Spacetime and the quantum: united by history

  • Publicado el 6 ene 2014
  • Professor Fay Dowker presents her Inaugural Lecture.
    Two major scientific developments - relativity and quantum theory - have advanced our understanding of the physical world. However, despite their success in predicting experimental results, they remain revolutions in waiting.
    I will argue that the full potential of these discoveries will only be realised when they are brought together into a unified whole. The revolution that general relativity represents - the replacement of three-dimensional space with four-dimensional space-time as both stage and actor in the universe's grand play - has so far been only partially incorporated into the scientific practice of fundamental physics.
    Taking space-time seriously, as general relativity demands, means adopting the Dirac-Feynman 'sum-over-histories' approach to quantum theory and gives us our best chance of discovering a theory of quantum gravity, a framework for all of physics.
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Comentarios • 45

  • Jonathan Tefera Endale
    Jonathan Tefera Endale Hace 7 años +1

    Exciting Talk and incredibly well explained so that even I, a non physist, could follow you!
    Thank you.

  • Will S
    Will S Hace 7 años +3

    Good lecture. Thank you.
    Very few physicists today are talking about the quantization of space & time. The implications are huge. Especially now that we have sigma 5 evidence that gravity is quantized...(cern 2012)
    I'm surprised she did not say (perhaps I missed it) that velocity (movement) would not be possible without quantized time and space.

    JR OFFICIAL Hace 7 años

    I had this idea when she mentioned the slices of spacetime that 'what if' there might even be a self created endpoint or shell wrapping around all the dimensions she described? and if so, do our beliefs about its existence and/or expectance of this total connected dimenshion to be there allows it to manifest in our physical reality?

    TOM NEEDHAM Hace 7 años +4

    Wonderful lecture! As a non-scientist with a passion for trying to understand the concepts contained in cosmology, quantum theory, general relativity, et al, there is an old adage which goes something like this: if you can't explain a theory to a bartender then you don't understand the theory. I am the bartender and Professor Dowker demonstrated clearly she understands the theories! QED!!

  • ClayZ
    ClayZ Hace 5 años

    Fay actually covers what happens if you do a triple slit experiment, which is illuminating in an ironic way. I suppose it makes no difference, but what happens if you rotate the slits to be horizontal, or some other angle?

  • dlwatib
    dlwatib Hace 7 años +3

    I must admit that I didn't get much out of this talk. I wish her well in her studies, but I see no reason to believe that whatever theory *appears on the surface* to be more unifying will in fact prove to be true in the end. The way forward is to learn how to measure quantum effects one bit of information at a time so that our measuring apparatus is entangled as minimally as possible with our experiments.

  • poesboes
    poesboes Hace 7 años

    What a brilliant presentation! It has left me with many new questions... (What patterns are formed by streams of particles in the three-slit experiment? Is there a link between the causality diagrams and the Feynman diagram representation; or is finding that link just the key to finding out about quantum gravity? ..)

  • Howard Treesong
    Howard Treesong Hace 7 años +6

    The profoundly frustrating idea behind this is that I, by and large, can understand the lecture while being fully aware of the fact that I don't understand the underlying physics one iota. It helps me being modest, I'm saddened that I don't understand it on a deeper level.

  • Frederico Flósculo
    Frederico Flósculo Hace 7 años

    Genious. History tell us about what can really be understood about the universe. That's reaaly our universe.

  • huepix
    huepix Hace 7 años

    there is no matter. its just our perception of a natural phenomena. space moves. It moves at different rates/speeds/velocities. like movement of the earth effects water going down the plug hole, so the movement of space causes vortexes of space. the point where this vortex approaches the speed of light means that space collapses into a different time/space reality, which is why we percieve empty space as solid. sub atomic particles are nothing more than empty space spinning at (nearly) speed of light relative to our speed. This means there is no particles, just feilds of moveing space.
    I cant go into all the details here but, but this explains the double slit experiment, expansion, and the shape of the universe. relative ti us. the icon next to this comment is a photograph of the result of a multipule lens experiment i designed. Interesting shape?

  • Ivan Rodriguez
    Ivan Rodriguez Hace 8 años +3

    …Imagine a one dimensional point displacing in one axis. A two- dimensional being “sees” the point…is aware of what it really is…just a point. The 2D being perceives the point in motion…but cannot sense it’s true trajectory (the point could move diagonal to the 2D observer but the 2D observer can only perceive it’s movement to the left or right). The observer’s 2D existence only empowers him to see the one dimensional creature’s spatial nature or “spatial possibility” (true form) but not his “temporal possibilities” or “true time-line”….he cannot predict the position of the point in space and time. To be able to perceive the one-dimensional creature’s “temporal possibilities” the 2D creature must look the one-dimensional creature from a three-dimensional world or universe.
    The 2D object could try to “move around” in his 2D world to try to track the trajectory of the 1D creature…but the 2D creature’s own movement will only further distort his perception of the one dimensional creature’s direction and speed. Again…only a creature two dimensions higher (three dimensional) can see it’s true trajectory …predict it’s position in time-space.
    This can be proven by imaging a point moving in a sheet of paper in one direction…we that live in a 3D world or “universe” can very easily see it’s “time-line”…we see where the point was…where the point is…and where the point will be.
    Let’s go one dimension higher this time…
    We in a three-dimensional world look at a 2D creature moving in a 2d plane (for example a triangular creature) …since it is two-dimensional we can obviously perceive his complete “spatial possibilities” or” true complete form” but since it moves in two axes (can turn around… move straight etc.) we cannot perceive it’s full “temporal possibilities” or trajectory in time and space. Again this happens because we are dimensionally limited to perceive it. Only a person living in a fourth dimension…orthogonal to our 3D world… can see the full time-line of the 2D creature (again it needs to be two dimensions higher).
    Let’s put it in a basic formula or axiom…
    The “full spatial possibilities” or true form of an X dimensional element can be perceived by an observer living in an 2X dimensional world or “universe” But the “full temporal possibilities” or “true time-line” of X dimensional creatures can only be completely perceived by a creature living in a 3X dimensional world or “universe”.
    This means that we, as 3D creatures… to be able to see our complete “temporal possibilities” or “time-line” (past, present and future of any person on earth and any part or our 3D universe)… We must be seen or visited from a fifth dimensional world . In purely dimensional terms of course …this could be one of the basic principles….for Time Travel 

  • ExiledGypsy
    ExiledGypsy Hace 6 años +18

    What bothers me about all demonstrations of double split experiment is that no one ever explains the limits of the distance between the two splits. They can not be larger than a certain length but no one seem to think that is important. Furthermore there are plenty of reference to the theory of wave guided particles which makes things a lot easier to explain but again no one bothers to mention that.
    There are now at least two videos that I have seen that reasonably challenge this so called weirdness of quantum mechanics.

  • Will Hart
    Will Hart Hace 7 años

    It seems to me that this conflict is so fundamental that it ought to make us call how our perceptions function to create the universe we precieve. We are reductionist creatures by nature, our bodies and brains are limited. Science auotmatically and unquestionaly used this methodology assuming it could solve all problems and give us total knowledge and truth. But that assumption may be false. We are made of the same atoms as all other matter in the universe, where is there any division? There is a basic conundrum in here that we are not getting ahold of...

  • Satish Malhotra
    Satish Malhotra Hace 7 años

    the merger of quantum mechanics and gravity will not be so easily achieved, it will need changing physics from its fundamentals both relativity and quantum mechanics need to change from its foundations. relativity has a built in error that has remained for hundred years: the giving up of absoluteness of space and time is faulty. if we were to treat space and time as flows of gravity and give its velocity the same absoluteness as that to light, relativity of velocities will get easily explained as all other velocities can be compared with this absoluteness of space flow. On quantum mechanics there is no explanation for quantum mechanical freedom, within determinism, we have change the foundations of physics from determinism to freedom. once we make these fundamental changes the merger of quantum mechanics and relativity (discard of relativity) is easily achieved.
    I have written papers on both the issue, but found that physicists are not prepared to even look at them deeply. any suggestions as to what can I do so that these ideas that strike at the fundamentals of physics are at least considered are argued about? sk

  • Mohamed Saleh
    Mohamed Saleh Hace 7 años

    I have newbie question. I wonder if they tried the particle split experiment in vacuum chamber or environment. did they get the same result?

  • HeilTec
    HeilTec Hace 8 años +2

    If Space is indeed quantized, then the lattice-QCD model could be closer to truth than just a numerical method to remove infinities.

    • nacho73
      nacho73 Hace 7 años

      The problem is, how can space time be quantized, granular, atomic or appear in discrete values at the Planck length? What would be between the discrete values? Inside what would this space time "atoms" be embedded? What are this st. atoms made out of?
      It can't be nothing, since this space time atoms wouldn't exist at all since nothing can possibly be inside nothing.
      The other alternative would be that it is space time itself but this would contradict their discredity and atom like structure because there wouldn't be any place for the atoms to lay in between. Or maybe, this is the case but interactions can't take place with the upper units and making them an own irreducible system with entropy.
      However, something just don't seem right with this theory

  • Matt Mars
    Matt Mars Hace 8 años +8

    With respect to professor Dowker.
    To unify any two theories (e.g. Relativity and Quantum), one should be very clear that each and all of the phenomena suggested by both theories Is reasonably confirmed.
    Otherwise, if one or other theory is believed to prove something that it in fact does not, and this not noticed, then one may be endlessly trying to fit two pieces of a puzzle together, thinking the problem is very hard, because one is not realising that one piece may actually be bogus.
    In this talk, Professor Dowker refers to, and incorporates into her explanation, Relativity, and space-“time”. Suggesting that she accepts that “time” is a phenomena that exists, and is merged with space, and that this is proven to a reasonable extent by Relativity. And thus is trying to work out how to merge space-time with the quantum arena.
    However, if we actually check for ourselves, and look at the seminal paper on Relativity, ( translated ) *“The electrodynamics of moving bodies”*, we find that concerning the theory of time it actually says...
    *A.Einstein, (Section § 1. Definition of Simultaneity) quote...*
    *“If we wish to describe the motion of a material point, we give the values of its co-ordinates as functions of the time. Now we must bear carefully in mind that a mathematical description of this kind has no physical meaning unless we are quite clear as to what we understand by **_“time.”_** “*
    *“If, for instance, I say, “That train arrives here at 7 o'clock,” I mean something like this: “The pointing of **_the small hand of my watch_** to 7 and the arrival of the **_train_** are simultaneous events.” “*

    Here, to avoid accepting, and attempting to explain and incorporate phenomena which may in fact not be proven be Relativity, I think it is important that professor Dowker considers the following.
    Where apparently describing a thing called *“time”*, “The electrodynamics of moving bodies”, says we describe “the motion of a material point” , “as functions of the “time” “.
    However the paper clearly only actually describes *the comparing the motion of a material point ( a train)* , with *the motion of another material point* “a *motorised pointer* on a numbered dial”.
    In other words, from the outset Special Relativity does not actually show the existence of a past, a future or a thing called time, that must exist and pass for things to be able to exist and move, but instead Relativity only assumes that a thing called time exists, and that a rotating hand in some way proves or indicates this.
    (i.e. just *saying* "time is that which clocks measure, is nonsense, no matter who says it, unless one can scientifically prove, rather than just assume, there is a "past" and or "future", and *an extra thing called time* that must exist, extra to the energy in a spring or battery that IS clearly measured by such a motor).
    SR does show us that for easily understood reasons that
    “all moving oscillators are oscillating more slowly than expected”,
    And this fact is of course essentially incorporated in GPS satellite oscillators etc.
    But logically, and scientifically, just observing the rotating tip of a motorised hand and “calling” that motion “time”, is in no way at all scientific proof, as per the scientific method, that there IS a past, or a future, or a thing called time that exists and passes between a past and future.
    And, more importantly, just observing that a moving oscillator is oscillating more slowly than expected, is not scientific proof as per the scientific method, that one’s “guess” that a thing or place called the “past”, and or the “ future” and a thing called “time” must exist. Logically, it is only confirmation bias that would make us assume this.
    In other words, while it is agreed with the professor, that a rapidly moving twin will be “changing more slowly” that a stationary twin, without specific proof it cannot actually be logically and scientifically accepted that this is because of, or proves the existence of a thing called “time”, or that the moving twin is changing more slowly becasue a thing called time is dilated in its passage between a "past and "future", and is thus affecting the twin.
    (imo, the importance and consequences of seeing how SR may in fact in no way prove the existence of a 4th dimension, and realizing tha many professionals assume, without actually checking, that it does , cannot be over estimated. I.e it may lead to the conclusion that matter just exists, moves changes and interacts "now", or "timelessly" so to speak, effectively disolving and solving the so called *"problem of time"*, and all eliminating all discussion of temporal paradoxes etc)
    And, despite the fact that many people cite Relativity as apparently proving that extra to space, matter and motion, a thing called time exists, *unless they can actually show where Relativity from the outset **_proves_**, rather than just **_assumes_**, the existence of a thing called “time”*, and where the paper proves there may be a thing or place called “past” and or “future”, rather than just assuming these “things” are obvious, and for some reason exempt from needing proof as per the scientific method, the concept of “time”, and the existence of 4 dimensional space-“time”, should not be considered scientific fact.
    Therefore , if the professor is trying to unify quantum mechanics, with the concept of space”time”, but the time component she has _just accepted as proven_, but cannot actually cite the proof of, then this “time” component may be a falsehood that does not exist, and need not be included in the unification.
    i.e imo, probably *wrongly* assuming a thing called “time” does exist, and must be incorporated as in space time, will make professors Dowkers problem seem harder to solve than it may actually be.
    Matthew Marsden
    (Auth “A Brief History of Timelessness)

    • nacho73
      nacho73 Hace 6 años

      @Questing You'Re welcome.
      I'm sorry, i didn't have found enough time until yet.
      What came to my mind is that not only the analogy provides itself very well for possible suggestions but that deduced verifiable propositions of it should be based on experiments to test them. But that is something which can happen in the future.
      The natural selection of e.g. most dense places and others concerning the field would be one way to look at it.
      I hope your theory grows, also on popularity and substainability and I'll stay behind you.
      If you celebrate it and read it at the right time, then, marry christmas, keep going and please never give up :)

    • Questing
      Questing Hace 6 años +1

      @nadjim73 Thank you for reading and commentating cosmoquest. I do have firm opinions the universe owes its existence to evolutionary process, and am enjoying presenting the idea. And glad to have some that appreciate it. Some of my ideas are already being adopted by other people, so that’s flattering.
      Yes there are many basic questions need to be answered, and predictions need to be formally structured and tested. They are leveling lots of questions at me, some good and some silly, and its hard to keep up. It will take some time to develop the arguments, but I feel I will be able to answer to all of them in turn. Evolutionary process provides a very strong argument for many characteristics of the universe. I might have some aspects wrong, but know I got that bit right.
      The black hole theory kind of achieves an evolution scenario, but its crudely evolutionary. I think my theory is the first proper contender for a universal evolutionary theory. It would be a real thrill if the idea becomes more widely known and discussed. That’s my goal

  • Demetrius Anderson
    Demetrius Anderson Hace 7 años

    Double slit experiment
    The first thing that must be recognized and understood, that the particles are in a conscious and subconscious state of mind of spirit, in its behavior.
    The changing of the structure "The Slits" changed the perspective in the environment for the particles. The particle is behaving in it's conscious environment and it's Counterpart particles are behaving in a subconscious like environment.
    The particles are acting out of a structure, The Slits. As if the slits was, The First and The Last. And imitating there environment. ( The quantum vacuum Internal field )
    In changing the structure changes the perspective behavior of the particles in "The Field" which I call The Spirit Realm.
    The particle travels first through the quantum vacuum, of consciousness. When passing through the double slit's The particles are imitating The best they can, The intersect from one dimension into another. It's the same image behavior as the quantum leap, quantum totaling, and quantum entanglement, behavior. When the particles Enter through the double slit they are trying to mix water and oil in a perfect harmony, the best way they can. They are trying to imitate a similarity point between Time and The Eternal. They are Interfaced dimensionally, from a physical dimension enfolding into a spiritual dimension. As the kings of the earth call "The Field" I also call it The Field, of Magnification. Where Sounds are magnified and Spiritual Energies are reflected as elemental forces. In that field things float and Ripple.

    • Rolando Moreira
      Rolando Moreira Hace 7 años +4

      +Demetrius Anderson What did you get last Xmas from Santa?. It seems you did not get the brain you wanted...Pity.

  • OrphanPaper
    OrphanPaper Hace 7 años

    space time/ time decreases with radius in the curved plane time = the interval an object take to transvers 2 set points, the distance increases

  • RamanSB100
    RamanSB100 Hace 6 años

    my maths analysis lecturer, very good

  • Tim Bo
    Tim Bo Hace 6 años

    While the lecture certainly makes the case that quantum spacetime is intrigueing and beguilling, I'm still not clear how it relates to particle physics. If the unit of space is of the scale of the Planck length then all the particles we know (or the energy of the fields) - must occupy (and partially occupy?) a very large number of these "cells" and obviously overlap the boundaries. Is this the right picture?
    Also, am I right to conclude from the lecture that the "causality" of spacetime only applies to spacetime; otherwise we could know what path the particle takes.
    I was on the verge of giving up Feynman's particles for quantum field theory but after seeing this lecture (and another by Dowker) I'm now forced to reconcsider. QFT strikes me as a better model for everything else.
    Finally, this is the first time I've heard of the two views of physics as being rooted in the difference between the basic mathematical functions: the "Hamiltonian" and the "Lagrangian". This is really refreshing. Maybe we need some new maths! (or "math!", if you prefer)

  • YFLOInternational
    YFLOInternational Hace 7 años

    time is gravity and gravity is time

  • sherrishah
    sherrishah Hace 7 años +1

    very good talk!

  • Kinthesky
    Kinthesky Hace 7 años +1

    Very good talk. I wish I could rub up against this beautiful mind ( in a non-sexual, consensual manner ) in the faint hope that some of what she covered, I might retain to pass on.

  • OrphanPaper
    OrphanPaper Hace 7 años

    what about heat in a vacuum ?crossing the boundary of a black hole the crushing gravity may be a clue not a lot about gravity

  • Thinktank
    Thinktank Hace 6 años

    Weird when I learn about faraday Tesla and more, space is not something that act on something. oh wait nevermind, they don't teach that kind of stuff in kinder garden :O

  • ณัฐพล อัตถทิพพหลคุณ

    quantum theory explain the path history of electron
    quantum gravity explain the path history of spacetime

  • YTuberosity
    YTuberosity Hace 7 años +2

    Damn her lecture style is stilted at times making it very slow-going.

  • Dave Rucci
    Dave Rucci Hace 5 años +1

    What happens w 3 slits?

  • Branko Zivlak
    Branko Zivlak Hace 6 años

    At 37:50 "Black hole horizon is comprized of number of Planck sized m o l e c u l e s"! Really?!!!

  • abcd
    abcd Hace 7 años +3

    Gravity doesn't exist!

  • MrLewooz
    MrLewooz Hace 6 años +22

    even on a blurry video Fay Dowker is unbelievably hot!!!!

  • Kinthesky
    Kinthesky Hace 7 años

    are not is

  • StringGene
    StringGene Hace 7 años +5

    There is no spacetime, there is space and time is not related. Time is only "now".

  • FeanorFelagund
    FeanorFelagund Hace 8 años +9

    This is actually brilliant, but it needs to be remade with Morgan Freeman

    • nacho73
      nacho73 Hace 7 años +1

      @FeanorFelagund It is actually in Season 5 and even 4 in "through the wormhole". Miss Dowker was even there several times