[mass noun] The property (displayed by solutions of some compounds, notably many sugars) of rotating the plane of polarization of plane-polarized light.
- ‘In the slightly different situation of a crystal with optical activity, the center of the bull's-eye is not black, and its color gives information about the amount of twist.’
- ‘These materials are said to display optical activity, and are rapidly gaining popularity among engineers.’
- ‘If the product and catalyst of a reaction were the same, then amplification of optical activity might just be possible, they reasoned.’
- ‘Surprisingly no optical activity was found, even with a 100-fold magnification of the scale, although strong UV absorption was retained.’