We should note that this latter type of shift was successfully amplified to a considerable extent by Russian physicists using the intense light of a ruby laser whose wavelength is close to that of a transition of the potassium atom. ↗
The idea of copyright did not exist in ancient times, when authors frequently copied other authors at length in works of non-fiction. This practice was useful, and is the only way many authors' works have survived even in part. ↗
How often one reads a contemporary full-length novel and thinks quietly, mutinously, that it would have worked out better at half or a third the length. ↗