This comes from the Chinese and Spanish scientists – see https://www.doi.org/10.1038/s41377-022-00979-2 … and https://phys.org/news/2022-10-complex-maxwell-stress-tensor-theorem.html … when an electromagnetic wave, such as a monochromatic plane wave, impinges on a body, charges are separated. This introduces multipoles. Hence, optical manipulation of matter by using the mechanical action of light is one of the vibrant subjects of micro and nanoscience. The Maxwell stress tensor, which expresses the conservation of linear and angular momentum, is the cornerstone of electromagnetic forces. In a new study, Light: Science and Applications, demonstrate that the theory describes only half the physics of the electromagnetic optical force. The other half of the theorem needs an explanation.
Staying on Physics, Polish scientists, in cooperation with Italy, the UK, and Ireland, have built a new photonic system with electrically tuned topological features – see Science Advances journal at https://www.doi.org/10.1126/sciadv.abq7533 … but see also https://phys.org/news/2022-10-physicists-photonic-electrically-tuned-topological.html ..