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	<title>Comments on: the King&#8217;s problem on MUBs</title>
	<atom:link href="http://www.neverendingbooks.org/index.php/the-kings-problem-on-mubs.html/feed" rel="self" type="application/rss+xml" />
	<link>http://www.neverendingbooks.org/index.php/the-kings-problem-on-mubs.html</link>
	<description>lieven le bruyn&#039;s blog</description>
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		<title>By: lieven</title>
		<link>http://www.neverendingbooks.org/index.php/the-kings-problem-on-mubs.html/comment-page-1#comment-5041</link>
		<dc:creator>lieven</dc:creator>
		<pubDate>Fri, 29 Feb 2008 17:41:06 +0000</pubDate>
		<guid isPermaLink="false">http://www.neverendingbooks.org/index.php/the-kings-problem-on-mubs.html#comment-5041</guid>
		<description>&lt;p&gt;[quote comment=&quot;5040&quot;]&lt;p&gt;Thanks for the link; I should make an interesting comment in return.&lt;/p&gt;
[/quote]&lt;/p&gt;

&lt;p&gt;Carl, if only all people would react this way, I&#039;d only write link-posts from now on...&lt;/p&gt;
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		<content:encoded><![CDATA[<p>[quote comment="5040"]</p><p>Thanks for the link; I should make an interesting comment in return.</p>
[/quote]

<p>Carl, if only all people would react this way, I&#8217;d only write link-posts from now on&#8230;</p>]]></content:encoded>
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		<title>By: Carl Brannen</title>
		<link>http://www.neverendingbooks.org/index.php/the-kings-problem-on-mubs.html/comment-page-1#comment-5040</link>
		<dc:creator>Carl Brannen</dc:creator>
		<pubDate>Fri, 29 Feb 2008 00:39:54 +0000</pubDate>
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		<description>&lt;p&gt;Thanks for the link; I should make an interesting comment in return.&lt;/p&gt;

&lt;p&gt;One of the mysteries of spin-1/2 quantum mechanics is why two eigenstates are sufficient to describe a state. Everyone knows how the math works, but physically, it is difficult to understand especially for those who wish their physics to have a classical interpretation.&lt;/p&gt;

&lt;p&gt;In elementary particles, the electron is most naturally described as a combination of left and right handed particles. To get a left / right handed electron, you accelerate a regular electron in the direction / against the direction of its spin vector. How much do you accelerate it? To infinity, but not beyond. You have to get the electron to speed c. The left handed electron interacts weakly; the right handed one does not.&lt;/p&gt;

&lt;p&gt;If one considers waves in 3 dimensions, say sound waves or classical light waves, to obtain sufficient degrees of freedom to describe an arbitrary direction wave requires that one begin with three degrees of freedom, say three waves travelling in perpendicular directions. This is one more than the quantum spin 1/2 case even though the electron is apparently built from components that do travel at speed c, and therefore should take 3 degrees of freedom, or maybe 6 (so that the waves can go either way, or you can account for position and momentum rather than just position), but certainly not 2.&lt;/p&gt;

&lt;p&gt;When you replace the usual spin-1/2 basis states (spin up and spin down) with a Pauli MUB of 3 basis states, you end up with the classically expected 3 / 6 degrees of freedom. So MUBs are tied up with a more classical way of looking at quantum mechanics. From a preon point of view, this says that classical mechanics may be hiding underneath a quantum facade.&lt;/p&gt;

&lt;p&gt;I guess I should admit that I&#039;ve temporarily given up on the d=3 MUB case and am working on d=2 cases. Kea, I should have a post out soon with a new preon model that uses this idea.&lt;/p&gt;
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		<content:encoded><![CDATA[<p>Thanks for the link; I should make an interesting comment in return.</p>

<p>One of the mysteries of spin-1/2 quantum mechanics is why two eigenstates are sufficient to describe a state. Everyone knows how the math works, but physically, it is difficult to understand especially for those who wish their physics to have a classical interpretation.</p>

<p>In elementary particles, the electron is most naturally described as a combination of left and right handed particles. To get a left / right handed electron, you accelerate a regular electron in the direction / against the direction of its spin vector. How much do you accelerate it? To infinity, but not beyond. You have to get the electron to speed c. The left handed electron interacts weakly; the right handed one does not.</p>

<p>If one considers waves in 3 dimensions, say sound waves or classical light waves, to obtain sufficient degrees of freedom to describe an arbitrary direction wave requires that one begin with three degrees of freedom, say three waves travelling in perpendicular directions. This is one more than the quantum spin 1/2 case even though the electron is apparently built from components that do travel at speed c, and therefore should take 3 degrees of freedom, or maybe 6 (so that the waves can go either way, or you can account for position and momentum rather than just position), but certainly not 2.</p>

<p>When you replace the usual spin-1/2 basis states (spin up and spin down) with a Pauli MUB of 3 basis states, you end up with the classically expected 3 / 6 degrees of freedom. So MUBs are tied up with a more classical way of looking at quantum mechanics. From a preon point of view, this says that classical mechanics may be hiding underneath a quantum facade.</p>

<p>I guess I should admit that I&#8217;ve temporarily given up on the d=3 MUB case and am working on d=2 cases. Kea, I should have a post out soon with a new preon model that uses this idea.</p>]]></content:encoded>
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		<title>By: Kea</title>
		<link>http://www.neverendingbooks.org/index.php/the-kings-problem-on-mubs.html/comment-page-1#comment-5039</link>
		<dc:creator>Kea</dc:creator>
		<pubDate>Thu, 28 Feb 2008 23:58:22 +0000</pubDate>
		<guid isPermaLink="false">http://www.neverendingbooks.org/index.php/the-kings-problem-on-mubs.html#comment-5039</guid>
		<description>&lt;p&gt;Cool!!! And thanks. Note that we are associating the d=3 case with mass operators, from which one may derive actual rest masses. This is extremely controversial, physically speaking, because all good physicists &#039;know&#039; that masses run in QFT renormalisation, and they don&#039;t necessarily believe there is anything fundamental about the rest mass values. This applies also (sigh) to most physicists working in &#039;quantum gravity&#039;. My recent interest in codes stems from the urgent need to derive more than the 3 charged lepton masses, or the unknown neutrino masses, since the only truly convincing physical test is a set of numbers far beyond &#039;coincidence&#039;.&lt;/p&gt;
</description>
		<content:encoded><![CDATA[<p>Cool!!! And thanks. Note that we are associating the d=3 case with mass operators, from which one may derive actual rest masses. This is extremely controversial, physically speaking, because all good physicists &#8216;know&#8217; that masses run in QFT renormalisation, and they don&#8217;t necessarily believe there is anything fundamental about the rest mass values. This applies also (sigh) to most physicists working in &#8216;quantum gravity&#8217;. My recent interest in codes stems from the urgent need to derive more than the 3 charged lepton masses, or the unknown neutrino masses, since the only truly convincing physical test is a set of numbers far beyond &#8216;coincidence&#8217;.</p>]]></content:encoded>
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		<title>By: the King’s problem on MUBs</title>
		<link>http://www.neverendingbooks.org/index.php/the-kings-problem-on-mubs.html/comment-page-1#comment-5036</link>
		<dc:creator>the King’s problem on MUBs</dc:creator>
		<pubDate>Thu, 28 Feb 2008 15:19:29 +0000</pubDate>
		<guid isPermaLink="false">http://www.neverendingbooks.org/index.php/the-kings-problem-on-mubs.html#comment-5036</guid>
		<description>&lt;p&gt;[...] TrueGameHeadz BlogHeadz wrote an interesting post today onHere&#8217;s a quick excerpt MUBs (for Mutually Unbiased Bases) are quite popular at the moment. Kea is running a mini-series Mutual Unbias as is Carl Brannen. Further, the Perimeter Institute has a good website for its seminars where they offer streaming video (I like their MacromediaFlash format giving video and slides/blackboard shots simultaneously, in distinct windows) including a talk on MUBs (as well as an old talk by Wootters). So what are MUBs to mathematicians? Recall that a d-state quantum system is just the [...]&lt;/p&gt;
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		<content:encoded><![CDATA[<p>[...] TrueGameHeadz BlogHeadz wrote an interesting post today onHere&#8217;s a quick excerpt MUBs (for Mutually Unbiased Bases) are quite popular at the moment. Kea is running a mini-series Mutual Unbias as is Carl Brannen. Further, the Perimeter Institute has a good website for its seminars where they offer streaming video (I like their MacromediaFlash format giving video and slides/blackboard shots simultaneously, in distinct windows) including a talk on MUBs (as well as an old talk by Wootters). So what are MUBs to mathematicians? Recall that a d-state quantum system is just the [...]</p>]]></content:encoded>
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