Q. I have a silver comb, brush and mirror set. The tortoiseshell teeth have fallen out of the comb. (I’m not sure if they’re real tortoiseshell or plastic.) Also, the silver needs polishing. Whom can ...

Optical frequency comb sources provide thousands of precise and accurate optical lines in a single device enabling the broadband and high-speed detection required in many applications. A main ...

An important technique for discovering and characterizing planets beyond our solar system relies upon measurement of weak Doppler shifts in the spectra of host stars induced by the influence of ...