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CactusMan
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Quantum Question

January 9th, 2014, 1:04 am

Now, say I go outside. I find a good star in the sky, and set up my double slit. I observe the beam after it passes through the double slits.Does the theory say that I changed the particle-wave character WAY back when the light left the star? 100 years ago, or even 1 billion years ago (depending on the distance of the star)? That's insane!!!
Last edited by CactusMan on January 8th, 2014, 11:00 pm, edited 1 time in total.
 
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CactusMan
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Quantum Question

January 9th, 2014, 1:09 am

Now, say I do another experiment: I place the double slit screen on the other side of Saturn. I sit I my back yard and observe the beam. It changes to a particle. Does the theory say that I changed what happened when it left Saturn?
 
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Alan
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Quantum Question

January 9th, 2014, 3:56 am

QuoteOriginally posted by: CactusManNow, say I go outside. I find a good star in the sky, and set up my double slit. I observe the beam after it passes through the double slits.Does the theory say that I changed the particle-wave character WAY back when the light left the star? 100 years ago, or even 1 billion years ago (depending on the distance of the star)? That's insane!!!No, the point of the experiment has nothing to do with how far away the source is. It has to do with seeing, in one experiment, an interference pattern (which is wave-like) --yet the pattern itself emerges one photon click at a time (which is particle-like). Your light source can be one meter away or 10 million light years away. Watch Feynman -- imagine his source is your star, his electrons are your photons from the star, and both the slits and detector are on the Earth.link, There are some long distance quantum entanglement effects which arise in other experiments (sometimeshypothetical, but the outcome is in little doubt). Those long distance effects famously troubled Einstein and a few others.Those experiments are not this one. By the way, if you listen carefully, you will hear Feynman essentially agree withyour "that's insane" comment anyway
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CactusMan
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Quantum Question

January 9th, 2014, 10:54 pm

Thanks. But observing it seems to change what is did (in the past) when it went thru the slits, right?
 
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Traden4Alpha
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Quantum Question

January 9th, 2014, 11:16 pm

QuoteOriginally posted by: CactusManThanks. But observing it seems to change what is did (in the past) when it went thru the slits, right?Yes. And it's worse than that. The one-photon-at-a-time version of the experiment seems to imply that each photon particle interacts with both past and future photons.
 
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Alan
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Quantum Question

January 10th, 2014, 12:03 am

QuoteOriginally posted by: CactusManThanks. But observing it seems to change what is did (in the past) when it went thru the slits, right?I'd say no, but the point is probably debatable. I'd say, observing it localizes it at the spatial point and time of the observation (up to possible constraints due to Heisenberg uncertainty) and changes what it does in the future (doesn't intefere).If the observation point is very close to one of the slits, then you know it went through that slit.But, knowing that it went through a particular slit is not the same as saying you've changed 'what it did in the past'.By 'past' I mean times before entering a slit.It has full quantum character up to the point (in time) of the observation. Having quantum character means that you never definitively know what it did in the past.So it becomes operationally meaningless (under that framework) to say you've changed what it did prior to entering a slit.That's my interpretation anyway. Apparently T4A has another and you may have a valid third.Not surpising, as everybody's mental interpretation of the same theory is somewhat different, since asFeynman notes "nobody (really) understands it". They agree on the calculation rules only. If yourmental picture leads to correct calculations, then physicists will admit you to the club.
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farmer
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Quantum Question

January 10th, 2014, 1:15 am

Suppose there is a street full of car dealerships. They sell cars for $10,000. It will not be any surprise, that they only observe money in $10,000 chunks. In fact, they have intended this.So suppose there are some popcorn vendors, and some hookers, and some other people. A car dealer takes his $10,000 from a sale, and walks into the street. He spends a few hundred on a hooker, a few hundred on clothes, buys some popcorn. The popcorn vendor saves up and buys a coat. The coat salesman also pimps for the hooker. So the coat salesman saves up, and walks into a car dealership with $10,000.So is it a single $10,000 chunk, or is it lots of pieces of money, that travel different paths?It will always arrive as a single $10,000 piece, if a dealership selling cars for $10,000 is your means to observe money. But which car dealership it arrives at, will depend if it flows through the hooker and the popcorn vendor, or the grocer and the clothier. The more complicated the topology, the more interesting the pattern of arrival of 10k rolls up and down the street of car dealers.Whereas if there were only one vendor in the whole city, then all money from all sales would flow to his single favorite dealership, which he has his shop in front of.
 
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Traden4Alpha
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Quantum Question

January 10th, 2014, 12:48 pm

Perhaps CactusMan is thinking about Wheeler's delayed choice experiment in which observational choices made long after the photons have gone through the double slit affect whether the photons seemed to act like particles or waves at the slit.
 
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CactusMan
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Quantum Question

January 10th, 2014, 9:04 pm

Wow, I just realized something: I independently formulated Wheeler's delayed choice experiment while sitting on my arse drinking beer, listening to Gothic and playing on Wilmott! How about that?! I must be really really smart!Seriously, I am beginning to think I am really really smart: As you see in my other post, I increased the power of Macro5 by 15 times one night just because I was too drunk to f**k so started writing some computer code for the Psion.By they way, I met Wheeler one time. We only talked about bulls***, not any of this stuff! I don't know who was smarter, Wheeler or Artin's grand-daughter who I dated for a while. She was smart but a bit too mathy for my taste.
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ppauper
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Quantum Question

January 10th, 2014, 9:42 pm

QuoteOriginally posted by: CactusManSeriously, I am beginning to think I am really really smart: As you see in my other post, I increased the power of Macro5 by 15 times one night just because I was too drunk to f**ktheme song
 
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CactusMan
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Quantum Question

January 10th, 2014, 9:43 pm

QuoteOriginally posted by: outrun..but can you go back and decide if you had continue to date her some more?Cool that you went to write macro5's instead ofNay, ------- Artin was not the girl for me. Tho she was a neat girl.
 
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CactusMan
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Quantum Question

January 10th, 2014, 11:01 pm

Plus, I say screw Artin, I got tired of algebra.
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ppauper
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Quantum Question

January 10th, 2014, 11:29 pm

QuoteOriginally posted by: outrunQuoteOriginally posted by: CactusManPlus, I say screw Artin, I got tired of algebra.Yes stop that coding of marco5 and go back and screw her!is he still to drunk to screw ?