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 👍
"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. 😁
Physicists should proud themselves for having a great criticizer like Sabine who never shy to criticize herself. Thanks for this beautiful and great confession.
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.
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.
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.
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?
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! 👋 😊
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.
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!
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!
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 🙏🏼💯♥️
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.
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!!!!!
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 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.
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.
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 ..
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.
Many true discoveries in math and physics have come from pushing existing theories past their limit - e.g. this function is undefined past this boundary but what happens if we treat it as if it were. That this type of thinking has often worked out "correctly" (or at least, has some sensible outcome) means that this type of exploring is worthwhile, even if it produces no results as in your antigravity case. At the very least, who you are today is the sum of all your past experiences, so you (and therefore all of us viewers) wouldn't be the same without that experience, so it was a net positive 😁 cheers
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).
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 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!
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.?!?
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 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.
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!
@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.
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.
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! 👍👍😉😉
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
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.
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.
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.
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.
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!
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.
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.
Danke Sabine, das war sehr aufschlussreich. Laienhaft war mir die Idee mit der Dunklen Materie die von außen Drückt auch schon vor Jahren gekommen, sie ist ja auch sehr naheliegend, aber eben doch zu schön um wahr zu sein. Ich finde die Vorstellung beruhigend, dass man doch genau hinschauen muss, um der Wahrheit näher zu kommen, und es nicht ausreicht schöne Theorien zu entwickeln, nur weil sie einfach und elegant sind.
Die Idee ist grundsätzlich falsch. Probier zu berechnen den Flux des Schwerkraftfeld mit den Gauß integral auf eine Oberfläche die einem Objekt umkreist....den Flux ist nur den Flux der Objekten in der Oberfläche davon keine Kraft ist empfunden von Objekten innerhalb der anti Gravity Verteilung
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.
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 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!
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?
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?
It is possible (and really very easy) to study particles with negative mass in general relativity. If the equivalence principle holds, then positive masses attract everything and negative masses repel everything (the passive partner falls along geodesics, so its sign plays no role). This means that a pair of a positive and a negative particle will chase each other thru the universe: the negative particle pushes the positive one away, but it is attracted by it and follows it. These things have exact solutions (Bonnor-Swaminarayan and similar). Using the methods developed in the 60s by Bondi, Metzner and Sachs, one can compute that these pairs emit gravitational waves.
When in the studies theoretical physicists do, an equation comes out, and the mass is "negative", then there could be the possibility to apply that equation to an experimental situation, to check whether it works or not, and how. This could make sense of "negative mass", like many applications make sense of "complex numbers".
Professor Hossenfelder, in the video you state that “it’s that the ratio of the energy density over the pressure is negative.” However, the video displays Pressure /Energy density
I am always troubled when anyone writes both Newton's law of gravity and Coulomb's law for electrostatics. It directly states that both forces are, well, forces. The deep lesson about general relativity is that gravity is NOT a force. It is a principle of symmetry that is difficult to put into words, but does get summarized with the phrase "the equivalence principle". I am also an anti-spin-2 gravity person. On paper, one can construct loop diagrams with photons and gravitons that those who are skilled at these arts say are not renormalizable (a bad thing). A photon is something so simple it cannot experience the click of a clock. I don't understand how it has time to interact with a graviton ever. Gravity in GR is caused by diffeomorphism symmetry. Again, another phrase that is very hard to understand. The really hard trick for a novel approach to gravity is to get light to work like we KNOW it does. One theory that plays with light in many beautiful ways is special relativity. There we have those fun Minkowski light cones and parabolas. Could we do something fun and different with such parabolas? What about rotating the parabola by 45 degrees? It would be fun! It would be strange! Why, because the "correct" parabolas make sure that light travels at the same speed according to all inertial observers. The 45-degree parabolas would make sure that two non-inertial observers do not agree about the speed of light. That is what happens in a gravity field with light, but we usually say that light bends. With a little thought, it is apparent that this 45-degree collection of parabolas only has a chance of working in tangent spaces of space-time, say momentum-energy. Minkowski space-time is Minkowski space-time with its normal parabolas. In a gravitational field, the symmetry that is used for momentum-energy is this 45-degree collection of parabolas that preserves energy * momentum. An odd symmetry indeed, but still can be explained simply. For a photon with no gravitational field, the ratio of |momentum|/energy = 1. in a gravity field, that ratio is no longer equal to one. Thanks for the video.
As Mat over at Space Time states a lot of people in Quantium mechanics would be very sad as no Gravitational Force a very large number of people would be sad as the math keeps pointing to it being a force yet it could be lost in the beauty of the math as she says. And at the practical end that math has allowed a lot of discovery of practical things we use every day. I hate when they use Newton's law period as it a disproven Law. It just doing the same thing in Relativity is so much additional math which for normal life stuff is unnecessary as the effect can't be observed for practical use. I'm torn as Sabine could do the example using Relativity but it would be a lot harder for the audience to understand.
@@RedRocket4000 I have tried to figure out any group of people that might be "happy" with the proposed "gravity is just a symmetry you can draw in a tangent space" idea. There are people that work on something called "conformal geometries". Those do not change angles in space-time. Since I am squaring momentum and energy, the angles should stay the same. We should always show respect for Newton. Once one has done the technical achievement of solving the Einstein field equations, one is NOT done. There are constants that have to be eliminated. One constraint is that empty space has the empty space interval. The other one is basically Newton's law! I was kind of surprised to see it was required at such a late step in the game. I spent 4 months slowly going through Sean Carroll's research notes. That subject will remain out of reach. The reason for this is really something known as the Riemannian Curvature tensor. This is a rank 4 tensor, so it has something like 4x4x4x4 parts. And there are technical options one can make in there that one needs a Ph.D. to understand. I believe Sabine has pointed out that some of these choices mean that the 1915 version of GR cannot deal correctly with fermions, a rather serious flaw. Pros are aware of it, but it is very difficult to solve. Now I know you can find a picture of a Minkowski space-time diagram on the Internet and in some of her videos. And I am confident you can rotate them by 45 degrees and change the t -> m dt/dtau=E and R -> m dR/dtau=P. That bit of graph paper magic is going to work for photons, bosons, and fermions. It is so hard to even start a conversation because people want equations to SOLVE. There are not really equations to solve in SR, it is just a symmetry that applies to the velocities of observers. Rotate by 45 degrees and again there are no equations to solve. This time there are escape velocities to observe. I get why that doesn't feel satisfying to the well-trained, but such is the fate of my current efforts. Folks train in something that is 4x4x4x4 complicated will be sad at simple drawing.
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."
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.
If you see this, please consider the idea of bosons having only inertial mass, while fermions cause curvature (time dilation) and anti-fermions cause anti-curvature (time compression).
I once played with this thought that particles can be of (at least) 4 types: 1st: opposite attract and same repel (charge) 2nd: opposite repel and same attract. (mass) 3rd: opposite attract and same ALSO attract. This is the interesting one. This particle would wander around without preference to + or -. So randomness will make it either grow a bit bigger when + clump together, but quickly disappear when some - make it annihilate again. Therefore it can't grow too big. Often it will randomly disappear into thin air but should also be able to appear from nothing. I later learned about quantum foam and it kind of matched type 3. (?) 4th: opposite repel and same also repel. Particles of this type should be very rare, since they just fly apart whenever created.
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. ❤️
The same argument is used in courtrooms by referring to equivocation of ambiguous terms as objectionable. The ambiguity of a term that could work may be confounded by the application of another meaning of it's capacity which can frustrate when used to distract us from the point (as in the defense used at Babel by fragmentation language and a scattering of the people). My hope is that we’ll be able to write with more clarity about positions and intentions by using the greater specificity we’re afforded here in this medium because it’s not even possible to perceive without doing so.
A few people provide remarkably similar explanations about the formation of the universe but there are some MAJOR gaps in the sequence of events. I really enjoy your channel Sabine and look forward to hearing an answer to what I'm missing. Hours after the event referred to as the "Big Bang" the only things in existence were "hydrogen and helium ions plus electrons" and this plasma was too hot to allow atoms to form. This primordial soup continued to expand at a rapid rate and cooled. "After about 380 000 years, when the temperature decreased to 1000K, atoms were able to form". The cooler plasma was "now neutral, allowing photons to pass through" and the light starting dimming to make the universe dark (due to decreased intensity of photons). Why would the electrons bind with ions at 1000K to form atoms and even more incredulous is these ions / atoms are moving rapidly apart so why would they coalesce to begin forming stars in the first place? The fusion process described to explain stars requires a high density of hydrogen at high temperature and high gravitational pressure, which assumes that stars have already formed to provide the appropriate conditions when this is clearly not the case - as the stars did not exist yet. There are some MAJOR gaps in these explanations. By coincidence a brand new video "Where did Dark Matter and Dark Energy Come From" (alphabet keeps removing the link!!) was published on 03.12.2021 by The History of the Universe Channel and at the 20:00 mark touches exactly on this topic. I also don't buy the explanation given there but it sparked off an idea that I have never heard anyone speak about. I describe this briefly below. There is a universe of dark matter and dark energy (which we realize we know nothing about other than it's observed affects that have made us aware of this mysterious 'stuff'). For some reason an event was triggered (which we call the Big Bang) and this took place inside the dark universe. The behavior and characteristics of the items that we know about and (incorrectly) call the universe are determined by the properties of the dark universe, which is the actual universe. We've never thought about it in this way. We are trying to explain phenomenon that we observe in 'our observed universe' but we are the result of an event in the dark universe. And we know extremely little about it. So when the plasma of hydrogen ions, electrons, photons plus other things that may be there (380 000 years later), all sparked by the 'Big Bang' event, are flying through what we thought was empty space (but is actually the dark universe), the dark universe matter and energy interact with the outputs of the event which gave rise to the " 'primordial components' of our 'observed universe' " and determine its shape, characteristics and properties. The effect of the interaction of the dark universe (matter and energy) causes the 'primordial plasma' (more accurately the products of the Big Bang event in the dark universe) to clump together (due to 'dark gravity'?) and to continue expanding at an accelerated rate (a baffling observed phenomenon which we call inflation). Sabine, I would love to hear your response to this.
Good point showing the analogous nature of electrical potential and gravity. As in particle physics if we refer to mass in mega electron volts, then mass takes on a more understandable Energy relation. Energy attracts energy. Gravity, electrostatic, electromagnetic, are only moving to equipotential.
The important thing is that one learned from it. To many refuse to accept beeing wrong, or risk beeing wrong in the first place and dont learn from it up to the point of biased data to fit to the theory. I liked a phrase i picked up somewhere: "Why should i be disappointed? Even if its wrong, i know now that ist is and discoverd something new ths way, that what science is about, right?"
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!
You mention that antigravity would only be possible with clumping antigravitational matter and reason this by giving known properties of fields (i.e. spin count). I have two problems with this reasoning: ① The spin count property is an observable effect in the fields as far as we know them. Here we are talking about an unknown effect. What reason do you have to assume it must follow the known mechanisms? ② If we don't assume to find matter of gravity in a negative sense (i.e. repelling) but matter with something _like_ gravity which is generally repelling (i.e. also with each other) we would simply have a completely new field which could (as far as I understand it) follow the existing spin count rule and still be repelling with normal matter and with each other. Both ways of thinking would allow only repelling matter which therefore would have no reason to clump together and thus all your following arguments would fall. Do you have any more arguments against my ideas?
Hi. As far as I see, your effort has been very useful to get deeper in understanding nature , in any case. And wonderful lesson about beeing wrong. With the usual elegance. 😳👌❤️
Little bit confusing and I'm an EM guy. Maybe leave the visual aids up longer as you are talking and juxtapose them for clarity. Fascinating topic. I spent 15 years 'wasting my time' on a topic which is finally producing fruit. Never give up trying to find solutions, that's the fun part of the puzzle.
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?
I think, particles are some structures made of the same stuff, which the space itself is made of. Suppose that space is made of some minimal units. Those units are connected together, which form the space. The space arises from the regular connections of those units. But suppose, there may be also some irregular connections, some knots. Such knots, the perurbations of the fabric of space, may be what we perceive as 'particles'. Now, let's imagine that some of those perturbations may be absolutely the same yet have different chirality. Different chirality arises from almost anything, when something is connected to something else in a specific way to form a certain structure. What could different chirality mean? - The structures with opposite chirality would likely annihilate each other when meet together. Because the perturbations those structures are made of will have an opportunity to compensate and staighten each other. - If a structure (that is particle) possesses a certain property described with a certain value, the same structure however with different chirality will likely have the equivalent property but described with the mathematically opposite value. Especially that will concern, when the value is component one, that is some kind of vector. This is what particle/antiparticle dualism could actually be.
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.
@Sabine Hossenfelder, then I have a question. Let's suppose we have a small machine like a watch. You can attach it to objects. It works like it creates a field and within that the you can shield the gravitational force. You can adjust the efficiency of shielding. So you attach it to a rock that fits in the field. You turn it on and starts to adjust the shielding. Let's say we put the rock on a scale and are measuring it's weight. It shows 1 kg at the begining, 900g at 10% shielding, 500g at 50% shielding. We are of course on Earth. What happens if we turn it on 100%?
I always get confused if physicists alternate between two states. One state is where they claim that gravity is a force - and look for a way to unite it with the other forces. The other state is where it is a contraction of spacetime (yeah - that guy again). So, looking at an atomic level the mass of an atom's nucleus is mainly caused by the strong force. My image was that the strong force causes the space at nucleus to contract and thereby creating the contraction of spacetime. Looking for the opposite we should look for ways to expand spacetime.
"You don't get something from nothing, you can't have freedom for free, you won't get wise with the sleep still in your eyes, no matter what your dreams might be." Something from Nothing by the band Rush
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 👍
"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. 😁
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
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.
Biene brilliant as usual:
"Sometimes I even listen to myself."
Well, there you're probably ahead of most of us...
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 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?
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.
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?
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! 👋 😊
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.
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 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.
It is extremely enlightening to learn how a physicist has struggled with these different ideas. Thanks!
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!
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!
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 🙏🏼💯♥️
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.
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!!!!!
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!
This definitely clarified some things for me that I have wondered about. Thank you.
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.
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.
You're quickly becoming my favorite science educator
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 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.
Many true discoveries in math and physics have come from pushing existing theories past their limit - e.g. this function is undefined past this boundary but what happens if we treat it as if it were. That this type of thinking has often worked out "correctly" (or at least, has some sensible outcome) means that this type of exploring is worthwhile, even if it produces no results as in your antigravity case. At the very least, who you are today is the sum of all your past experiences, so you (and therefore all of us viewers) wouldn't be the same without that experience, so it was a net positive 😁 cheers
I like the candid way you say when you are wrong! It's a rare gift in our days!
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).
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.
Loved the book, btw. Thanks.
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!
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.?!?
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 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.
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!
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.
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.
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! 👍👍😉😉
You are the most knowledgeable, understandable by your audience and straightforward scientist I have ever seen in the internet ❤️
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
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.
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.
Awesome again Sabine! About a year ago you replaced PBS space time as my favorite physics channel.
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.
Dear Sabine, I have just purchased your book (Lost in math). I look forward to reading it.
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.
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!
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 🙄
Great video Sabine!
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.
Danke Sabine, das war sehr aufschlussreich. Laienhaft war mir die Idee mit der Dunklen Materie die von außen Drückt auch schon vor Jahren gekommen, sie ist ja auch sehr naheliegend, aber eben doch zu schön um wahr zu sein. Ich finde die Vorstellung beruhigend, dass man doch genau hinschauen muss, um der Wahrheit näher zu kommen, und es nicht ausreicht schöne Theorien zu entwickeln, nur weil sie einfach und elegant sind.
Die Idee ist grundsätzlich falsch. Probier zu berechnen den Flux des Schwerkraftfeld mit den Gauß integral auf eine Oberfläche die einem Objekt umkreist....den Flux ist nur den Flux der Objekten in der Oberfläche davon keine Kraft ist empfunden von Objekten innerhalb der anti Gravity Verteilung
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.
Sabine, Thank you for telling like it is, so many hide the complexity of their trajectories in science.
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 UA-cam... You know. 😕
@@Ava31415 a wormhole??
Best science correspondent on UA-cam. Actually, I can't think of anyone better outside UA-cam
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 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!
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?
One of the best videos I've seen on the subject. Thank you, Sabine!
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?
A very lucid and well thought out presentation. Thank you.
The moving photon has mass: 10^-54 kg ( 5.610 x 10^-25 MeV c^-2 ). They don't use inertial mass anymore, for obvious reasons.
It is possible (and really very easy) to study particles with negative mass in general relativity. If the equivalence principle holds, then positive masses attract everything and negative masses repel everything (the passive partner falls along geodesics, so its sign plays no role).
This means that a pair of a positive and a negative particle will chase each other thru the universe: the negative particle pushes the positive one away, but it is attracted by it and follows it. These things have exact solutions (Bonnor-Swaminarayan and similar). Using the methods developed in the 60s by Bondi, Metzner and Sachs, one can compute that these pairs emit gravitational waves.
Wouldn't that violate Newton's third law?
@@anderslvolljohansen1556 No, the total mass (and therefore momentum and kinetic energy) are zero.
As always top of the game,dissection of subject to arrive at a logical conclusion.Thanks for your info.
When in the studies theoretical physicists do, an equation comes out, and the mass is "negative", then there could be the possibility to apply that equation to an experimental situation, to check whether it works or not, and how. This could make sense of "negative mass", like many applications make sense of "complex numbers".
Professor Hossenfelder, in the video you state that “it’s that the ratio of the energy density over the pressure is negative.” However, the video displays Pressure /Energy density
I am always troubled when anyone writes both Newton's law of gravity and Coulomb's law for electrostatics. It directly states that both forces are, well, forces. The deep lesson about general relativity is that gravity is NOT a force. It is a principle of symmetry that is difficult to put into words, but does get summarized with the phrase "the equivalence principle". I am also an anti-spin-2 gravity person. On paper, one can construct loop diagrams with photons and gravitons that those who are skilled at these arts say are not renormalizable (a bad thing). A photon is something so simple it cannot experience the click of a clock. I don't understand how it has time to interact with a graviton ever.
Gravity in GR is caused by diffeomorphism symmetry. Again, another phrase that is very hard to understand.
The really hard trick for a novel approach to gravity is to get light to work like we KNOW it does. One theory that plays with light in many beautiful ways is special relativity. There we have those fun Minkowski light cones and parabolas. Could we do something fun and different with such parabolas?
What about rotating the parabola by 45 degrees? It would be fun! It would be strange! Why, because the "correct" parabolas make sure that light travels at the same speed according to all inertial observers. The 45-degree parabolas would make sure that two non-inertial observers do not agree about the speed of light. That is what happens in a gravity field with light, but we usually say that light bends.
With a little thought, it is apparent that this 45-degree collection of parabolas only has a chance of working in tangent spaces of space-time, say momentum-energy. Minkowski space-time is Minkowski space-time with its normal parabolas. In a gravitational field, the symmetry that is used for momentum-energy is this 45-degree collection of parabolas that preserves energy * momentum. An odd symmetry indeed, but still can be explained simply. For a photon with no gravitational field, the ratio of |momentum|/energy = 1. in a gravity field, that ratio is no longer equal to one.
Thanks for the video.
As Mat over at Space Time states a lot of people in Quantium mechanics would be very sad as no Gravitational Force a very large number of people would be sad as the math keeps pointing to it being a force yet it could be lost in the beauty of the math as she says. And at the practical end that math has allowed a lot of discovery of practical things we use every day.
I hate when they use Newton's law period as it a disproven Law. It just doing the same thing in Relativity is so much additional math which for normal life stuff is unnecessary as the effect can't be observed for practical use.
I'm torn as Sabine could do the example using Relativity but it would be a lot harder for the audience to understand.
@@RedRocket4000 I have tried to figure out any group of people that might be "happy" with the proposed "gravity is just a symmetry you can draw in a tangent space" idea. There are people that work on something called "conformal geometries". Those do not change angles in space-time. Since I am squaring momentum and energy, the angles should stay the same.
We should always show respect for Newton. Once one has done the technical achievement of solving the Einstein field equations, one is NOT done. There are constants that have to be eliminated. One constraint is that empty space has the empty space interval. The other one is basically Newton's law! I was kind of surprised to see it was required at such a late step in the game.
I spent 4 months slowly going through Sean Carroll's research notes. That subject will remain out of reach. The reason for this is really something known as the Riemannian Curvature tensor. This is a rank 4 tensor, so it has something like 4x4x4x4 parts. And there are technical options one can make in there that one needs a Ph.D. to understand. I believe Sabine has pointed out that some of these choices mean that the 1915 version of GR cannot deal correctly with fermions, a rather serious flaw. Pros are aware of it, but it is very difficult to solve.
Now I know you can find a picture of a Minkowski space-time diagram on the Internet and in some of her videos. And I am confident you can rotate them by 45 degrees and change the t -> m dt/dtau=E and R -> m dR/dtau=P. That bit of graph paper magic is going to work for photons, bosons, and fermions. It is so hard to even start a conversation because people want equations to SOLVE. There are not really equations to solve in SR, it is just a symmetry that applies to the velocities of observers. Rotate by 45 degrees and again there are no equations to solve. This time there are escape velocities to observe. I get why that doesn't feel satisfying to the well-trained, but such is the fate of my current efforts. Folks train in something that is 4x4x4x4 complicated will be sad at simple drawing.
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."
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.
Thanks for sharing your experience. Und viel Erfolg für künftige Theorien! ☺️
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.
just brilliant! rarely a sponsor brand fits that well
If you see this, please consider the idea of bosons having only inertial mass, while fermions cause curvature (time dilation) and anti-fermions cause anti-curvature (time compression).
I once played with this thought that particles can be of (at least) 4 types:
1st: opposite attract and same repel (charge)
2nd: opposite repel and same attract. (mass)
3rd: opposite attract and same ALSO attract. This is the interesting one. This particle would wander around without preference to + or -. So randomness will make it either grow a bit bigger when + clump together, but quickly disappear when some - make it annihilate again. Therefore it can't grow too big. Often it will randomly disappear into thin air but should also be able to appear from nothing. I later learned about quantum foam and it kind of matched type 3. (?)
4th: opposite repel and same also repel. Particles of this type should be very rare, since they just fly apart whenever created.
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. ❤️
The same argument is used in courtrooms by referring to equivocation of ambiguous terms as objectionable. The ambiguity of a term that could work may be confounded by the application of another meaning of it's capacity which can frustrate when used to distract us from the point (as in the defense used at Babel by fragmentation language and a scattering of the people). My hope is that we’ll be able to write with more clarity about positions and intentions by using the greater specificity we’re afforded here in this medium because it’s not even possible to perceive without doing so.
Words like "Equivalance"... I see, right?
A few people provide remarkably similar explanations about the formation of the universe but there are some MAJOR gaps in the sequence of events. I really enjoy your channel Sabine and look forward to hearing an answer to what I'm missing.
Hours after the event referred to as the "Big Bang" the only things in existence were "hydrogen and helium ions plus electrons" and this plasma was too hot to allow atoms to form. This primordial soup continued to expand at a rapid rate and cooled. "After about 380 000 years, when the temperature decreased to 1000K, atoms were able to form". The cooler plasma was "now neutral, allowing photons to pass through" and the light starting dimming to make the universe dark (due to decreased intensity of photons). Why would the electrons bind with ions at 1000K to form atoms and even more incredulous is these ions / atoms are moving rapidly apart so why would they coalesce to begin forming stars in the first place? The fusion process described to explain stars requires a high density of hydrogen at high temperature and high gravitational pressure, which assumes that stars have already formed to provide the appropriate conditions when this is clearly not the case - as the stars did not exist yet. There are some MAJOR gaps in these explanations.
By coincidence a brand new video "Where did Dark Matter and Dark Energy Come From" (alphabet keeps removing the link!!) was published on 03.12.2021 by The History of the Universe Channel and at the 20:00 mark touches exactly on this topic. I also don't buy the explanation given there but it sparked off an idea that I have never heard anyone speak about. I describe this briefly below.
There is a universe of dark matter and dark energy (which we realize we know nothing about other than it's observed affects that have made us aware of this mysterious 'stuff'). For some reason an event was triggered (which we call the Big Bang) and this took place inside the dark universe. The behavior and characteristics of the items that we know about and (incorrectly) call the universe are determined by the properties of the dark universe, which is the actual universe.
We've never thought about it in this way. We are trying to explain phenomenon that we observe in 'our observed universe' but we are the result of an event in the dark universe. And we know extremely little about it.
So when the plasma of hydrogen ions, electrons, photons plus other things that may be there (380 000 years later), all sparked by the 'Big Bang' event, are flying through what we thought was empty space (but is actually the dark universe), the dark universe matter and energy interact with the outputs of the event which gave rise to the " 'primordial components' of our 'observed universe' " and determine its shape, characteristics and properties.
The effect of the interaction of the dark universe (matter and energy) causes the 'primordial plasma' (more accurately the products of the Big Bang event in the dark universe) to clump together (due to 'dark gravity'?) and to continue expanding at an accelerated rate (a baffling observed phenomenon which we call inflation).
Sabine, I would love to hear your response to this.
Good point showing the analogous nature of electrical potential and gravity.
As in particle physics if we refer to mass in mega electron volts, then mass takes on a more understandable Energy relation. Energy attracts energy.
Gravity, electrostatic, electromagnetic, are only moving to equipotential.
Mam, Do video about your Physics research journey and how you get into popular science, it'll be really helpful.
🙏🙏🙏
I recommend you to check her blog, backreaction. She writes there since 2006.
The important thing is that one learned from it.
To many refuse to accept beeing wrong, or risk beeing wrong in the first place and dont learn from it up to the point of biased data to fit to the theory.
I liked a phrase i picked up somewhere: "Why should i be disappointed? Even if its wrong, i know now that ist is and discoverd something new ths way, that what science is about, right?"
What a great scientist, you inspire me and many others Sabine, I hope you know that
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!
You mention that antigravity would only be possible with clumping antigravitational matter and reason this by giving known properties of fields (i.e. spin count). I have two problems with this reasoning: ① The spin count property is an observable effect in the fields as far as we know them. Here we are talking about an unknown effect. What reason do you have to assume it must follow the known mechanisms? ② If we don't assume to find matter of gravity in a negative sense (i.e. repelling) but matter with something _like_ gravity which is generally repelling (i.e. also with each other) we would simply have a completely new field which could (as far as I understand it) follow the existing spin count rule and still be repelling with normal matter and with each other. Both ways of thinking would allow only repelling matter which therefore would have no reason to clump together and thus all your following arguments would fall. Do you have any more arguments against my ideas?
Hi. As far as I see, your effort has been very useful to get deeper in understanding nature , in any case. And wonderful lesson about beeing wrong. With the usual elegance. 😳👌❤️
Thank you Sabine for sharing your insights. :-)
"Yes, that guy again." It never gets old
Little bit confusing and I'm an EM guy. Maybe leave the visual aids up longer as you are talking and juxtapose them for clarity. Fascinating topic. I spent 15 years 'wasting my time' on a topic which is finally producing fruit. Never give up trying to find solutions, that's the fun part of the puzzle.
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?
I think, particles are some structures made of the same stuff, which the space itself is made of. Suppose that space is made of some minimal units. Those units are connected together, which form the space. The space arises from the regular connections of those units. But suppose, there may be also some irregular connections, some knots. Such knots, the perurbations of the fabric of space, may be what we perceive as 'particles'.
Now, let's imagine that some of those perturbations may be absolutely the same yet have different chirality. Different chirality arises from almost anything, when something is connected to something else in a specific way to form a certain structure.
What could different chirality mean?
- The structures with opposite chirality would likely annihilate each other when meet together. Because the perturbations those structures are made of will have an opportunity to compensate and staighten each other.
- If a structure (that is particle) possesses a certain property described with a certain value, the same structure however with different chirality will likely have the equivalent property but described with the mathematically opposite value. Especially that will concern, when the value is component one, that is some kind of vector.
This is what particle/antiparticle dualism could actually be.
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.
@Sabine Hossenfelder, then I have a question. Let's suppose we have a small machine like a watch. You can attach it to objects. It works like it creates a field and within that the you can shield the gravitational force. You can adjust the efficiency of shielding. So you attach it to a rock that fits in the field. You turn it on and starts to adjust the shielding. Let's say we put the rock on a scale and are measuring it's weight. It shows 1 kg at the begining, 900g at 10% shielding, 500g at 50% shielding. We are of course on Earth. What happens if we turn it on 100%?
I always get confused if physicists alternate between two states. One state is where they claim that gravity is a force - and look for a way to unite it with the other forces. The other state is where it is a contraction of spacetime (yeah - that guy again). So, looking at an atomic level the mass of an atom's nucleus is mainly caused by the strong force. My image was that the strong force causes the space at nucleus to contract and thereby creating the contraction of spacetime. Looking for the opposite we should look for ways to expand spacetime.
"You don't get something from nothing, you can't have freedom for free, you won't get wise with the sleep still in your eyes, no matter what your dreams might be." Something from Nothing by the band Rush