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<TITLE>RE: [extropy-chat] Cramer on Afshar</TITLE>
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<P><FONT SIZE=2>Good analysis.</FONT>
<BR><FONT SIZE=2>Does Afshar agree that his V<<1 only as you suggest?</FONT>
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<P><FONT SIZE=2>Thanks.</FONT>
<BR><FONT SIZE=2> </FONT>
<BR><FONT SIZE=2>Walter.</FONT>
<BR><FONT SIZE=2>---------</FONT>
</P>
<P><FONT SIZE=2>-----Original Message-----</FONT>
<BR><FONT SIZE=2>From: extropy-chat-bounces@lists.extropy.org [<A HREF="mailto:extropy-chat-bounces@lists.extropy.org">mailto:extropy-chat-bounces@lists.extropy.org</A>] On Behalf Of scerir</FONT>
<BR><FONT SIZE=2>Sent: Saturday, November 13, 2004 3:50 PM</FONT>
<BR><FONT SIZE=2>To: ExI chat list</FONT>
<BR><FONT SIZE=2>Subject: Re: [extropy-chat] Cramer on Afshar</FONT>
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<P><FONT SIZE=2>[Cramer]</FONT>
<BR><FONT SIZE=2>> I predict that a new generation of "Quantum Lawyers" </FONT>
<BR><FONT SIZE=2>> will begin to populate the physics literature with </FONT>
<BR><FONT SIZE=2>> arguments challenging what "is" is and claming</FONT>
<BR><FONT SIZE=2>> that the wounded interpretations never said that </FONT>
<BR><FONT SIZE=2>> interference should be completely absent in a quantum </FONT>
<BR><FONT SIZE=2>> which-way measurement.</FONT>
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<P><FONT SIZE=2>This seems perfect. Unfortunately the first 'lawyer'</FONT>
<BR><FONT SIZE=2>is Afshar. Essentially his experiment is based on</FONT>
<BR><FONT SIZE=2>the Greenberger-YaSin-Englert-Zeilinger-etc.</FONT>
<BR><FONT SIZE=2>relation V^2 + K^2 = 1, which says that the</FONT>
<BR><FONT SIZE=2>Visibility of interference fringes becomes</FONT>
<BR><FONT SIZE=2>more and more vanishing when the Knowledge</FONT>
<BR><FONT SIZE=2>of the 'which way' the particle went through</FONT>
<BR><FONT SIZE=2>becomes more and more definite. In general</FONT>
<BR><FONT SIZE=2>there is a smooth (also in experiments eh!)</FONT>
<BR><FONT SIZE=2>transition between the particle-like and</FONT>
<BR><FONT SIZE=2>the wave-like behaviour. So the orthodoxia</FONT>
<BR><FONT SIZE=2>just says that we cannot reveal a 'sharp'</FONT>
<BR><FONT SIZE=2>particle-like and a 'sharp' wave-like behaviour</FONT>
<BR><FONT SIZE=2>at the same time (for a single quantum).</FONT>
<BR><FONT SIZE=2>That is to say we cannot set V=1 and K=1</FONT>
<BR><FONT SIZE=2>at the same time, in the above (uncertainty)</FONT>
<BR><FONT SIZE=2>relation.</FONT>
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<P><FONT SIZE=2>Afshar claims that he was able to reveal</FONT>
<BR><FONT SIZE=2>the 'sharp' particle-like and the 'sharp'</FONT>
<BR><FONT SIZE=2>wave-like behaviours 'at the same time'</FONT>
<BR><FONT SIZE=2>(= in the same experiment). He claims that</FONT>
<BR><FONT SIZE=2>in his experiment V=1 and K=1. Unfortunately</FONT>
<BR><FONT SIZE=2>in his experiment V<<1, by definition, since</FONT>
<BR><FONT SIZE=2>his little wires do not positively show interference</FONT>
<BR><FONT SIZE=2>fringes at all.</FONT>
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<P><FONT SIZE=2>That said, imo, Afshar experiment *is* great,</FONT>
<BR><FONT SIZE=2>because it shows that something unexpected</FONT>
<BR><FONT SIZE=2>is going on. It is the possibility of following</FONT>
<BR><FONT SIZE=2>the (causal, reasonable) course of quanta</FONT>
<BR><FONT SIZE=2>in space and time. And this is exactly what Bohr</FONT>
<BR><FONT SIZE=2>thought.</FONT>
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<P><FONT SIZE=2>'However, since the discovery of the quantum of action, </FONT>
<BR><FONT SIZE=2>we know that the classical ideal cannot be attained </FONT>
<BR><FONT SIZE=2>in the description of atomic phenomena. In particular, </FONT>
<BR><FONT SIZE=2>any attempt at an ordering in space-time leads to a break</FONT>
<BR><FONT SIZE=2>in the causal chain, since such an attempt is bound up </FONT>
<BR><FONT SIZE=2>with an essential exchange of momentum and energy between </FONT>
<BR><FONT SIZE=2>the individuals and the measuring rods and clocks used </FONT>
<BR><FONT SIZE=2>for observation; and just this exchange cannot be</FONT>
<BR><FONT SIZE=2>taken into account if the measuring instruments are </FONT>
<BR><FONT SIZE=2>to fulfil their purpose. Conversely, any conclusion, </FONT>
<BR><FONT SIZE=2>based in an unambiguous manner upon the strict conservation </FONT>
<BR><FONT SIZE=2>of energy and momentum, with regard to the dynamical</FONT>
<BR><FONT SIZE=2>behaviour of the individual units obviously necessitates </FONT>
<BR><FONT SIZE=2>a complete renunciation of following their course </FONT>
<BR><FONT SIZE=2>in space and time'. </FONT>
<BR><FONT SIZE=2>[Bohr, Atomic Theory and the Description of Nature, pp. 97-8, </FONT>
<BR><FONT SIZE=2>Cambridge University Press, 1934]</FONT>
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