Help, please, with quantum physics
- springrain
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Nor should it be - how can anything be 'equally uncertain'?
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springrain wrote:Nor should it be - how can anything be 'equally uncertain'?
I mean the relativist fallacy; for example since we cannot ultimately prove that you and I exist, it doesn't make believing in fairies at the bottom of the garden equally valid. I fought this logical battle with New-Agers for decades.
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That was what I was referring to. SM's articulation of the outcome of the two slit experiment, reinforced by the delayed choice quantum eraser experiment were some of the most mind blowing examples of validated science I have ever heard. Honestly.starkmonster wrote:
...All matter exists as a wave of possibilities until it is observed can be proven. This proof was many decades in the making, but it started with the two slit experiment which was devised to show us whether light is a wave or a particle which uncovered some very unexpected results.
...There has been lots of debate about why this was, why the act of observing a particle (recording information) changed its behaviour. Many argued that it was the particles that were being used to make the observation that changed the behaviour not the act of observation itself. That was proved to be incorrect by the delayed choice quantum eraser experiment.
This experiment has now been taken one step further and has been repeated using helium atoms which shows it applies to all matter, not just light
...and his post above I nominate for post of the year.
Haha - my money’s on Playboy
- springrain
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I find your argument weak - just as you & I cannot prove that we exist, nor can it be proven that we do not exist - and your argument that leads 'infallibly' to a link 'believing in fairies at the bottom of the garden' is equally spurious. There is no discernible connection.andyinasia wrote:springrain wrote:Nor should it be - how can anything be 'equally uncertain'?
I mean the relativist fallacy; for example since we cannot ultimately prove that you and I exist, it doesn't make believing in fairies at the bottom of the garden equally valid. I fought this logical battle with New-Agers for decades.
In my mind, I can choose whether or not you 'exist'. Just as you can (in reverse) with 'I'. But I (or you, if you have the mettle) can also choose whether or not to pursue your spurious arguments. Remember, they (your spurious arguments) are here for all posters to see. 'Now is not the time to make enemies' as one sage once said ...
'History is a set of lies agreed upon.'
Attributed to Napoleon
Attributed to Napoleon
Have to agree. But I'd be biassed toward anyone who's able to convey the mysteries of quantum physics with such aplomb, hence my almost idolization of Feynman, perhaps the greatest popularizer of particle physics there has ever been....and his post above I nominate for post of the year.
Fabric of the Cosmos by Brian Green is a great read for anyone interested in such things as quantum physics, many worlds, string, quantum loop gravity and other such theories dealing with our reality at the smallest scales.
Last edited by Londo on Mon Nov 09, 2015 9:27 pm, edited 1 time in total.
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- springrain
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Bless you, Londers!
'History is a set of lies agreed upon.'
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springrain wrote: 'Now is not the time to make enemies' as one sage once said ...
Sorry, I was goaded into thinking you were looking for a serious discussion. Just trolling, as per
Out.
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If I'm in the reality where MC Hammer poos out Rubics Cubes I'm happy.Pol Pothead wrote:E = mc Hammer
pew, pew, pew, pew!
The OP is of course complete drivel.
When we observe the smallest particles, they really do behave in strange ways. QM is a mathematical description of what we will see, even if it can't really describe a reality that you can imagine, especially if you are thinking in terms of billiard-ball particles bouncing around in 3D space.
For example, quantum entaglement is pretty much at the heart of QM and involves "superposition of states"; photons that go through both slits of a double-slit experiment at the same time, or electrons that are both spin-up and spin-down.
As a somewhat reasonable analogy, imagine you have two coins, and you "entangle" them in such a way that when one lands as heads, the other will magically always be tails, and vice versa (this is analogus to entangled electrons, whose "spins" must be opposite due to the pauli exclusion principle).
Now throw one of the coins to a far away friend, and flip the other in the air and catch it yourself.
As the coins spin randomly through the air, we could say they are in no definite state, each is a "superposition" of heads and tails, and they won't resolve into a definite state until you catch one, to observe it.
But as soon as you "observe" one, say it's heads, you immediately "collapse the wave function" of the entangled two-coin system, guaranteeing that the other will be tails, even while it's still spinning through the air, and even if your friend is standing so far away that the coins couldn't possibly communicate with each other to signal what state they should assume.
This "spooky action at a distance" whereby the coins resolve to a definite state (as far as you are concerned), even instantaneously across great distances, has essentially been proven to be the way things really are, give or take the accuracy of this analogy. The two coins form a coherent unit, and only really resolve to individual coins with particular heads or tails state when they are "observed".
Note that from your friend's POV, until he catches the coin, the outcome is still completely random, unless you send a signal to him to say what it will be before he catches it. He has no special information about the system until he observes it, either by catching the coin, or you telling him.
So, one of the first things people confuse about QM is what is meant by an "observation". In the coin example, we can't just look at the coin, we have to catch it. At the quantum level, an observation, any exchange of information at all, neccessarily means an interaction; absorbing a photon, forcing it through a polarization filter, or whatever. This of course can affect the observed system, and may "collapse the wave-function", ie resolve the quantum possibilities into a definite state,
Various QM interpretations claim that "observation" can only be done by a conscious observer, or that the universe splits into multiple copies on each quantum event, or that a critical mass of coherent particles results in collapse, maybe due to gravity. Clearly the universe evolved just as expected long before there were any conscious observers, so I find these kinds of explanatons circuitous.
In the "relative interpretation" of QM, an observation/interaction causes the observer to become entangled with the "observed" system. The maths says that the event "collapses the wave-function", but actually, only really from the point of view of the newly entangled "observer" particle, which now sees the system "from the inside". From the outside (apart from having no knowledge at all without making an observation) there's still a "superposition of states", but it now includes the "observer" and possibly altered properties of the original system, which will be shown when an observation is made.
This interpretation also explains away schrodingers cat; the cat does what it does (it "observes" the poison vial and dies, or not), but an outside observer cannot possibly deduce anything about the internal state until it becomes part of it, by observing. If the entire vignette were also in a box, an outside observer again would similarly have no knowledge. There is however, no "ultimate observer" causing everything to collapse, it's an evolution, and collapse of any particular system happens only from your point of view (hence, relative) when you become part of it by observation, and "see it from the inside", briefly, before it interacts again and becomes part of your unobserved.
Many quantum experiments generate apparent paradoxes of causality and locality, though if you "follow the information" carefully, causality remains; the quantum eraser experiments usually involve some combination of filtering/recombining a subset of complementarily interfering photons, revealing (not magically restoring, or creating) interference in the remaining subset. Grossly simplifying, imagine you have two interference patterns, one the inverse of the other. When you shine both together, they mesh, and presto, no interference. Filter one subset out, and kazzam, you get interference again.
None of this really explains reality and doesn't mesh with Einsten's relativity, indeed locality almost certainly goes out the window. It seems extremely plausible that the 3 dimensions of space and "dimension" of time, emerge, or are a projection from more, or fewer dimensions, as some theories propose, and perhaps time is merely the procession of quantum interactions, and therefore doesn't exist "outside" our universe of interactions.
I don't buy any of the quantum-consciousness, anthropic principle, or other new-agey stuff, but it's at least possible that, for example, our universe is the inside or surface of a black hole in another universe, or that it's a simulation on an alien computer and our physics (and therefore most likely maths too, with all it's weird prime numbers, irrationals and so on) is a projection from a fuller or simpler version.
Then again, why something, not nothing at all (not even a quantum field from which the universe can fluctuate into existence, etc)?
I don't believe this is the case, though it's easy to confuse what's going on in various experiments, and of course, if you think you understand Quantum Mechanics (QM), you don't understand QM.starkmonster wrote:Many argued that it was the particles that were being used to make the observation that changed the behaviour not the act of observation itself. That was proved to be incorrect by the delayed choice quantum eraser experiment.
When we observe the smallest particles, they really do behave in strange ways. QM is a mathematical description of what we will see, even if it can't really describe a reality that you can imagine, especially if you are thinking in terms of billiard-ball particles bouncing around in 3D space.
For example, quantum entaglement is pretty much at the heart of QM and involves "superposition of states"; photons that go through both slits of a double-slit experiment at the same time, or electrons that are both spin-up and spin-down.
As a somewhat reasonable analogy, imagine you have two coins, and you "entangle" them in such a way that when one lands as heads, the other will magically always be tails, and vice versa (this is analogus to entangled electrons, whose "spins" must be opposite due to the pauli exclusion principle).
Now throw one of the coins to a far away friend, and flip the other in the air and catch it yourself.
As the coins spin randomly through the air, we could say they are in no definite state, each is a "superposition" of heads and tails, and they won't resolve into a definite state until you catch one, to observe it.
But as soon as you "observe" one, say it's heads, you immediately "collapse the wave function" of the entangled two-coin system, guaranteeing that the other will be tails, even while it's still spinning through the air, and even if your friend is standing so far away that the coins couldn't possibly communicate with each other to signal what state they should assume.
This "spooky action at a distance" whereby the coins resolve to a definite state (as far as you are concerned), even instantaneously across great distances, has essentially been proven to be the way things really are, give or take the accuracy of this analogy. The two coins form a coherent unit, and only really resolve to individual coins with particular heads or tails state when they are "observed".
Note that from your friend's POV, until he catches the coin, the outcome is still completely random, unless you send a signal to him to say what it will be before he catches it. He has no special information about the system until he observes it, either by catching the coin, or you telling him.
So, one of the first things people confuse about QM is what is meant by an "observation". In the coin example, we can't just look at the coin, we have to catch it. At the quantum level, an observation, any exchange of information at all, neccessarily means an interaction; absorbing a photon, forcing it through a polarization filter, or whatever. This of course can affect the observed system, and may "collapse the wave-function", ie resolve the quantum possibilities into a definite state,
Various QM interpretations claim that "observation" can only be done by a conscious observer, or that the universe splits into multiple copies on each quantum event, or that a critical mass of coherent particles results in collapse, maybe due to gravity. Clearly the universe evolved just as expected long before there were any conscious observers, so I find these kinds of explanatons circuitous.
In the "relative interpretation" of QM, an observation/interaction causes the observer to become entangled with the "observed" system. The maths says that the event "collapses the wave-function", but actually, only really from the point of view of the newly entangled "observer" particle, which now sees the system "from the inside". From the outside (apart from having no knowledge at all without making an observation) there's still a "superposition of states", but it now includes the "observer" and possibly altered properties of the original system, which will be shown when an observation is made.
This interpretation also explains away schrodingers cat; the cat does what it does (it "observes" the poison vial and dies, or not), but an outside observer cannot possibly deduce anything about the internal state until it becomes part of it, by observing. If the entire vignette were also in a box, an outside observer again would similarly have no knowledge. There is however, no "ultimate observer" causing everything to collapse, it's an evolution, and collapse of any particular system happens only from your point of view (hence, relative) when you become part of it by observation, and "see it from the inside", briefly, before it interacts again and becomes part of your unobserved.
Many quantum experiments generate apparent paradoxes of causality and locality, though if you "follow the information" carefully, causality remains; the quantum eraser experiments usually involve some combination of filtering/recombining a subset of complementarily interfering photons, revealing (not magically restoring, or creating) interference in the remaining subset. Grossly simplifying, imagine you have two interference patterns, one the inverse of the other. When you shine both together, they mesh, and presto, no interference. Filter one subset out, and kazzam, you get interference again.
None of this really explains reality and doesn't mesh with Einsten's relativity, indeed locality almost certainly goes out the window. It seems extremely plausible that the 3 dimensions of space and "dimension" of time, emerge, or are a projection from more, or fewer dimensions, as some theories propose, and perhaps time is merely the procession of quantum interactions, and therefore doesn't exist "outside" our universe of interactions.
I don't buy any of the quantum-consciousness, anthropic principle, or other new-agey stuff, but it's at least possible that, for example, our universe is the inside or surface of a black hole in another universe, or that it's a simulation on an alien computer and our physics (and therefore most likely maths too, with all it's weird prime numbers, irrationals and so on) is a projection from a fuller or simpler version.
Then again, why something, not nothing at all (not even a quantum field from which the universe can fluctuate into existence, etc)?
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The multiverse theory has credibility. But it doesn't mean there's any interaction between the different universes.springrain wrote:Thanks for your input, JC. Somehow, I knew you would say that. Never mind, I asked for your opinion and I got it. But without the aliens & lizards part, would there be any credibility in the 'parallel universe' conjecture?
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====================
Why are the gods such vicious cunts?
Where is the god of tits and wine?
Why are the gods such vicious cunts?
Where is the god of tits and wine?
But in an alternate universe that cat most definitely ended up being renamed 'Pirelli' for at least 50m ...
Meum est propositum in taberna mori,
ut sint Guinness proxima morientis ori.
tunc cantabunt letius angelorum chori:
"Sit Deus propitius huic potatori."
ut sint Guinness proxima morientis ori.
tunc cantabunt letius angelorum chori:
"Sit Deus propitius huic potatori."