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100 thoughts on “Mach’s Principle – Sixty Symbols

  1. If the universe was rotating around you, wouldn't pretty much everything out there be moving faster than the speed of light? lol

  2. The easy way to tell the whole universe isn't rotating is that in order to do so, things past a certain distance would have to be moving at a velocity greater than c, isn't it?

  3. I wonder if there's any rotation of the universe that could account for the outward acceleration of the universe, contributing to the 'dark energy' contribution?

  4. Basically as Mach's principle is described here it is incomplete, the first problem is the way it is described here the principle is asymmetrical, the better way to think about rotations is to take the case that the observer has a relative rotation with respect to the inertial frame. Relative to say an ice skater spinning around, from the skater's perspective, they see their arms fly out because relative to them the inertial frame is rotating around them. At a rate equal to the centripetal acceleration. What I mean by its asymmetrical is there is no mention of the foreground's influence on the background frame. For every relative rotation between the foreground and the background there is an outward centripetal acceleration imparted on the foreground, and the foreground imparts an outward centripetal acceleration on the background frame (well its more complicated than that) you really have to have a conception of rotating inertial frames. The background frame's true rotation is undefined. So the way I describe Mach's principle is Its like a democracy of matter in which every mass unit has a vote. A unit of mass can be a part of multiple rotational frames, the day/night cycle of the earth is one rotation, on that same earth is going around the sun, and the earth and sun goes around the galaxy..etc etc. So each unit of mass can cast like votes for multiple rotational frames. I have a thought experiment where I talk about this using a ball and a donut in my video Mach's Principle: The Democracy of Matter. To kind of explain Brady's question about how they communicate the best way I can think of to answer the question, and it might not make sense to you, but its that "mass defines the inertial frame." I have a thought experiment to explain the concept and it is kind of like a bridge between philosophy and science. It is a very core concept to Mach's principle that in order for their to be motion there must be a reference frame by which to gauge it. The supposition is that mass is the reference frame by which we gauge inertia. Please watch my video Mach's Principle: The Democracy of Matter.

  5. So to answer Brady's question and this might seem crazy. That asking; "how the mass knows its relationship to other mass?" is like asking the question; "how does the number 2 know its relationship to other numbers?" How does the number 2 know its 3 away from 5? How does it know that? We'd answer that question by saying "numbers define the relationship between them". And the analogy is mass are like numbers and the inertial frame is the relationship between them and we would say "Mass defines the inertial frame" that's why I say that Mach's principle really is like the bridge between philosophy and science. To get a better understanding of this you really have to turn abstract thinking up to eleven and imagine how we would recreate phenomenon like motion in our minds. Of course a requirement of motion is a reference frame like an inertial frame, in order to have that you need more than one object of mass. The state of motion of an object with no inertial frame of reference is undefined, in order for motion to have meaning there has to be frame by which to gauge it. My intuition tells me from thinking about Mach's principle for a long time, that its like a Platonic basis for reality.

  6. We're gravitationally bound to everything else in the universe but the influence of everything is here locally right now and there's no need to come up with creative ideas on how an object is somehow communicating with the rest of the universe over very large distances because every object gets its "marching orders" locally from the gravitational field present locally.

  7. What if whole universe expansion as well as acceleration of universe expansion is due to the fact that whole universe is rotating? 🙂

  8. I was always told the reason we assume the room is rotating, and the universe is still, is because the math is MUCH easier that way. So we fall back, in an "Occam's Razor" sort of way, to "it must be correct, because the math is way simpler."

  9. If the universe is spinning and the room is not the the skater is free to move, if the universe and the room are spinning on the axis of the room the skater would be forced against the wall and know that the universe and the room are spinning.

  10. OOPS!
    #1 The animation on skates should have him stationary and only going "left / outward" after some friction pushes his skates.

    #2 @ 2:24: "By the time you're pressed to the wall, you're neither being accelerated away from the wall, nor towards it…" Serious mis-speak ! This is constant centripetal Acceleration.

  11. What I hear is that there is a reluctance to conclude that rotation is indeed absolute.

    It seems that because velocity (at least linear) and location are relative, that everything else must also be and there can be no absolutes…

    It doesn't seem that simply removing the stars deletes the space they were in. Why can't we delete the stars, but not the space? We can't see this reference any more, but it seems that the 'space' is still there. I know this implies that there is something 'holding' this space, but stranger things are proposed.

    Aren't these things invariant with location and speed (absolute):
    Mass and the inertia that comes with it.
    Acceleration and therefore force.
    Straight lines.

    This seems to imply that "space" is an absolute 'place' in which the stars exist.
    I also can't find where he actually says: "Mach's Principle is …"

  12. I take a disc of some material and spin it at very high RPM until it shatters. Centrifugal (Cf) force was all in the disks head. We know rotational motion is mathematically equivalent to linear acceleration and thus the concept of centripetal (Cp) force as the actual force causing the acceleration. Then Cf must be the effect of inertia. Now here's the interesting thought experiment: Let's take our disc shattering apparatus (we've statistically characterized the shatter RPM of our set of discs already at rest in the lab), turn it on and 1. drop it from a tall building (i.e. free-fall) and record the RPM when the disc shatters. Then 2. Put it on a rocket at constant velocity (10 km/s or more) and record the shatter RPM. Then compare in lab, free-falling and constant velocity. Would there be a difference in RPM (statistically significant)?

  13. Wouldnt you beable to tell that you are moving (if you are in the cirlce) because by moving in a circle you are accelerating due to the change in direction??? If someone would be able to explain why this would be incorrect that would be appreciated 🙂

  14. My name's Peter and I work in a lab. Once when I tried to rename the centrifuge "centripete" they accused me of being self-centred.

  15. wait im a little lost… so, if the universe is rotating and the room is not, that also makes the guy in rollerskates move away from the center of the room? also, i dont understand how centripetal is "more natural" than centrifugal, if what is causing centripetal force is the presence of the wall… without the wall the guy would just move away from the center, nothing would make him stick to it… no?

  16. Isn't spinning a continuous state of acceleration? where our minds can detect acceleration of our skin cells (probably because of the compression effect). maybe thats why we get dizzy, because the brain is constantly trying to adjust for acceleration, while constantly readjusting for position

  17. But wasn't Einstein a proponent of the idea of locality? How can Mach's principle be reconciled with locality then?

  18. Normally Sixty Symbol videos make sense but this just seems wrong. What does the distribution of the mass of the universe have to do with the spinning framework? If all the mass of the outside universe suddenly vanished, I don't see how it would affect the experience of someone in the spinning part.

  19. The centre of the universe is bollocks then mach infinity achieved and to the other universes , just having a 600 knot experience with virtual flight principles as mam makes whatever he can of the concepts .This goes well with the hole people who imagine such accuracy so far in astro physics

  20. Has the space dragging sphere around a pendulum been demonstrated experimentally? It's probably the most counter intuitive consequence of general relativity and would be awesome if it could actually be shown. Kinda like a crazy version of the Cavendish experiment haha.

  21. couldn't it be that the coordinates the universe uses aren't points but rather velocities? No object has a location but it does have a fixed velocity. It's rest state is thus in motion.

  22. A rotating room + non-rotating Universe is the only 'sensible' interpretation for at least 2 reasons:
    1) the far reaches of the rotating Universe will need to exceed the speed of light to keep up, and
    2) any rotating Universe can have only 1 axis of rotation, so any rotation will prevent other room/Universe combinations from rotating (unless they happen to lie on the axis).

    From point 2 you also get a special axis/direction in the Universe. Hmmm, I think not. Therefore, as the Universe cannot rotate, the room musy be. No spooky stuff required.

  23. You can't rotate the entire universe because the sizes are too big, and your relative velocity is too small to notest, the same way we don't notest the earth spinning.

  24. Particles move from a higher concentration to a lower concentration to fill space or rearranging and the opposing ones are the dimensionality.

  25. I am prepared to be proved wrong, but it was my understanding that reference frames are all equally valid as long as neither is experiencing acceleration. The rotating room certainly is, so, as I understand, it is distinguishable from a non-accelerating frame.

  26. Ehhh… I don't see any absolute nature in rotation that is any different from any other direction of motion. If you're on a bus and the bus is stationary but the universe suddenly starts moving in the opposite direction you don't get fling to the back of the bus with it.

  27. So basically if you are in a rotating room the direction in which you are traveling is constantly changing meaning your velocity is constantly changing and so your momentum is constantly changing. We feel that change in momentum over time as a force. If the universe spins we spin with it and we don't feel an impulse cuz our location in space doesn't change since we are moving with space. So the room may be spinning but it is inside the universe and the space the room occupies isn't spinning. Therefore you are moving through space and gotta follow the laws of motion. My mediocre interpretation.

  28. The universe is muttering to itself? Perhaps it should be kept in the psych unit for observation overnight, just to be safe. Who knows, maybe it just needs a vacation.

  29. So principles like momentum are only relative to the rest of the universe? Machs principle says if the entire universe is rotating you have no reference point of static things, but you would also feel your own momentum, or not?

  30. If you had paint on the wheels of the roller skates you would not see a straight line on the floor of the rotating room. It would in fact be a curved line observing from above. This would be an effect of centrifugal forces and the wall is resistance against that acceleration.

  31. I love how the universe is calling, but you have "reject" button on the phone. I wonder if you could block the number. If you answer they'll probably try to sell you an extended warranty for you old, worn out automobile

  32. I don't understand why this is a problem: relativity says that the laws of motion are the same whether we are at rest or moving at a constant linear velocity.
    The fact that we are rotating – even if we're rotating at a constant speed – means that we are subject to centripetal acceleration (otherwise, we wouldn't be rotating). Since we are accelerating, the laws of motion aren't the same as if we were at rest.

  33. Why is the skater flung sideways like that? is it friction or does he start with the same angular velocity as the floor under him? It doesn't make sense to me.

  34. you could also throw a ball to the center of the room, and if the ball doesn't travel to the center of the room… your rotating. Sooooo maybe the Universe is rotating and gravity is just the effect of the Universe spinning (revelitive to little things.)

  35. If the entire universe was rotating at an arbitrary speed, that would imply the very distant objects would have speeds far greater than c from your refference frame, which is not quite easy to swallow.

  36. only one thing bugs me in this vid… how could WE (humans) know, that our universe is stationary/rotating…. we cannot… we are in the box.

  37. If the whole universe was rotating, wouldn't this mean that we should observe a coreolis effect in say the voyager spacecrafts?

  38. Wait … what? So if you're accelerating upward than your frame of reference doesn't matter, but if you're accelerating in a circle then your frame of reference matters?

  39. Annnnnnnnnnnddddddddddddd thats why this guys a great professor. That's the best explanation of why centripetal forces exist I've heard. 1:20

  40. If the room were stationary and the rest of the universe was rotating then anything significantly far away (on the scale of lightyears) would have to be violating the speed of light. Also, unlike linear motion, when you rotate then the different atoms inside you aren't all stationary relative to each other. The ones near the axis of rotation are practically stationary and the ones farthest out are moving quite fast.

  41. This is an interesting logical problem – I think the most intuitive way of tackling it would be trough conservation of energy – if you introduce energy to that room, you'll end up with some tensions, that persist until energy gets freed (say if wall fails and guy on roller skates falls trough the hole)

    If you spin the univese, well you're introducing the energy to the universe causing stuff to happen, but not to your room. The problem is, that you need to take into account where the energy comes from, because, it'doesn't seem to be rational to introduce energy from nowhere, even if it's just tought experiment in this case

  42. Why would anyone even entertain the idea that the universe is not rotating? It is probably rotating on two axis at the same time, but very, very, slowly. I don't know why there is talk about objects and the universe communicating with each other. If a set of atoms have a change in their rotational acceleration, it had to be caused by some other set of atoms imparting energy to them, and those atoms had energy imparted to them. There is a string of cause and effect going back to the beginning of the universe.

  43. I am doubting Mach's principal is actually something , at best it is part of some other mechanism of the universe . Gravity is created by mass and mass is a by product of the magnito-electric universe .. think toroidal …

  44. if both were rotating, wouldnt everything in them move away from the centre, or; doesnt the centrifugal force prove both arent rotating

  45. So im gonna bet that if I rotated the universe instead of the room I would still stick to the wall so can someone please help me spin the universe???

  46. Any resulting motion caused by a force projected along an axis first effects the inertia of the proximal space where the force occurs such that space in any direction is populated by inertia that the force interacts with such that the force and its proliferation is limited by its magnitude and cannot effect the entire universe because the universe has other forces present which any signal force faces as inertia. Therefore force only travels by means of its magnitude and direction and interacts with other forces that amplify or counter the force.

  47. "Universe talking, nobody knows how" – bullshi… 10 seconds thinking makes clear "how". Inertia. This is the thing that "communicates" the information about the fact of something rotating. Simple rule: the thing tends to not change the direction of movement. Any deviation from strait line takes energy to compensate for. Rotating is CONTINUOUS effort to keep something moving, but not flying away. This effect can be counteracted by forces, that holds things together: strong atomic interactions and gravity.

  48. If the universe was rotating, you would definitely notice since the stars would fling out and everything would turn into a disc shape.
    I think the crux here is simply how you define rotation. A rotation is two things or more moving in opposite direction. In order to sustain this rotation you need a centripetal force to keep the system together. Otherwise the rotational speed will approach zero as the distance increase.

  49. Am I missing something? You can easily tell whether it is the room or the universe that is spinning. If the room your in is stationery, you WOULD NOT be pinned against the wall. You would not even be aware that the universe is spinning!

  50. Whats the thought experiment with the sphere around a pendulum called? I really want to flesh out the idea cos it blew my mind

  51. Since a rotating mass affects the acceleration of objects inside it, what if the rotating universe has relativistic effects on objects in the stationary room that result in identical behavior to the case where room is rotating? That would mean Mach's principle is actually false because rotation becomes relative again. Idk if the maths works out on that though.

  52. Feels eerily similar to the (thought) experiment: If a flock of geese fly up from a lorry, at what point do they not contribute to the weight of the car. What if the lorry is closed or open.

  53. If you put a large rotating sphere around a pendulum and watch the pendulum rotate… aren’t you watching gravity affect the pendulum? Like if you swirl water around a fish the fish will rotate… I need to watch this a third time..

  54. Wrong. Action and reaction act on different bodies in contact. The force exerted by the wall on the man is centripetal. The force exerted by the man on the wall is centrifugal. And they don’t cancel, because they act on different bodies.

  55. I believe mass and inertia are built into atoms. This frees me from needing to believe in the fiction that time and space are things.

  56. Can you explain how a bicycle works? I’m very curious what all your mind would spew forth in this case.

  57. @6:50 bet my bottom dollar that there is absolute NO experimental evidence that the sphere -pendulum hypothesis is true. If so please forward and I may be the very first person in the history of the internet to apologize for being wrong.

    ( Ok, ok  so I embellished a bit in the second sentence,maybe not the First person sorry ( see apologies come easy for me;))

  58. General relativity is wrong, because it doesn’t yield Mach’s principle in the most general case. Instead, General Relativity yields an absolute frame of reference for rotating systems. This isn’t relativity.

  59. Ok… Based on example with sphere and pendulum…. If you rotate the whole universe, would't that create the same "drag" (as sphere creates for pendulum) on rollerskater? Then rollerskater would move towards the wall of centrifuge. Would relativity principle be preserved?

  60. Isn't rotation just a constant change in inertia ? I don't see why this is an Issue or to say the universe is talking to itself. What is the difference between this and the floor going up but picking up speed. U would feel it and know it's you moving and not the universe. Rotation should be the same.

  61. Mach‘s principle relies on dimensions we don‘t realise are there, which connect everything, which is how quantum entanglement functions. These dimensions manifest in our 4D and baryonic experience throughout the whole universe as the “unexplained things“, dark energy, dark matter and so on. We learned to think quantum, so let us think multidimensional thus we shall begin to understand and find answers.

  62. The difference between the two forces seem to highlight a shorelineembankment. Superposition illudes a possibility of humans to observe the source of ALL energy. The whole time we could be thinking that a physical reality is an illusion but space could be the true fundamental physical object.

    It the object or observer and the rotating centrifuge had enough integrity to spin really fast, beyond what was demonstrated, a sense of weightlessness will occur to the observed or observer.

  63. Really love how a rotating bucket with water in it is one of the most controversial experiments in the history of physics.

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