This is a very interesting physical phenomenon, often measured experimentally using a torsional pendulum illuminated by a laser on one of its two faces, I only also wanted to explain that o entirely realize these sci pieces are not to everyone's taste, certainly, I only thought to introduce those with sci interests on the site here to ideas they might not otherwise typically encounter, I'm of course by no means expecting universal interest, certainly, I hope there's some interest in such material, I'd gotten some good feedback thus far, many thanks....