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Sunday, January 12, 2014

Randomness in nature

I have talked before about randomness. Somehow it seems important to know whether the world we live in is driven in part by fundamentally random processes.

Some recent findings seem to confirm (though 'confirm' is probably too strong a word) what quantum theory has suggested all along: that there are basic physical processes which are truly random.

I might also mention in this context that, in doing a bit of reading on probability and related matters, I happened to come across some references to, and a paper by, the physicist Edwin Thompson Jaynes (1922-1998). Jaynes promoted the view that probability theory is an extension of logic.

This is intuitively plausible. The concept of truth (and truth tables) lies at the heart of propositional logic, and T is, of course, equivalent to a probability of 1, F to a probability of 0. Probability theory just fills in the bits in between in a quantitative way!*

Of particular interest to me is Jaynes's notion of a 'mind projection fallacy' which he sees as a root cause of much false thinking, including what he sees as the mistaken ascription of randomness to (certain) natural events or processes.

But his case seems to suffer from an overdependence on personal intuition as well as from a lack of historical perspective. For example, he develops** his concept of a mind projection fallacy without (to my knowledge) relating it to other clearly similar or related concepts – from animism to teleological reasoning – which have been widely discussed over the last century-and-a-half.

Jaynes argues that this fallacy is evident not only in the thinking of primitive cultures and amongst uneducated people but also in scientific contexts. He uses his mind projection idea to argue against certain interpretations of probability theory and statistics as well as against certain interpretations of quantum mechanics.

The basic thought seems to be that theoreticians are all too inclined to project their perspectives (their particular states of knowledge or ignorance) on to reality. He rejects, for example, the ascription by probability theorists – and physicists, it seems – of 'randomness' or 'stochastic processes' to nature. He rejects the Copenhagen interpretation of quantum theory as a mere projection of our ignorance.

But, as I say, I find it a bit off-putting that (in the cited paper, at any rate) he not only fails to acknowledge that others have developed and discussed notions very similar to his own, but also – ironically – that he seems to sensationalize and exaggerate the significance of his own insights and intuitions.

More on the substance of his claims later, perhaps.


Let me take this opportunity to thank past readers for their interest and commenters for their comments and to wish everyone a pleasant 2014.



* Like other objective Bayesians, Jaynes sees probabability theory as a formal, axiomatic system, and the calculus of propositions as a special case of the calculus of probabilities.

** Here, for example (PDF).

2 comments:

  1. If everything were totally random, lead could turn to gold (or water) on next Wednesday and the sun might rise in the west now and then. Hume thought we couldn't be sure about any of that, but if the universe were truly random, it probably would go blank. Meanwhile every time I drop my shoe, it lands on my foot.

    So I can see the point in Jaynes identifying a possible fallacy in finding "too much" randomness (in places it doesn't occur). I'm never too troubled by an original thinker who lacks historical precedents; sometimes they turn out to be right. Leaving related thinkers undiscussed is impolite, perhaps. But blaming him for that depends on what he misses, no? (Grain of salt here: I've always been something of a rebel.)

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  2. GC

    Your comment made me realize that I phrased my introductory remarks rather loosely. I've now revised them slightly.

    Quantum randomness, of course, has a very precise and restricted application and in no way threatens macroscopic order. Even so, it does appear to represent something very important: an end, if you like, to the explanatory chain.

    Jaynes seems to be saying that in talking about randomness 'out there' we are just projecting our ignorance, the limits (whether they are just current or permanent, contingent or necessary) of our understanding.

    This is an interesting thought.

    But I am just a bit skeptical on account of the way Jaynes presents his views: the idea that there is this fallacy that only he has clearly identified and which explains so much (too much?) about how scientific thinking has (supposedly) gone wrong.

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