DwayneEMTP Posted September 29, 2012 Posted September 29, 2012 Hi all, I'd originally was posting this to chbare's email but then thought, first, he probably has better things to do than answer my stupid physics questions, and second, that maybe others are curious about such things too. My physics education is about 30 years stale now, but it's something that interestes me so I kind of play with it on the very basic, very layman level. In that spirit I was reading "The search for Schrodinger's cat." In there the author talks about the "two hole experiment" (stop it, friggin' pervs...). I'd been familiar with the three slit (Really! Stop it!) experiement, and thought that I'd understood it, but I guess that I didn't. You can gain much more information on either experiment with Google and/or ChrisB than I can explain here, so I'm just going to state my understandings of the possible conclusions. I'm going to state things as fact, just so that I don't have to write "as I understand it" or "seems to be" in every sentence. They should be assumed to belong there however. So basically the two hole experiment seems to show that particles are aware of being observed and in fact change their behavior based on the expectations of the observer. No, I didn't make that up! This is a preliminary conclusion that a lot of really, really smart people have come to. That a particle can/does change it's behavior based on observer expectations. I can see this two ways. That it can change it's behavior passively, like electricity following an open channel. That an observer's intentions create a physical change that the particle reacts to, but we've just not discovered the link yet. Or more active, with the particle, or something controlling the particle being aware of the observers intentions and therefore making a logical, "aware" decision on it's path. As you might imagine, though this idea is fun to follow, it freaks me out too. Likely there are many other options that I just can't see now. If individual particles can/do change their behavior based on the expectations of the observer, does this then seem to imply that the particle is 'aware?' And if so, does it then possibly imply an 'aware' universe(s)? (If so, DFIB is so going to kick my ass all over this thread...) I'm not asking anyone to teach me physics, but I thought that it might make for an interesting discussion... I look forward to your thoughts... 1
chbare Posted September 30, 2012 Posted September 30, 2012 Particles are not aware. One component of the double slit experiment that is easy to understand is the following: First, we need to define the energy of light as a wave. Energy can be defined as the product of a coefficient called Planck's constant that we will state as being "h" multiplied by the frequency that will be called "v." Therefore E = hu. The wavelength of light can be defined as being equal to the speed of light "c" divided by frequency or Y = c/v. We can combine both concepts into a unified formula: Energy = Planck's constant * speed of light / wavelength or E = hc/Y From this understanding, we can agree that the smaller the wavelength the more energy of the light. When we attempt to "look" at something as small as an electron, we need to use very small wavelengths of light. Unfortunately, this also means we are hitting the electron with very high energies and disturbing the "system." The following is the easiest and most intuitive concept to understand. However, the world of the small is fundamentally non-deterministic and governed by something called the uncertainty principle. It may be natural to assume some sort of intelligence is involved, but the reality is much more complicated. Hope that helps. *Also, the double slit experiment is not literally as commonly demonstrated when dealing with particles that have rest mass. We typically have to scatter these particles off of crystalline solids, but the net result is the same as running the "traditional" double slit experiment. 1
DwayneEMTP Posted September 30, 2012 Author Posted September 30, 2012 But the double slit and the 'two hole' experiment aren't really the same are they? The two hole, as was explained in the book, has the issue of a single particle changing behavior based on whether or not there is one hole, or two holes available as possible options. The recorded patterns of accumulated particles being different whether or not one hole or two are being utilized at the moment. What I found strange, and perhaps I misunderstood or it was reported in the book incorrectly, is that despite there being no other paticles to interact with, if a particle is passing through a single hole, but both holes are available, then that particle, and those following will record a pattern of interference as expected if both holes are occupied by many particles. If, even at the very last moment, the second whole is closed, then the same particle, and those that follow will record a pattern as if a single hole only was used. Again, according to the book, attempts to 'fool' the particles were unsuccessful and the particles seem to continue to make the pattern expected by the observer, (the observer knowing if one or two holes are available at that moment) the assumption being that the observer will expect pattern A if both holes are available, or B if only one hole is available, and it seems to make no difference that those patterns "shouldn't" vary when only single particles are being deployed at a given time..right? Though I more or less (in layman's terms) get the uncertainty principle, that we're unable to observe small things without effecting them, and the fact that intuitive large 'real world' physical theory can't be applied to quantum mechanics, this still seems like a strange issue...Or am I screwing the pooch in my understanding somewhere? (Sorry, in a hurry. Can't proof! Apologies for errors both intellectual and gramatical.)
DFIB Posted September 30, 2012 Posted September 30, 2012 (edited) If individual particles can/do change their behavior based on the expectations of the observer, does this then seem to imply that the particle is 'aware?' And if so, does it then possibly imply an 'aware' universe(s)? (If so, DFIB is so going to kick my ass all over this thread...) Thanks for the vote of confidence but I don't have a clue. I mean, like I had never heard of either experiment or the theory of "particle awareness". It kinda ticks me off that I am gonna have to compulsively invest the time energy into researching it now. Thanks a lot! EDIT: It would seem to me, just from a third world laymen view, that the existence of a space (hole) at that level would create enough environmental disturbance or instability (not familiar with the terminology) to create a predictable pattern. Wouldn't the presence or absence of matter cause changes in electrical fields and probably other variables as well? I am counting on chris to tell me how far in the ditch that idea is. Now I will go read the theories and find out how goofy that idea is. Edited September 30, 2012 by DFIB
chbare Posted September 30, 2012 Posted September 30, 2012 (edited) Yes, your two hole experiment is the same thing as the double slit experiment. I think some of your confusion comes from the fact that you are ignoring that these particles have wave like behaviour. It some sense calling them waves or particles is not accurate at all, but these simplistic models are the best the human brain can conjure to develop some type of intuition of what is going on. When both slits are open and the distance between the slits is small enough, the electron's wave like properties are noted. The electron in essence can propagate as a wave and interfere with it's self as is passes through both slits. Do you remember learning about constructive and destructive interference in physics? It is this destructive and constructive interference that causes the characteristic pattern seen when both slits are open. You would see the same thing using light waves. Yes, one interpretation is that the electron passes through both slits and interferes with it's self. Edit: Unfortunately, we do people a great dis-service when we anthropomorphise these objects. We are not trying to "fool" electrons. We are making measurements and noting that the act of measuring changes the outcome. Edited September 30, 2012 by chbare 1
scratrat Posted September 30, 2012 Posted September 30, 2012 My physics education is about 30 years stale now, but it's something that interestes me so I kind of play with it on the very basic, very layman level. In that spirit I was reading "The search for Schrodinger's cat." In there the author talks about the "two hole experiment" (stop it, friggin' pervs...). I I think I just peed a little! :lol: That was hilarious!! What made you think that someone would misconstrue the "two hole experiment" with a cat? Particles are not aware. One component of the double slit experiment that is easy to understand is the following: Double slit experiments?? Two hole experiments?? Cats?? I don't know WHAT the hell you two are talking about, but I'm horny now!!! Thanks a lot!!! And I'm at work
DFIB Posted September 30, 2012 Posted September 30, 2012 Double slit experiments?? Two hole experiments?? Cats?? I don't know WHAT the hell you two are talking about, but I'm horny now!!! Thanks a lot!!! And I'm at work I bet Dwayne was disappointed when he found out the book was about physics! 1
Bieber Posted September 30, 2012 Posted September 30, 2012 I've actually read a lot about this (I'll admit it, though I'm terrible at math I'm deeply in love with quantum physics), and like Chris said, particles aren't actually aware, but their nature is definitely curious nonetheless! If you haven't read about it already, read up on wave function collapse and the Copenhagen interpretation. There's a ton of great videos on youtube as well about physics (Khan academy is a great educational channel). Another really mind-blowing thing to learn about is special relativity (how the very nature of light can cause the universe to shrink and expand). Good on you for learning about something new, brother. 1
chbare Posted September 30, 2012 Posted September 30, 2012 (edited) Bieber, the Copenhagen interpretation is not as relevant as it once was. Many people now favour the many worlds interpretation. I'm not nearly educated enough to make definitive statements about such things; however, I don't really look at a wave function as a real, physical thing. Rather, the wavefunction is a verb, a handy device that helps make predictions. Also remember, the wavefunction is but one way to look at the mathematics of quantum mechanics. Before the Schrodinger equation, Heisenburg developed a working theory based on matrix mathematics (linear algebra) but it was so complicated, it didn't stick. Schrodinger's equation stuck because it was based on wave mechanics and differential equations, something physicists already intuitively understood. Now we know both matrix and wave mechanics are essentially equal and we often use both types of math to solve problems. For example, the binding energy values that fall out of the Schrodinger equation are also easily viewed as Eigenvalues of a matrix. In addition, matrices are able to solve systems of linear equations. As far as this topic goes, I have a great video about what can happen if we become too philosophical. It is a recording of one of my contemporary heroes: Edited September 30, 2012 by chbare
DwayneEMTP Posted September 30, 2012 Author Posted September 30, 2012 I saw a quote somewhere where one of the world brainiacs was saying, "Before you can try and understand quantum physics you have to accept the fact that when you look away from the moon that it does in fact cease to exist." Now, I'm ok when crazy people talk like that, but when people that seem to be globally respected for their intelligence say such things it's freaky!! That's actually what got me reinterested in physics and walking down this path that I've now come to understand that I have no friggin' chance of understanding in this lifetime. And despite my reading, I still have no idea what he meant by the above quote. Particles that need to make two rotations before you see the same face again? That can vibrate at two frequencies at the same time? Electrons that move from one state to another without ever occupying the space in between? A single particle that can go through two holes at the same time? Multiple universes as a logical explanation for....anything!? Craziness....but really cool...and the puzzle is fun. And I do understand, to a point, that the above descriptions of 'things' are still ways that we try and use common physical descriptions to describe a world that can't be described in such a way...And that's maybe even crazier. I'm working on a theory that posits the idea that the world's physicists don't know what the hell is going on so they are all getting together, in a secret club somewhere...maybe, like an old warehouse, to come up with ideas that no sane person can really visualize, just so they don't have to tell anyone that they don't know why light does that funny thing when you shine it through a couple of slits. I'm much more comfortable with that theory than I am with quantum physics... I'm really excited that you guys joined in here!
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