Monday, March 09, 2015

Conflicting accounts

Whenever Bible history is thought to conflict with extrabiblical historical sources, unbelievers just assume the Bible must be wrong. Can't be the extrabiblical sources.

In this post I'm going to briefly discuss two conflicting accounts regarding the semantic origins of information theology. It's a question of no great intrinsic importance, but it nicely illustrates the difficulty, in the case of conflicting accounts, of determining which account is correct–or if both accounts get some things right and some things wrong. How does a historian sift through conflicting evidence? 

During this meeting, Tribus queried Shannon as to his reason for choosing to call his information function by the name ‘entropy’, the details of which were first made public in Tribus' 1971 article “Energy and Information”, wherein he states: [4]
“What’s in a name? In the case of Shannon’s measure the naming was not accidental. In 1961 one of us (Tribus) asked Shannon what he had thought about when he had finally confirmed his famous measure. Shannon replied: ‘My greatest concern was what to call it. I thought of calling it ‘information’, but the word was overly used, so I decided to call it ‘uncertainty’. When I discussed it with John von Neumann, he had a better idea. Von Neumann told me, ‘You should call it entropy, for two reasons. In the first place you uncertainty function has been used in statistical mechanics under that name. In the second place, and more importantly, no one knows what entropy really is, so in a debate you will always have the advantage.” 
Tribus, in his 1987 article “An Engineer Looks at Bayles”, recounts his discussion with Shannon on this question as follows: [5]
“The same function appears in statistical mechanics and, on the advice of John von Neumann, Claude Shannon called it ‘entropy’. I talked with Dr. Shannon once about this, asking him why he had called his function by a name that was already in use in another field. I said that it was bound to cause some confusion between the theory of information and thermodynamics. He said that Von Neumann had told him: ‘No one really understands entropy. Therefore, if you know what you mean by it and you use it when you are in an argument, you will win every time.” 
1. Tribus, M. (1998). “A Tribute to Edwin T. Jaynes”. In Maximum Entropy and Bayesian Methods, Garching, Germany 1998: Proceedings of the 18th International Workshop on Maximum Entropy and Bayesian Methods of Statistical Analysis (pgs. 11-20) by Wolfgang von der Linde, Volker Dose, Rainer Fischer, and Roland Preuss. 1999. Springer.
2. (a) Jaynes, E. T. (1957) “Information theory and statistical mechanics”, (PDF), Physical Review 106:620.
(b) Jaynes, E. T. (1957) “Information theory and statistical mechanics II”, (PDF), Physical Review 108:171.
3. Tribus, Myron. (1961). Thermostatics and Thermodynamics: an Introduction to Energy, Information and States of Matter. Van Nostrand.
4. (a) Tribus, Myron and McIrving, Edward C. (1971). “Energy and Information”, Scientific American, 225: 179-88.
(b) Ben-Naim, Arieh. (2010). Discover Entropy and the Second Law of Thermodynamics: a Playful Way of Discovering a Law of Nature (pg. 12). World Scientific.
5. Tribus, Myron. (1987). “An Engineer Looks at Bayes”, Seventh Annual Workshop: Maximum Entropy and Bayesian Methods, Seattle University August, in: Foundations (editor: Gary J. Erickson) (pgs. 31-32, etc.), Springer, 1988.

Thermodynamics and entropy; cryptography 

Shannon:Well, let me also throw into this pot, Szilard, the physicist. And von Neumann, and I’m trying to remember the story. Do you know the story I’m trying to remember?
Price:Well, there are a couple of stories. There’s the one that Myron Tribus says that von Neumann gave you the word entropy, saying to use it because nobody, you’d win every time because nobody would understand what it was.
Price:And furthermore, it fitted p*log(p) perfectly. But that, but then I’ve heard . . .
Shannon:von Neumann told that to me?
Price:That’s what you told Tribus that von Neumann told that to you.
Shannon:[laughs – both talking at once]
Price:Bell Labs too, that entropy could be used. That you already made that identification. And furthermore in your cryptography report in 1945, you actually point out, you say the word entropy exactly once in that report. Now this is 1945, and you liken it to Statistical Mechanics. And I don’t believe you were in contact with von Neumann in 1945, were you? So it doesn’t sound to me as though von Neumann told you entropy. 
Shannon:No, I don’t think he did.
Price:This is what Tribus quoted.
Shannon:Yeah, I think this conversation, it’s a very odd thing that this same story that you just told me was told to me at Norwich in England. A fellow —
Price:About von Neumann, you mean?
Shannon:Yeah, von Neumann and me, this conversation, this man, a physicist there, and I’ve forgotten his name, but he came and asked me whether von Neumann, just about the thing that you told me, that Tribus just told you, about this fellow. . .
Price:That was Jaynes, I imagine the physicist might have been [Edwin] Jaynes.
Shannon:Yes, I think it was, I think so. Do you know him?
Price:Well, he’s published in the same book as Tribus, you see. This is a book called The Maximum Entropy Formalism. You’ve probably seen that book, but they have chapters in it, and Jaynes, the physicist —
Shannon:Now, I’m not sure where I got that idea, but I think I, somebody had told me that. But anyway, I think I can, I’m quite sure that it didn’t happen between von Neumann and me.
Price:Right. Well, I think that the fact that it’s in your 1945 cryptography report establishes that, well, you didn’t get it from von Neumann, that you had made the p*log(p) identification with entropy by some other means. But you hadn’t been —
Shannon:Well, that’s an old thing anyway, you know.
Price:You knew it from thermodynamics.
Shannon:Oh, yes, from thermodynamics. That goes way back.
Price:That was part of your regular undergraduate and graduate education of thermodynamics and the entropy?
Shannon:Well, not in class, exactly, but I read a lot, you know. 

i) In the first account, Myron Tribus says Claude Shannon told him that von Neumann advised him to choose the word "entropy." 

In the second account, when Shannon was queried on that story, he denies it. So who is right?

ii) Consider the abstract possibilities:

a) Shannon misremembered

b) Tribus misremembered

c) Shannon misspoke 

d) Shannon misunderstood the question (by Tribus)

e) Tribus misunderstood the answer (by Shannon)

f) Shannon lied

iii) Even though these two accounts conflict, they also intersect. The interview mentions Edwin Jaynes as somebody who asked Shannon the same question.

And the first account includes several references to Jaynes, including a tribute to Jaynes by Tribus.

It seems likely that Tribus told Jaynes what he thought Shannon told him. In other words, Jaynes is not an independent source. This isn't multiple attestation. Rather, Jaynes was apparently dependent on Tribus for that information–or misinformation (as the case may be). 

iv) Another oddity is that Shannon did, of course, use "information" to label his theory. So it's not as if he used "entropy" as a preferred alternative to "information." Both were used.

v) Did he lie? Was he too proud to give von Neuman any credit? Seems unlikely. This isn't like giving credit or sharing credit for a scientific theory or scientific discovery. Rather, this is just a question of what to name it. Shannon's reputation doesn't rise or fall one the purely semantic issue.

Moreover, Shannon admits that he may have gotten the idea from somebody else–just not von Neumann. 

Unless there was bad blood between the two, there's no reason Shannon would lie about it–that I can see.

vi) Did Shannon misremember? Suppose he was becoming forgetful at the time of the interview.

vii) To begin with, there are two different issues:

a) Did he learn about the word from von Neumann?

b) Did he choose that word to label his theory on advice from von Neumann?

It seems clear that he knew the word before he ever met von Neumann. "Entropy" was a commonly used word in his field of studies.

viii) The question of whether he misremembered is complicated by the fact that he recalls a much earlier conversation (with Jaynes) on the very same subject. Even if he was forgetful at the time of the interview (which may or may not be the case), presumably he wasn't forgetful years earlier when that prior conversation took place.

If he misremembered, it wasn't due to the aging process. Rather, he didn't remember the original conversation (with Tribus) correctly in the first place. Not that the details become fuzzy in the intervening years. 

ix) Assuming that we've eliminated some possibilities, it's harder to narrow down the list any farther. At least, based on what I quoted, I don't know who is right. Clearly there was some confusion somewhere along the line, but the evidence is insufficient to say which account is correct. 

At the time of writing, Tribus is still alive. In principle, one could ask him to clear it up. However, he's in his 90s. He's now much older than Shannon was during the interview. And his recollection hasn't improved with the passage of time. 

Of course, I don't think Scripture is ever in doubt. My point, though, is that even if we bracket inspiration, the partisan bias of the critics is unwarranted. At the very least, they should suspend judgment.  

1 comment:

  1. Why waste time trying to resolve irreconcilable contradictions? Any reconciliation or harmonization can only be ad hoc. Shannon, Price, Tribus and von Neumann (et al.) NEVER EXISTED.

    This is obvious, since the story conforms to the Mythic Scientist/Mathematician Archetype. A rehashing of the Archimedes Myth.