In chemistry,<unk>  assays the rotational diffusion of a molecule from the decorrelation of polarization in<unk> , i.e., between the exciting and emitted (fluorescent) photons.  This decorrelation can measure the "tumbling time" of the molecule as a whole, or of a part of the molecule relative to the whole.  From the rotational diffusion constants, one can estimate the rough shape of a macromolecule.
Fluorescence anisotropy
Anion gap
Extraction ratio
Molecular mass
Electrochemical gradient
Spin quantum number
Chemical polarity
Isoelectric point