What I learned as a hired consultant to autodidact physicists

Re:What I learned as a hired consultant to autodidact physic... by Analemma_ on Thursday August 11, 2016 @04:12PM (#12271265)

I can see it happening. As a non-physicist programmer who knows a little bit about a little bit through popular science (like the people being discussed in the article), I know "just enough to be dangerous" about renormalization. i.e., that it was for a while a controversial practice derided by opponents as "handwaving problems away with division by infinity".

I also know that much smarter people than me don't consider it a problem anymore, but it's exactly the kind of gap in the door that self-taught "experts" would use to say that the whole edifice of science needs to be torn down as incorrect and replaced with their personal theory.

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Re:What I learned as a hired consultant to autodidact physic... by Analog24 on Thursday August 11, 2016 @04:29PM (#12271339)

"handwaving problems away with division by infinity"

I'm being very pedantic here but it's a bit better to think of it as subtracting infinity from another infinity.

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Re:What I learned as a hired consultant to autodidact physic... by noobermin on Friday August 12, 2016 @12:25AM (#12273389)

Renormalization is not the same thing as regularization. Regularization is a mathematical trick while renormalization has a very physical interpretation, for example, its use in statistical mechanics. In QFT, they are related and I think sometimes conflated, which is unfortunate.

You can easily describe renormalization without math because it's a physical concept. Regularization is more difficult. If the OP decided divergent integral regularization was an interesting conversation topic then I am on your side.

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Re:What I learned as a hired consultant to autodidact physic... by aminorex on Friday August 12, 2016 @04:18PM (#12278486)

Please do then. Explain it without math, I mean.

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Re:What I learned as a hired consultant to autodidact physic... by noobermin on Friday August 12, 2016 @08:55PM (#12279704)

The entire content of renormalization is summarized as this, given a calculation, you make it match the interaction at some energy. Assuming that the fix is essentially choosing the "scale" of quantities (say, voltage of the electric field, or how strongly electrons tug on other electrons) you are calculating, you fix that scale by making sure that after including it in your theory now, that your result matches the measured interaction at your chosen energy scale exactly. That is renormalization.

If you do this, you find that you need to choose a scale that "absorbs" the infinities of your calculations (yes, an "infinite" scale). But, the stuff that is not absorbed is a function of energy, and this actually agrees very well with experiment beyond the scale you normalized to.

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Re:What I learned as a hired consultant to autodidact physic... by dylukes on Thursday August 11, 2016 @08:43PM (#12272790)

In log scale yes.

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Re:What I learned as a hired consultant to autodidact physic... by gohrt on Thursday August 11, 2016 @06:51PM (#12272227)

eh, raise the terms as an exponent and subtraction becomes division. :)

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Re:What I learned as a hired consultant to autodidact physic... by philtar on Thursday August 11, 2016 @06:43PM (#12272172)

Pretty sure he means people like you when he talks about his non-physicist friends.

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