Light intensity as mechanical potential: a symmetry-based approach

ABSTRACT

Light-induced motion is of increasing importance in materials development. In many situations, modelling the detailed dynamics of light-induced phenomena is not practical, yet a description of the behaviour is needed. We attempt to show here that in some such situations, symmetry arguments can prove useful. We outline a simple scheme where symmetry arguments can be useful in modelling the dynamics, and show, in three examples, that in some instances, light intensity may be regarded as a mechanical potential. Such an approach may help in understanding photoactuations in situations where more detailed analyses are impractical.

Graphical Abstract

KEYWORDS:

• Light-induced motion
• symmetry arguments
• mechanical potential

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. For realistic modelling, the temperature here would need to be an effective temperature, related to the kinetic energy of particles.

2. Similar behaviour has been observed at the surface as well as in the bulk fluid by Y. Yu [20].

3. Here we ignore relativity and time reversal.

4. Murray Gell-Mann likened physics to totalitarianism, where ‘what is not forbidden is compulsory’ [25].

Additional information

Funding

This work was supported by the Office of Naval Research [ONR N00014-18-1-2624].