When light is an equal mix of all visible frequencies, we call it white light. By analogy, sound that is a mix of all audible frequencies is called white noise. For sound, there is an additional ...
Imagine we are observing a star. The light coming from a star enters an optical instrument that will give us some observed data, such as the spectrum of light say. What we observe is not the true ...
A purely phase-modulated signal has no power modulation. This is obvious enough if you look at the time series, but I'd like to "see" it in the frequency domain. In physical terms, if we take a ...