When a `theory’ is not a theory


My good friend Adam is a postgrad at the Cambridge Institute of Astronomy. He’s active in science outreach and is good at identifying key points where the general public and practicing scientists often misunderstand one another.

One particular point that has come up several times is the use of the word “theory” in high energy physics. Let’s start out with a few select definitions from wiktionary:

theory, n.

  1. (general usage) An unproven conjecture
  2. (science) A logical structure that enables one to deduce the possible results of every experiment that falls within its purview
  3. (mathematics) A field of study attempting to exhaustively describe a particular class of constructs

When creationists say “evolution is just a theory,” they are expressing their fundamental confusion between the first and the second definitions, i.e. between the common and the scientific use of the word ‘theory.’

Adam claims that there is also potential for confusion between the scientific and the mathematical (second and third) definitions when physicists refer to “string theory.” He proposes that while strings are a mathematical theory, it is scientifically a ‘string hypothesis.’ (I am not totally convinced by this.) I should note that this is not meant to discount the relevance of string research, only to make a point of nomenclature.

For a theoretical physicist nomenclature is irrelevant and string theory is judged by its scientific and mathematical content, not its label. Adam’s concern, however, is that this sends mixed messages to the general public, large portions of whom—unfortunately—seem to still be hung up about the difference between the first and second definitions of the word ‘theory.’

One solution is to rename grade school mathematics and append the word “theory” after every subject, e.g., “multiplication theory.” Hey, how did my credit card bill get so large? Compound interest? But that’s just a theory!

So here’s the question: does the phrase “string theory” send mixed messages to the general public? Or is this just dictionary nit-picking?

2 Responses to “When a `theory’ is not a theory”

  1. 1 robert

    In enlightened company, the word theory is a problematic in part because of its role in ‘soft’ subjects, in literary and social ‘theory’. Practitioners of the ‘hard’ sciences only know these fields of intellectual endeavour as the butt of Sokal’s hoax, and that they stand as a dire warning of what theoretical physics might become should it continue to eschew contact with experiment. To a large part of the soi-dissant educated elite, however, this casuistical nonsense, with its word-play, self-reference and appeal to specious authority, is the only experience of theory they have. So it’s no surprise that they think that the word can replaced by ‘bollocks’, with little if any loss of meaning. More generally, the appropriation of terminology, that is then used merely for effect, does nothing to foster inter-disciplinary understanding.

  2. 2 Karim

    Given that we still have to hear of any experimental confimation of a prediction made by string theory, the first definition (An unproven conjecture) is more applicable. QED, on the other hand, has had unparalleled experimental successes and fully deserves the second definition.

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