From: george murphy (gmurphy@raex.com)
Date: Thu Jul 03 2003 - 07:33:42 EDT
Richard McGough wrote:
> Hi Glen,
>
> You wrote:
>
> >If you are correct, then I would challenge you to write a letter or article to a PEER-REVIEWED physics journal pointing out the simple and supposedly stupid error that Tegmark made. It would be good for you to go through the same peer review so that we can be sure that your criticisms are valid.
>
> I think I would prefer to have the issue settled here. To my understanding, many folks here are fully competent to judge such "small matters" as this. My criticism is not very involved - it would fit in a single paragraph in the letter to the editor. There is no need for what you suggest.
>
> >Gee, then I guess, G.F.R. Ellis, a 'minor' figure in cosmology today, makes the same mistake.
>
> Sure, why not? I'm not into authority worship. He wouldn't be the first great mind to err. May I suggest you read Jeremiah 17.5 and Proverbs 3.5f?
>
> You seem to be retreating from logical argument to empty challenges and name dropping.
>
> In response to my statement that "somebody who knew first year quantum physics should have mentioned that physical states generally involve infinite superpositions of eigenstates" you said:
>
> >Well I have had first year quantum physics. And what I read doesn't agree with what you are saying. there is only an infinite summation if there are an infinite number of different states for the system.
>
> You then went on to blunder through some first year QM. It took me a while to figure out your fundamental confusion, but I got it now. It stemmed from the ambiguity of the phrase "infinite supperpostion of eigenstates" which by itself could mean either
>
> 1) A single state that results from summing an inifinite number of eigenstates
>
> or
>
> 2) An infinite number of states that are each superpositions of eigenstates.
>
> You wrote a great deal about #1, as if it were somehow a response to something I wrote. Your confusion of #1 for #2 appears incomprehensible in light of the fact that my WHOLE ARGUMENT was based on the infinite number of distinct states that can be formed by linear superposition of two eigenstates in the form of a FINITE SUM:
>
> |s> = a|u> + b|d> with aa* + bb* = 1
>
> This is the equation I wrote in my original post. My point stands.
>
> You really seem to be in way over your head, Glen. You simply are not tracking the argument. The things I am saying really are first year quantum physics. What is your occupation? Are you an academic?
> You then went on to quote more calculations from Tegmark (from a different publication) that contained the same flaws as the original, namely, he treats all possible physical configuations in the binary "there is or is not a proton at point (x,y,z)." This approach is not merely silly, it is unphysical. It doesn't match any model of reality, and it completely ignores the FACT that the number of possible physical configurations of finite systems can be and typically is INFINTE. His tiny little finite number 2^10^118 is ludicrous. It should be obvious to anybody with knowledge of physics, even those familar with only classical mechanics since there also is a continuous infinity of classical states.
>
> Finally, you left us all with yet another profound insight into your own character:
>
> >In that way, you can show everyone that you are correct and he is a hopeless incompentent.
>
> Yes, well, your words speak for themselves.
Richard et al -
There is of course an infinite number of linear combinations of 2 linearly independent vectors &
in that sense an infinite number of possible states for an electron when only spin is considered. But there are only two linearly indepndent vectors, & such a system is commonly referred to as "a two state system" by physicists. & as David points out, it is the latter enumeration which is important for purposes of ststistical mechanics.
That it follows from such considerations that there is an exact replica of each of us somewhere if the universe is large enough seems to me more debatable, especially when one takes into account the time development (both via Schroedinger and the measurement process). So Tegmark's claim is not obviously false but is certainly debatable.
But, you may say, that's just my opinion & you don't have to accept it on my authority as a physicist. You certainly won't if you can dismiss George Ellis. But how are we going to "settle it here" as you put it? You can continue to debate everyone who posts an argument disagreeing with you, & the matter may never be settled to your satisfaction. Peer-review is not infallible but it is one way in which a broad community of scholars in a discipline can indicate that a particular claim is or is not worthy of consideration - which is of course not the same thing as simply true or false. It is one thing to object to the way in which peer-review has dealt with a paper. It's another to refuse
submit an idea to such review. Glenn's suggestion was perfectly reasonable and I think you should follow it up.
Your questions to Glenn, "What is your occupation? Are you an academic?" suggest an appeal to authority which is hardly consistent with your earlier statement about "authority worship." & in fact the whole tone of your post to him is snottier than one would expect from someone who signs off with "B'Shem El Elyon".
Shalom,
George
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