they don't resemble reality anymore. Gulf War Intelligence failure a great lesson on how heavy bias can make people think something that is not true. Especially if one of the bosses lies in information they give out at start. This is why investigations looking for deliberate lies on this and other intelligence failures don't find anything as everyone thought they telling the truth but group think and heavy bias caused information countering their views ignored looked at briefly and filed away often with no recall of ever reading it. Here of course Saddam refusing to fully cooperate and hassling inspectors combined with fact he did have chemical weapons and did have an atomic bomb project before the Israelis blew it up feed the heavy bias. Saddam is over fifty percent responsible for that war. Simple full access and sharing all records quickly would have allowed inspectors prove he had no weapons. But Saddam wanted to have eat his cake yet still have the cake uneaten so to scare others with him possible having WMD while getting West to leave him alone.
I don't quite get why "negative gravitational mass" would necessarily have to be of positive inertial mass? I mean, such a hypothetical substance could as well be of negative mass in BOTH equations, right? Such mass would not only fall up, but also move in the direction from where it is pushed by an external agent, unless that agent was of negative inertial mass as well (because then, it's a would be negative), right? What makes this necessarily impossible?
Very much enjoy your videos Sabine. I studied physics up to research Masters level in the UK, and this channel really helps me keep up my interest in the Big Questions of physics and the latest developments despite me not being a full time physicist. Keep up the good work!
I don't think it's a mistake for the physics community to spend a little time pursuing theories that ultimately turn out to be useless. That's one of the reasons why grad students exist.
I appreciate the willingness to say an idea didn't work. In Pauling's words: "The best way to have a good idea is: to have a lot of ideas and throw away the bad ones." Kudos Dr. Sabine.
You can derive this in an approximation. This is nicely explained in Zee's QFT book (which is generally awesome): www.amazon.com/Quantum-Field-Theory-Nutshell-nutshell/dp/0691140340
Sabine, I read your book. The courage you have to criticize well-established concepts and theories is only surpassed by your honesty in criticizing yourself. This is the true scientific spirit and I greatly admire you for that.
At t=3:09 changing F=ma to F=|m|a solves the apparent contradiction with F =-G m1 times m2 /Rexp2. Have you considered that option and its consequences?
I think Sabine just explained a path to becoming a great scientist. I'm not qualified to judge the value that her excursion into antigravity presented to science, but perhaps there should be an award similar to a Nobel for some contributions to science that explored and disproved an idea that was incorrect. There are certainly some "anti-discoveries" that are foundational and represent great achievement. Have such examples been recognized and just don't occur to me? As for Sabine, perhaps this "resume item" especially qualifies her to be considering a challenging concept like superdeterminism.
SH said it was a waste of time, so your interpretation of the video is in contradiction to what she is saying. But it shows that many of her fans do not really get what she is saying and implying. It is just her strawman anti-mainstream bias they are fascinated.
She lamented that it was a waste of time scientifically, but clearly it was not a waste of time for her personal and professional development as she explains it led to her book and contributed to her judgement.
Michelson Morley experiment. They won a nobel price for a negative result. I think the novelty was in the experimental procedure and setup rather than the theory it was supposed to test (luminiferous ether).
Super awesome to see a really smart person so calmly discuss being incorrect and why they changed their mind. We need more researchers saying this in public.
I absolutely love your candid approach to dark energy and matter which is clearly at the cutting edge of current theory. Im trying to imagine what a post dark matter theory would be like . .i.e. whats next.?!?
Nice that you can take a step back & admit being wrong about something Sabine! The fact that you made this video definitely puts a positive spin on that subject matter. Well done! 👍👍😉😉
I always just assumed that anti-matter had the same mass as matter of equivalent type, so would be effected by gravity in the same way regular matter was. And my understanding of the concept of anti-gravity was not an oppose to gravity, but a *_neutralisation_* of gravity. On it's own not a force so wouldn't make things fall up, just stop matter (or anti-matter) from falling down.
The source of the idea of negative mass is from the Klein Gordon equations. Some of the solutions are negative energy which at first was considered an invalid solution. It turned out to be the solution to anti-matter. Feynman once ran with the idea of negative mass for anti-matter.
Part of that the Quantum Mechanics ideas that call for Gravity to be a force like the others with a Gravitron then in that case one could counter gravity with a opposite gravity field projecting Gravitrons. And use the same wave canceling ideas that are done with sound. Unfortunately Gravity still not Quantized and if Relativity is right it will never be. One of the lost in the math things. This long and still no Quantum gravity detected and relativity applies to the smallest levels we can measure. Maybe time to give more support the lessor number chasing Relativity complaint Quantum Mechanics were Gravity is not a force that will combine with the other forces in a combined force right after the Big Bang. Gravity in Relativity best described as an effect, a measurement of SpaceTime curvature not something it self.
The idea in 9:00 is pretty clever. I wonder what could push from the outside? Residue of astro jet or Fermi bubbles? Is the outskirts of a Galaxy like a grave yard for planets and stars?
I succeed because I have failed. Unfortunately we are rarely taught this as children because it would apparently hurt our self-esteem. Sadly this leads to ignorant people feeling as qualified as experts.
I understand only a part of what is being presented here, but it is very comforting to listen to such a brilliant scientist speak. I am reminded that there are still a few people that appear to know what they know, and more importantly, to know and understand what they don’t know, and be able to effectively communicate that to the world-a rare gem, indeed!
Gravity is explained by bending the space. Often illustrated by valley in elastic fabric caused by massive object. Can the space be bent the other way to form a hill? That would be antigravity.
I think you could if you had enough ‘negative’ mass !! ( that’s not anti matter ) anti matter is just positive matter with its charges reversed I believe 🤔 . negative mass would be something very different to anti-matter, to use the rubber sheet idea , the negative mass sphere would be under the rubber sheet pushing up to create your hill !! , it would have some cool properties, like reverse time dilation , time travel into the past would become possible , anti-gravity would be possible etc ..
@Jonathan Camp I rather wish I found Sabine's blog last decade, then I wouldn't have wasted time on getting into woo metaphysical life-coaching crap a few years ago. Sabine is a much better role-model.
@@CAThompson Hi C Thompson. How is my favorite Aussie? Don't underestimate the power of your mind. You'll never anti-gravitate yourself off from the planet, but no astronaut ever made it into orbit without first having been mindful of what it takes to get there. Keep what is important to you at the forefront of your thoughts and things will happen to make them happen.
I had a similar thought back in 2005 or 2005. I wondered if there could be a negative gravity particle with the following attributes: 1) Negative gravitation 2) Non-clumping to like particles 3) Neutrino-like neutrality to normal matter I further assumed that such particles would "fall" towards the voids between galaxies collecting in vast invisible clouds. Their collective mass could represent dark matter and their collective push could represent dark energy. I also assumed the source for such "Darkticles" could be the anti-quarks from the creation. My question is: Do we know that all combinations of anti-quarks cannot exist for long extents of time within the voids between the galaxies?
I had the same thought, that antigravitating particles would avoid each other and move away to create voids and a pressure on us in the galaxy, and drive galaxies apart. Seems so reasonable.
In order to include negative mass in cosmology, you developed and published for the first time in 2008 indeed (paper ""A Bi-Metric Theory with Exchange Symmetry") a bigravity framework where like masses attract and unlike masses repel. It means that negative mass is self-attracting and auto-gravitates, so it could in theory form dense nebulae of negative mass hydrogen indeed, as you notice in your video at 8:19 But those nebulae populating such a negative metric would build up into stars and galaxies ONLY if they have cooled down enough since the Big Bang, like our own matter. When the gas in the universe was too hot, it could not coalesce into denser clouds back then, because of the outward counter-pressure within, due to the kinetic energy of thermal origin. When the positive mass matter cooled enough by radiative process, the kinetic pressure decreased inside and the cosmic clouds of hydrogen eventually collapsed gravitationally, igniting nuclear fusion reactions in their core, that created the first stars, etc. Now, why do you consider only an absolute symmetry from the beginning between the two population densities? It sure does not work, as you say. Then, why don't you consider on the contrary the hypothesis of an asymmetry, with a negative mass population much denser than the positive mass one? Because when you do so, it apparently solves all the problems you are describing in the video.
Because in such a case scenario with strong asymmetry, it is the greater negative mass density that drives the whole cosmic game and generates the large-scale structure of the universe (of the positive mass) as we observe it. Due to its greater density, negative mass is the first to coalesce into giant conglomerates of hot gas. The positive mass then has no choice but to be repelled into the interstitial space between such giant negative nebulae (the giant repelling cosmic voids we observe, that are in reality not "void" but full of (invisible) repelling negative mass. Into these reduced spaces, the positive mass is compressed and organizes as elongated filaments, flat walls and sheets, like the thin walls of soap around joint bubbles, and there, they benefit from a MUCH FASTER radiative cooling, while giant invisible negative mass stays very hot at the heart of their massive conglomerates, never cooling down enough to ignite and form stars. That's why hot negative mass can confine our cold galaxies by repulsive antigravity, giving the apparent "missing mass effect" we call "dark matter" and that we interpret classically as undetectable cold attractive baryonic matter of positive mass inside the galaxies, whereas it may be repulsive hot negative mass instead, that appears to be invisible because such negative mass emits negative energy photons that follow the null-geodesics of their own, distinct metric. But you are well aware of this hypothesis already, whose basis have been written down in the scientific peer-reviewed literature under the prior name of the "twin universe theory) back to 1977… You just choose not to talk about it.
@@fluxcapacitor You just translated the Janus theory of Jean Pierre Petit in english, that's great. I'm just an engineer, I don't pretend to manage physics at the point where I can tell if it's true or not, but I find it really brilliant.
So we've been thinking about negatives and positives, but what about complex numbers? I feel like because we aren't used to seeing them we might not have an intuitive understanding and therefore it may be much harder for us to come up with theories involving complex numbers than real numbers? Like for example for the spin we use positive integers, but what even is a complex integer and what meaning does it have? Maybe that's partially why we have difficulties finding new theories?
Thank you. Because at some point, I have asked the same questions, but lacking the knowledge to take it any further, that's about how far I ever got. Asking the questions. So it is very validating to see someone has been asking the same questions and actually worked on it. And also to finally get an answer.
Negative energy does exist, but it isn't caused by negative mass - rather imaginary velocity. This is common in badly run projects where progress is orthogonal to the objectives.
Sabine I still can't wait to see you on Sean Carroll's podcast. He does invite guests that disagree with him and that does result in an interesting dialog. He's certainly qualified enough to defend his point and you're qualified enough to question it. He's not afraid of being confronted and you aren't afraid to confront, that has to be really interesting!
Best part of weekend. You should go to lex’s podcast Sabine, you are on of the best explaining this shit imo, I’m looking forward to seeing you in a long conversation.
Also, the gravitational field has a negative field energy which implies its inertial mass is also negative from m = E/c^2, as opposed to the electromagnetic field which has a positive field energy and hence positive inertial mass.
Can someone help me with a crazy thought? (please be kind) Could the visible universe be inside the jet of a really big black hole in a very very much older greater universe (think visible universe = pea just above a black hole represented by a beach ball) It would mean the outside universe would have to be insanely old. The formation of the jet would have to be energetic enough to look like the big bang. The starting point 14 billion years ago would be the "essentially flat" Event Horizon. The "stuff" that formed the jet would have been sorted some North Pole some South Pole, & then In / Out from the EH. Could this explain, imbalance between matter and anti matter, the absence of mono poles, why space appears more or less "flat" and things like the "great attractor"? As you can tell I'm not a physicist but saw a thing where Roger Penrose asked if anyone had any alternative ideas so thought I'd have a stab at it🤣🤣🤣
In a sense this could indeed be. But you're not the first one thinking of it. An aspect that is almost certainly wrong tough is that our particle horizon would be the event horizon of the outer black hole, that would mean, earth would be right in the center.. and this is almost certainly not the case. It is a result of Einstein-Cartan (EC) theory, that black holes wouldn't in the inside go to an singularity, but space-time on the inside would blow up again. Which also sounds like dark energy. The basic idea of EC is that space-time can not only bend, but also twist. The downside of the theory, is that it is incredibly difficult to proof if it's true. It is beyond our current abilities. However, I keep wondering why it isn't often mentioned at least as a possibility.. my understanding to the why tough is, in the later 20th century it was expedited by some guy who was perceived as a dick, and because people disliked him, they disregarded the theory as a whole..
The jet of a black hole is parts of the accretion disc being diverted by magnetic fields from the accretion disc to shoot out at the poles. This is a very chaotic process, so I bet the CMB would not look as homogenous as it does. Jets have a direction, so there would be other effects than just an area which seems to attract parts of our universe, like the expansion and redshift would be different depending on the direction you look.
First THANK YOU! Hopefully I can drop this one now😂 Just two points String Theory doesn't have a singularity, the black hole is a fuzzy ball. Not sure if that makes a difference? Also would the "evenness" depend on the relative sizes? After all the visible universe would still have started out very small inside a very large high energy event. Wouldn't that prevent large deviations in energy density?
A big THANK YOU! Hopefully I can drop this one now. Just one thing, wouldn't "evenness" depend on the relative sizes? After all, the visible universe would still have been extremely small in a very large high energy event. Wouldn't that prevent any significant variations?
Finding a negative result is extremely important because eliminating possibilities helps close in on the truth. If there are 7 possible explanations, and you eliminate 1 of them, you're much closer to the correct one than before. That's huge!
I disagree that it would’ve been a wasted time. We cannot have successful theories without going through a bunch of failed theories first. Excluding the wrong answers brings us closer to the right answer. And I’m pretty sure you learned a lot during this time, just as me learning from reviewing how this theory failed.
*Failed hypotheses. A scientific theory is the result of a bunch of hypotheses that have gone through the scientific method. You first form a hypothesis and subject it to a lot of tests and experiments and observations to arrive at something that would be called a theory. So it's never a *theory* until it's been through all kinds of scrutiny. A scientific law is a statement about what something is, while a scientific theory is an explanation of how or why, after the theory has been compiled through running a bunch of hypotheses through all kinds of tests to verify them.
She is referring to the true waste of time chasing the beautiful math for way way too long when the facts showed it was not going anywhere or it clear there was no way to falsify so no point in continuing at this moment. (excepting like pure math the mind developing part) She picking on string theory a bit here at least the huge efforts on it plus dark matter projects to find a dark matter particle that keep failing for decades. I in no way saying these areas should have no effort but it as the point were at least traditional things need reexamining. There is a proposed dark matter string math that just came out that has some promise but still lacks proof. Wish people including Space Time would stop stating Hawking radiation as a proven fact when as far as I know proof of it a long way off if ever.
Things like this make me continue to seriously doubt cosmic inflation. If we have gravitational lensing, and then we add...anti gravity over similarly distant observations surely that would make scientists have to recalculate everything. So many things we could be missing that could lead to our model being 'wrong' rather than just missing elements.
All you're saying, especially after 9:00 strongly suggest Dark Energy... if we accept it is a property of vacuum and thus "improper" of mass (thus there will be much less Dark Energy inside galaxies, let alone planets, stars, etc.) and would still provide the "anti-gravitational" pressure required to explain Dark Matter. Are you going to deal with this some time?
The hypothesis that I've recently come up with to explain the appearance of dark matter is, what if Space/Time isn't the flat sheet that we generally visualize it as, but is more akin to a wrinkled paper bag, where you have creases which would be regions of increased gravity (and would be where most matter would be found), and bulges (where gravity would be reduced). Unfortunately, being a lay person, I'm not really sure how I would go about testing this hypothesis - but I think it is a novel take on what is traditionally attributed to Dark Matter.
I am an artist of 36+ years, I have been a commercial artist for a good portion of my career and now I am a fine artist. One of the biggest surprises along the way was how just because I like something, does not make it appealing to broad groups of people- making the art less likely to sell. Today, I look at compositions and subjects differently than I used to, to increase my potential for success. I am not always doing what I think looks good, but the results are much more rewarding in the end!
Don’t be too hard on yourself Sabine. Your theory of negative gravitational mass probably has some interesting insights. And it raises useful questions such as why gravity seems to have the same effect no matter the type of particle, except photons. Keep mathing.
I dont think you wasted your time at all. A massive part of doing "science" is explaining to others why something is or is not true. As much as it pains me, my high school english teacher was right, communication is most of the work most humans do and the fact you can explain why this line of work did not pan out have me understand and believe you on argument alone is a testament to your work. Thanks Sabine, excited for the next video!
Your premise is that because anti-matter particles contribute to the glue that holds quarks together in protons and neutrons, those AM particles must exert a positive (attractive) gravitational force. I'm totally just a physics amateur but I'm not sure one can make that assumption. Hypothetically, anti-matter particles could have negative gravity while still participating in all the other particle drama according to standard physics. The amount of negative gravity produced by a single anti-matter particle would be infinitesimal even by particle standards. But across galactic scales, the total number of anti-particles would be great, and then their cumulative negative gravitational force might modify the attractive kind of gravity we're all familiar with. I note as well that CERN has been trying to pin down the polarity of anti-particle gravity for some years, and has yet to do so.
I loved you. Nobody knows because they haven't made experiments yet. It could explain all the repulsive force from Dark Energy and even explain Dark Matter. If so, then our universe has a lot more anti-matter than normal ordinary matter. The universe has a slight ASYMMETRY imprint between normal matter and anti-matter. That's why it wasn't completely annihilated. The universe left out a little amount of normal matter so it could exist and that would implicate in having a bunch of anti-matter too or else it wouldn't have anything at all. It doesn't make sense why would anti-electrons or positrons act contrary to to electrons under electromagnetism while gravity would not also be inverted. It would repel normal matter and attract other anti-matter. There is no such need to invoke "negative mass" or "negative energy". Why wouldn't it just use normal energy? It doesn't need to interfere with the Equivalence Principle.
3:30 Here is a link to a free pdf of her paper, for any of you physicists who are interested. Full disclosure, I have not read it yet, I have almost a dozen other papers still waiting to be read, so I have no comments on it, based on the abstract and my cursory scan.
Finding something that doesn't work or a theory that leads nowhere is still solid science. Finding something like this protects future researchers from wasting time on it, and if by chance the theory resurfaces later, it is good for the new researcher to have some background. Being "wrong" does not mean that the time is wasted. It is still time well spent, just less glorious. I found this video very interesting! Thank you Sabine.
if default gravity pulls space then antigravity should push space and how curve would look like? Raising to infinity or dropping from mass point? Would space stiffness prefer one direction over another? Is space expanding because empty space have no zero gravity value? But that shud work only as in reality with infinity raising curve otherwise everything will find equilibrium. And at end i know nothing and can only imagine.
I was thinking, why would an anti gravity matter annulus around a normal matter galaxy be unstable? It would be like a cylinder containing high pressure gas. While the pressure inside wants to blow outward, gas molecules very slightly attract each other while the wall atoms are strongly bonded to each other, so as long as the hoop stress of the cylinder doesnt exceed UTS, it should be fine. With a thick enough anti gravity matter boundary, the arrangement wouldnt blow itself apart. Offcourse that would mean that there should be a lot of ring galaxies too.
4:43 Or as a result of radiactive β+ decay. An example is a PET scan where usually 18F decays, forming a neutrino and a positron. The latter soon annihilates after it encounters an electron, this in turn produces two γ fotons which are detected to form the image
9:55 WRONG Why would they clump? Normal Matter clump not because of gravity. They clump because collision is non-elastic i.e they give out energy. If this doesn't happen that Matter wouldn't clump.
As always, I love your videos. This one, however my head spin until I thought it would explode... until the end when you said: "Oops, doesn't work." You magically healed me. ❤️
Hi! what if there were more than two types of matter, not just anti and normal matter? 7:49 : -1 to the power of the spin makes sure that this particular symmetry made of two parts. Lets call this a tool. Changing this tool to a tool that could handle an arbitrary number of symmetry parts would lead to all the like matter attracted eachother, and all the unlike matter repeled as long as the spin would be 2. Therefore as long as an arbitrary number of matter types created by our new tool, it is quiet possible to modell our univerze structure (refering to 8:58 ).
Mass, inertial or gravitational or simply mass, doesn't resist acceleration. Every body with mass, that is every body, accelerates when under the action of net force. Does a bucket resist it's filling with water? No, it gets filled exactly according the mass flow of water. Similarly a massive body's momentum increases exactly depending of the time change of the momentum = force on the body. There is no resistance to acceleration, that is: There is no force resisting the accelertion of a mass.
At 5:22, How do we know the "virtual particles" make a substantial contribution to the gravitational mass? Is there a reference where I can see the calculation, specifically considering anti-particles? Maybe virtual particles only contribute gravitationally up to a sign as you said. According to Wikipedia: "Virtual particles do not necessarily carry the same mass as the corresponding real particle" and "A virtual particle does not precisely obey the energy-momentum relation m2c4 = E2 − p2c2. Its kinetic energy may not have the usual relationship to velocity. It can be negative. This is expressed by the phrase off mass shell." Plus, Occam's Razor supports the ideal of simple, elegant theories, so you were not wrong in your approach imo. Even Einstein once said, "Everything should be made as simple as possible, but no simpler" I'm also one of those people who believed anti-matter repels matter gravitationally, but I no longer do physics.
This problem you present a focus on (Though I have not read your book yet), is a problem that stretches philosophically to encompass all thinking everywhere and I'm very pleased that you present a focus on it. I want to read your book now, because I (being a casual reader, with a computer science BA with a math minor, who does have a basic understanding of some fundamental physics) was bothered by how easily something elegant or symmetrical or pretty captures our attention, to the detriment of truth and objectivity. To make this real, I ask: what does e=mcc actually mean, or refer to? I understood that there is a larger equation which contains this, but that the larger equation is never even talked about. So something like e=mcc + C, where C is the rest of what's going on. Only when the other stuff is 0 or ignored, does e=mcc. Or a more obvious example is that old expression by Mark Twain, "A lie goes around the world in the same amount of time that the truth ties its shoes."
Never thought I would ever hear somebody say "one of the lesser known facts about me is that I am one of the few world experts on anti-gravity". Sabine, you're a legend! Thank you so much for sharing all your knowledge with such a broad audience.
no doubt you have in mind Feynman's example of an antigravity device: a chair.
Feynman was one of the few dreaming followers of the religion scientism, that had the wits to recognise that it is no more than a religion. 'Anti-gravity ' my arse!
@@vhawk1951kl And, how is this helpful? I'm withholding judgement here, to ask the question. tia!
That's just how iconic Dr. Hossenfelder is. I deeply admire this woman.
Knowing that Sabine herself developed a theory based on beauty really changes how her "lost in math" thesis comes across. Definitely makes her seem more humble.
Fascinating to hear an expert talk about the experience of being wrong. We don't hear enough about this in pop-sci media, but it's critical to the scientific process that we understand when we're wrong and how to handle being wrong.
Because even wrong answers can give interesting and useful insights.
Thank you!
I was reflecting on my own science education as a kid and how my science fair project one year didn't produce the results I wanted, and I was so conditioned that wrong=bad that I faked the results and still passed.
I think it could have changed a lot about how I approached science if things has been otherwise and I was more comfortable examining why I was wrong rather than just "getting the right answer"
I said something similar with rather more words. This is one of many reasons I low-key adore Sabine.
@@comradequestion4206 If you were a physicist, you might've been able to spin a paper out of it. :-9
A negative result is always a positive thing, not for the people hoping(thinking) that it would yield a positive result, for the scientific field it is part of. Knowing what something is not slims down the possibilities what it can be and therefore avoid scientific research furthering going down paths that are incorrect.
I learned more from failed theories than from successful theories. Understanding why they are wrong is valuable knowledge.
I often participate in “pointless” online arguments just because often they have arguments which seems to be wrong (and they ARE wrong), but I can’t clearly explain why they are wrong.
An argument with a flat-Earth theorist will never persuade them that the Earth is round, but I learn a lot about geometry, light refraction and gravity.
This is my favorite video of yours so far.
Same. So much important context
Yes! I agree. I learned a lot.
Indeed; the more we learn the more we understand how much we don’t know
Thomas Huxley said (in various ways): “The saddest day in my life was to see a beautiful theory destroyed by an ugly fact.“
This presentation is beautiful on many levels.
Thanks again, Sabine!
Actually, the real quote from Huxley is "...the great tragedy of Science-the slaying of a beautiful hypothesis by an ugly fact..." From a speech to fellow scientists in Liverpool England in 1870. The text of his speech was reproduced in _Nature_ magazine, and went down in history. The quote has variously been falsely attributed to Charles Darwin, Benjamin Franklin, and John Tyndall, among others. It is often rearranged or phrased differently, even by Huxley himself. None of this makes it any less poignant and relatable to scientific thinkers.
Aldous Huxley experienced a conscious state of binary superposition in his 1950s "Doors of Perception" where a conscious singular observer sees the beauty of its own existence. He recognized this could be seen as both a blissful revelation of one's conscious existence or a horrifying realisation of singular but isolated loneliness, very eloquently.
Depending on ones viewpoint and situation, the observation problem, there's a binary superposition of positive and negative, so to speak.
Conspiracy theorists agree on that.
he later became a mathematician to circumvent this dilemma (not actually, I think)
That's when you have the wrong theory. I always tend to have the right theory, it's simply better.
My boss used to say "if the experiment always turns out the expected way, it wasn't an experiment". You are the sort of scientist that can make fundamental contributions since you can see when your ideas need to change, and learn along on the journey. Thank you for sharing your experience.
That is a good quote. Your boss sounds like a wise man (woman?).
Love this video. I disagree that your work was wasted, negatives are as important as positives and no one knows whether your negative result may become crucial to some later endeavour. I would also support 'guessing' (at least informed guessing), one ever knows. Keep up the excellent work and keep guessing.
Her point is part of a long standing argument she's been making: informed guessing is fine so long as it is warranted and driven by real inconsistencies/problems to be resolved. It's not okay when it's just driven by aesthetics. That is, beauty in a theory is no indication of truthfulness.
So she's demonstrating this applies to her own work, too. And more, she's revealing a bit about why, on a personal and not merely professional level, this is important to her.
i agree, i would argue it certainly was not wasted since it is part of her personal and scientific development.
I was going to say the same thing. Finding out what doesn't work is crucial to finding out what does work.
I agree.
@@GulfsideMinistries yes 100% agree with you. The OP has validity too though because her own growth (and now ability to help others investigate more fruitfully) was attained in large part due to learning from that "waste" thereby not truly being a waste. Just absolutely a worthwhile and valuable lesson to empart on others 👍
Thanks!
Physicists should proud themselves for having a great criticizer like Sabine who never shy to criticize herself.
Thanks for this beautiful and great confession.
Thanks for the kind words 😊
you are kissing her behind :D)) she isn't doing physics anyway
It's not wrong to explore a theory and conclude that it doesn't work. Sometimes more is learnt that way than exploring a theory that does work.
@@bogdy72000 That's a behind worth kissing, metaphorically speaking.
@@CAThompson kiss it all you want :D that's hylarious
"The theory of negative masses would therefore predict that the universe doesn't exist, which is in conflict with evidence."
You are such a joy to listen to! I'm adding this to my quote collection.
Also, the apple was clever.
Also also, how cool would it be in a few billion years if the Andromeda galaxy turns out to be anti-gravitating?
Finally also, I'm really enjoying Lost in Math.
Who’s to say the universe exists??
At the stake, dear Michael Piz (I swear you aren't myself) is if geometry might give birth to anything, or either gravitation comes from a Higgs- like mechanics.
@@anywallsocket Well who can then?
@@anywallsocket If the universe didn't exist, neither would you. You commented, therefore you exist, therefore the universe exists.
@@micaelapizza510 Geometry is a human invention designed to describe the universe, i.e. that which existed prior to geometry. So geometry doesn't "give birth" to anything but more ideas in the human mind.
Nice name. 😁
Biene brilliant as usual:
"Sometimes I even listen to myself."
Well, there you're probably ahead of most of us...
I think we are all attracted to intelligence. Ms Sabine is like the super massive black hole of intelligence. Even though I only understand less than 50% of her videos because of my lack of knowledge, I still learn and love every video. So much free knowledge and honest insight. Amazing amazing teacher.
This is such a great post on so many levels. First, taking a logical idea - that anti-gravitating matter may finally explain dark matter - and showing how it doesn't hold up to observation helps all future students and researchers in the area. Proving why something is wrong in science is just like "negative space" in art... the positive space couldn't exist without it.
Second, this post was personal to me because I fervently believe that the field of anti-gravity will become an enormous area of innovation, and I believe (hope) it will provide tremendous fodder for science fiction between now and then.
Thank you again for all your tremendous work!
I think it's an area where Edison's quote applies - it's not a failure, it's successfully identifying one approach that doesn't work so that people can move on to the next.
It wasn't proven wrong. This is the current best theory, like everything else in science.
If 'gravity' is due to spacetime distortions, what would 'anti-gravity' be due to? It takes 'energy' to distort spacetime in order to produce gravity so if it is the case that 'negative energy' is required to produce 'anti-gravity' then that would mean that 'negative energy' would be subject to a different Second Law of Thermodynamics than the one that governs 'positive energy'.
And there is one more confusing issue I have: if a particle annihilates with its anti-particle counterpart, is it 'energy' or 'anti-energy' that is released? I mean, we can account for the masses of the original particles in terms of the debris and energy released and there is nothing left unaccounted for that would require the need to consider that some of the mass had been converted into a form of energy, 'anti-energy', that cannot be detected by our equipment except by deduction. Right?
Surely 'anti-gravity' is a scientific cul-de-sac?
Sabine, Thank you for telling like it is, so many hide the complexity of their trajectories in science.
I hear too often those in the applied sciences claiming their research was a "waste of time" when information (through scientific means) indicates that the outcomes are not what they or their institution had hoped for. Part of learning is through experience, and experience can teach us not only what to do, but most importantly what NOT to do.
Please be supportive when someone shares wisdom of what NOT to do; it's a difficult pill to swallow but also very valuable information.
Heck. Finding a dead end and a wrong answer in science is discovery in itself. Being wrong is pure discovery. The real answer remains unknown. As much as we crave being right: We love a mystery.
Exactly. It's a HUGE part of the process of science.
I think it says a lot about this woman. Humility is a virtue.
What you say is in strong contradiction to the video. SH is NOT supporting your view!
@@soren6045 What, exactly, is she saying?
Sabine!!! This is so close to what I'm working on, but instead of tying RG to a form of mass, it's an inherent property of spacetime, just like quantum gravity!
0:00 "One of the lesser known facts about me is that I am one of the few world experts on anti-gravity"
Sounds like the intro of a great scifi-movie.
JA VIEL BITTE
Sabine acts the part of Einstein's granddaughter - she's already got that lovely accent - she's inherited Einstein's last lost secret papers on antigrav technology that he kept secret for fear of what the military would do with it. But now the technology is needed to save Earth.
@@DavidOfWhitehills 🙂
@@DavidOfWhitehills Considering Einstein's attitude to the US military after WW2, I have watched many a hollywood movie that started with a far, far weaker premise. I have read Sci-Fi books that were far weaker too. Maybe you should expand that into at least a short story?
@@DavidOfWhitehills You forgot to mention she inherited his hair too.
As the saying goes "If you don't learn from your mistakes, there is no point in making them in the first place". Well done!
I love this video. I believe every road should be explored even when it gets us no where. Yes, it may have been a mistake and a waste of time. However, the effort can still have good value. It can serve as a guide to those of us that may have wanted to take the same path late on. Thereby saving others from making the same mistake. Thank you Sabine!
We can’t know for sure that it doesn’t work, until we prove beyond the shadow of a doubt that it doesn’t work, and eliminates that possibility from our reasoning. So yes, it’s important to prove what is and what isn’t. Deductive reasoning. Some things we’ve recently discovered about quantum physics doesn’t make a lot of sense, a good thing someone did pursue those avenues of thought and not just assumed it was too crazy to work.
The phrase "waste of time" makes me wonder out loud: Could "time" not be a field that is ever present in physics as well as natural languages? If time indeed might be a field, what does it imply? that it might not be emergent, virtual or non-existent?
Indeed, but also her follow up point is a good one touched in philosophy of science. Much, much, much of the effort has been done on how one can determine if a hypothesis is a true one or wrong one. There is actually little to no work one how you can get good hypothesis. In classical PoS they just come from nowhere.
You must have seen another video. Sabine said exactly the opposite, it was a pure waste of time.
I wonder if this misunderstanding is intended by her to reach antiscientiest crackpot but also science fans.
Of course any scientist knows that you learn most from your failing ideas and experiments. Understanding why it fails is usually a big step forward.
But this is clearly not said in the video and also not in her anti scientist book.
Every road? I'm not sure if I agree. I guess explore sufficiently to know the road is a cul de sac - it would then not be logical to continue further down that path. Just saying.
Sometimes it feels good to stretch the brain towards something I really don't understand. I do enjoy Sabine's calm presentations of hard to grasp theories, it's almost like meditation.
Wonderful video Sabine. I didn't understand much of what you were talking about other than on a cursory level, but your method of presentation makes for an engaging and incredibly interesting viewing experience. Even if much of it was outside my sphere of knowledge the information was presented in such a way as to make it enjoyable and informative to watch. Thanks, and do keep making these videos!
Dear Sabine, I have just purchased your book (Lost in math). I look forward to reading it.
Read it last year, it´s an eye opener for me. The talk with Steven Weinberg belongs to the best I´ve ever read. Just read her new book "Exitential Physics", which I recommend too, hopeful and entertaining.
I am so into your communications, elegant , confident and courageously communicated. Thanks for being a hero to my curiosity. I’m able to develop on my own ideas from a solid angle 🙏🏼💯♥️
It is extremely enlightening to learn how a physicist has struggled with these different ideas. Thanks!
Excellent presentation with lots of “gems!” I’ve watched it twice and may do a third after I’ve had a chance to process the information. I admire your tenacity exploring the possibility of anti-gravity. Great video!!!!!
This is extremely cool! I had no idea you'd toyed with the idea of antigravity and it being what dark energy might be! And explaining why you had to abandon the hypothesis was quite clear, which helped me to understand it! Thank you! Here's a comment for the Almighty Algorithm! 👋 😊
You seem like a wonderful and awesome human being Sabine. Thank you for taking the time to educate us.
I wish you happiness and good health.
I like the honesty in this one. It's hard when time we spent on stuff appears to be wasted. But if you're positive then there's always something to take away from it. A deeper learning, a new understanding and perhaps a step to the next successful theory! All the best Sabine!
Mad respects for you. Its not everyday you see someone talking about how they were wrong on a theory. And please do not think of it as wasted time, your time has provided us with invaluable information of what darkmatter isnt, and the more and more we look into it, and rule out alternatives, the closer we are to the thruth.
I believe she referring to spending tons of time ignoring the fact that facts were not going to let her beautiful math ever work out. In other words she could have found out she was wrong way faster without her bias preventing accepting she was wrong.
So her being wrong on theory helpful, spending way to much time before accepting wrongness only helpful if others heed the warning that there a time to accept your wrong and to always watch if your own bias is preventing you from knowing your wrong.
Bias actually warps reality is been shown to have people unable to recall reading facts opposing their view and in other cases warping recall of the facts to support your idea so much they don't resemble reality anymore.
Gulf War Intelligence failure a great lesson on how heavy bias can make people think something that is not true. Especially if one of the bosses lies in information they give out at start.
This is why investigations looking for deliberate lies on this and other intelligence failures don't find anything as everyone thought they telling the truth but group think and heavy bias caused information countering their views ignored looked at briefly and filed away often with no recall of ever reading it.
Here of course Saddam refusing to fully cooperate and hassling inspectors combined with fact he did have chemical weapons and did have an atomic bomb project before the Israelis blew it up feed the heavy bias.
Saddam is over fifty percent responsible for that war. Simple full access and sharing all records quickly would have allowed inspectors prove he had no weapons. But Saddam wanted to have eat his cake yet still have the cake uneaten so to scare others with him possible having WMD while getting West to leave him alone.
I don't quite get why "negative gravitational mass" would necessarily have to be of positive inertial mass? I mean, such a hypothetical substance could as well be of negative mass in BOTH equations, right? Such mass would not only fall up, but also move in the direction from where it is pushed by an external agent, unless that agent was of negative inertial mass as well (because then, it's a would be negative), right? What makes this necessarily impossible?
This definitely clarified some things for me that I have wondered about. Thank you.
Very much enjoy your videos Sabine. I studied physics up to research Masters level in the UK, and this channel really helps me keep up my interest in the Big Questions of physics and the latest developments despite me not being a full time physicist. Keep up the good work!
I don't think it's a mistake for the physics community to spend a little time pursuing theories that ultimately turn out to be useless. That's one of the reasons why grad students exist.
Agree
You don't know they're useless until after you pursue them. This is not bad science, it's just science.
LOL! The grad student part though.
@@KenOtwell thank you
@@KenOtwell Agreed Ken.
I appreciate the willingness to say an idea didn't work. In Pauling's words:
"The best way to have a good idea is: to have a lot of ideas and throw away the bad ones." Kudos Dr. Sabine.
7:40 Where did this equation come from? Is this just a definition, or have we experimentally verified it for all possible spins of particles?
You can derive this in an approximation. This is nicely explained in Zee's QFT book (which is generally awesome): www.amazon.com/Quantum-Field-Theory-Nutshell-nutshell/dp/0691140340
Sabine, I read your book. The courage you have to criticize well-established concepts and theories is only surpassed by your honesty in criticizing yourself. This is the true scientific spirit and I greatly admire you for that.
Loved the book, btw. Thanks.
At t=3:09 changing F=ma to F=|m|a solves the apparent contradiction with F =-G m1 times m2 /Rexp2. Have you considered that option and its consequences?
I think Sabine just explained a path to becoming a great scientist. I'm not qualified to judge the value that her excursion into antigravity presented to science, but perhaps there should be an award similar to a Nobel for some contributions to science that explored and disproved an idea that was incorrect. There are certainly some "anti-discoveries" that are foundational and represent great achievement. Have such examples been recognized and just don't occur to me? As for Sabine, perhaps this "resume item" especially qualifies her to be considering a challenging concept like superdeterminism.
Think of all the people Sabine has saved from following this bunny trail if they simply read her paper.
SH said it was a waste of time, so your interpretation of the video is in contradiction to what she is saying.
But it shows that many of her fans do not really get what she is saying and implying.
It is just her strawman anti-mainstream bias they are fascinated.
She lamented that it was a waste of time scientifically, but clearly it was not a waste of time for her personal and professional development as she explains it led to her book and contributed to her judgement.
A Nobel exclusion principle?
Michelson Morley experiment. They won a nobel price for a negative result. I think the novelty was in the experimental procedure and setup rather than the theory it was supposed to test (luminiferous ether).
Super awesome to see a really smart person so calmly discuss being incorrect and why they changed their mind. We need more researchers saying this in public.
I absolutely love your candid approach to dark energy and matter which is clearly at the cutting edge of current theory. Im trying to imagine what a post dark matter theory would be like . .i.e. whats next.?!?
Great video Sabine!
Nice that you can take a step back & admit being wrong about something Sabine! The fact that you made this video definitely puts a positive spin on that subject matter. Well done! 👍👍😉😉
Thank you Sabine for sharing your insights. :-)
I always just assumed that anti-matter had the same mass as matter of equivalent type, so would be effected by gravity in the same way regular matter was. And my understanding of the concept of anti-gravity was not an oppose to gravity, but a *_neutralisation_* of gravity. On it's own not a force so wouldn't make things fall up, just stop matter (or anti-matter) from falling down.
The source of the idea of negative mass is from the Klein Gordon equations. Some of the solutions are negative energy which at first was considered an invalid solution. It turned out to be the solution to anti-matter. Feynman once ran with the idea of negative mass for anti-matter.
Part of that the Quantum Mechanics ideas that call for Gravity to be a force like the others with a Gravitron then in that case one could counter gravity with a opposite gravity field projecting Gravitrons. And use the same wave canceling ideas that are done with sound.
Unfortunately Gravity still not Quantized and if Relativity is right it will never be. One of the lost in the math things. This long and still no Quantum gravity detected and relativity applies to the smallest levels we can measure. Maybe time to give more support the lessor number chasing Relativity complaint Quantum Mechanics were Gravity is not a force that will combine with the other forces in a combined force right after the Big Bang.
Gravity in Relativity best described as an effect, a measurement of SpaceTime curvature not something it self.
The idea in 9:00 is pretty clever.
I wonder what could push from the outside? Residue of astro jet or Fermi bubbles?
Is the outskirts of a Galaxy like a grave yard for planets and stars?
I succeed because I have failed. Unfortunately we are rarely taught this as children because it would apparently hurt our self-esteem. Sadly this leads to ignorant people feeling as qualified as experts.
I understand only a part of what is being presented here, but it is very comforting to listen to such a brilliant scientist speak. I am reminded that there are still a few people that appear to know what they know, and more importantly, to know and understand what they don’t know, and be able to effectively communicate that to the world-a rare gem, indeed!
Gravity is explained by bending the space. Often illustrated by valley in elastic fabric caused by massive object. Can the space be bent the other way to form a hill? That would be antigravity.
I think you could if you had enough ‘negative’ mass !! ( that’s not anti matter ) anti matter is just positive matter with its charges reversed I believe 🤔 . negative mass would be something very different to anti-matter, to use the rubber sheet idea , the negative mass sphere would be under the rubber sheet pushing up to create your hill !! , it would have some cool properties, like reverse time dilation , time travel into the past would become possible , anti-gravity would be possible etc ..
Sounds like what they are calling "dark energy".
i’m excited already omg
My biggest mistakes have been in not taking my own advice.
This is where Sabine differs from most of us...it's a mistake for the rest of us to take our own advice...
Advises are usually reserved for others (eg students)
@Jonathan Camp I rather wish I found Sabine's blog last decade, then I wouldn't have wasted time on getting into woo metaphysical life-coaching crap a few years ago.
Sabine is a much better role-model.
@@janami-dharmam That'd because it's easier to tell other people what you think they should do. :)
@@CAThompson Hi C Thompson. How is my favorite Aussie?
Don't underestimate the power of your mind. You'll never anti-gravitate yourself off from the planet, but no astronaut ever made it into orbit without first having been mindful of what it takes to get there.
Keep what is important to you at the forefront of your thoughts and things will happen to make them happen.
I had a similar thought back in 2005 or 2005. I wondered if there could be a negative gravity particle with the following attributes:
1) Negative gravitation
2) Non-clumping to like particles
3) Neutrino-like neutrality to normal matter
I further assumed that such particles would "fall" towards the voids between galaxies collecting in vast invisible clouds. Their collective mass could represent dark matter and their collective push could represent dark energy. I also assumed the source for such "Darkticles" could be the anti-quarks from the creation. My question is:
Do we know that all combinations of anti-quarks cannot exist for long extents of time within the voids between the galaxies?
I had the same thought, that antigravitating particles would avoid each other and move away to create voids and a pressure on us in the galaxy, and drive galaxies apart. Seems so reasonable.
In order to include negative mass in cosmology, you developed and published for the first time in 2008 indeed (paper ""A Bi-Metric Theory with Exchange Symmetry") a bigravity framework where like masses attract and unlike masses repel. It means that negative mass is self-attracting and auto-gravitates, so it could in theory form dense nebulae of negative mass hydrogen indeed, as you notice in your video at 8:19
But those nebulae populating such a negative metric would build up into stars and galaxies ONLY if they have cooled down enough since the Big Bang, like our own matter. When the gas in the universe was too hot, it could not coalesce into denser clouds back then, because of the outward counter-pressure within, due to the kinetic energy of thermal origin. When the positive mass matter cooled enough by radiative process, the kinetic pressure decreased inside and the cosmic clouds of hydrogen eventually collapsed gravitationally, igniting nuclear fusion reactions in their core, that created the first stars, etc.
Now, why do you consider only an absolute symmetry from the beginning between the two population densities? It sure does not work, as you say. Then, why don't you consider on the contrary the hypothesis of an asymmetry, with a negative mass population much denser than the positive mass one? Because when you do so, it apparently solves all the problems you are describing in the video.
Because in such a case scenario with strong asymmetry, it is the greater negative mass density that drives the whole cosmic game and generates the large-scale structure of the universe (of the positive mass) as we observe it.
Due to its greater density, negative mass is the first to coalesce into giant conglomerates of hot gas. The positive mass then has no choice but to be repelled into the interstitial space between such giant negative nebulae (the giant repelling cosmic voids we observe, that are in reality not "void" but full of (invisible) repelling negative mass. Into these reduced spaces, the positive mass is compressed and organizes as elongated filaments, flat walls and sheets, like the thin walls of soap around joint bubbles, and there, they benefit from a MUCH FASTER radiative cooling, while giant invisible negative mass stays very hot at the heart of their massive conglomerates, never cooling down enough to ignite and form stars. That's why hot negative mass can confine our cold galaxies by repulsive antigravity, giving the apparent "missing mass effect" we call "dark matter" and that we interpret classically as undetectable cold attractive baryonic matter of positive mass inside the galaxies, whereas it may be repulsive hot negative mass instead, that appears to be invisible because such negative mass emits negative energy photons that follow the null-geodesics of their own, distinct metric. But you are well aware of this hypothesis already, whose basis have been written down in the scientific peer-reviewed literature under the prior name of the "twin universe theory) back to 1977… You just choose not to talk about it.
@@fluxcapacitor You just translated the Janus theory of Jean Pierre Petit in english, that's great.
I'm just an engineer, I don't pretend to manage physics at the point where I can tell if it's true or not, but I find it really brilliant.
So we've been thinking about negatives and positives, but what about complex numbers? I feel like because we aren't used to seeing them we might not have an intuitive understanding and therefore it may be much harder for us to come up with theories involving complex numbers than real numbers? Like for example for the spin we use positive integers, but what even is a complex integer and what meaning does it have? Maybe that's partially why we have difficulties finding new theories?
Sabine, I read about a month ago of the detection of negative mass electrons. Was it debunked already?
Thanks! 😊
Stay safe there with your family! 🖖😊
well I must have missed that... do you have a link?
@@SabineHossenfelder Well, the article I read was in Portuguese, from Brazil. But I'm going to search for it!
I think there may be a hole in your translation?
@@Ava31415 I already posted a link in English here. But TH-cam... You know. 😕
@@Ava31415 a wormhole??
Thank you.
Because at some point, I have asked the same questions, but lacking the knowledge to take it any further, that's about how far I ever got. Asking the questions. So it is very validating to see someone has been asking the same questions and actually worked on it. And also to finally get an answer.
Negative energy does exist, but it isn't caused by negative mass - rather imaginary velocity. This is common in badly run projects where progress is orthogonal to the objectives.
What would be the parallel way to the objectives to show that NE does exist?
Thanks for the new word, I had no idea what 'orthogonal' meant.
@@CAThompson Some strange extra dimensions, I suppose. But I don't see how to cancel out energy without cancelling out momentum as well.
Sabine I still can't wait to see you on Sean Carroll's podcast. He does invite guests that disagree with him and that does result in an interesting dialog. He's certainly qualified enough to defend his point and you're qualified enough to question it. He's not afraid of being confronted and you aren't afraid to confront, that has to be really interesting!
Best part of weekend. You should go to lex’s podcast Sabine, you are on of the best explaining this shit imo, I’m looking forward to seeing you in a long conversation.
Also, the gravitational field has a negative field energy which implies its inertial mass is also negative from m = E/c^2, as opposed to the electromagnetic field which has a positive field energy and hence positive inertial mass.
Can someone help me with a crazy thought? (please be kind)
Could the visible universe be inside the jet of a really big black hole in a very very much older greater universe (think visible universe = pea just above a black hole represented by a beach ball)
It would mean the outside universe would have to be insanely old.
The formation of the jet would have to be energetic enough to look like the big bang.
The starting point 14 billion years ago would be the "essentially flat" Event Horizon. The "stuff" that formed the jet would have been sorted some North Pole some South Pole, & then In / Out from the EH.
Could this explain, imbalance between matter and anti matter, the absence of mono poles, why space appears more or less "flat" and things like the "great attractor"?
As you can tell I'm not a physicist but saw a thing where Roger Penrose asked if anyone had any alternative ideas so thought I'd have a stab at it🤣🤣🤣
In a sense this could indeed be. But you're not the first one thinking of it. An aspect that is almost certainly wrong tough is that our particle horizon would be the event horizon of the outer black hole, that would mean, earth would be right in the center.. and this is almost certainly not the case. It is a result of Einstein-Cartan (EC) theory, that black holes wouldn't in the inside go to an singularity, but space-time on the inside would blow up again. Which also sounds like dark energy. The basic idea of EC is that space-time can not only bend, but also twist. The downside of the theory, is that it is incredibly difficult to proof if it's true. It is beyond our current abilities. However, I keep wondering why it isn't often mentioned at least as a possibility.. my understanding to the why tough is, in the later 20th century it was expedited by some guy who was perceived as a dick, and because people disliked him, they disregarded the theory as a whole..
The jet of a black hole is parts of the accretion disc being diverted by magnetic fields from the accretion disc to shoot out at the poles. This is a very chaotic process, so I bet the CMB would not look as homogenous as it does. Jets have a direction, so there would be other effects than just an area which seems to attract parts of our universe, like the expansion and redshift would be different depending on the direction you look.
I think your idea's crazy, that's why I like it.
First THANK YOU!
Hopefully I can drop this one now😂
Just two points
String Theory doesn't have a singularity, the black hole is a fuzzy ball.
Not sure if that makes a difference?
Also would the "evenness" depend on the relative sizes? After all the visible universe would still have started out very small inside a very large high energy event. Wouldn't that prevent large deviations in energy density?
A big THANK YOU!
Hopefully I can drop this one now.
Just one thing, wouldn't "evenness" depend on the relative sizes? After all, the visible universe would still have been extremely small in a very large high energy event. Wouldn't that prevent any significant variations?
Finding a negative result is extremely important because eliminating possibilities helps close in on the truth. If there are 7 possible explanations, and you eliminate 1 of them, you're much closer to the correct one than before. That's huge!
I disagree that it would’ve been a wasted time. We cannot have successful theories without going through a bunch of failed theories first. Excluding the wrong answers brings us closer to the right answer.
And I’m pretty sure you learned a lot during this time, just as me learning from reviewing how this theory failed.
*Failed hypotheses. A scientific theory is the result of a bunch of hypotheses that have gone through the scientific method. You first form a hypothesis and subject it to a lot of tests and experiments and observations to arrive at something that would be called a theory. So it's never a *theory* until it's been through all kinds of scrutiny. A scientific law is a statement about what something is, while a scientific theory is an explanation of how or why, after the theory has been compiled through running a bunch of hypotheses through all kinds of tests to verify them.
She is referring to the true waste of time chasing the beautiful math for way way too long when the facts showed it was not going anywhere or it clear there was no way to falsify so no point in continuing at this moment. (excepting like pure math the mind developing part)
She picking on string theory a bit here at least the huge efforts on it plus dark matter projects to find a dark matter particle that keep failing for decades.
I in no way saying these areas should have no effort but it as the point were at least traditional things need reexamining.
There is a proposed dark matter string math that just came out that has some promise but still lacks proof.
Wish people including Space Time would stop stating Hawking radiation as a proven fact when as far as I know proof of it a long way off if ever.
Best science correspondent on TH-cam. Actually, I can't think of anyone better outside TH-cam
Things like this make me continue to seriously doubt cosmic inflation.
If we have gravitational lensing, and then we add...anti gravity over similarly distant observations surely that would make scientists have to recalculate everything.
So many things we could be missing that could lead to our model being 'wrong' rather than just missing elements.
If you feel generous I would love someone smart to look at the crazy thought i had and posted in the comments 🙄
All you're saying, especially after 9:00 strongly suggest Dark Energy... if we accept it is a property of vacuum and thus "improper" of mass (thus there will be much less Dark Energy inside galaxies, let alone planets, stars, etc.) and would still provide the "anti-gravitational" pressure required to explain Dark Matter. Are you going to deal with this some time?
The hypothesis that I've recently come up with to explain the appearance of dark matter is, what if Space/Time isn't the flat sheet that we generally visualize it as, but is more akin to a wrinkled paper bag, where you have creases which would be regions of increased gravity (and would be where most matter would be found), and bulges (where gravity would be reduced). Unfortunately, being a lay person, I'm not really sure how I would go about testing this hypothesis - but I think it is a novel take on what is traditionally attributed to Dark Matter.
i like these longer, more explanatory videos
8:11 aren't gravitons hypothetical?
Awesome again Sabine! About a year ago you replaced PBS space time as my favorite physics channel.
just brilliant! rarely a sponsor brand fits that well
One of the best videos I've seen on the subject. Thank you, Sabine!
I am an artist of 36+ years, I have been a commercial artist for a good portion of my career and now I am a fine artist. One of the biggest surprises along the way was how just because I like something, does not make it appealing to broad groups of people- making the art less likely to sell. Today, I look at compositions and subjects differently than I used to, to increase my potential for success. I am not always doing what I think looks good, but the results are much more rewarding in the end!
As always top of the game,dissection of subject to arrive at a logical conclusion.Thanks for your info.
A very lucid and well thought out presentation. Thank you.
Don’t be too hard on yourself Sabine. Your theory of negative gravitational mass probably has some interesting insights. And it raises useful questions such as why gravity seems to have the same effect no matter the type of particle, except photons. Keep mathing.
Honest and interesting! Sabine is really a great scientist.
I dont think you wasted your time at all. A massive part of doing "science" is explaining to others why something is or is not true. As much as it pains me, my high school english teacher was right, communication is most of the work most humans do and the fact you can explain why this line of work did not pan out have me understand and believe you on argument alone is a testament to your work.
Thanks Sabine, excited for the next video!
Your premise is that because anti-matter particles contribute to the glue that holds quarks together in protons and neutrons, those AM particles must exert a positive (attractive) gravitational force. I'm totally just a physics amateur but I'm not sure one can make that assumption. Hypothetically, anti-matter particles could have negative gravity while still participating in all the other particle drama according to standard physics. The amount of negative gravity produced by a single anti-matter particle would be infinitesimal even by particle standards. But across galactic scales, the total number of anti-particles would be great, and then their cumulative negative gravitational force might modify the attractive kind of gravity we're all familiar with. I note as well that CERN has been trying to pin down the polarity of anti-particle gravity for some years, and has yet to do so.
I loved you. Nobody knows because they haven't made experiments yet. It could explain all the repulsive force from Dark Energy and even explain Dark Matter.
If so, then our universe has a lot more anti-matter than normal ordinary matter.
The universe has a slight ASYMMETRY imprint between normal matter and anti-matter. That's why it wasn't completely annihilated. The universe left out a little amount of normal matter so it could exist and that would implicate in having a bunch of anti-matter too or else it wouldn't have anything at all.
It doesn't make sense why would anti-electrons or positrons act contrary to to electrons under electromagnetism while gravity would not also be inverted. It would repel normal matter and attract other anti-matter. There is no such need to invoke "negative mass" or "negative energy". Why wouldn't it just use normal energy? It doesn't need to interfere with the Equivalence Principle.
3:30 Here is a link to a free pdf of her paper, for any of you physicists who are interested. Full disclosure, I have not read it yet, I have almost a dozen other papers still waiting to be read, so I have no comments on it, based on the abstract and my cursory scan.
You are the most knowledgeable, understandable by your audience and straightforward scientist I have ever seen in the internet ❤️
Finding something that doesn't work or a theory that leads nowhere is still solid science. Finding something like this protects future researchers from wasting time on it, and if by chance the theory resurfaces later, it is good for the new researcher to have some background. Being "wrong" does not mean that the time is wasted. It is still time well spent, just less glorious. I found this video very interesting! Thank you Sabine.
if default gravity pulls space then antigravity should push space and how curve would look like? Raising to infinity or dropping from mass point? Would space stiffness prefer one direction over another? Is space expanding because empty space have no zero gravity value? But that shud work only as in reality with infinity raising curve otherwise everything will find equilibrium. And at end i know nothing and can only imagine.
When you can't be sure what truth is it helps to verify what it isn't. Just subscribed, loving the content and how clear spoken you are.
I was thinking, why would an anti gravity matter annulus around a normal matter galaxy be unstable? It would be like a cylinder containing high pressure gas. While the pressure inside wants to blow outward, gas molecules very slightly attract each other while the wall atoms are strongly bonded to each other, so as long as the hoop stress of the cylinder doesnt exceed UTS, it should be fine. With a thick enough anti gravity matter boundary, the arrangement wouldnt blow itself apart.
Offcourse that would mean that there should be a lot of ring galaxies too.
That's Dark Energy and Dark Matter. Michio Kaku said that to keep a wormhole open you need dark matter around it to keep it from bowing itself apart.
Pressure is on! Love the fact that it can be negative or; and positive!!
4:43 Or as a result of radiactive β+ decay.
An example is a PET scan where usually 18F decays, forming a neutrino and a positron. The latter soon annihilates after it encounters an electron, this in turn produces two γ fotons which are detected to form the image
9:55 WRONG Why would they clump? Normal Matter clump not because of gravity. They clump because collision is non-elastic i.e they give out energy. If this doesn't happen that Matter wouldn't clump.
As always, I love your videos. This one, however my head spin until I thought it would explode... until the end when you said: "Oops, doesn't work." You magically healed me. ❤️
Hi! what if there were more than two types of matter, not just anti and normal matter?
7:49 : -1 to the power of the spin makes sure that this particular symmetry made of two parts. Lets call this a tool. Changing this tool to a tool that could handle an arbitrary number of symmetry parts would lead to all the like matter attracted eachother, and all the unlike matter repeled as long as the spin would be 2. Therefore as long as an arbitrary number of matter types created by our new tool, it is quiet possible to modell our univerze structure (refering to 8:58 ).
Thanks for sharing your experience. Und viel Erfolg für künftige Theorien! ☺️
Thank you Dr. Hossenfelder! Beautiful perspective on a seldom discussed aspect of Physics theory!
Mass, inertial or gravitational or simply mass, doesn't resist acceleration. Every body with mass, that is every body, accelerates when under the action of net force. Does a bucket resist it's filling with water? No, it gets filled exactly according the mass flow of water. Similarly a massive body's momentum increases exactly depending of the time change of the momentum = force on the body.
There is no resistance to acceleration, that is: There is no force resisting the accelertion of a mass.
"Yes, that guy again." It never gets old
What an excellent explanation of this issue. Thanks for providing such clear explanations about complex topics such as this.
Bravo! ... A real Lesson ... for all scientist to listen to ... and reflect upon.
At 5:22, How do we know the "virtual particles" make a substantial contribution to the gravitational mass? Is there a reference where I can see the calculation, specifically considering anti-particles? Maybe virtual particles only contribute gravitationally up to a sign as you said.
According to Wikipedia: "Virtual particles do not necessarily carry the same mass as the corresponding real particle" and "A virtual particle does not precisely obey the energy-momentum relation m2c4 = E2 − p2c2. Its kinetic energy may not have the usual relationship to velocity. It can be negative. This is expressed by the phrase off mass shell."
Plus, Occam's Razor supports the ideal of simple, elegant theories, so you were not wrong in your approach imo. Even Einstein once said, "Everything should be made as simple as possible, but no simpler"
I'm also one of those people who believed anti-matter repels matter gravitationally, but I no longer do physics.
This problem you present a focus on (Though I have not read your book yet), is a problem that stretches philosophically to encompass all thinking everywhere and I'm very pleased that you present a focus on it. I want to read your book now, because I (being a casual reader, with a computer science BA with a math minor, who does have a basic understanding of some fundamental physics) was bothered by how easily something elegant or symmetrical or pretty captures our attention, to the detriment of truth and objectivity.
To make this real, I ask: what does e=mcc actually mean, or refer to? I understood that there is a larger equation which contains this, but that the larger equation is never even talked about. So something like e=mcc + C, where C is the rest of what's going on. Only when the other stuff is 0 or ignored, does e=mcc.
Or a more obvious example is that old expression by Mark Twain, "A lie goes around the world in the same amount of time that the truth ties its shoes."
Another outstanding video! Thanks. This is precisely why I keep watching your channel and why I support you on patreon.
What a great scientist, you inspire me and many others Sabine, I hope you know that