Do we need String Theory for Quantum Gravity? - Lance Dixon (SETI Talks)

[@SETIInstitute]

Hi Mino, yes the maths behind String theory is extremely important - despite dealing with things on a quantum (tiny) scale, in effect this 'scales up' to the real world, so quantum mechanics rules the entire world despite describing the smallest of domains. You might want to check out our talk by Alex Westphal on String Theory too!

[@YuzuruA]

Warning... you tube experts on physics, magic, and UFOS below

[@SETIInstitute]

We have a Higgs Boson talk coming up - but please feel free to suggest a speaker and we'll try to get them.

[@SETIInstitute]

Thanks Gergs, our lovely intro was done for us by the Turner Duckworth branding firm. Glad you enjoy it!

[@DancesWGenomes]

Lol-- at 53:22, he says he's going to "skip through some of this stuff because it's a little bit technical." Then again, it was also the most sensical thing he said during the second half of the talk.

[@CACBCCCU]

I suppose the quantized flux loops through e.g. Josephson-junction rings are supposed to behave just as sets of closed strings, one closed-string per magnetic loop flux-quantum. As far as linking rings to qbits goes, I guess selectively-coupled sets of rings could carry modulated phase differences, giving enough phase information to carry several qbits, depending on phase-resolution limits. Seems like a quantum version of D8PSK or D16PSK would carry 3 or 4 qbits. Could be wrong, I don't know.

[@CACBCCCU]

Another reason to think gravitons could be spin_1 is that 'gluon chains' have been used as a replacement for gravity quanta with great success in simulation even though gluons are spin_1, not that I think gluon chains can replace all gravitational effects quantum gravitons could produce, i.e. all gravity. Still seems conceivable that all forces are mediated by spin_1 particles, implying the Higgs effect (inertia) is a resonance of spin_1 forces rather than a product of spin_0 (Higgs) particles.

[@Dyslexic-Artist-Theory-on-Time]

Could gravitational potential and electrical potential be linked together? They both use the inverse square law! In this theory gravity is a secondary force to the EM force. Objects just free-fall towards the greatest energy because it has the greatest time dilation! Because the photon of quantum mechanics is also the carries of the EM force this would link gravity with quantum mechanics!

[@EminorReal]

I ask myself: The fact that String Theory's maths can be used for reliable predictions on the quantum entanglement between three and four qbits, does it actually have some importance of is it just a big woop?

[@claireaaa1]

Did they pass around a collection box after this lecture to reflect the degree of puzzlement or enlightenment that was experienced by each spectator? More to the point, was he able to retire from the proceeds?

[@JSprayaEntertainment]

4:00 Gravity is not weaker than electro magnetism ... try putting the paper clip in space and see if it gets pulled toward a magnet 60 miles away on earth .... .... electro magnetism is only stronger at very small distances ... we need to grasp and understand this to move forward correctly

[@enigma9306]

Your a genius... You know that's not really much of a revelation, physics describes that. The strong nuclear force acts on even shorter distances, but the field strength is greater than the electrostatic field strength. The strength is defined by a number=the density of the probabability amplitude wave of electrons for electrostatic interactions. But this has a very short range, whereas for gravity, with gravitons replacing electrons, the range is much larger because it takes allot more gravitons than electrons to have the same probability amplitude.

[@olly3700]

+J-N-H-M The point that you make doesn't Support the Notion that EM ist weaker than G.One Thing you forgot to take into account is geometry. EM force decreases with the square of the distance. Since it is very strong, you Need only to take a small magnet, compared to a huge planet. However, by that you have to buy the fast decay of the force cince taking the object away for only a small distance, you multiply the effective distance.

[@observer6294]

+J-N-H-M ...There is something true, about what You are saying. Try to put a piece of wood, instead of paperclip, and magnet does not do much nothing, and try to put little bit of water, and magnet will repel it. but to compare or calculate which is stronger, is question of relative, and I dont think it lead to anywhere.

[@JSprayaEntertainment]

thinkrealify you should see my video " whats wrong with gravity " you seem smart

[@JSprayaEntertainment]

thinkrealify thats good stuff but i thought the edges of galaxies went faster than expected, not the inside is going slower .... and if light or the electromagnetic spectrum is the force carrier of gravity , then black holes would have no gravity since no light or electromagnetic radiation could escape it ... ( good thing i don't think black holes are Real either ) (( as in my video " Why blackholes Don't Exist "))

[@CACBCCCU]

I guess I should be clearer about saying "graviton-graviton scattering" could be nonexistent - I mean there seems no reason to suppose gravity couples to itself as suggested at 30:50 if quantum gravitons are massless, pointlike and spin_1. Just as an electron is needed for a central loop in so-called "photon-photon scattering" a mass particle, probably a collection of mass particles actually, would be one requirement to form a central loop for any sort of "graviton-graviton scattering" effect.

[@Aluminata]

String theory makes for a good yarn.

[@sonicase]

he says gravity has an effect on all particles, however there are massless particles (gauge bosons). i know light can be bent around a large mass like a star but i think space is just curved around it. so it's not really the gravity. i'm a particle physics noob but that part seemed a little iffy. there's been no real evidence for string theory(i think). it makes me wonder if we're over complicating the situation like astronomers were over complicating the movement of the planets before kepler

[@CACBCCCU]

Looking at AREPO's time-lapse simulation reassures me that spin_1 gravitons, if they retroreflectively tend to balanced spin-handedness and tend to pair-off oppositely and thereby generate a balanced spin_2 effect, would do a much better job simulating cosmological gravity. The most interesting galaxies AREPO generates just aren't round enough to impress, they lack the distinct radial phase-contrasts of a prototypical ring or spiral galaxy. Bilateral spiral arm balance seems rare and ephemeral.

[@msms47]

hey guys ! can some 1 answer this is the gravitional force on earth serface ( 40.000 KM/h ) is same at higher lvl of earth or does it get less the higher we get for exp at 50,000 km on serfce or 100km .. thanx

[@xen000]

pls somme answer isn't gravity just the spin of the particles dragging the higgs field or sommthing like that?

[@cosmocasper]

Or was he? Ok so we know the problem is when you apply T.O.R. to a black hole and work out the long complex math you end up with infinity for the density, mass, and gravity on the singularity. But to me that just simply suggests that inside the black hole would exist another Universe.

[@CACBCCCU]

A classical gravity wave seems like an abstract ocean lacking water molecules. A ship strains in ocean waves much like it would in gravity waves of the same rate, a molecular analysis is superfluous to that, although the ship's strains are generated by spin_1 interactions on the molecular level, the effect at the macro-level is spin_2. For many reasons I believe quantum gravitons are pointlike spin-one particles with macro-spin-2 effect, so graviton-graviton scatter should be nonexistant, imo.

[@TailoredReaction]

That's the least of your worries. Early on he mentions phenomena and states, "we will cover to this later". Then when 'later on' arrives, he proudly states, "as discussed earlier".

[@TenzinLundrup]

What a great speaker. Very down to earth and clear.

[@ufotofu9]

How? I'd love to know how you can know that!

[@stevenos100]

a stable phase is a particle - a phasing particle is EMR - any type of particle - just what phase is it frozen in = A neutron is a black hole a proton is free space

[@janjohandealgenman]

This. It depresses me that so few people realize we should do this

[@Dyslexic-Artist-Theory-on-Time]

This is an invitation to see an alternative to String Theory! Where the different dimensions are just future possibilities in our one 3D Universe. Based on the postulates: 1. The Ψ probability function represents the forward passage of time with the future coming into existence photon by photon. 2. Is that HUP ∆×∆p×≥h/4π that is formed by the w-function is the same uncertainty we have with any future event within our own ref-frame that we can interact with turning the possible into the actual!

[@Dyslexic-Artist-Theory-on-Time]

This is an invitation to see an alternative view! Where the different dimensions of String Theory are just future possibilities in our one 3D Universe Based on: 1 Is that the quantum wave particle function Ψ or probability function represents the forward passage of time itself photon by photon 2 Is that HUP ∆×∆p×≥h/4π that is formed by the w-function is the same uncertainty we have with any future event within our own ref-frame that we can interact with turning the possible into the actual!

[@JSprayaEntertainment]

the Loops will Probably Follow a (" Fibonacci & JNHM ") sequence ... 49:00 starting with 7-7-14-21- ect.. or 18-18-36 - ect to infinity ..

[@erwinmarschall2465]

10-D SUGRAs are low energy limits of superstring-theories. N=8 SUGRA in 4-D (presented in this talk) can be found from a dimensional reduction of 11-D SUGRA (Wikipedia: SUGRA). So why does Dixon claim that N=8 SUGRA in 4-D is fundamentally different from string-theory?

[@seanmcpherson5595]

They are getting the idea that Energy is space-time compress. When E is liberate is generating a violent expansion of the space-time getting back to it's previous volume. The velocity of the expansion is the speed of light C. Each sub-atomic particle is just space-time compress. From there, we can have protons, electrons, neutrons, etc. The biggest concentration of E or M, is just when the E or M disappear from our universe, and just leave their gravity (compression of space-time). We call that black hole.

[@TailoredReaction]

In an attempt to breed snakes for their Natural History Museum, the scientists created a natural habitat that included a few hollow logs for the snakes to lay their eggs in. Months went by and the snakes did not breed. A lone scientist watching the habitat through a viewing pane pondered aloud, "Why are these snakes not reproducing?" You can imagine his surprise when one of the snakes replied, "Silly scientists, we don't use logs to multiply, we are adders!". (only comp sci students get this)

[@superawesomegrapes]

a black hole is a 4th dimensional object. but we can only see it as a kind of hologram effect of being 3 dimensionally projected around a center point around an spherical area of time.

[@CACBCCCU]

I guess the point would be one can call it a string or call it a flux-loop, and that is the operative distinction. So, yeah, I think it's just a big woop.

[@bris1tol]

Platonic physics on why quantum gravity is so difficult In Platonic physics, as in Leibniz, the physical world is completely made of bodies of matter. Each of these bodies simultaneously has a mental correpondent, a quantum, called a monad. But if there is no physical correspondent-- and no graviton has yet been found - there is no corresponding quntum (monad). Hence quantum gravity appears to be a search for something that can't be. Dr. Roger B Clough NIST (retired, 2000). See my Leibniz site: [e-mail]/RogerClough For personal messages use [e-mail]

[@PiEndsWith0]

Around the 13th minute, Hawking radiation is mentioned - that is yet to be experimentally confirmed, no? Asking since it's presented as, within scientific reason, a fact. Thanks :-)

[@superawesomegrapes]

we are living in reality 3/11. we are conscious in the 3rd dimension, but as dimensions go down, we control the 2&1, while 4+ control us. can you have gravity without time? time is controlling us, along with 7 other ones.

[@ebindanjan]

I can safely say now that the principal contradiction is not one of technical like devising new theories or inventing new math. The principal contradiction at this stage of the intellectual struggle is one of framework of approach. I concur with the suggestion of Max Tegmark of MIT, an entirely new way is imperative to resolve all the contradictions and conflicts in all-round-way, and once-and-for-all. I devised an entirely new approach that is consistent, coherent and comprehensive in my book.

[@azraaell]

individuality is physical not quantum physical hope this helps

[@ebindanjan]

If the old keepers of the two seemingly competing visions that uphold a time-dependent universe are entangled with creation, the new generation of theorist are entangled with multiple creations. This simply means that the keepers are in a state of confusion with respect to the intellectual struggle. The real central issue is survival and not one of finding or proving how the universe was created.

[@SETIInstitute]

@PelicanGodOfJupiter Yes, it takes alot of Strings to pull off this illusion. :-)

[@SETIInstitute]

We hear you! Thanks!

[@EminorReal]

Thanks, I will surely check that out.

[@ebindanjan]

The principal contradiction at this critical juncture is not like any other contradiction that fundamental physics has encountered in its brief history. If we take the first great revolution in human thoughts of the great Ionian Awakening, we are supposed to be in the sixth stage of the intellectual struggle but as it is the keepers of the two so-called competing visions are stuck, they are entangle with creation. That's if we discard the timeless universe put forward by Xenophanes.

[@ThrillaWhale]

...? Like all great scientists, Einstein was right about some things and wrong about others - quantum mechanics was just taking shape during his time and was less understood. But I'm sure a modern Einstein would be able to build upon the tremendous physical and mathematical evidence put forth since the early 1900s. And the things he was right about, relativity and his contributions to wave-particle duality among others, have remained cornerstones of modern physics.

[@bobobox1000]

I suggest Dr. Leslie Winkle :)

[@gerrynightingale9045]

"All of energy and matter that existed still exists. The actions of matter enable energy to become manifest".

[@Luxylol]

cloneing would have alot of diffrent problems, 1 beeing consciousnesses, is this your "soul"? cloneing the consciousnesses of some one or thing thats dead and gone is gonna be hard, would prolly be easier to work on time travel and go back and get him. growing a synthetic body should be easier, then u just have to find a way to transfer consciousnesses to that body

[@carlosroy9212]

in grade 11 learning about grade 10 canadian history theories to come home and listen about string theories, quantum mechanics/gravity and read up on 11th dimensional super gravity...sigh i hate highschool, but ima need it to be a physicist :3

[@MrBeiragua]

carlos roy Physics is awesome!

[@RogerKeulen]

SETI, please don't use the laser pointer. Or put a cursor in it.

[@SETIInstitute]

There are some good ideas there ... :-)

[@azraaell]

if you want to believe that strings connect sub mass together thats upto you but i can see many things wrong with that and the truth stares you in the face, im amazed i seam to be the only one that sees it

[@zajec11]

This may not work just like that ;/

[@azraaell]

i know that because ive thought about it and debunked it from the foundations, strings are a physical idea , implies direction of travel this is a physical thing there is no definition between energy and mass to energy or mass so there is no definition between mass and mass, there is no "connection" physical premises can not explain quantum physical things and this is by for not it all, photons escape from nucleus its dark at night isnt it? piece

[@fractalnomics]

I can solve this. Or at least help.

[@das_it_mane]

Curious...go on...

[@fractalnomics]

@@das_it_mane Well, I study fractal geometry and think - from my experiments on them - they explain quantum mechanics paradoxes, our reality, and cosmic observations. I am currently writing up my quantum fractal towards publication. We'll see, but I have it doing it (QM) all.

[@KevinP32270]

would love to see this done in cartoon and using words an 8th grader can understand.

[@elentrenadordecarrus188]

You can hear the closest realistic aproach to gravity in "atomic gravity theory, the atomic irritation". Out of mathematics without reality like space time travelling, worn holes interconection, those are wrong paths by common sense. Give a chance to "atomic gravity theory".

[@leo00o83]

you lost me at "non-renormalizable", no, wait, you lost me at 10^500 ground states, *head explodes*

[@TailoredReaction]

Could the lecturer be more nervous and totally disconnected from his audience? Someone asks a legitimate question about what he meant by the "toy models" physicists use in their quest for understanding. He couldn't have answered any worse than he did. Simply, a toy model is something, either physical or abstract, that allows one to see or visualize what is going on - while being far from accurate depictions of reality. Eg, those models of atoms with little coloured balls joined like tinkertoys.

[@wesleylindemulder8739]

String theory was developed, as we all know, to avoid the "nonsense" of infinity. But is infinity really nonsense? QM and some other popular physics theories always result in infinity. Maybe the inability to explain infinity marks the limit of human intelligence. After all, is it possible for humans to know everything?

[@dangeloj2]

I like your point of view. I've often thought that maybe we are supposed to get the infinities after all it is in the center of a black hole that this mathematics arises. If space and time are different there then why not infinity?

[@SeanMauer]

Yes, it could be that the infinities are really there, but quantized space-time prevents their actual resolution, i.e. the present is too short.

[@enigma9306]

An infinity with one set of parameters mus r be resolved w with other sets of parameters. Infinities are where a theory breaks down. If you used air to figure out if a boat was going to behave well in water, up you get Infinities. Thats all the infinity means, it means the wrong approach has been taken in the first place.

[@wesleylindemulder8739]

Interesting. Thanks.

[@MorbidPhilosophy]

Lord Raiden = Michio Kaku = Yahiro Mazda(sky god)

[@nahuelrobles4526]

There ARE and will be better scientists than Einstein. Geniuses, that have their own way of looking at the universe.

[@THINGLEADER]

They said this dude was aight I mean he ain't gettin' the Chrysler... na he was kinda wack actually he gettin' the coffee mug

[@travisbaskerfield]

Don't forget your invisibility cloak and your universal translator and a good supply of nanodocs.

[@stephaniesadie832]

Point is the problems become harder to solve, even if men become smarter, At some point we will need machine intelligence or AI/Human interface to go further.

[@smith951]

hi

[@triggerfinger777]

Hi; Please take a large stir stick aimed at the moon and stir. Drop a bowling ball no wait try a marble first into the whirlpool you created with the stir stick. Get back to me how fast the marble gets to the moon. Consider me published. Space travel solved by John Albert.

[@Namal23]

SWAGGING!?

[@sijojosephdr]

But First you have to make believe Einstein that quantum mechanics is right !

[@hbloops]

rather have 1 newton than 10 einsteins

[@jesusrodriguez4277]

Of course we need strings. How else are going to tie stuff with? Duhhhh

[@kousoulides]

If only I got a $ for each time I had to hear that Joke..

[@KevinP32270]

why would gravity be the weakest when it is the thing that creates....SUPER MASSIVE BLACK SPHERES!?!?!

[@BlueinRhapsody]

Use a magnet to pick up a paper clip. That one magnet's magnetic force is stronger than the entire Earth's gravitational force.

[@KevinP32270]

but the eaths magnetic field is spread over the entire planet. the little magnet is focused. if we squeezed the earth to the size of that magnet the gravitational force would most likely create a black sphere. response please?

[@rodluvan1976]

Kevin Pean you are conflating earth magnetic field and earth's gravitational pull. "squeezing" earth to the size of a magnet _would not_ increase gravitational pull, as that hinges on mass alone and that doesn't change in your hypothetical (density does). for earth to create a black hole, its radius would need to be 8,7mm.

[@KevinP32270]

rodluvan1976...i respectfully disagree. as you squeeze the eath down to a smaller sphere the gravitational pull/squees would increase. that is why it would be a black sphere at the 8.7mm size. there is lost of space between atoms where gravitons live. concentrate them and the strength gets stronger.

[@BlueinRhapsody]

Kevin Pean If all the mass of the Earth was concentrated to the size of a magnet at the center of the Earth and you remained where you are right now, the force of gravity acting on you would actually be slightly weaker. Forces are determined by the distance between two object and the force constant. For gravity this is mass, for electromagnetism it is charge. F = k q_1 q_2 / r^2 for the electric force. F = G m_1 m_2 / r^2 for gravity. k is a lot bigger than G. You need a lot more mass than charge to obtain the same level of force at the same distance. For example, if you had two objects w/ the charge of an electron, to get the same force, you'd need two objects at the same distance to have the mass of 20 billion times the mass of an electron.

[@baggybag1987]

already happening but kept secret : )

[@cosmocasper]

Lets stop wasting time. I say we take Einsteins DNA and make a few hundred clones (we have the technology). Educate the Einstein clones from a young age on physics and math with our top minds. And lets solve this shit already so i can travel around in my time machine with my anti gravity boots.

[@nikolamilivojevic6004]

a bit delusional. you still can't clone a cat that will have the same personality, let alone the same intellect as the host.

[@MrTweetyhack]

Although this talk is good, but the association with SETI seems to lower its credibility. Get any calls from aliens yet?

[@DarkskiesSiren]

You guys treated this so much like a lecture it is a bit ridiculous and really narrows your audience, making it difficult to gather interest... anyway the models are interesting but I rather discuss experimental results and then explore models... this lecture starts getting incredibly dull due to pussyfooting around various things... for the sake of model building...

[@TailoredReaction]

This is a poor lecture to post to the internet. The physicist introduces far too many words and concepts with no explanation what they are. By about the ten minute mark, even the most intent concentration leaves the viewer baffled and befuddled. One can only imagine how the audience at the SETI Institute reacted. Typically, the ending is a Q and A session where the intellectually irrelevant start constructing their most imaginative unrelated questions in some act of self-confirmation. Rates a D.

[@Pammudada1]

False speculation in science

[@MrTweetyhack]

how is it a joke? I wouldn't waste my time with any of the seti crap. Are you telling me we have comm from the aliens? Nice of them to waste computing power, electricity, and other resources for nothing. Yes, nothing.

[@savvys3782]

get real. einstein was wrong

[@reto-fassbind]

This is such a lame joke. If you had seen any of the seti talks, you would know better.

[@msms47]

hey guys ! can some 1 answer this is the gravitional force on earth serface ( 40.000 KM/h ) is same at higher lvl of earth or does it get less the higher we get for exp at 50,000 km on serfce or 100km .. thanx