What Scientific Term or Concept Ought to be More Widely Known?

Re:What Scientific Term or Concept Ought to be More Widely K... by m00n on Monday January 02, 2017 @05:14AM (#13300280)

This is a pictorial description of the proof in the sibling comment. It does not use calculus of variations, just the definition of the path length of a (differentiable parametrized) curve. If you want to call your parametrization a "light-ray" thats fine, but muddies the waters for me.

Just spell out what we mean by path, length of a path, and use calculus of a single variable. No need to introduce 'time', 'constant speed' or the like.

BTW, a truly variational proof is in the wikipedia article [0].

[0] https://en.wikipedia.org/wiki/Calculus_of_variations#Example

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Re:What Scientific Term or Concept Ought to be More Widely K... by wfunction on Monday January 02, 2017 @05:44AM (#13300386)

> This is a pictorial description of the proof in the sibling comment.

Well, for starters, it was also posted an hour before that one...

But it's not the same. The sibling comment performs a change of basis. I don't.

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