I’ve often wondered what broadcast radio/tv waves would look like if you could blue shift them into the visible spectrum. I’m guessing the analog broadcasts would be a light of continuously shifting color and digital broadcasts would simply flash on/off?
I’m also wondering how photons propagate such that even at infinite distance a star doesn’t blink in and out as you move laterally. Even if you take planck length points and expand them outward, at great distances you’re going to have separation between them. So why don’t photons behave this way?
AM broadcasts would be beacons of steady color that vary in brightness.
FM broadcasts would be beacons of steady brightness that vary in color.
Any star bright enough to see with the naked eye is close enough that your eye is receiving a stream of numerous photons. There are so many they fill in any gaps. However, telescopes that observe very distant stars do build up an image one photon at a time. But, they also gather all the photons from a large area and focus them using a lens or a reflector. (As does your eye to a lesser extent.) The effect you’re describing would be much more pronounced if you used a pinhole camera to form your image instead of a large aperture lens/reflector.
Basically, yes. I’m assuming that you’re envisioning taking the entire FM spectrum (say) and shifting it so that its wavelengths are in the 400–700 nm range. In that case, the amount of light at different wavelengths would vary in intensity (either continuously or discretely, depending on whether the band was digital or analog), resulting in different perceived colors at different moments. However, in practical terms the signal would be varying incredibly quickly, and your eye would have too much persistence of vision to distinguish between the rapid changes of color. In other words, it would just “look” white.
Because they’re quantum-mechanical objects that exhibit the infamous wave-particle duality. Roughly speaking, while photons are propagating through space, they don’t act like particles, they act like waves; it’s only when they’re detected that they “decide” to act like individual particles. Why and how this occurs, exactly, is a question without a universally accepted answer among physicists.
Not really. Digital broadcasts like North American digital TV would be shifting brightness and color, because it’s done using both amplitude modulation and phase shifting, and in order to shift phases you have to shift frequency. Nobody transmits a high bitrate digital signal long distance just by flipping the carrier on and off. Here’s a simple example.
Not necessarily. FM signals shift frequency with the amplitude of the sound waveform. A 20 Hz bass note should be visible as visual flicker. However, that’s only if you stretch out the radio->light frequency mapping. You wouldn’t see a color change if you took the entire FM spectrum and mapped it to 400-700 nm. However, if you looked at a station at a time it should be fairly obvious.
Also, the whole spectrum could appear as any number of colors depending on the station distribution and the power level. It’ll certainly be whitish under most circumstances, but will probably have at least some kind of color cast to it.
Digital transmissions tend to have more even spectral distributions and resemble white noise. If you looked only at the “HD Radio” sidelobes of FM broadcasts, they would indeed appear white.