I would like to know more about the interactions in nature. Here's an example based on the observation of how radio waves efficiently transmit music from the radio stations. You can carry the radio with you around the city, and the signal never disappears. It seems as though the position and the orientation of the radio in space do not represent any particular filter for the incoming signals. Of course, some glitches are possible when you are driving in a bus. I conclude that the radio signal is "one-dimensional", because it does not possess any directionality or "shape". It is just a series of oscillations in space that are affecting the receiving antenna wherever it is located. The radio is not that perfect, however. You could find a special kind of directional antenna and point out the direction of the radio station emitter. You could find the obstacles that the radio waves cannot pass. Most of the time, none of this seems to represent a problem. Most of the time the radio signals seem to have a single dimension. Mobile/cell phones operate at higher frequencies and their signals possess much smaller "shape"; their wavelength is measured in centimeters. Their signal reception is more sensitive to direction and the obstacles make the signals bounce around. Also, there are many more antennas for mobile operators all around the neighborhood. It seems that the classical radio creates the best illusion of having a one-dimensional signal. What does it mean to be one-dimensional? Imagine a computer screen. It has many individual pixels in different colors. The light coming from each pixel to the eyes is keeping its direction in some relevant way, so that we can distinguish the individual pixels. A grid of radio antennas cannot accomplish the same thing as pixels can. They are all fuzzy in the "eye" of a common radio receiver. It can only choose a single frequency and listen to whichever antenna or antennas are broadcasting at that frequency. My question is the following. Are there any true one-dimensional signals in the nature?