Notices
Results 1 to 29 of 29

Thread: Two Places at Once

  1. #1 Two Places at Once 
    Forum Radioactive Isotope zinjanthropos's Avatar
    Join Date
    Dec 2005
    Location
    Driving in my car
    Posts
    4,998
    https://www.livescience.com/2000-ato...s-at-once.html

    This one has me stumped. If particles can be in more than one place at once then what does that say about space-time coordinates? Are they different for each place?


    Last edited by zinjanthropos; October 7th, 2019 at 11:36 PM.
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
    Reply With Quote  
     

  2.  
     

  3. #2  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,003
    It says
    "And waves occupy multiple places in space at once." in that article .

    I am not sure of how that works ,but I don't have a problem with particles being waves. The only question I would have is whether "waveness" is more fundamental than "particleness" (based on our present state of knowledge.) or whether it is better to regard the condition as entirely binary


    Reply With Quote  
     

  4. #3  
    Forum Radioactive Isotope zinjanthropos's Avatar
    Join Date
    Dec 2005
    Location
    Driving in my car
    Posts
    4,998
    Quote Originally Posted by geordief View Post
    It says
    "And waves occupy multiple places in space at once." in that article .

    I am not sure of how that works ,but I don't have a problem with particles being waves. The only question I would have is whether "waveness" is more fundamental than "particleness" (based on our present state of knowledge.) or whether it is better to regard the condition as entirely binary
    Like if a wave peters out then does the particle component (?) disappear along with it? Article had me thinking a particle is the result of a wave that dies or comes to an end.
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
    Reply With Quote  
     

  5. #4  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    16,965
    Quote Originally Posted by zinjanthropos View Post
    https://www.livescience.com/2000-ato...s-at-once.html

    This one has me stumped. If particles can be in more than one place at once then what does that say about space-time coordinates? Are they different for each place?
    They are not actually in two places at once. Like the famous cat, they will be in one place or the other when the position is measured. But, up until that point, there is a probability that they could be in either.

    This is not much different from electron orbitals, where the electron has a probability to be anywhere with the orbital (with a probability that is the function which describes the shape of the orbital) but when detected, it will be in a specific location.
    ei incumbit probatio qui dicit, non qui negat
    Reply With Quote  
     

  6. #5  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,003
    Quote Originally Posted by Strange View Post
    Quote Originally Posted by zinjanthropos View Post
    https://www.livescience.com/2000-ato...s-at-once.html

    This one has me stumped. If particles can be in more than one place at once then what does that say about space-time coordinates? Are they different for each place?
    They are not actually in two places at once. Like the famous cat, they will be in one place or the other when the position is measured. But, up until that point, there is a probability that they could be in either.

    This is not much different from electron orbitals, where the electron has a probability to be anywhere with the orbital (with a probability that is the function which describes the shape of the orbital) but when detected, it will be in a specific location.
    From the quote I gave in the article(post#2) , what is the wave it is talking about? Is it a "Probability Wave"?

    (I think there are different kinds of wave that come up in this area....there is a "Mattter Wave" as well It is not the same thing ,is it?)
    Reply With Quote  
     

  7. #6  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,003
    Quote Originally Posted by Strange View Post
    Quote Originally Posted by zinjanthropos View Post
    https://www.livescience.com/2000-ato...s-at-once.html

    This one has me stumped. If particles can be in more than one place at once then what does that say about space-time coordinates? Are they different for each place?
    They are not actually in two places at once. Like the famous cat, they will be in one place or the other when the position is measured. But, up until that point, there is a probability that they could be in either.

    This is not much different from electron orbitals, where the electron has a probability to be anywhere with the orbital (with a probability that is the function which describes the shape of the orbital) but when detected, it will be in a specific location.
    From the quote from the article in post#2 is that a Probabilty Wave it is talking about ? Or a Matter Wave? (there is a difference ,isn't there?)
    Reply With Quote  
     

  8. #7  
    Forum Radioactive Isotope zinjanthropos's Avatar
    Join Date
    Dec 2005
    Location
    Driving in my car
    Posts
    4,998
    Strange,,,,thanks for response. Need to clear up something....Isn’t the cat in the box thought experiment about state of cat being alive or dead and not whether there’s the probability of a cat actually in the box? Wouldn’t knowing a cat’s in the box be the result of a measurement/observation?
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
    Reply With Quote  
     

  9. #8  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,003
    Quote Originally Posted by zinjanthropos View Post
    Strange,,,,thanks for response. Need to clear up something....Isn’t the cat in the box thought experiment about state of cat being alive or dead and not whether there’s the probability of a cat actually in the box? Wouldn’t knowing a cat’s in the box be the result of a measurement/observation?
    (just my guess) It is the same thing ,being there or being alive-although different probabilities.

    It could be there ,but dead ,or be there but alive (or having sex with itself)

    Or it could be elsewhere but dead ,or be elsewhere but alive (or having sex with itself)

    Anything is possible (but the idea that the act of observation magics the scenario into existence is not mainstream ,I think.-not that you were bringing it up)
    Reply With Quote  
     

  10. #9  
    Forum Radioactive Isotope zinjanthropos's Avatar
    Join Date
    Dec 2005
    Location
    Driving in my car
    Posts
    4,998
    Quote Originally Posted by geordief View Post
    Quote Originally Posted by zinjanthropos View Post
    Strange,,,,thanks for response. Need to clear up something....Isn’t the cat in the box thought experiment about state of cat being alive or dead and not whether there’s the probability of a cat actually in the box? Wouldn’t knowing a cat’s in the box be the result of a measurement/observation?
    (just my guess) It is the same thing ,being there or being alive-although different probabilities.

    It could be there ,but dead ,or be there but alive (or having sex with itself)

    Or it could be elsewhere but dead ,or be elsewhere but alive (or having sex with itself)

    Anything is possible (but the idea that the act of observation magics the scenario into existence is not mainstream ,I think.-not that you were bringing it up)
    For the sake of this thought experiment I can’t see how one can think there’s the probability of a cat not in the box especially when you put a live cat in there to begin with. At some point one has to trust what they’ve observe, and in this case I think there has to be 100% certainty that a cat, amongst other things used for experiment, is in that box. Otherwise why bother?
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
    Reply With Quote  
     

  11. #10  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,003
    Quote Originally Posted by zinjanthropos View Post
    Quote Originally Posted by geordief View Post
    Quote Originally Posted by zinjanthropos View Post
    Strange,,,,thanks for response. Need to clear up something....Isn’t the cat in the box thought experiment about state of cat being alive or dead and not whether there’s the probability of a cat actually in the box? Wouldn’t knowing a cat’s in the box be the result of a measurement/observation?
    (just my guess) It is the same thing ,being there or being alive-although different probabilities.

    It could be there ,but dead ,or be there but alive (or having sex with itself)

    Or it could be elsewhere but dead ,or be elsewhere but alive (or having sex with itself)

    Anything is possible (but the idea that the act of observation magics the scenario into existence is not mainstream ,I think.-not that you were bringing it up)
    For the sake of this thought experiment I can’t see how one can think there’s the probability of a cat not in the box especially when you put a live cat in there to begin with. At some point one has to trust what they’ve observe, and in this case I think there has to be 100% certainty that a cat, amongst other things used for experiment, is in that box. Otherwise why bother?
    If you observed the cat in the box at the outset of the experiment that does not give 100% probability that ,if you look again later it will still be there.(my opinion is just based on what I have picked up over the years so I might have got the wrong end of the stick )

    You can still trust what you observed and yet this may not transfer to your next act of observation of the "same"(nothing is ever the same) scenario.
    Reply With Quote  
     

  12. #11  
    Forum Radioactive Isotope zinjanthropos's Avatar
    Join Date
    Dec 2005
    Location
    Driving in my car
    Posts
    4,998
    If you observed the cat in the box at the outset of the experiment that does not give 100% probability that ,if you look again later it will still be there.(my opinion is just based on what I have picked up over the years so I might have got the wrong end of the stick )

    You can still trust what you observed and yet this may not transfer to your next act of observation of the "same"(nothing is ever the same) scenario.
    I would agree that as time passes, what was once a live cat will look nothing like a live cat in a box upon observation. So does that mean the live cat that was originally put in the box was actually something else at one time too? Could you say the entire universe was once something else and so on and so on? Is there a probability that it isn't even there? I'm not here? What good is observation then? It almost sounds like saying nothing exists....nothing being something in some broad sense. Crazy shit!!! I'm thinking this is what happens when we don't have all the information.
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
    Reply With Quote  
     

  13. #12  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    16,965
    Quote Originally Posted by geordief View Post
    From the quote I gave in the article(post#2) , what is the wave it is talking about? Is it a "Probability Wave"?

    (I think there are different kinds of wave that come up in this area....there is a "Mattter Wave" as well It is not the same thing ,is it?)
    They are (I assume) talking about the wavefunction that describes the object. This can be used to calculate the a probability of the object being in a particular state (which includes position). The wave function is spread out (through all of space) and has its greatest amplitude at the most likely position (or positions) that the object will be detected.
    ei incumbit probatio qui dicit, non qui negat
    Reply With Quote  
     

  14. #13  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    16,965
    Quote Originally Posted by zinjanthropos View Post
    I would agree that as time passes, what was once a live cat will look nothing like a live cat in a box upon observation. So does that mean the live cat that was originally put in the box was actually something else at one time too? Could you say the entire universe was once something else and so on and so on? Is there a probability that it isn't even there? I'm not here? What good is observation then? It almost sounds like saying nothing exists....nothing being something in some broad sense. Crazy shit!!! I'm thinking this is what happens when we don't have all the information.
    The whole cat experiment was intended to show how silly it becomes when you try and apply these things on a large scale. There is an extension of the thought experiment where one person opens the box. From the point of view of other people, that person is then in a superposition of knowing the cat is dead and knowing it is alive.

    I don't think it makes much sense to think of the cat being both dead and alive. But there is no way of showing that interpretation is QM is wrong.
    ei incumbit probatio qui dicit, non qui negat
    Reply With Quote  
     

  15. #14  
    Forum Radioactive Isotope zinjanthropos's Avatar
    Join Date
    Dec 2005
    Location
    Driving in my car
    Posts
    4,998
    When I see ripples in a pond am I observing particles moving up and down or the actual or semblance of vibration itself. I mean if a wave can be a particle then why can't a particle be a wave? Is it because that's the only way nature could take a life form to evolve a sense of the wave (by turning it into a particle for convenience.....simplest way) or are vibrations just particles of some kind. When I think of vibrating strings, as in string theory's most fundamental particle, I wonder if that language/description is wrong because I'm questioning what's more fundamental ...the wave or the particle, or is it 50/50? Can I have a particle without the wave or vice versa?
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
    Reply With Quote  
     

  16. #15  
    ox
    ox is offline
    Forum Professor
    Join Date
    Mar 2009
    Posts
    1,563
    You are always going to struggle to apply QM to the real world.
    Curiosity kills the cat.
    I try to think that nothing is real. Even you are not real. Just an assembly of atoms or vibrating strings.
    Reply With Quote  
     

  17. #16  
    Forum Radioactive Isotope zinjanthropos's Avatar
    Join Date
    Dec 2005
    Location
    Driving in my car
    Posts
    4,998
    Just curious.....Is a 2d pixel a space? I'm moving my cursor across the screen and notice that it can appear to completely disappear or blend in with another image on the screen if lined up correctly. I don't think they are objects sharing pixels but I was wondering if it is at least analogous to superposition? Two images sharing the same pixels or space on the screen?
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
    Reply With Quote  
     

  18. #17  
    KJW
    KJW is offline
    Forum Professor
    Join Date
    Jun 2013
    Posts
    1,507
    Quote Originally Posted by geordief View Post
    The only question I would have is whether "waveness" is more fundamental than "particleness"
    It depends on what is meant by "wave". If by "wave" it is meant a sinusoidal wave, then wave and particle are equally fundamental. A particle can be regarded as an entity that is at a single location in position space, whereas a wave can be regarded as an entity that is at a single location in momentum space. A notable aspect of the wave-particle duality is that wave and particle represent complementary properties that are subject to the Heisenberg uncertainty principle. But if by "wave" it is meant an arbitrary waveform, then everything is a wave, including a particle, so that a wave is more fundamental.


    Quote Originally Posted by geordief View Post
    or whether it is better to regard the condition as entirely binary
    No. This would suggest that wave and particle are the only two possibilities, but a quantum state can be prepared in many ways that do not result in either wave or particle. For example, the entity emerging from the two slits in the double-slit experiment is neither a wave nor a particle (it is not at a single location in either position or momentum space).
    There are no paradoxes in relativity, just people's misunderstandings of it.
    Reply With Quote  
     

  19. #18  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,003
    Quote Originally Posted by KJW View Post

    It depends on what is meant by "wave". If by "wave" it is meant a sinusoidal wave, then wave and particle are equally fundamental. A particle can be regarded as an entity that is at a single location in position space, whereas a wave can be regarded as an entity that is at a single location in momentum space.
    Is every "point" in momentum space unique in the same way it is in position space?

    Might there be a one to one relation between the two sets?
    Last edited by geordief; October 13th, 2019 at 04:03 AM.
    Reply With Quote  
     

  20. #19  
    KJW
    KJW is offline
    Forum Professor
    Join Date
    Jun 2013
    Posts
    1,507
    Quote Originally Posted by geordief View Post
    Quote Originally Posted by KJW View Post
    It depends on what is meant by "wave". If by "wave" it is meant a sinusoidal wave, then wave and particle are equally fundamental. A particle can be regarded as an entity that is at a single location in position space, whereas a wave can be regarded as an entity that is at a single location in momentum space.
    Is every "point" in momentum space unique in the same way it is in position space?

    Might there be a one to one relation between the two sets?
    There is a one-to-one relation between these two sets. Indeed, they are connected to each other via a Fourier transformation.

    It is worth noting that a wavefunction is a vector in an infinite-dimensional Hilbert space, and in a similar way that ordinary space has different coordinate systems, so does Hilbert space, and position space and momentum space are two of many different coordinate systems in Hilbert space. And just as one has rotations in ordinary space or Lorentz transformations in spacetime, one has integral transformations such as Fourier transformations in Hilbert space.
    There are no paradoxes in relativity, just people's misunderstandings of it.
    Reply With Quote  
     

  21. #20  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,003
    Quote Originally Posted by KJW View Post
    Quote Originally Posted by geordief View Post
    Quote Originally Posted by KJW View Post
    It depends on what is meant by "wave". If by "wave" it is meant a sinusoidal wave, then wave and particle are equally fundamental. A particle can be regarded as an entity that is at a single location in position space, whereas a wave can be regarded as an entity that is at a single location in momentum space.
    Is every "point" in momentum space unique in the same way it is in position space?

    Might there be a one to one relation between the two sets?
    There is a one-to-one relation between these two sets. Indeed, they are connected to each other via a Fourier transformation.

    It is worth noting that a wavefunction is a vector in an infinite-dimensional Hilbert space, and in a similar way that ordinary space has different coordinate systems, so does Hilbert space, and position space and momentum space are two of many different coordinate systems in Hilbert space. And just as one has rotations in ordinary space or Lorentz transformations in spacetime, one has integral transformations such as Fourier transformations in Hilbert space.
    So "position space" is not the common or garden 3d,xyz space I assumed it was?

    Is there a relationship between these two spaces?
    Reply With Quote  
     

  22. #21  
    KJW
    KJW is offline
    Forum Professor
    Join Date
    Jun 2013
    Posts
    1,507
    Quote Originally Posted by geordief View Post
    So "position space" is not the common or garden 3d,xyz space I assumed it was?

    Is there a relationship between these two spaces?
    Position space is the "common or garden 3d,xyz space" (or 4d spacetime). Each point in position space is a direction in Hilbert space, the set of all points of position space is the set of all directions in Hilbert space. Each point in momentum space is also a direction in Hilbert space, the set of all points of momentum space is also the set of all directions in Hilbert space, but the directions are different to those corresponding to position space. However, set of all directions in Hilbert space corresponding to momentum space span the same Hilbert space as the set of all directions corresponding to position space.
    There are no paradoxes in relativity, just people's misunderstandings of it.
    Reply With Quote  
     

  23. #22  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,003
    Thanks for all that.It will hopefully serve for future reference.
    Reply With Quote  
     

  24. #23  
    Forum Radioactive Isotope zinjanthropos's Avatar
    Join Date
    Dec 2005
    Location
    Driving in my car
    Posts
    4,998
    Wrong thread
    Last edited by zinjanthropos; October 17th, 2019 at 05:10 PM. Reason: F**ked up
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
    Reply With Quote  
     

  25. #24  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,003
    Last edited by geordief; October 17th, 2019 at 05:36 PM.
    Reply With Quote  
     

  26. #25  
    Forum Radioactive Isotope zinjanthropos's Avatar
    Join Date
    Dec 2005
    Location
    Driving in my car
    Posts
    4,998
    Quote Originally Posted by geordief View Post
    For a moment there, I had the same response existing in two threads at the same time.

    Could it be as simple as all that? The particles really do exist in many places until deletion(s) are made. Brains are computers, so maybe that’s what they do, correct via deletion. Until then the same information exists in many places but only one fits Info deleted but place remains.
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
    Reply With Quote  
     

  27. #26  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,003
    You are not falling into the trap of thinking that the way we process information has a fundamental input into the way reality is ordered,are you?

    As William Blake noted we only see through a glass darkly....

    Otoh perhaps there could be two realities,the fundamental one that just "is" and the one wherein we perceive and form ideas which may have its own set of rules.


    It would be less fundamental (a subset of the "just is" arrangement but an equal - or perhaps vastly superior in terms of simple complexity and refinement)

    I expect I have blundered into the monism/dualism debate....
    Reply With Quote  
     

  28. #27  
    Forum Radioactive Isotope zinjanthropos's Avatar
    Join Date
    Dec 2005
    Location
    Driving in my car
    Posts
    4,998
    Quote Originally Posted by geordief View Post
    You are not falling into the trap of thinking that the way we process information has a fundamental input into the way reality is ordered,are you?

    As William Blake noted we only see through a glass darkly....

    Otoh perhaps there could be two realities,the fundamental one that just "is" and the one wherein we perceive and form ideas which may have its own set of rules.


    It would be less fundamental (a subset of the "just is" arrangement but an equal - or perhaps vastly superior in terms of simple complexity and refinement)

    I expect I have blundered into the monism/dualism debate....
    Maybe I did fall into a trap, but unwittingly. I'm not familiar with William Blake or his philosophies.

    Is the brain a computer, a quantum one at that? I'd say so but I'm only speaking casually.

    Don't take the following seriously......I'd call a computer a place the same as I'd call a file within in it a place. If I were to google William Blake then I am going to receive many pages of information regarding him, but I will zero in on what I think I'm looking for and disregard the rest with a click. If someone else wants it at the same time then the info I have and the disregarded info is still in the same accessible place, a file/database/computer over at Google.

    Oh, I'm probably missing much but the similarities between computing and what we experience is somewhat astonishing to me.
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
    Reply With Quote  
     

  29. #28  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,003
    Would a "computer" exist if we had not created it?

    If we had not designed it to our purpose would it just be a monkey at a typewriter composing As You Like It?

    We say that Nature follows the Laws of Nature,but does that mean it doesn't have the gumption to shuffle the pack at any stage?

    Same with us ,I suppose...we just follow the rules from beginning to end.

    But then does the random nature of things as apparently sown in Quantum Mechanics slip a Joker into the pack and refute all that?

    Was passing a shop window this afternoon where a religious outlet was displaying a book/pamphlet titled (rhetorically) Does Science Know Everything?

    I think here we know that is a pointless question but the author seems to think he/she can get mileage out of it...
    Reply With Quote  
     

  30. #29  
    Forum Radioactive Isotope zinjanthropos's Avatar
    Join Date
    Dec 2005
    Location
    Driving in my car
    Posts
    4,998
    Thinking about how we measure a particle and whether it was possible to observe a photon in motion. Apparently scientists say there's a way to know if the photon is in the area without destroying it. Still sounds like it's not directly observed but it apparently leaves a trace.

    I was only thinking about that because Strange commented earlier "There is an extension of the thought experiment where one person opens the box. From the point of view of other people, that person is then in a superposition of knowing the cat is dead and knowing it is alive." A super positioned particle would contain all the information if that's the case. Would it mean we observe only a super positioned photon?
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
    Reply With Quote  
     

Similar Threads

  1. Replies: 12
    Last Post: June 4th, 2014, 07:43 AM
  2. Bad Places to Work
    By arKane in forum Business & Economics
    Replies: 26
    Last Post: December 31st, 2013, 05:34 PM
  3. Device for wiping out infections in places like hospitals
    By quantumintel in forum Electrical and Electronics
    Replies: 9
    Last Post: March 18th, 2009, 04:25 PM
  4. Google maps, satellite images of interesting places
    By william in forum Earth Sciences
    Replies: 17
    Last Post: March 18th, 2008, 10:17 PM
  5. Is moving production to places with cheap labor really wise?
    By kojax in forum Business & Economics
    Replies: 11
    Last Post: November 27th, 2007, 02:01 PM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •