Solving the secrets of gravity - with Claudia de Rham

[@vPeteB]

My wife and I took my three girls ages 8, 12, and 13 to this talk by Dr. de Rham. We were on vacation in London. She kept us all entertained and we learned so much. I love the Royal Institute.

[@muzikhed]

What a lucky family you are.

[@vPeteB]

@@muzikhed we sure are. I hit the jackpot.

[@hooked4215]

@@vPeteB I would love to go to your girls biryhday party.

[@creativesource3514]

I have 13, 12 and 6 yr old boys......they would definitely not sit there. Your girls are special!

[@peterjones958]

What a brilliant speaker who really knows her subject. Kept me spellbound through the entire speech.

[@nuranichandra2177]

The style and manner with which Dr de Rahm has conducted this lecture dealing with extremely complex subjects in just amazing.

[@toma5153]

Compliments to Dr. de Rahm on delivering this lecture straight through with barely any hesitation. Something very few people can do. Other pluses: 1) Great audio 2) Great integration of the lecture with the PowerPoint or Keynote slides 3) Good physical demonstrations.

[@DarthVader20201]

She lectures it all the time in college to students who want to learn new stuff

[@edwardlee2794]

All these years, after a number of lectures in physics, astronomy, cosmology, I thought a thing or 2 about gravity already only now, I really scratch the surface of gravity. Thanks for the efforts and keep up the good work.

[@pidaras_pidarasina]

You probably should read books then since lectures on pop-science that you watch are useless to you.

[@dazzassti]

KZbin scienceclic english, gravity visualised. Thank me later ;-)

[@keithbushnell2007]

​@da no nozzassti

[@willem878]

I saw a lot of these videos coming by on this channel. But this one grabbed my attention. Claudia de Rham has so much knowledge about this subject. I can hardly understand the contents. I will play it back many times until I know what she is talking about. it's a pity that I didn't heard before from her. If she gives more classes I would be a student of her. Why? Because she knows.

[@castell44555]

What a great channel i just found .I like youtube for videos and channels like that , because this on tv its impossible to see . Thanks from spain.

[@jonslg240]

"Thank you for coming, and thank you for coming on a Saturday night.. I'm sure none of you have anything else you'd rather be doing" [Audience doesn't laugh] because there isn't anything they'd rather be doing on a Saturday night 😊 It's excellent that there are always tons of people who'd rather be getting their knowledge on, than be out partying/etc. At first, I was sad for her that the joke fell flat, but it quickly turned into enthusiasm for the human "race".

[@abcde_fz]

LOTS of good stuff from RI. You may also like Gresham College channel, and Perimeter Institute channel. Gresham College is various lectures, Perimeter Institute primarily physics.

[@johnalbinson4641]

A remarkably fluid and cnfident speaker who knows her subject!

[@terrizittritsch745]

What, what a wonderful lecture bringing many difficult and complex topics to an understandable level.

[@johnanderson350]

I enjoy these lectures so much. I wish I could really understand the content on the level she does...it must be very empowering!

[@PacificAirwave144]

Love, love, love these Royal Institution uploads!

[@Turbohh]

So beautifully explained, personalized, dramatized and exciting. Wow. You are the best! Thank you.

[@MesonCounter]

Marvelous talk, simply marvelous!

[@DigitalDawg]

Thanks!

[@PhysicsNative]

The speculation here is that there is a Higgs mechanism for gravity that gives the graviton an exceedingly small mass that solves the cosmological constant problem, explaining the observed expansion of the universe on exceedingly large scales, but otherwise yields Einstein GR at smaller scales. The problem here is that the massive gravity model proposed around 2011 by the speaker and collaborators is an “effective field theory” that relies on rescaling, decoupling and screening mechanisms that avoid ghost (unphysical) modes and avoid failing well-constrained solar system and gravitational wave tests that GR passes. This is not a clean theory, namely a quantum theory of gravity that couples to the standard model and that might naturally admit such a graviton mass. Also the screening mechanisms the model relies on to pass constraint tests (that other modified gravity models have failed) is in question with recent observations and numerical studies at the cluster scale, per recently published papers. There are modified gravity models based on a massless spin-2 graviton that do not have these problems, namely John Moffat’s MOG and a few others. These models address the problems with GR on Kpc+ scales, i.e. the need for dark matter to explain galaxy rotation, cluster and large scale structure dynamics, yet pass local constraint tests since they revert to GR on smaller scales.

[@Naturalmedicineprescription]

if you say so

[@roberttarquinio1288]

The graviton does not exist

[@j.jwhitty5861]

Speculative

[@PotentialSpaceHolder]

Time flow Continuum appears and collapses at a blink of energy flow. Fascinating and beautiful. Example is looking into someone's eyes and their pupal opens and collapses.

[@AlecFarr-j1b]

I wonder if Apollo 15 commander David Scott had any idea how influential that gravity demonstration - which wasn’t in the flight plan - was going to be. This is at least the third Royal Academy lecture I’ve seen that refers to it. Apollo 15 was also the mission where they found the genesis stone that gave us the best understanding (at the time) of how old the moon and earth are. And by then the world was bored and not watching. Great lecture.

[@RFC3514]

It may not have been explicitly mentioned on the flight plan shown to the public, but it was obviously planned. They didn't just happen to find a feather on the Moon (in fact, he took two feathers, both from the Air Force Academy's mascot falcon). And I'm pretty sure he knew that a demonstration made *on the Moon,* being broadcast *live to the whole world,* would become pretty famous. 😄

[@shaneschuller2513]

I'm not knowledgeable on physics and because I've been trying to research the source of Light, it took me on a journey from having to understand what mass, matter, antimatter,.energy, momentum and and and...here I am trying to understand gravity. I really appreciated this eloquent explanation 👌🏻. Claudia is the perfect teacher.

[@stewiesaidthat]

F=ma. Mass TIMES Acceleration. Mass has no force without acceleration. So it's F=a or Acceleration equals Acceleration. There is no mass equals Acceleration. Believe. I've looked. There is however. Plenty of evidence that shows Acceleration equals mass. E=mc. Mass is stored energy and c is absolute acceleration of the mass. E=mc then becomes E=a or Energy comes from Acceleration of the mass. Everything is an emergent property of acceleration including mass. How can mass create acceleration when its acceleration that creates mass? Some experiments that disprove mass (gravitational attraction) as an actionable force. Galileo's ball drops at the Tower of Pisa. Nasa's hammer&feather drop test on the moon. The LIGO detectors being pushed out of alignment. Not pulled. Galileo theorized thar its the Earth's motion in space thst creates the tides. Not it's mass. Using Newton's and Kepler's of Motion, the earth rotating on its axis, is accelerating its mass outward, creating the tidal bulge. The orbit around the sun creates a directional change, first clockwise, the counterclockwise. Tide comes in tide goes out. The earth experiences it's greatest velocity as it makes its closest pass to the sun on an elliptical orbit according to Kepler's laws of motion. The high tide is on the opposite side of the sun as this is where the most acceleration occurs. As you can see, the moon and sun's 'gravity' does not create the tides otherwise high tide would be on the side facing the sun. I'm afraid, what you have, is a flat earthers peddling there mathematical nonsense on a gullible public. The errors are so blatantly obvious, why do they persist in this charade? F=ma/E=mc explains it. If force does not come from mass, then it must come from Acceleration. What then, is acceleration. The Bible days Acceleration is god. Let there be light. Can't have science validating religion so the entire scientific community is left with explaining the universe by its mass factor. F=ma. Two frames of reference. An inertial frame or an outside force is acting upon the universe (god?). Or the universe is a non-inertial frame. Accelerating itself. Now explain infinity. So. You either have to explain god or explain infinity or go back to your flat earth sandbox and explain why sand falls back down. E=mc. An unbounded infinite universe bounded light. The universe is infinite in size and you cam only see thst which the speed of light allows. The visible universe. Photons lose energy over the course of about 14 billion years so you won't see anything past a 14 billion LY radius. Acceleration = god/infinity. Non-tangibles. Mass = a physical entity. Something tangible. Is the universe real or a simulation? A construct of a god - an outside force? The Hitchhiker's Guide to the Galaxy. The answer to the ultimate question. 42. The * symbol in the ascii table. The universe is whatever you want it to be. Futurama and Benders upgrade where he went on a spiritual downgrade journey during the software upgrade. Bender asked about his experience and the attendant replied, your experience is whatever you want to make of it. Bender walks out into a world of rainbows and unicorns. Science can't answer what acceleration is so they concocted fanciful stories centered around mass. So where does Science go from here. They are either lying to you about gravity or are extremely ignorant and of low intelligence. Einstein's light clock and time-dilation? Photons travel in their own frame of reference. Time-dilation is strictly limited to the photon's frame and not the observer's. You have to be pretty ignorant to not understand that. It's the same with gravity. Electromagnetic waves are force carriers. Which way is the force being carried? Which way did the LIGO detectors move? How can the Earth's mass be both accelerated outward and pulled inward. Gravitational attraction just doesn't add up. As Nicholas Tesla said. Mathematical nonsense making people blind to its errors.

[@shaneschuller2513]

@@stewiesaidthat Thanks for the long explaination. Although I'm not sure if you intended it for me? I'm not a flat earther 🤣 Also Not sure how God came into the whole explaination?

[@stewiesaidthat]

@@shaneschuller2513 a flat earther is a science denier. Gravity, as a fundamental force of nature, was disproved a long time ago. There is no mass attraction because mass is not an actionable force. The fact that the scientific community wrote Galileo off as a thought experiment and astronaut Scott's as the Equivalence principle, is the hallmark of a religious institute, not a scientific institute. Add in Einstein’s Light clock nonsense, photon's travel I'm their own frame of reference. The time-dilation is limited to the photon's frame, solidifies Relativity being Religion. F=ma. Two possibilities. A god of mass or a god of Acceleration.

[@hififlipper]

Very interesting. I have studied the secrets of gravity as a child and found it to be very dangerous. Good that finally some professionals deal with it. Hope we can overcome it, soon.

[@LJWHan]

Wow! Standing ovation along with my applause. Incredible. 10/10

[@theextragalactic1]

Always so many brilliant talks here! Your summer programme is superb.

[@jesmarina]

The part about the development of and reasoning behind Massive Gravity theory was absolutely excellent stuff. Right on the cutting edge, with a scientist that's in the thick of it and can explain it to perfection. Brilliant. Chapeau.

[@falsemcnuggethope]

"The Beauty of Gravity" sounds like a body positivity slogan.

[@paulwary]

The beauty of gravity taking a vacuum bath.

[@Scuba72Chris]

"Mass loss for the gravitationally challenged". 😄

[@mybrass41]

Love your humor, subtle and quick!

[@charleslaurice]

Thank you Mr.Cain for putting the cookies down low enough for me to get them,I’m 70 retired in the Philippines and very low tech I wish you were my neighbor!

[@robertodetree1049]

What a fascinating experience, this huge force that connect us with the entire universe explained in its entire complexity. Thank you very much Dr. Claudia de Rham!

[@AM-dn4lk]

A truly amazing lecture. An excellent lecturer.

[@sarasvensson7082]

What a exremly god speach. This hour felt like 10 minuts. Claudia is indeed burning for her work

[@dgnash]

Surely the equivalence principle is not that a coin and a feather fall in the same way. It is that the force felt due to gravity is indistinguishable from the force felt when being accelerated. Anyway I think that's what Einstein said.

[@skhotzim_bacon]

I'm pretty sure she was explaining the weak equivalence principle. All objects fall at the same rate in a gravitational field. It has nothing to do with force.

[@hyperduality2838]

Gravitation is equivalent or dual (isomorphic) to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). The force of gravity is the same for all observers -- absolute democracy! "Always two there are" -- Yoda.

[@dodatroda]

Correct.

[@abcde_fz]

In Einstein's mind, Special Relativity was more about time and simultaneity, and General Relativity about time and simultaneity in relation to spacetime's actual structure. Einstein didn't approach either from a POV relating to gravity, he came at both of them from a POV relating to time. Kip Thorne explains this better than anyone. I don't believe Einstein ever used the term "equivalence", and I know he actually preferred to use the term simultaneity to relativity. Perhaps because he spoke German before English and there's a built in bias for the term in that language?

[@JoshJamesification]

Gravitational force follows the inverse square law and gets weaker the higher up you go and the earth's gravitational force is not even constant at surface level

[@PardhaS]

Brilliant! The lecturer is so clear and lucid. It’s a real skill to capture the nuances of a complex topic and make it understandable.

[@anthonyinzerillo3882]

Carl Sagan Christmas lectures at Royal Institution were classics.

[@MedellínInsider-n3o]

If you know nothing about physics and astronomy, and are gullible, then yes. I invite you to watch his pseudo-scientific series "Cosmos" and you will see it for yourself. Many of the claims he made back then have long been abandoned by the scientists as wrong, to put it mildly.

[@MrStoffzor]

​@@MedellínInsider-n3ocharisma is the 5th and strongest force of nature.

[@MedellínInsider-n3o]

@@MrStoffzor Charisma is an effect, not a force. But I can see how, and why, it may be confused with the force on a cotton farm.

[@PBeringer]

@@MedellínInsider-n3o Any claims in particular? What would be the most resoundingly debunked since? Science is a self-correcting process; all scientists have had ideas that were eventually proved wrong ... that's just how it works. Your implication that being historically incorrect points to some sinister original motive is just ridiculous - how could anyone know anything more than the present state of a scientific discipline? But I'm still curious to know what he was so "wrong" about. Most people who know something "about physics and astronomy" would agree that he was, if anything, a prophetic scientist. His early work on the atmospheres of Venus and Titan is a pretty stunning example. But anyway ...

[@davecarsley8773]

That has nothing to do with this video. Cool comment though.

[@sukumaryendrathi5931]

Thanks Dr. De Rham, for the new approach and the wonderful insights of Gravity.

[@SuperBongface]

Thank you Dr. Higgs...Bless you and RIP to you... a very great scientist and believer

[@GlassEyedDetectives]

Fascinating stuff indeed, thank you. I'm quite familiar with the notion of the Expanding Universe model, and what really thrills me is the expansion of my mind....though, after factoring in Relativity, i'm quickly grounded by the gravity of knowing that it is still, proportionally speaking; the same size relative to everybody else who expanded theirs!...😁

[@hyperduality2838]

Gravitation is equivalent or dual (isomorphic) to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). The force of gravity is the same for all observers -- absolute democracy! "Always two there are" -- Yoda.

[@GlassEyedDetectives]

​@@hyperduality2838 hey hi there, i agree that it seems dualistic, though duality itself hints at an original whole must've been split...how think you?

[@hyperduality2838]

@@GlassEyedDetectives Energy is dual to mass -- Einstein. Space is dual to time -- Einstein. Time dilation is dual to length contraction -- Einstein, special relativity. Vectors (contravariant) are dual to co-vectors (covariant) -- dual bases. Riemann geometry or curvature is actually dual as it contains a dual bases:- Upper indices are dual to lower indices -- Tensors are dual. Positive curvature (attraction, syntropy) is dual to negative curvature (repulsion, entropy) -- Gauss, Riemann geometry. Curvature or gravitation is dual, potential energy is dual to kinetic energy. Negative curvature is missing from the Einstein field equations! Dark energy is dual to dark matter. The laws of physics are the same for all observers hence they conform to a principle of objective or absolute democracy -- 100% democracy. The velocity of light is the same and equal for all observers at all times -- objective democracy. The principle of equivalence (duality) and hence objective democracy is hardwired into the physics of reality, that is the good news. Good is dual to bad. The bad news is that there are virtually no scientists or physicists pushing this idea into the public domain The universe and reality are fundamentally democratic at its core. Objective is dual to subjective, absolute is dual to relative, Independence is dual to dependence -- duality! The laws of physics are independent of the observer's perspective -- 100% democratic. Science wins through consensus, consensus means mutual agreement or objective democracy! The force of gravity via the principle of equivalence is empirical proof that objective democracy is real. Objective democracy is dual to subjective democracy -- democracy or the laws of physics are dual.

[@GlassEyedDetectives]

@@hyperduality2838 great list hyper'....have you ever been in a Superposition?

[@hyperduality2838]

@@GlassEyedDetectives Yes all the time. Alive is dual to not alive -- Schrodinger's cat. Being is dual to non being creates becoming -- Plato's cat. Thesis (alive, being) is dual to anti-thesis (not alive, non being) creates the converging or syntropic thesis, synthesis (becoming) -- the time independent Hegelian dialectic or Hegel's cat. Schrodinger's cat is based upon Hegel's cat and he stole it from Plato (Socrates). On is dual to off -- Qubits or superposition is duality!

[@sol029]

I need to go to these lectures. Literally just up the street.

[@ClodODirt]

I am constantly hearing the term "visible universe." Can someone please explain why she says "the universe is not expanding into anything", when it's expanding in the direction of things we can't see? How do we know it's expanding into nothing? Couldn't there quite simply be enough matter outside of our visible universe to pull our visible universe apart without us being able to see it?

[@RFC3514]

Gravity propagates at the speed of light, so anything outside the observable universe would not affect us through gravity. And the universe isn't expanding in any specific _direction_ or _into_ anything; it's simply expanding. The term "visible universe" refers to the parts of the universe whose radiation has had time to reach the Earth (or any observer - for creatures in other parts of the universe, Earth might be outside their "visible universe"). It's essentially a sphere centred on the observer, that grows at the speed of light - if you wait one year, you can "see" one light-year further away (note that this increase in the visible volume isn't directly related to the expansion of the universe itself - though that will _also_ impose a limit on the visible universe, as any radiation being emitted more than ~20 billion parsecs away will never reach the Earth, no matter how long you wait - it's simply a consequence of the speed of light and the passage of time).

[@NanookoftheNorth1]

Once the universe expands past 13.5 Billion light years away, you're moving faster away than the speed of light so we'll never see it.

[@jesse75]

​@@RFC3514who said ? Where's Mr reference ?

[@ClodODirt]

I guess what really concerns me is that our visible universe must be just a tiny speck compared to all of that which lies beyond it... how can we begin to know that what is beyond our visible universe wouldn't have a profound effect on what happens to the part of the universe we can see?

[@RFC3514]

@@ClodODirt - Again, because the same thing that makes distant parts of the universe unobservable (i.e., the speed of light) also makes them not affect the place where we live. If they _did_ have an influence on us, then we _would_ be observing them (that's kind of what "observing" means - being able to detect _anything_ about them). Also, I'm not sure how the observable universe (which is already _unreachably_ large, and constantly growing at the speed of light) can be described as "a tiny speck". It's literally as big as the fastest thing in it could reach if it had been going full speed since day one. There's plenty in it that we still haven't figured out (and probably never will), so it's kind of pointless to worry about parts that are moving away from us faster than light. It's a bit like worrying about what the weather will be like in your home town ten billion years from now.

[@anotherfreediver3639]

Freediving is the closest I've got to being free of gravity, but only because the medium I'm in is experiencing the same forces. But it's fun to be upside down, but without all the blood rushing to your head!

[@JohnHoranzy]

Freediving the crystal waters off Grand Caymen was a high point in my life. 😊

[@IskarJarak]

She is so smart and interesting and engaging-I would love to have a person like this to stay up all night talking to for the rest of my life.

[@sirfer6969]

I know what you mean, but she might get bored with you ;o)

[@DarthVader20201]

If you mean you find her very beautiful, as you looking behind her pants.

[@wayneenosjr4747]

Wow She is a superhero of an instructor! She explains it in away that is easier to understand with it being such a hard to grasp concept! 👍

[@lukegratrix]

Or such a hard concept to grasp

[@lukegratrix]

The concept of a singularity is as nonsensical as the concept of infinity

[@epiccurious3536]

A Hypothetical Question: If the Sun were to somehow instantaneously flash out of existence, when would the Earth feel the lack of gravity? Would it be instantaneous or would the Earth still feel the Sun's gravity for the ~8 minutes it takes for light from the Sun to reach us?

[@lukegratrix]

Earth would still feel the gravity for eight minutes according to our wrist watches. You and I wouldn't notice the change, except that we would be in the dark after eight minutes also. Get your flashlights!

[@lukegratrix]

Wouldn't it be nice to be able to interact with gravitons and other hypothetical particles. Maybe they are the dark matter particles we so desperately seek!

[@lukegratrix]

Of course we'll run into wave-particle duality all over again which begins to sound something like string theory playing a familiar song called Unity

[@letMeSayThatInIrish]

I asked my physics teacher this exact question some 21 years ago. He looked at me in horror and disbelief, as if I had gone completely nuts. "But the sun is never going to disappear! Why would the sun disappear!?" There was no way to make him understand the point of the question 😄

[@epiccurious3536]

@@letMeSayThatInIrish Funny, silly and so so sad that any physics professor would react like that. Bad teacher.

[@MoshkitaTheCat]

A delightful lecture, thank you, both host and guest.

[@oliverjamito9902]

Thank you my Beautiful Claudia for attending unto our OWN! Love you too!

[@Gamerock82]

Truly fascinating subject matter that has held me spellbound since childhood, so wonderfully discussed. Thank you from here.

[@shawns0762]

Here is the explanation for dark matter/galaxy rotation curves - Wherever there is an astronomical quantity of mass the known, fundamental phenomenon of dilation (sometimes called gamma or y) will occur. Mass that is dilated is smeared through spacetime relative to an outside observer. It's the phenomenon behind the phrase "mass becomes infinite at the speed of light". Time dilation is just one aspect of dilation, it's not just time that gets dilated. A 2 axis graph illustrates the squared nature of the phenomenon, dilation increases at an exponential rate the closer you get to the speed of light. Dilation will occur wherever there is an astronomical quantity of mass because high mass means high momentum. This includes the centers of very high mass stars and the overwhelming majority of galaxy centers. It can be inferred mathematically that the mass at the center of our own galaxy must be dilated. This means that there is no valid XYZ coordinate we can attribute to it, you can't point your finger at something that is smeared through spacetime. More precisely, everywhere you point is equally valid. In other words that mass is all around us. Dilation does not occur in galaxies with low mass centers because they do not have enough mass to achieve relativistic velocities. It has recently been confirmed in 6 very low mass galaxies including NGC 1052-DF2 and DF4 to have no dark matter. In other words they have normal rotation rates. This also explains why all binary stars are normal rotation rates, not 3 times normal.

[@ShaifBasier]

Amazing content. Lucid and so helpful to help keep our focus on the basic premises.

[@TheTuubster]

To me the beauty of gravity is that it makes you experience the effects of spacetime first hand. The weight you feel is the result of time running faster above you and slower below you. That's what pushes you against our planet, against the floor of your home: Time itself.

[@alberteinstein3078]

It's a seamless fabric.

[@Crazyfootballguy]

that's not how it works

[@Mentaculus42]

So you (as a conglomeration of energy) needs to “flow down the time gradient of faster time to slower time” ‽ That has an interesting perspective on looking at gravity.

[@Bugside]

It's the other way around, mass influences time, time doesn't move mass

[@alberteinstein3078]

@@Bugside e=mc2

[@machonco50]

Ohhhmmm the agitation of spacetime. Salutations Dr. Claudia. What a mind clearing introspect on a theory of gravity "anomaly". With what we percieve as empty SPACE (But not empty at all)being the repulsive force and then I assume TIME as the attractive, stabilizing and nuetralizing force that keeps all matter from being pulverized.

[@mitchbrook4112]

the main thing i've learned from watching Ri lectures on this channel is; dont make jokes in your Ri lecture

[@RFC3514]

It's fine to make jokes, they just have to be good. And just like most comedians aren't very good at physics, most physicists aren't very good at jokes.

[@davebennett5069]

@@RFC3514 They're good jokes if you understand the subject matter as intimately as she does. Good comedians find the line between the knowledge of the audience, and the subject matter of the joke, and walk along it.

[@RFC3514]

@@davebennett5069 - A few of them are, but a _lot_ of jokes in RI lectures are very lame, and seem to have been added because someone told the speaker(s) it was a good idea. The end result is just a banal sentence followed by the lecturers chuckling at their _own_ words, and everyone else being silent. But hey, some "science communicators" (cough*aderin-pocock*cough) seem to have built an entire career on that "format".

[@johnzander9990]

@@davebennett5069 As a physicist, who thought her explanation of a geodesic was the worst explanation I've ever with tiles on some heart object, I can assure you, her jokes weren't funny.

[@charleslaurice]

You’re exactly right there’s a time and place for joking, but in this platform is not one of them so thank you for not joking around about these maters . This way, I can stay totally focused. Thank you.

[@TusharkantiDutta-h9h]

It is important to understand logical interactions of interactive realities.( I am from India).

[@stephanieparker1250]

Thank god, it’s back in the auditorium and not through zoom.

[@RFC3514]

It's been back in the auditorium for a couple of years now.

[@stephanieparker1250]

@@RFC3514 true but they continued to show “zoom” presentations, which I can’t stand.

[@UdiDol]

Quite a fascinated explanation by a scientist, where a layman can understand a little bit of the sciences and the quest for such, by the scientists of today, through threrization and practical experience and experimentation. Thank You!

[@brookestephen]

why didn't the "missing mass" within the universe lead to an estimate of the larger size of the universe, a region that we cannot see, rather than lead to the positing of the existence of dark matter?

[@logangodofcandy]

It did exactly that. The "size" of the universe being the amount of localized mass/energy rather than the amount of empty space. We can't see it, that's why they call it dark.

[@Teddy_Miljard_Genius_Work]

My consept of "phantom light gravity" is so simply and logical. Mr. Occami's razor blade is not needed any more. 😊

[@BrianFedirko]

The Equivalent Principle being shown in the tube is incredible. This should be shown in science classes, but with two separate tubes side by side to show they aren't getting caught up in each other. Maybe for class 2 together, and one with both, and the class can write about it. So Cool. Damn, I thought my head was blown with the Brian Cox bowling ball and feather demo... this one is personal and can reasonably be done at home. Gr8! Peace ☮💜Love

[@SingHouse]

I'm a bit puzzled at this being described as the equivalence principle. I'm no expert, I gladly confess my ignorance but I thought the equivalence principle was that there is no difference between floating in space and being in free fall. In both cases you appear to be floating without feeling any forces.

[@hyperduality2838]

Gravitation is equivalent or dual (isomorphic) to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). The force of gravity is the same for all observers -- absolute democracy! "Always two there are" -- Yoda.

[@SingHouse]

​@@hyperduality2838right, so no relation to the Moon experiment she refers to? Isn't this quite a major mistake in this lecture?

[@hyperduality2838]

@@SingHouse Energy is dual to mass -- Einstein. Action is dual to reaction -- Sir Isaac Newton or the duality of force. Attraction (sympathy) is dual to repulsion (antipathy), stretch is dual to squeeze, push is dual to pull -- all forces are dual. If forces are dual then energy must be dual:- Energy = force * distance -- simple physics. Everything in physics is made from energy or duality. Energy is duality, duality is energy. Electro is dual to magnetic -- electromagnetic energy is dual. Positive is dual to negative -- electric charge, numbers or curvature. North poles are dual to south poles -- magnetic fields. Space is dual to time. Vectors (contravariant) are dual to covectors (covariant) -- dual bases or Riemann geometry. Curvature, gravitation or Riemann geometry is dual -- the equivalence principle.

[@paulo.8899]

I wish people like you didn't exist on the internet. You just typed all that just to say nothing, and confuse people. The equivalence principle states that there's no difference between inertial and gravitational forces. That's seemingly not what she's referring to at all in her whole lecture.

[@exoyt7575]

Great speaker!! Great lecture!! RI worthy.

[@perosusinger6239]

I'm not a physicist but somehow (without understanding the math behind) I find it logical that gravity is fading to zero beyond a certain distance. As gravity is discrete and holds a minimum finite amount of energy (28:45) that can't be splited into smaller packages, wouldn't it be logical that there is a certain distance beyond which the gravitational force would be weaker than this quantum and so must fade to zero? (50:48) Me, I find this logical.

[@videojones59]

I am surprised to hear her say that the graviton is a feature of Einstein's general theory of relativity.

[@tasmedic]

Yes, she seems to be parading her own, unproven ideas as fact. That's not very scientific, or ethical.

[@charleslaurice]

I am not a physicist, but Claudia is absolutely beyond over-the-top smart wow wow we

[@UncleArthur44]

I don’t believe general relativity predicts the existence of a graviton.

[@carlorossi2788]

he doesn't know what he's saying! Gravitone don't existe

[@davecarsley8773]

It doesn't. At all.

[@davidschneide5422]

String theory predicts a spin-2 graviton, but it also predicts everything

[@UncleArthur44]

@@davidschneide5422 string “theory”is not a theory. It makes no verifiable or falsifiable predictions. And it has nothing to do with general relativity.

[@dennisalbert6115]

If anything it's a virtual particle, it doesn't really exist but you can create it

[@Ranjanapati07]

Fact is ,we are still in the infancy of our understanding of this amazing universe, we need to keep up the good work without hesitation. Her fluent compilation is worth the applause 👏

[@grandixximo]

Should mention more clearly that the graviton has not been proven to exist.

[@RFC3514]

Neither has the square root of minus one. But if it allows more calculations to work, it's still a valid tool. The issue is whether it _does_ allow new calculations to be made or not. If it doesn't, then it's kind of useless.

[@jamesritter4813]

Yeah it's a really weird thing. Like the idea of being near a black hole for a small amount of time and then if u can come back to earth the ppl there aged significantly more than you. Another thing you look at with cosmology, if there is something they can't prove with equations then they add another thing that is not even proven to make it work. Then they kept doing that to the point were some professors just took a step back and said this isn't working at all! They feel they wasted years and years going down the wrong path. Another thing they can't work out is how general relativity and qautum physics don't work together. Maybe they don't have too! Mayby there is 2 or more fundamental laws that coexist simultaneously.

[@MCMTL]

You mean the graviton beam emitter that powers my flying car is all in my head?

[@mattsf1980]

You haven’t been proven to exist!

[@jesse75]

If it does it comes from nowhere.

[@kxqe]

1. Rham asserts the existence of the graviton and then uses that proposed particle to "disprove" Einstein's general relativity, however, Einstein never proposed the graviton. 2. At 1:00:04 Rham says we will never detect the graviton. If this is the case, then the hypothesis of the graviton is not valid because a scientific hypothesis must be experimentally provable (or disprovable) to be a valid hypothesis. 3. At 32:20 Rham argues that the probability of outcomes of a proposed GR experiment produces probabilities that are greater than 100% or less than 0%, however GR is not a probabilistic theory, so the inconsistency is due to QM, not GR. 4. At 35:30 Rham says that a person or other object that falls into a super-massive black hole would experience tidal spaghettification prior to reaching the event horizon. This is not true for a super-massive black hole because the gradient of the curvature of spacetime of a super-massive black hole is relatively shallow at the event horizon and the tidal forces needed for spaghettification do not occur until much closer to the center of the black hole. 5. The Barbie doll was cute, though.

[@Bugside]

I thought gravitrons were theoretical still

[@ZigSputnik]

They are.

[@Bugside]

@@ZigSputnik so this talk is a bit, inaccurate

[@alexalke1417]

@@Bugside She speaks like it was already observed which is misleading indeed.

[@epsig1507]

@@Bugside at 48:28 she does say that the idea is "a crazy one"

[@RFC3514]

All particles are "theoretical". They're just perturbations in fields. We treat them as particles because that's a practical way to make measurements and predictions (except when it all kind of breaks down). Think of them as a tool, like imaginary numbers (only not as useful, at least so far).

[@noneofyourbizness]

superb delivery for laymen such as myself. easy to follow and understand (relatively) the thread.

[@OpenWorldRichard]

Great presentation but I don’t buy the idea of restricting the range of gravity. Richard

[@paulthew2]

Great lecture. I love it when a physicist makes a physicist joke and they laugh at it, and everyone else is thinking 'where's the joke?' Dr Paul M Sutter has a regular podcast, and he did a two (or was it three) part series on gravity a couple of years ago - if you liked this, you may like it. Wonderful to have such fascinating and interesting lectures available for everyone.

[@rtmoore4]

“Deep down Gravity is still a force” you say? Please provide some proof of this statement, when you freely admit gravity is merely an expression of curved space-time. I’m sorry, but I have yet to see a single physicist explain this with anything other than, “well these other things that are legitimate forces have force carrying particles and they can be quantized, so clearly gravity must as well.” That is such a self-justified argument. In fact, gravity is NOT a force, it’s merely curved space-time. Gravitons do not exist. And since gravity is not a force, it can’t be quantized. It’s not a force in quantum mechanics either.

[@axle.student]

What actually curves space-time?

[@rtmoore4]

@@axle.student Mass

[@axle.student]

@@rtmoore4 Mass curves space-time. How does it do that? Does it grab hold of space and bend it into place? :)

[@lukegratrix]

Claudia is the Beauty of Gravity. I appreciate her sense of humor

[@seanmostert4213]

If you need to restrict gravity in the equations, use geometry. Look at gravity as a pair of vortices that rotate with equal opposite rotations and chirality, akin to the shape of DNA, and, when viewed from the side there is an hourglass shape, like the effect of breathing or even a heartbeat. These strands of paired vortices follow a curvature and there is a cross crossing pattern overall. The geometry is the key. You can see these shapes in everything around you. For example the bark of trees has this crisscross pattern for example the iron bark tree or the bottle brush tree. Or when you pour water from a jug look at the surface of the laminar flow as the water leaves the jug, there is a crisscross. This can also be seen on the pair of vortice that wrap around the underside of waves at the beach. This pattern may even be the reason why lighting and tree branches follow the same crisscrossing pattern, the same as veins, nerves, rivers etc. The pair of twisted vortices can be seen in many observable phenomena as well, you can see that muscle fibres under a microscope are made of pairs of fibres, passion fruit vine branches have this geometry, so does (as mentioned before) DNA, solar flares (look closely and you will see it), or look directly down through the veils of the Auroras from satellite imagery and there too you will see this twisted pair of vortices. Look at a linear slice of a human hair under a microscope and you will see that it is made up of this twisted vortice pattern, also, magnetic flux lines when observed through space telescopes of distant galaxies show that upon close observation the magnetic waves are a pair of twisted vortice which by the way can also be seen if you sandwich Ferro fluid between two sheets of glass while shining a light from underneath and moving a magnet around on top there are the same twisted pairs. Again in the flow of sand across the dunes or the waves across the surface of the ocean, if you stand back and observe them you can see that every now and then the waves/sand ripples converge linearly and appear as a twisted pair. We often study these effects and we can explain what is happening from a physics perspective, such as surface tension, action and reaction, etc. but what we seem to not grasp is that the geometry of completely different things has a fundamental similarity. Hope this helps anyone who is looking for answers from a different perspective. We can only ever observe one side of a ball with our own eyes, it takes multiple perspectives together to have a complete understanding.

[@logangodofcandy]

You have to restrict the velocity of gravity. You can do this by giving it mass. To have mass, it has to be interacting with the higgs field. You're suggesting that a particle have a complex shape and pattern, making it not so much a quantum particle

[@ciberbri59]

I vote against the graviton.

[@toby9999]

How would you know?

[@j.a.weishaupt1748]

I love her pronunciation of the word “phenomenon” 😊

[@Jesus.the.Christ]

Einstein was clear enough, "Gravity is not a force".

[@lastchance8142]

Yes. These string theorists insist on talking about "gravitons" as if there was any evidence they existed.

[@EinsteinsHair]

Mass tells space how to curve, space tells mass how to move. Something is bending that space.

[@Jesus.the.Christ]

@@EinsteinsHair You are off topic. Einstein was very clear: gravity is not a force, it is an emergent behavior when an object moves through a curved spacetime. This is abundantly clear if you dig into Relativity. What is irksome is that many particle physicists ignore this, usually it seems, because they do not like that Relativity and quantum mechanics do not meld. The lack of melding is most likely because our mathematics are lacking. There are several impossibilities that arise with both theories when mathematics are applied to them, such as renormalization and singularities. Particle physicists would meld the two by throwing away Relativity (the single best tested theory in scientific history) to replace it with half baked theories that usually involve a particle that would literally elude a particle collider that was the size of our solar system. Here is a simple difference that Einstein did not point out, but is an easy way to differentiate: the particle forces are transactional. When those force are involved in an interaction a particle or particles move, transferring energy. There is no such transaction happen when there is an interaction that involves gravity. The next time you encounter some particle physicist blathering on about "quantized gravity" or some such, ask them for proof. If they can't provide it, and they won't because they can't, tell them to make it clear that they are talking about conjecture at best, and fantasy (String "Theory") at worst.

[@RFC3514]

@@lastchance8142 - All "particles" are just a practical human interpretation of perturbations in fields that happen to cross certain thresholds. None of them "exists" in the sense that kids are taught in high school (i.e., as a little ball with a well-defined surface that moves around a neat little orbit). The square root of minus one also "doesn't exist" (for normal values of the word "exist") and it's still very useful in maths (and, in fact, essential to some branches of physics).

[@juliodeluna2774]

When did Einstein ever said that? Einstein in his conversations with Reichenbach had an entire different opinion: "You are completely right. It is incorrect to believe that ‘geometrization’ means something essential. It is instead a mnemonic device to find numerical laws. If one combines geometrical representations with a theory, it is an inessential, private issue."

[@kinghyrule86]

When Claudia showed the tube experiment, I couldn’t help but think of the energy she put into it transferred by the tube itself and how that energy had to have pushed that ball through it

[@paullondei5744]

Sympathy to Higgs passing away, a great physcist

[@Joshua-by4qv]

Claudia. Recessional velocity of each galaxy is accelerating away faster and faster, but the Hubble constant itself is decreasing.

[@simesaid]

You can't feel gravity exert a force upon you because gravity is not a force. And the reason that any two objects dropped near the surface of the Earth will _always_ hit the ground at the same time is because they do not, in reality, go _anywhere._ When you let go the objects stay _exactly_ where they are in space, and it is the surface of the Earth, expanding radially out from its centre due to the pressure of its mass, that comes up to hit them. You, me and indeed Ms Rahms are constantly being accelerated, at 8.7 metres per second, per second, and this is a force we _can_ feel. We feel it in our feet, and we feel it in our bums. And _this_ is the equivalence principle - that "in a small region of spacetime the effects of gravity are indistinguishable from acceleration". For a supposed expert on the topic, I'm surprised that the speaker apparently knows less about general relativity than myself - a layperson and high school drop-out.

[@benjamindover4337]

I believe you are correct in that the experience of gravity is actually the continual outward expansion of all matter. If one steps out of an airplane, you don't fall down. Instead, the continual expansion of yourself and the Earth lead to you and planet eventually meeting. An object at rest, stays at rest. As you step out of the airplane, the air is being pushed past you by the expanding planet. You aren't falling at all. You are expanding in size. If you jump up, you don't fall back down. The Earth expands to meet you. Perhaps an imbalance between the weak and strong nuclear forces could account for this expansion.

[@dgnash]

Agreed. I could hardly believe my ears. I think this woman should stick to lowbrow BBC programs.

[@gheorghepretenaru2945]

9.8 m/s^2

[@Bugside]

So if you drop from a plane a mile high with no parachute you aren't actually traveling down to meet earth, the earth is stretching a mile to reach you?

[@gheorghepretenaru2945]

@@Bugside - it's happening something beyond our day by day understanding that is perfectly equivalent with what you just described - the space-time is curving exactly as in the case of an accelerating motion

[@hesketh1965]

My question would be, If a Graviton has a mass it must travel slower than the speed of light. Is this correct?

[@alfadog67]

Yes, it must unless general relativity is wrong.

[@ronmexico5908]

Too much fluff

[@bobjackson6669]

Great lecture on gravity and gravitons and so much more. I found the talk deep, and leaves me thinking. I like to think.

[@lfb3441]

Sorry to see even the RI talks are getting worse these days

[@MrStoffzor]

How so? Because not everyone is a native English speaker?

[@shitedriver8490]

@lfb3441 that's what happens when you spend too much time wearing red hat, everything sounds complicated to you.

[@srmxe417]

Great lecture!

[@CarlAyers-x8h]

I keep gravitating back to this subject. :)

[@srinivasanmuralidharan5344]

Excellent, Vazhga Valamudan.

[@tanveerbhatti8849]

Great lecture

[@OpenWorldRichard]

Correction. Gravitational waves travel at the same speed which is the same speed as gamma radiation and light. This is observed in multi messenger astronomy. Richard

[@arvindseewoosungkur9061]

Thank yo very much for this talk and sharing your knowledge. Keep up the great work and good luck with your projects.

[@peter5455]

Great sensational touch about Gravitation

[@BethBarany]

loved your talk 🎉

[@TheoPrinse]

Thank you, Claudia de Rahm. Gravity is material and its particle is the graviton. The graviton exerts an attracting force between all protons (matter) beginning at the center of a larger object of mass and any proton. The more matter, the more gravitational attracting force. The graviton particle is orders of magnitude smaller than electrons and neutrinos. The gravitons form lines or strings originating from the center of the mass object outwards and connect to strings of gravitons of nearby bodies of mass. There is only one connection between two protons. But protons have more single strings with nearby protons. From a molecular level, there are relatively few connections. But on the planetary level like Earth and the Moon, the number of the connecting strings are enormous. During Earth's movement, the graviton strings between the center of the Earth connected with the strings of gravitons centered in the Moon are constantly reconnecting per zeptosecond because the position of the most opportune strings is continual changing due to the movement of the Moon, and to a lesser extent that of the movement of the Earth. Every quadrillion of graviton strings strives for the shortest connection, a straight line. But because the bodies are moving the lines of the strings of gravitons are bent and the strings exert force on the corresponding string to become straight ... or disconnect and reconnect to the next most opportunist string. Every reconnecting is a process of shortening the number of occupied gravitons in the specific string. This is where the force of gravity comes about. When a person is standing on the surface of the Earth, the atoms of the ground prohibit the person from falling deeper into the Earth unless it is water or quicksand. But when the person jumps upward the connected lines of the person with the surrounding air molecules are way in the minority with the connected strings of gravitons between the person and the earth. The Earth wants to have straight lines and forces the person to decent until the connected strings are straight lines again and the atoms on the surface of the Earth become an obstacle again to this straightening and attracting process between the Earth and the person

[@peterwielinga]

Gravity is a very interesting not yet fully understood force. A secret. however, there is no secret once you know how it works. Claudia talk about a lot of different forces and nicely explains some, the relationship’s between them, and the experimental proof we have. Yet gravity stays a secret, or better a not yet fully understood force. Once you are releasing this you can seek the explanation for this and I can tell you that explanation is out there:)

[@hattmarvey1989]

Where does an electron get its energy? The current "standard model" could be wrong. Gravity and the weak forces could be the same force (it's a field, not a force). With that model, maybe everything works without the "fiddle factors". Dark matter and dark energy go away too. I'll let you know when I've done the maths...

[@colinchambers3433]

@@hattmarvey1989. Well done ,well said, 1:00:43

[@autonate_ai]

She is amazing! Looking forward to seeing the rest of the 50 mins I have left. Just had to pause and say thank you! This may be the research I have been uncovering for quite some time now. Thank you so much, so far! 10:01

[@twopenace403]

Exceptional summary of modern physics.

[@johnl5974]

Fantastic presentation, thank you.

[@PotentialSpaceHolder]

Yes, you are correct, a graviton. Try additional properties. Dark matter, spins, expands, in gray smooth Subtle Energy. Then add the separation of a graviton spiral in gold color that moves down and away. Now that the dark matter is stationary and no motion, the graviton will spiral towards the gray matter, integrate and the matter collapse.

[@brianmason9803]

We are told that gravity is not a force but simply the curvature of space-time. I can see that for moving objects within that curvature. However it doesn't seem to work when considering an object that is released from a static position under the influence of this curved space-time. In this scenario the object begins to move. If 'Force' is something that creates movement, what is the force that begins the object's movement toward its neighbouring mass now that we have said that gravity is not a force?

[@PotentialSpaceHolder]

For billions of years, it's called I'm feeling the Good Vibrations.

[@CheeseWyrm]

Correct me if I'm wrong, but is this "Higgs Bath" the same as what is also postulated as "the quantum foam", where there exists a probabilistic potential for 'massive' (ie: having Mass) particles to appear in 'empty' SpaceTime, and disappear again. If you will - a sea (bath?) of foaming, emergent, collapsing wave-functions that may or may not continue to collapse into distinct particles (be they ever so smaill!) Also, does this 'bath' relate to the Branes of String Theory???

[@hyperduality2838]

Gravitation is equivalent or dual (isomorphic) to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). The force of gravity is the same for all observers -- absolute democracy! "Always two there are" -- Yoda.

[@CheeseWyrm]

@@hyperduality2838 Thanks for your reply, but I must be missing something here as I don't see how it relates to my statement & question 🤔

[@hyperduality2838]

@@CheeseWyrm Energy is dual to mass -- Einstein. Space is dual to time -- Einstein. The force of gravity is dual. Potential energy is dual to kinetic energy -- gravitational energy is dual. Vectors (contravariant) are dual to co-vectors (covariant) -- dual bases. Riemann geometry or curvature is dual. Particles are dual to waves -- quantum duality. Distinct particles or localized particles or your localized quantum foam are dual to that which is non localized. Generalization (waves, non local) is dual to localization (particles). The infinitely small is dual to the infinitely big. Your logic requires duality to work!

[@CheeseWyrm]

@@hyperduality2838 OK, ta for elaborating. So, to re-word my questions: 1. Is this 'Higgs Bath' the same concept as the 'Quantum Foam? 2. How does it relate to Branes?

[@hyperduality2838]

@@CheeseWyrm I do not know enough about these two subjects to comment about them. Space is dual to time -- Einstein. Energy is dual to mass -- Einstein. Teleological physics (syntropy) is dual to non teleological physics (entropy). Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics! Claudia is correct about the laws of physics they are fundamentally democratic or 100% democratic at all times. Objective is dual to subjective, absolute is dual to relative -- the laws of physics! The bad news is that physicists do not talk about absolute or objective democracy -- proper democracy. Even Einstein failed to comment on this important subject -- physics fundamentally at its core is 100% democratic!

[@stevelympany3203]

"Gravitational waves of different colour travel at different speeds" (58m). I'd assumed (I'm no physicist) that they travelled at C. Great lecture 👏

[@spa11199]

❤❤❤ thank you for such knowledge accessibility. It's a she after all, Mrs graviton.

[@marthafernandez9220]

Excellent. Thank you…peace.