Roomtemperature superconductivity?
tbh im having trouble visualising the double slit experiment, and the videos i saw werent very helpful
ladajo said 'you are thinking of the electron as a physical entity'
http://www.telegraph.co.uk/science/scie ... cover.html
i thought they were physical because how else we know they are round?
if they are a round 'ball', in what way are they also a wave ? u mean their trajectory isnt ballistic , but follows this shrodinger wave equation (which im imagining as a sine wave)?
am i getting photons and electrons mixed up?
when a single photon is fired, its fired at the wall between the two slits, and somehow spreads out and goes through both slits? not just horizontally but vertically too ?
so a single photon expresses itself at every possible path on this 3d wave function ?
a single photon produces an interference pattern? just one photon fired in total and a pattern is made?
sorry for the questions, if they are too basic , feel free tell me to piss off and go read a book or something!!
ladajo said 'you are thinking of the electron as a physical entity'
http://www.telegraph.co.uk/science/scie ... cover.html
i thought they were physical because how else we know they are round?
if they are a round 'ball', in what way are they also a wave ? u mean their trajectory isnt ballistic , but follows this shrodinger wave equation (which im imagining as a sine wave)?
am i getting photons and electrons mixed up?
when a single photon is fired, its fired at the wall between the two slits, and somehow spreads out and goes through both slits? not just horizontally but vertically too ?
so a single photon expresses itself at every possible path on this 3d wave function ?
a single photon produces an interference pattern? just one photon fired in total and a pattern is made?
sorry for the questions, if they are too basic , feel free tell me to piss off and go read a book or something!!

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rcain wrote:happyjack27 wrote:303 wrote:tx for your interesting reply
*however, it was still left to be discovered why electrons didn't just smash into protons, thus perfectly neutralizing every point in the universe. and that is where quantum physics begins...
... more to the point, why does it ALWAYS NOT happen when classical physics tells us it ALWAYS SHOULD?
i'm not sure that's quite true  just a case of (subatomic) 'temporal separation' during the inflationary period after BB  say according to momentum. ensures that nucleons start to form first. yes?
no, you're still not getting it. it's not about what forms first or last, it's about simple mechanics. like the two little magnetic steel balls, electrons should ALWAYS fly right into the proton thus making a neutron, no matter how long they're been around or how far apart they are. but in reality they almost NEVER do. (the only exception being the "weak interaction" which is exceedingly rare)
Last edited by happyjack27 on Fri Jan 27, 2012 2:51 pm, edited 1 time in total.

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303 wrote:tbh im having trouble visualising the double slit experiment, and the videos i saw werent very helpful
ladajo said 'you are thinking of the electron as a physical entity'
http://www.telegraph.co.uk/science/scie ... cover.html
i thought they were physical because how else we know they are round?
we don't know they're round.
if they are a round 'ball', in what way are they also a wave ? u mean their trajectory isnt ballistic , but follows this shrodinger wave equation (which im imagining as a sine wave)?
we don't know they're round. and best we can tell that's backwards; the schrodinger equation is prior and they are waves first, and only appear as particles when we measure them. if you want to think in terms of trajectories, check out the feymann path integral, which is equivalent to the shrodinger equation.
am i getting photons and electrons mixed up?
doesn't matter. we could just as well be talking about protons or neutrinos. they all do this. just different mass/charge/spin.
when a single photon is fired, its fired at the wall between the two slits, and somehow spreads out and goes through both slits? not just horizontally but vertically too ?
again it's the classical notion of particles that may be misleading here. i refer you to the feymann path integral once again for this one.so a single photon expresses itself at every possible path on this 3d wave function ?
i guess you could put it that way, yes. "expresses". and every possible path is correct. that's the basis (or "region of integration", to be more technical) for the feymann path integral.a single photon produces an interference pattern? just one photon fired in total and a pattern is made?
just one photon fired AT A TIME, so that the photons can't interact with each other. proving that the interference pattern is not a result of photons interfering with each other, but, for lack of a better term, is "intrinsic".
http://en.wikipedia.org/wiki/Doublesli ... experimentsorry for the questions, if they are too basic , feel free tell me to piss off and go read a book or something!!
a brief synopsis of the path integral formulation of quantum physics i wrote up: http://en.wikipedia.org/wiki/Doublesli ... ormulation
also if you prefer video from a famous professor: http://www.youtube.com/watch?v=LPDP_8X5Hug
np. i kind of enjoy answering, gives me something to do.
thanks, im beginning to appreciate the peculiarities and problems arising from them
the feynman video was interesting and entertaining, though even he refers to light in terms of spinning objects, in the section about his arrow method
what im still not really getting is how a photon fired from a gun, transitions into a wavefront that hits both slits to make the interference pattern
furthermore, with regards to observation of things moving at speed relative to each other, i dont see how this actually AFFECTS anything. A ship passing me walking the dog, moving at light speed(the ship, not me or dog!) sees me differently to how i see it. This seems obvious to anyone who has stared out of the window of a train. But surely 'time' is still ticking away , tick tock, and the only difference is the ship at speed has travelled a greater distance than the dog in the same 'time'
and within the twins example, each clock is stationary within its own frame, ie on the captains mantlepiece within the ship, thus is 'unaware' of the speed its travelling at , thus both clocks have the exact same time
(i think this is what johan argues, using the lorentz transform to back it up ? )
the feynman video was interesting and entertaining, though even he refers to light in terms of spinning objects, in the section about his arrow method
what im still not really getting is how a photon fired from a gun, transitions into a wavefront that hits both slits to make the interference pattern
furthermore, with regards to observation of things moving at speed relative to each other, i dont see how this actually AFFECTS anything. A ship passing me walking the dog, moving at light speed(the ship, not me or dog!) sees me differently to how i see it. This seems obvious to anyone who has stared out of the window of a train. But surely 'time' is still ticking away , tick tock, and the only difference is the ship at speed has travelled a greater distance than the dog in the same 'time'
and within the twins example, each clock is stationary within its own frame, ie on the captains mantlepiece within the ship, thus is 'unaware' of the speed its travelling at , thus both clocks have the exact same time
(i think this is what johan argues, using the lorentz transform to back it up ? )

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I could not have stated it better! Congratulations. I had to post this, but I still do not have the time to be drawn into meandering discussions, by people like tomclarke, which are based on metaphysics. You are correct: Both clocks are stationary and MUST thus keep the same time.303 wrote: and within the twins example, each clock is stationary within its own frame, ie on the captains mantlepiece within the ship, thus is 'unaware' of the speed its travelling at , thus both clocks have the exact same time
(i think this is what johan argues, using the lorentz transform to back it up ? )
303 wrote:thanks, im beginning to appreciate the peculiarities and problems arising from them
the feynman video was interesting and entertaining, though even he refers to light in terms of spinning objects, in the section about his arrow method
what im still not really getting is how a photon fired from a gun, transitions into a wavefront that hits both slits to make the interference pattern
furthermore, with regards to observation of things moving at speed relative to each other, i dont see how this actually AFFECTS anything. A ship passing me walking the dog, moving at light speed(the ship, not me or dog!) sees me differently to how i see it. This seems obvious to anyone who has stared out of the window of a train. But surely 'time' is still ticking away , tick tock, and the only difference is the ship at speed has travelled a greater distance than the dog in the same 'time'
and within the twins example, each clock is stationary within its own frame, ie on the captains mantlepiece within the ship, thus is 'unaware' of the speed its travelling at , thus both clocks have the exact same time
(i think this is what johan argues, using the lorentz transform to back it up ? )
This is agreed by all.
Johan extends this to claim that the clocks will read the same time when reunited. In a relativistic universe time is not simple and that cannot be guaranteed.
Think of it as the clock with the bent trajectory (that turns around midjourney) travelling on a slightly shorter spacetime path. But still working as normal in its own instantaneous frame.

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 Joined: Wed Jul 14, 2010 5:27 pm
tomclarke wrote:303 wrote:thanks, im beginning to appreciate the peculiarities and problems arising from them
the feynman video was interesting and entertaining, though even he refers to light in terms of spinning objects, in the section about his arrow method
what im still not really getting is how a photon fired from a gun, transitions into a wavefront that hits both slits to make the interference pattern
furthermore, with regards to observation of things moving at speed relative to each other, i dont see how this actually AFFECTS anything. A ship passing me walking the dog, moving at light speed(the ship, not me or dog!) sees me differently to how i see it. This seems obvious to anyone who has stared out of the window of a train. But surely 'time' is still ticking away , tick tock, and the only difference is the ship at speed has travelled a greater distance than the dog in the same 'time'
and within the twins example, each clock is stationary within its own frame, ie on the captains mantlepiece within the ship, thus is 'unaware' of the speed its travelling at , thus both clocks have the exact same time
(i think this is what johan argues, using the lorentz transform to back it up ? )
This is agreed by all.
Johan extends this to claim that the clocks will read the same time when reunited. In a relativistic universe time is not simple and that cannot be guaranteed.
Think of it as the clock with the bent trajectory (that turns around midjourney) travelling on a slightly shorter spacetime path. But still working as normal in its own instantaneous frame.
johan is saying that in the absence of general relativity, each observer will read the same time on _their own_ clocks. this will be different than what they read on _each other_'s clocks. however, likewise, the time a reads on b's clock will match the time b reads on a's clock.
this symmetry is gauraunteed by the fact that the paths they see each other travel are only differ by a rotation and/or reflection.
however, if you follow this logic mathematically, and aren't very careful, it seems to imply that a<>a, hence the term "twin paradox". a=b, a'=b', a>b', b>a' does not imply a contradiction, but if you simply remove the prime ('), it does.
Last edited by happyjack27 on Tue Jan 31, 2012 12:36 am, edited 1 time in total.

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303 wrote:thanks, im beginning to appreciate the peculiarities and problems arising from them
the feynman video was interesting and entertaining, though even he refers to light in terms of spinning objects, in the section about his arrow method
glad to know you like it. so did i, hence the recommendation.
the "spinning objects" are clocks, as in special relativity. what he's showing in a very visually intuitive manner is how quantum physics, and all of the phenomena we associate with it  or don't associate with it  results naturally from how space is connected spatiotemporally .
what im still not really getting is how a photon fired from a gun, transitions into a wavefront that hits both slits to make the interference pattern
that's because you're still assuming the gun fires a photon; that it fires a hard round static object like a ping pong ball. it does not.
it fires a singularity in an electomagnetic field, and to find out what happens to the singularity you have to follow the spatiotemporal connections of the underlying space, which feyman shows in his video w/his clocks and paths.
also you say single photon. for that i refer you to the very low light experiment in the wikipedia article on the doubleslit experiment.
there are many unanswered questions and competing theories on some of the more subtle nuances of quantum physics. for instance, if it's really a field, why do all our measurements show up as singularities? ("wavecollapse") personally, i would that the instruments we use to observe and amplify the signal also obey quantum physics, as in the feyman lectures  the clocks, and by the time they're human readable, well yes, we are still seeing an "interference pattern", as it were, but of our measuring and amplifying equipment in addition to the slits, not to mention our retinas. so when you consider the whole apparatus, it's not astounding that you don't see the raw "wave", rather, it would be astounding if you DID.
happyjack27 wrote:tomclarke wrote:303 wrote:thanks, im beginning to appreciate the peculiarities and problems arising from them
the feynman video was interesting and entertaining, though even he refers to light in terms of spinning objects, in the section about his arrow method
what im still not really getting is how a photon fired from a gun, transitions into a wavefront that hits both slits to make the interference pattern
furthermore, with regards to observation of things moving at speed relative to each other, i dont see how this actually AFFECTS anything. A ship passing me walking the dog, moving at light speed(the ship, not me or dog!) sees me differently to how i see it. This seems obvious to anyone who has stared out of the window of a train. But surely 'time' is still ticking away , tick tock, and the only difference is the ship at speed has travelled a greater distance than the dog in the same 'time'
and within the twins example, each clock is stationary within its own frame, ie on the captains mantlepiece within the ship, thus is 'unaware' of the speed its travelling at , thus both clocks have the exact same time
(i think this is what johan argues, using the lorentz transform to back it up ? )
This is agreed by all.
Johan extends this to claim that the clocks will read the same time when reunited. In a relativistic universe time is not simple and that cannot be guaranteed.
Think of it as the clock with the bent trajectory (that turns around midjourney) travelling on a slightly shorter spacetime path. But still working as normal in its own instantaneous frame.
johan is saying that in the absence of general relativity, each observer will read the same time on _their own_ clocks. this will be different than what they read on _each other_'s clocks. however, likewise, the time a reads on b's clock will match the time b reads on a's clock.
this symmetry is gauraunteed by the fact that the paths they see each other travel are only differ by a rotation and/or reflection.
however, if you follow this logic mathematically, and aren't very careful, it seems to imply that a<>a, hence the term "twin paradox". a=b, a'=b', a>b', b>a' does not imply a contradiction, but if you simply remove the prime ('), it does.
That is all true, for two clocks both on "unbent" trajectories.
When one of the trajectories is bent the symmetry no longer exists, but if you assume it does, you argue as Johan that the two clocks must read the same time when they come together. That would be trivially so were the situation symmetrical.
When calculating this case using LT there is a correction that must be made to the calculated time of the far clock when the frame in which this is calculated changes.
Best wishes, Tom

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tomclarke wrote:happyjack27 wrote:johan is saying that in the absence of general relativity, each observer will read the same time on _their own_ clocks. this will be different than what they read on _each other_'s clocks. however, likewise, the time a reads on b's clock will match the time b reads on a's clock.
this symmetry is gauraunteed by the fact that the paths they see each other travel are only differ by a rotation and/or reflection.
however, if you follow this logic mathematically, and aren't very careful, it seems to imply that a<>a, hence the term "twin paradox". a=b, a'=b', a>b', b>a' does not imply a contradiction, but if you simply remove the prime ('), it does.
That is all true, for two clocks both on "unbent" trajectories.
When one of the trajectories is bent the symmetry no longer exists, but if you assume it does, you argue as Johan that the two clocks must read the same time when they come together. That would be trivially so were the situation symmetrical.
When calculating this case using LT there is a correction that must be made to the calculated time of the far clock when the frame in which this is calculated changes.
Best wishes, Tom
what's this "bent" trajectory thing? you talking about curved space i.e. gravity? i'm talking about in the absence of gravity, any trajectory, "bent" or "unbent", spirals swirls hammerheads sharp right turns, oscillations, whatever. i am talking about what's, in technical parlance, is called A TRAJECTORY. REFERENCE FRAME A'S TRAJECTORY FROM THE POINT OF VIEW OF REFERENCE FRAME B IS THE SAME AS REFERENCE FRAME'S B'S TRAJECTORY FROM THE POINT OF VIEW OF REFERENCE FRAME A EXCEPT FOR A SINGLE 180 DEGREE ROTATION AND/OR A SINGLE REFLECTION. what part of that is so goddamned difficult for you to understand?!?!
happyjack27 wrote:tomclarke wrote:happyjack27 wrote:johan is saying that in the absence of general relativity, each observer will read the same time on _their own_ clocks. this will be different than what they read on _each other_'s clocks. however, likewise, the time a reads on b's clock will match the time b reads on a's clock.
this symmetry is gauraunteed by the fact that the paths they see each other travel are only differ by a rotation and/or reflection.
however, if you follow this logic mathematically, and aren't very careful, it seems to imply that a<>a, hence the term "twin paradox". a=b, a'=b', a>b', b>a' does not imply a contradiction, but if you simply remove the prime ('), it does.
That is all true, for two clocks both on "unbent" trajectories.
When one of the trajectories is bent the symmetry no longer exists, but if you assume it does, you argue as Johan that the two clocks must read the same time when they come together. That would be trivially so were the situation symmetrical.
When calculating this case using LT there is a correction that must be made to the calculated time of the far clock when the frame in which this is calculated changes.
Best wishes, Tom
what's this "bent" trajectory thing? you talking about curved space i.e. gravity? i'm talking about in the absence of gravity, any trajectory, "bent" or "unbent", spirals swirls hammerheads sharp right turns, oscillations, whatever. i am talking about what's, in technical parlance, is called A TRAJECTORY. REFERENCE FRAME A'S TRAJECTORY FROM THE POINT OF VIEW OF REFERENCE FRAME B IS THE SAME AS REFERENCE FRAME'S B'S TRAJECTORY FROM THE POINT OF VIEW OF REFERENCE FRAME A EXCEPT FOR A SINGLE 180 DEGREE ROTATION AND/OR A SINGLE REFLECTION. what part of that is so goddamned difficult for you to understand?!?!
Do you have evidence I was not understanding it?
I am not sure if we differ, but where we might differ is the significance of this 180 degree rotatin. That makes the trajectory into two sides of a triangle in spacetime  when compared with the straigt trajectory (one side of the same triangle).
All I am saying is that the two sides have a different elapsed time from the one side because of their shape.
In Euclideam space that would be blindingly obvious: the length would be larger.
The analogy I'm making is that the longer length is not a property of the straight sides, or of the vertex, it is a property of the whole path, so noone would think the two sides were symmetric (in terms of length) with the one straight side.
In Relativistic spacetime it is less obvious because we tend to think of time as a pathindependent constant, not a property of the path like Euclidean path length. Also, we find the opposite effect (the twosided path is shorter) counterintuitive.
I can't think of a short way to refer to this except "timellike bent paths are shorter than straight paths".

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tomclarke wrote:happyjack27 wrote:tomclarke wrote:happyjack27 wrote:johan is saying that in the absence of general relativity, each observer will read the same time on _their own_ clocks. this will be different than what they read on _each other_'s clocks. however, likewise, the time a reads on b's clock will match the time b reads on a's clock.
this symmetry is gauraunteed by the fact that the paths they see each other travel are only differ by a rotation and/or reflection.
however, if you follow this logic mathematically, and aren't very careful, it seems to imply that a<>a, hence the term "twin paradox". a=b, a'=b', a>b', b>a' does not imply a contradiction, but if you simply remove the prime ('), it does.
That is all true, for two clocks both on "unbent" trajectories.
When one of the trajectories is bent the symmetry no longer exists, but if you assume it does, you argue as Johan that the two clocks must read the same time when they come together. That would be trivially so were the situation symmetrical.
When calculating this case using LT there is a correction that must be made to the calculated time of the far clock when the frame in which this is calculated changes.
Best wishes, Tom
what's this "bent" trajectory thing? you talking about curved space i.e. gravity? i'm talking about in the absence of gravity, any trajectory, "bent" or "unbent", spirals swirls hammerheads sharp right turns, oscillations, whatever. i am talking about what's, in technical parlance, is called A TRAJECTORY. REFERENCE FRAME A'S TRAJECTORY FROM THE POINT OF VIEW OF REFERENCE FRAME B IS THE SAME AS REFERENCE FRAME'S B'S TRAJECTORY FROM THE POINT OF VIEW OF REFERENCE FRAME A EXCEPT FOR A SINGLE 180 DEGREE ROTATION AND/OR A SINGLE REFLECTION. what part of that is so goddamned difficult for you to understand?!?!
Do you have evidence I was not understanding it?
I am not sure if we differ, but where we might differ is the significance of this 180 degree rotatin. That makes the trajectory into two sides of a triangle in spacetime  when compared with the straigt trajectory (one side of the same triangle).
All I am saying is that the two sides have a different elapsed time from the one side because of their shape.
In Euclideam space that would be blindingly obvious: the length would be larger.
The analogy I'm making is that the longer length is not a property of the straight sides, or of the vertex, it is a property of the whole path, so noone would think the two sides were symmetric (in terms of length) with the one straight side.
In Relativistic spacetime it is less obvious because we tend to think of time as a pathindependent constant, not a property of the path like Euclidean path length. Also, we find the opposite effect (the twosided path is shorter) counterintuitive.
I can't think of a short way to refer to this except "timellike bent paths are shorter than straight paths".
i don't know how to put this politely.... what you say is wrong in so many ways. you are even more wrong now than you were before, and on a wider range of subjects.
i see know that john was right, this is utterly futile. beyond futile: the effect seems to be, shall we say, equal and opposite.
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