Given the harmful effects of light pollution, a pair of astronomers has coined a new term to help focus efforts to combat it. Their term, as reported in a brief paper in the preprint database arXiv and a letter to the journal Science, is “noctalgia.” In general, it means “sky grief,” and it captures the collective pain we are experiencing as we continue to lose access to the night sky.
That site is claiming that phosphor-converted amber LEDs provide all the benefits of low-pressure sodium. They do not; one of the benefits of LPS is that astronomers have a very narrow frequency band to filter out, while PC amber is much wider. Monochromatic amber LEDs are more comparable to LPS.