Not signed in (Sign In)

Start a new discussion

Not signed in

Want to take part in these discussions? Sign in if you have an account, or apply for one below

  • Sign in using OpenID

Site Tag Cloud

2-categories 2-category 2-category-theory abelian-categories adjoint algebra algebraic algebraic-geometry algebraic-topology analysis analytic-geometry arithmetic arithmetic-geometry beauty bundles calculus categories category category-theory chern-weil-theory cohesion cohesive-homotopy-type-theory cohomology combinatorics complex-geometry computable-mathematics computer-science connection constructive constructive-mathematics cosmology deformation-theory descent diagrams differential differential-cohomology differential-equations differential-geometry differential-topology digraphs duality education elliptic-cohomology enriched fibration finite foundations functional-analysis functor galois-theory gauge-theory gebra geometric-quantization geometry graph graphs gravity grothendieck group-theory harmonic-analysis higher higher-algebra higher-category-theory higher-differential-geometry higher-geometry higher-lie-theory higher-topos-theory homological homological-algebra homotopy homotopy-theory homotopy-type-theory index-theory infinity integration integration-theory k-theory lie lie-theory limits linear linear-algebra locale localization logic manifolds mathematics measure-theory modal-logic model model-category-theory monad monoidal monoidal-category-theory morphism motives motivic-cohomology multicategories noncommutative noncommutative-geometry number-theory of operads operator operator-algebra order-theory pasting philosophy physics planar pro-object probability probability-theory quantization quantum quantum-field quantum-field-theory quantum-mechanics quantum-physics quantum-theory question representation representation-theory riemannian-geometry scheme schemes set set-theory sheaf simplicial space spin-geometry stable-homotopy-theory stack string-theory subobject superalgebra supergeometry svg symplectic-geometry synthetic-differential-geometry terminology theory topology topos topos-theory type type-theory universal variational-calculus

Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to nForum
If you want to take part in these discussions either sign in now (if you have an account), apply for one now (if you don't).
    • CommentRowNumber1.
    • CommentAuthorUrs
    • CommentTimeJul 5th 2012

    started an entry Planck’s constant with a remark on its meaning from the point of view of geometric quantization (and nothing else, so far).

    • CommentRowNumber2.
    • CommentAuthorUrs
    • CommentTimeMar 29th 2014

    Added Planck constant – Basic definition, just for fun. (And also since it’s a point rarely made explicit, simple as it is.)

    • CommentRowNumber3.
    • CommentAuthorTodd_Trimble
    • CommentTimeMar 29th 2014
    • (edited Mar 30th 2014)

    Am a little surprised that nothing (or barely anything) was said about the dimension of hh as a physical unit, as measured in (kg)m 2s 1(kg)m^2 s^{-1} or whatever. Is that considered too low-level?

    • CommentRowNumber4.
    • CommentAuthorUrs
    • CommentTimeMar 30th 2014

    It’s not too low level, no. Please add it if you have energy.

    • CommentRowNumber5.
    • CommentAuthorTodd_Trimble
    • CommentTimeApr 1st 2014

    Well, I had the time and energy (measured in joule-seconds?) to put in a little something about Planck’s constant as a physical constant, but it might be considered embarrassingly low-level. In which case, please feel free to jazz it up to suit taste.

    • CommentRowNumber6.
    • CommentAuthorThomas Holder
    • CommentTimeApr 1st 2014

    Mentioning the Planck scale there would give a peg to hang on a funny observation of John L. Bell in some version of ch.1. of his primer of infinitesimal analysis, namely that the infinitesimal neighborhood of 0 is akin to the Planck scale in that there the order-theoretic structure of the smooth line breaks down. I wonder whether more could be made of this observation. Unfortunately, I can’t give a more precise reference here, because I have this version in electronic form only, and it isn’t contained in the first print edition nor can I find a corresponding text on his homepage.

    • CommentRowNumber7.
    • CommentAuthorUrs
    • CommentTimeApr 1st 2014

    Thanks, Todd.

    I have moved your addition up to the top. Then I added an Idea-section which points to the various subsections.

    Will have to create an entry physical unit now.

    • CommentRowNumber8.
    • CommentAuthorUrs
    • CommentTimeJan 26th 2019
    • (edited Jan 26th 2019)

    added a brief History-comment just so as to link back to entries such a black body radiation and ultraviolet catastrophe

    diff, v15, current

Add your comments
  • Please log in or leave your comment as a "guest post". If commenting as a "guest", please include your name in the message as a courtesy. Note: only certain categories allow guest posts.
  • To produce a hyperlink to an nLab entry, simply put double square brackets around its name, e.g. [[category]]. To use (La)TeX mathematics in your post, make sure Markdown+Itex is selected below and put your mathematics between dollar signs as usual. Only a subset of the usual TeX math commands are accepted: see here for a list.

  • (Help)