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Einstein’s Parable of Quantum Insanity

47 pointsby treefire86over 9 years ago

6 comments

graycatover 9 years ago
Physicists, here is a related question:<p>We have a gun that shoots electrons one at a time due north. A little ahead of the gun and in the path of the electrons we have a <i>beam splitter</i>, that is, a flat plate of material with horizontal normal along the line from south east to north west.<p>So, we fire the gun. The electron hits the beam splitter. The wave function splits with some going east and the rest passing through the beam splitter and going north.<p>One mile to the north of the beam splitter and in the line of the path of the wave function we have a very good electron detector. Similarly for one mile to the east.<p>So, we fire and some fraction of the time we get a detection from the north detector and the rest of the time, from the east detector.<p>Now, let&#x27;s move some of the mass of the electron faster than the speed of light: A little ahead of each detector we have a very sensitive detector of gravity (or, maybe charge).<p>So, as the two parts of the wave function pass the gravity detectors, we get a signal from both. If the beam splitter sends 10% of the wave function north and the other 90% east, then from the north gravity detector we should get a signal of 10% of an electron, and from the east, 90% of an electron.<p>Then, soon, one of the electron detectors gives a signal, of 100% of the mass (and charge) of an electron. So, 90% or 10% of the mass (and charge) of the electron moved instantly, faster than the speed of light. along the line between the two detectors.<p>Is this wrong? Why?<p>In more detail, what about the electromagnetic field from the moving parts of the wave function? E.g., if the electron is detected at the east detector, is there an electromagnetic field still from the path of part of the wave function to the north?
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GregBuchholzover 9 years ago
For the opposite take, some may like the article, &quot;Clearing Up Mysteries - The Original Goal&quot; by E.T. Jaynes:<p><a href="http:&#x2F;&#x2F;bayes.wustl.edu&#x2F;etj&#x2F;articles&#x2F;cmystery.pdf" rel="nofollow">http:&#x2F;&#x2F;bayes.wustl.edu&#x2F;etj&#x2F;articles&#x2F;cmystery.pdf</a><p>&gt;While it is easy to understand and agree with this on the epistemological level, the answer that I and many others would give is that we expect a physical theory to do more than merely predict experimental results in the manner of an empirical equation; we want to come down to Einstein&#x27;s ontological level and understand what is happening when an atom emits light, when a spin enters a Stern-Gerlach magnet, etc. The Copenhagen theory, having no answer to any question of the form: What is really happening when - - - ?&quot;, forbids us to ask such questions and tries to persuade us that it is philosophically naive to want to know what is happening. But I do want to know, and I do not think this is naive; and so for me QM is not a physical theory at all, only an empty mathematical shell in which a future theory may, perhaps, be built.<p>...and maybe chapter 10 of his book, &quot;Probability Theory: The Logic of Science&quot;.<p>&gt;We are fortunate that the principles of Newtonian mechanics could be developed and verified to great accuracy by studying astronomical phenomena, where friction and turbulence do not complicate what we see. But suppose the Earth were, like Venus, enclosed perpetually in thick clouds. The very existence of an external universe would be unknown for a long time, and to develop the laws of mechanics we would be dependent on the observations we could make locally.<p>&gt;Since tossing of small objects is nearly the first activity of every child, it would be observed very early that they do not always fall with the same side up, and that all one’s efforts to control the outcome are in vain. The natural hypothesis would be that it is the volition of the object tossed, not the volition of the tosser, that determines the outcome; indeed, that is the hypothesis that small children make when questioned about this. Then it would be a major discovery, once coins had been fabricated, that they tend to show both sides about equally often; and the equality appears to get better as the number of tosses increases. The equality of heads and tails would be seen as a fundamental law of physics; symmetric objects have a symmetric volition in falling.<p>&gt;With this beginning, we could develop the mathematical theory of object tossing, discovering the binomial distribution, the absence of time correlations, the limit theorems, the combinatorial frequency laws for tossing of several coins at once, the extension to more complicated symmetric objects like dice, etc. All the experimental confirmations of the theory would consist of more and more tossing experiments, measuring the frequencies in more and more elaborate scenarios. From such experiments, nothing would ever be found that called into question the existence of that volition of the object tossed; they only enable one to confirm that volition and measure it more and more accurately...<p>&gt;Biologists have a mechanistic picture of the world because, being trained to believe in causes, they continue to search for them and find them. Quantum physicists have only probability laws because for two generations we have been indoctrinated not to believe in causes - and so we have stopped looking for them. Indeed, any attempt to search for the causes of microphenomena is met with scorn and a charge of professional incompetence and &quot;obsolete mechanistic materialism.&quot; Therefore, to explain the indeterminacy in current quantum theory we need not suppose there is any indeterminacy in Nature; the mental attitude of quantum physicists is already sufficient to guarantee it.<p><a href="http:&#x2F;&#x2F;www.med.mcgill.ca&#x2F;epidemiology&#x2F;hanley&#x2F;bios601&#x2F;GaussianModel&#x2F;JaynesProbabilityTheory.pdf" rel="nofollow">http:&#x2F;&#x2F;www.med.mcgill.ca&#x2F;epidemiology&#x2F;hanley&#x2F;bios601&#x2F;Gaussia...</a>
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FrankenPCover 9 years ago
Charlton Einstein: &quot;You&#x27;ll pry my determinism from my cold dead hands&quot;
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yakultover 9 years ago
Wild guessing from someone who has no background in physics:<p>1. Simulating QM-level events is NP-complete.<p>2.Assuming P=&#x2F;=NP, a machine that simulates a volume of size X in QM-correct terms must be exponentially larger than X.<p>3. This includes X itself.<p>4. Therefore, the universe is taking sweeping shortcuts that look like classical mechanics at large scale. These are not &#x27;our&#x27; computational shortcuts, they&#x27;re actually how things work at a fundamental level.<p>5. ...maybe if we build a big enough quantum computer we can overflow the universe&#x27;s buffer.
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coldcodeover 9 years ago
Physics is a game best played by madmen.
spacehomeover 9 years ago
Einstein had amazingly good intuition for the character of physical laws, i.e. what shape the laws of physics must necessarily take. And in this case he was right, too. God doesn&#x27;t play dice; the universe <i>is</i> deterministic. Unfortunately, he didn&#x27;t stumble upon the right answer, Many Worlds. I sometimes wonder how much longer it will take popular science writers to stumble upon it, too.
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