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Like ∇^2 u = Δu = f? It's not really cryptic, it's taught in multivariable. And it's not done to look sophisticated, it's so that you can instantly recognize th
by augustt 6y ago
Like ∇^2 u = Δu = f? It's not really cryptic, it's taught in multivariable. And it's not done to look sophisticated, it's so that you can instantly recognize that it's Laplace, or Poisson, etc.
If I tell you B = (dA_z/dy - dA_y/dz)i + (dA_x/dz - dA_z/dx)j + (dA_y/dx - dA_x/dy)k do you instantly see what operator is applied? That's why you just write B = ∇×A.
People presenting ideas in shorter notation is not showing a lack of progress - usually it's the opposite. In old optimization papers people would write out the entire normal equations, entry by entry. Not really insightful at all, compared to A'Ax = A'b.
- StandardFuture 6y agoThis seems to be presenting a false dichotomy. B = (dA_z/dy - dA_y/dz)i + (dA_x/dz - dA_z/dx)j + (dA_y/dx - dA_x/dy)k and B = ∇×A are not the only ways, out of all possible strings, to encode that information. This is the power of modern programming languages. They are mathematics with much better syntax.
- vertbhrtn 6y agoThat's a trivial triangle. Modern papers go far beyond that and invent some partial diff operators, like "F.∇" which means "do the grad first, then dot product", use uncommon context-depenedent subscript and superscript indices that can mean fairly arbitrary things and so on. But my complaint is mostly about the use of unnecessary and terse formalism where a short full form is replaced by a 40% shorter form just to use a uber generic high order operator to look fancy and refer to couple mysterious (and useless in the context) theorems or other papers. This is when I have to read other similar papers and see wtf that cryptic equation really means (and often it means some mundane thing). Programmers have the same kind of mental problem: in order to look sophisticated, they intentionally use more cryptic and terse solutions to impress "less initiated" and to hide the fact that what they are doing isn't that complex.