4 ms·

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

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.

Analog24 10y ago
"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.
- gohrt 10y ago
  eh, raise the terms as an exponent and subtraction becomes division. :)
- dylukes 10y ago
  In log scale yes.
- noobermin 10y ago
  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.
  - aminorex 10y ago
    Please do then. Explain it without math, I mean.
    - noobermin 10y ago
      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.
philtar 10y ago
Pretty sure he means people like you when he talks about his non-physicist friends.

Analog24 10y ago

"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.

gohrt 10y ago
eh, raise the terms as an exponent and subtraction becomes division. :)
dylukes 10y ago
In log scale yes.
noobermin 10y ago
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.
- aminorex 10y ago
  Please do then. Explain it without math, I mean.
  - noobermin 10y ago
    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.

philtar 10y ago

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