'Wobbly Spacetime' May Help Resolve Contradictory Physics Theories (theguardian.com) 90
Scientists have proposed a framework that they say could unify quantum mechanics and Albert Einstein's theory of general relatively. "Quantum theory and Einstein's theory of general relativity are mathematically incompatible with each other, so it's important to understand how this contradiction is resolved," said Prof Jonathan Oppenheim, a physicist at University College London, who is behind the theory. The Guardian reports: Until now, the prevailing assumption has been that Einstein's theory of gravity must be modified, or "quantized," in order to fit within quantum theory. This is the approach of string theory, which advances the view that spacetime comprises 10, 11 or possibly 26 dimensions. Another leading candidate, advanced by Rovelli and others, is loop quantum gravity, in which spacetime is composed of finite loops woven into an extremely fine fabric. Oppenheim's theory, published in the journal Physical Review X, challenges the consensus by suggesting that spacetime may be classical and not governed by quantum theory at all. This means spacetime, however closely you zoomed in on it, would be smooth and continuous rather than "quantized" into discrete units. However, Oppenheim introduces the idea that spacetime is also inherently wobbly, subject to random fluctuations that create an intrinsic breakdown in predictability.
"The rate at which time flows is changing randomly and fluctuating in time," said Oppenheim, although he clarifies that time would never actually go into reverse. "It's quite mathematical," he added. "Picturing it in your head is quite difficult." This proposed "wobbliness" would result in a breakdown of predictability, which, Oppenheim says, "many physicists don't like." [...]
Ultimately, whether the theory is correct is not an aesthetic preference, but a question of whether it is a faithful representation of reality. A second paper, published simultaneously in Nature Communications and led by Dr Zach Weller-Davies, formerly of UCL and now at Canada's Perimeter Institute, proposes an experiment designed to uncover "wobbles" in spacetime through tiny fluctuations in the weight of an object. For example, the International Bureau of Weights and Measures in France routinely weigh a 1kg mass, which used to be the 1kg standard. If the fluctuations in measurements of this 1kg mass are smaller than a certain threshold, the theory can be ruled out. "We have shown that if spacetime doesn't have a quantum nature, then there must be random fluctuations in the curvature of spacetime which have a particular signature that can be verified experimentally," said Weller-Davies.
"The rate at which time flows is changing randomly and fluctuating in time," said Oppenheim, although he clarifies that time would never actually go into reverse. "It's quite mathematical," he added. "Picturing it in your head is quite difficult." This proposed "wobbliness" would result in a breakdown of predictability, which, Oppenheim says, "many physicists don't like." [...]
Ultimately, whether the theory is correct is not an aesthetic preference, but a question of whether it is a faithful representation of reality. A second paper, published simultaneously in Nature Communications and led by Dr Zach Weller-Davies, formerly of UCL and now at Canada's Perimeter Institute, proposes an experiment designed to uncover "wobbles" in spacetime through tiny fluctuations in the weight of an object. For example, the International Bureau of Weights and Measures in France routinely weigh a 1kg mass, which used to be the 1kg standard. If the fluctuations in measurements of this 1kg mass are smaller than a certain threshold, the theory can be ruled out. "We have shown that if spacetime doesn't have a quantum nature, then there must be random fluctuations in the curvature of spacetime which have a particular signature that can be verified experimentally," said Weller-Davies.
Wibbly wobbly timey wimey stuff? (Score:5, Insightful)
I watched Doctor Who on PBS when I was younger. Apparently it was educational after all.
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Not educational enough for the editors to catch this, though:
Albert Einstein's theory of general relatively
... maybe we should say Doctor Who was not "relatively" educational?
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Or maybe the editors are relatively uneducated?
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I'd say that it is relative to who you compare them to!
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I disagree! It is literally absolutely who I compare them to.
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"Blink" is one of my favorite episodes! I love the entire premise of the episode and how they worked all the time loops together.
Blink - Timey Wimey Stuff [youtube.com]
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What's wrong with woke? Even Gerard Butler does it.
https://www.youtube.com/watch?... [youtube.com]
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In the latest episode, Donna Noble being "binary" and her daughter Rose being "non-binary" is actually a plot point.
But it was handled much more deftly than Chibs, who hit you over the head with it like a disapproving parent.
I am so glad that RTD is back on the job.
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I think I gave up 3 episodes into Jodie Whittaker's run. She was fine. The writing not so much.
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Not really. The writing has gotten alot weaker, and a bit preachy as well. The acting for the most part is fine, but I legit can't think of a memorable story since Moffat. His departure really was the death knell.
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I watched Doctor Who on PBS when I was younger. Apparently it was educational after all.
Thanks for making me feel old, I believe "timey-wimey, wibbly-wobbly" was from the David Tennant era and that wasn't that long ago... surely?
Re: Wibbly wobbly timey wimey stuff? (Score:3)
Surely.
Jelly baby?
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Ten years ago.
i think gaps in science like this (Score:2)
Re:i think gaps in science like this (Score:5, Insightful)
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It's more difficult than that. The experiments (when accurate) reveal regularities. The regularities can be described by math. Sometimes, though, the exact same math has several very different translations into English. There's no substantive difference between the various interpretations of quantum theory. They all predict exactly the same things. But Many-Worlds sounds a lot different from the Copenhagen interpretation which sounds a lot different from super-pre-determinism, etc. Now quantum theor
How can time vary in time? (Score:3)
Sounds rather recursive to me.
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Be calm, it could be quite monotonous, going in one direction along that arrow, but at different speeds all the time.
Re:How can time vary in time? (Score:4, Funny)
I guess time will tell...
The rate of change varies in time. (Score:2)
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You completely missed the point and your analogies are rubbish. Its like saying velocity changes with velocity.
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Sounds rather recursive to me.
Yeah - it makes for new issues too. Like the people that believe that the universe - or at least the earth - was created in October 4004 BCE can point to this as indications that they are right. "It's not really billions of years old, it only looks that way."
I've seen the variable time hypothesis in the past used to "prove" that the angry desert god created, then time slowed down or sped up as was handy. Also used to prove that the seemingly longer life lengths of some of their book's characters were just
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I think the word currently favored is "hypotheses". It's a guess looking for evidence to turn it into a theory.
The problem that occurs to me is that, IIUC, there's no universal time, so this would need to be saying that the rate of progression through time varies from place to place independent of gravitational strength. (We've already got a time that varies with gravitational strength.) Having that be consistent with relativity is going to be a major project.
Noise? (Score:2)
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Neither am I. However, this may lead to an alternative way to test the hypothesis.
Quantum mechanics stipulates certain pieces of information have no actual existence unless observed. It's not simply that you don't know what the information is, the information itself really doesn't exist at all. There seem to be done quite strong proofs that this is an accurate reflection of reality.
If underlying reality is based in relativity, not QM, then that information must exist at all times. Which means that this new
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"Quantum mechanics stipulates certain pieces of information have no actual existence unless observed." I don't think so. QM is merely a calculation machine. It comes with no "interpretation". There are several models which have their own beables, but those are merely that, just artifacts of the models.
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No. Some information can't exist while the state is in superposition. Superposition is intrinsic to QM. Is the particle "up" or "down"? If it's in a superposition of those two states that information just doesn't exist until its state collapses into one of the eigenstates.
In fact this is the principle behind Bells theorem [wikipedia.org] which demonstrates the literal impossibility of it being a hidden (local) variable and as such really does not exist in a classical sense.
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IIUC, Bells theorem has more than one way around it. Non-locality is one, but not the only one. (The others are even more unsettling.)
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It merely demonstrates that any theory with local hidden variables must violate Bell's Inequality, assuming humans are a magically statistically independent observer.
Ergo, if Bell's Inequality is violated (and it is), any theory that correctly describes what happened must be stochastic.
It is entirely indistinguishable as to whether or not information exists, or is simply not knowable.
At this point, we enter
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Bell's Theorem does not imply that "information can't exist while the state is in superposition”
No one said this.
It merely demonstrates that any theory with local hidden variables must violate Bell's Inequality, assuming humans are a magically statistically independent observer. Ergo, if Bell's Inequality is violated (and it is), any theory that correctly describes what happened must be stochastic.
I think you might be referring to CHSH inequality [wikipedia.org] Which is a constraint on the occurrences of “coincidences”. The “humans are a magically independent observer” has also been ruled out as Alice in the experiment looked in one direction to near the edge of the visible universe and used a quasar as a random number generator to dictate her choice of measurement while Bob looked in the opposite direction to near the edge of the visible universe and used a quasar to dict
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No one said this.
Actually, the person you replied to did- and I had interpreted what you said as supporting that. If I was mistaken, that's my bad.
I think you might be referring to CHSH inequality [wikipedia.org] Which is a constraint on the occurrences of “coincidences”.
Bell Inequalities are any inequality like CHSH. To distinguish between them in this context is... non-productive.
The “humans are a magically independent observer” has also been ruled out as Alice in the experiment looked in one direction to near the edge of the visible universe and used a quasar as a random number generator to dictate her choice of measurement while Bob looked in the opposite direction to near the edge of the visible universe and used a quasar to dictate his choice of measurement.
Doesn't rule it out in the slightest.
Definitely very much pushes out the bounds for the entanglement of state.
Thus the statistical correlations of the observer would have to be across most all of visible spacetime at least, both in billions of light years but also billions of years into the past
Correct. Almost like we all came from the same big-bang.
demonstrating non-locality.
Wrong. Flatly wrong. It demonstrates no such thing. I'll grant you that it lends a lot of evidence tow
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I said it did not demonstrate non-locality.
It's perfectly feasible that a state of entanglement exists for hidden bell states originating back from the big bang.
Does it seem like a stretch? Of course it does. But then again, so does non-locality in a universe that demonstrates its locality at every turn.
The experiment was excellent, but you're over-selling it.
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No information is created or destroyed, it merely becomes knowable.
Dictating by fiat what it was before that is a matter of interpretation, not quantum mechanics.
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Quantum mechanics stipulates certain pieces of information have no actual existence unless observed.
Don't confused QM with the interpretations that try to figure out what it physically means.
QM stipulates no such thing; that's Copenhagen. And it's not no actual existence, it's a superposition- all actual existences- worse, really.
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You haven't heard that all basic constants depend on the temperature anyway, and some "freeze out" as it gets cold enough? I think that was old news decades ago.
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I can't do the math either way, but I prefer the theories which quantize everything, simulation theory just feels so natural giveen quantum effects.
We're just a shitty simulation of a continuous universe, with quantum effects being simulation artifacts. The explanation for why we seem to be so far down the simulation scale is because the continuous universe has near infinite undergrads running shitty simulations, making being in this shitty simulation level probable.
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Since you've clearly had it all sussed for a long time give us the link to your whitepaper or dissertation about it all.
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Not the "aether", that was gotten rid of experimentally. The big philosophical question is, is space-time really wobbly, or just the sticks we try to measure it with. As in, neo-lorentzian vs. general relativity.
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QM was notoriously non-lorentz-invariant until they forced it to follow the rules of SR.
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The Neo-lorentzian interpretation basically says that "spacetime" is Euclidean, but when things move, forces deform them, so we, who rely on EM to see the world, see the deformations as space-time curvature. More here: https://www.cambridge.org/core... [cambridge.org]
And in context, I'm just responding to OP's bullshit in kind :)
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The Neo-lorentzian interpretation basically says that "spacetime" is Euclidean, but when things move, forces deform them, so we, who rely on EM to see the world, see the deformations as space-time curvature. More here: https://www.cambridge.org/core... [cambridge.org]
And in context, I'm just responding to OP's bullshit in kind :)
I know your joking, and the paper breaks down at 2.2 because the earth is moving through space and it has been shown light does indeed move at C in all reference frames, but it is important to remember there are any number of ways to look at the same principle, even mathematically, and all that matters is how well they describe measurable data given the scope (time, scale, energy, mass, etc) they operate under. You could for example change the vector of gravity from pointing down to up and as long as your
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God knows I’ve been writing the direction of electron flow backwards my entire life
If that's your only sin, you're so damn lucky. To me, everything is either equal to 1, or is measured in GeVs.
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or is measured in GeVs.
That’s a whole new kind of anxiety when stepping on the bathroom scale I hadn’t considered.
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Depends on your specific universe, I guess.
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The Neo-lorentzian interpretation basically says that "spacetime" is Euclidean, but when things move, forces deform them, so we, who rely on EM to see the world, see the deformations as space-time curvature. More here: https://www.cambridge.org/core [cambridge.org]... [cambridge.org]
Ahhh. Got it.
And in context, I'm just responding to OP's bullshit in kind :)
Ya, I figured that much, I just wasn't familiar with the term neo-lorentzian.
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QM is still non-lorentz-invariant, that's why we have QFT now.
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QM is still non-lorentz-invariant
It need not be. That's why we have have the Dirac equation.
As mentioned, prior to forcing it to follow the rules of SR (Dirac Equation -> QFT), QM was never solved with any lorentz invariance whatsoever. Now its most successfully sub-theory requires it to work (which has always been a strong hint that Bohr was more than a little delusional, in my opinion)
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No. Only certain characteristics of the aether were gotten rid of experimentally. But once you got rid of those, there was no reason to postulate it.
FWIW, a space-time that weakens light as it travels through it does bear a strong resemblance to a "luminiferous aether". But people were taught that aether was a silly concept, so they don't use the word anymore. (OTOH, the original didn't use virtual particles as part of it's mechanism. They would probably have thought that silly.)
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FWIW, a space-time that weakens light as it travels through it does bear a strong resemblance to a "luminiferous aether".
It does. However, our space-time does not.
Tired light is convincingly ruled out as an explanation for the cosmological redshift.
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Sure, a-non.
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Nobody is triggered, they're shutting down a twat with the IQ of a gnat before their misinformation spreads to other similarly intellectually endowed twats.
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I'm guessing that you're sour because you failed your physics class.
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> I figured this out in the 1980s
Is that when you decided to stop learning?
What a shame. Heaviside would be disappointed.
Wolfram's spacetime is consistent with Maxwell.
Sutherland's equations are consistent with Bohm without having to use the Copenhagen Interpretation.
McCollough's QI is consistent with Einstein without needing Dark Matter.
All of this shit was discovered /after/ 2015.
You "Aether nuts" stick a banana in your ear about new discoveries and observations simply because some dumb ideas in the 1
"Albert Einstein's theory of general relatively" (Score:2)
Confused (Score:3)
I'm confused.
The force of gravity depends on the mass of the object and changes gradually. If the flow of time is discrete as this theory suggests (at least that's how I've understood it), quantization seemingly becomes infinite, IOW time becomes ... continuous.
Please advise :-)
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I got that it is unknowable, which essentially solves the uncertainty principle. I'm not smart enough to know if that's really provable, as it sounds to me like just moving the problem (in a direction I favor, I'll admit)
Time is continuous in GR.... and QM has yet to figure out how to quantize it.
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I don't know about that, but time may be variable depending on location/gravity. It is theorised that time stops inside a black hole, for example (Prof. Brian Cox has people looking at it, I'm told).
Given time can be variable due to gravity, I'd love to think that it's not at all uniform across the universe and so does not flow predictably at all. We on Earth are in such a localised position that we can't see it, and of course it messes up all our observations outwards too. At this point, I'm not sure we ca
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I don't know about that, but time may be variable depending on location/gravity. It is theorised that time stops inside a black hole, for example (Prof. Brian Cox has people looking at it, I'm told).
Stops- not really. Only from the perspective of someone outside of the black hole. Relativity, and all that.
Given time can be variable due to gravity,
If GR is correct, the variability of time is gravity.
I'd love to think that it's not at all uniform across the universe and so does not flow predictably at all.
It's only uniform in the most generalized sense ("on average")
Any measurable chunk of space time varies with the sum of all the gravitational waves hitting it at any point in time. This is, for all intents and purposes, indistinguishable from noise in any but the largest productions of said noise- even classically speaking.
FWIW, I'd like to think that the nice sheet of checked cloth we call spacetime is not flat at all - just as if you zoomed into the cloth you'd find all kinds of irregularities in it, so too spacetime.
Indeed! And the universe
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Maybe its more of a rubber membrane. If things are bouncing/distorting it from the other side then that could be considered antigravity and also a parallel yet reversed universe.
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The force of gravity depends on the mass of the object and changes gradually.
Why does the force of gravity gradually change? What causes that change? Or did I misunderstand your wording?
Maybe you are talking about the mass gradually changing due to particle and energy loss? I don't get it.
Stretching a metaphor to fit ... (Score:2)
Wobbly-wobbly, timey-wimey stuff (Score:2)
Unpredictable... (Score:2)
For now.
Think about how many things were "unpredictable" 50, 100, 500 years ago.
I would tend to believe a theory that fits into a well-understood framework but has some gaps over a completely new theory that rejects the existing framework entirely. Our understanding evolves too.
Epicycles (Score:2)
This sounds like epicycles. Eh, the planet is moving funky, add an epicycle that ought to fix it.
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No, that would be the Standard Model. Another similarity is the degree of precision with which things are calculated. No wobbliness allowed if less than three sigmas.
Planck length (Score:3)
Layman's, non-physicist opinion here. Feel free to ignore.
When we're measuring things less than the Planck length, as all of quantum physics has done for a century, we are dealing in probability and estimation. It can't be precisely measured by any known instrument AFAIK. We are no longer modeling observed reality with math, we are constructing reality through math. This is my meager understanding of it at least. And math itself has its own inconsistencies.*
I'm always amused when the incredible feats of approximation and statistical likelihood of the unmeasurable that make this all work are presumed to be "the way the universe actually works(TM)" by the press. Contradictory states exist because we're making best guesses, not because matter randomly appears from nothing or exists in opposition to each other. It's either too fast or too small. Velocity vs. precise location (which are sub-Planck fractions when dealing with atomic particles). Can't know both. Statistical variance is a thing. The physicists know this, but still we get articles like this. We get a continuous barrage of thought experiments comparable to Schrödinger's Cat [xkcd.com] (sorry, I'm a dog person), because the press finds it amusing. Regardless, IMHO, it is the press not the physics. Most human minds are not fit to accept variance and uncertainty at all and even fewer, i.e.: no-one, understands what's happening completely. I assure you, what is happening with any surety is math, and its results have never made complete sense. They literally can't.
"If you think you understand quantum mechanics then you don't understand quantum mechanics" ~Feynman
My opinion is still that "God" (an inadequate proxy word for undiscovered objective existence) does not actually play dice with the universe. We do. Physics does play dice now, in a very involved and carefully confirmed way. This is why macro and micro analysis don't match. The macro deals with things you can precisely measure, and has been confirmed by such measurements. Einstein is correct. Quantum mechanics has always been wibbly wobbly, because it has to be, but remains astonishingly accurate due to the incredible, herculean mathematics and experimental apparatus underpinning it.
This is why we build colliders, despite all the numbskulls who think it is a waste of money.
Personally, I refuse to believe that epicycles are the best we can do, but it's what we have. We'll figure it out someday, with a better mathematical model that doesn't try to bolt adjustments onto the current one in order to match Einstein.
----
* That mostly stem, in my best guess, from the invention of zero. Zero is a philosophical concept. There is very rarely, possibly never, complete absence. i exists as an imaginary number because we have a separate problem. Zero exists in the same imaginary way. You can't divide by it because it is "undefined," not because you literally can't. It's undefined because we don't actually know what it means. Zero is just useful.
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When we're measuring things less than the Planck length, as all of quantum physics has done for a century, we are dealing in probability and estimation.
What have we been measuring that's less than the Planck length?
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Point taken. We're not.
We're approximating velocity, position, and size at those intervals.
IOW we can't measure it. That's why we're using prob/stat to construct a mathematical model. It might be here. It might be over there. Maybe it's going this fast. Preponderance of evidence says yes. It's all prob/stat, to a high degree of significance.
That's my understanding of it at least, if we're looking for things like the Higgs boson. If Higgs is bigger than Planck, we still can't measure it, but I withdraw menti
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Point taken. We're not.
We're approximating velocity, position, and size at those intervals.
You might be interested in complementarity [wikipedia.org].
As I understand it (and I probably don't) there are certain specific pairs of properties that can't be measured at the same time, such as position and momentum. And it's not just impractical: it simply isn't possible.
Just another one of those strange QM things...
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When we're measuring things less than the Planck length, as all of quantum physics has done for a century, we are dealing in probability and estimation.
What have we been measuring that's less than the Planck length?
If this were a philosophical late-night debate with my bros? The answer would be, "Your penis."
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IIUC, we're several orders of magnitude away from measuring things close to the Planck length. (about 10^-33 cm). And we don't have any expectation of ever getting that close.
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Yup. Poor choice of words. We're describing things in physics that we have no hope of measuring. The whole point of the post is that we can't measure it. The measurement is the empirical data set, not a physical measurement of a discrete thing.
rate? (Score:2)
What exactly is "the rate at which time flows"? According to my calculations, dt/dt = 1. So, is he saying time is not differentiable? But he says spacetime is smooth. So, this whole summary is a no-op.
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