5 ms·

Color doesn't have 3 dimensions, humans have 3 types of color receptors (and 1 type of broadband receptor). Spacetime has 4 dimensions. Sound can have as many

• dylan604 6y ago
  For video, a vectorscope is a way used to view the color of the video signal.[0] While it looks like a circular view, it is actually representing a sphere. QED color has 3 dimenisions [0]https://en.wikipedia.org/wiki/Vectorscope https://en.wikipedia.org/wiki/Vectorscope
  • andrewla 6y ago
    A video signal contains the assumption that color can be represented by three parameters. But those three parameters are not capable of expressing the complete gamut of visible colors. It's just close enough that there's really no point in pursuing it further.
    • sudosysgen 6y ago
      There is no biological basis for a fourth dimension of colour perception in humans. It is true that in practice we are unable to replicate the colours we can perceive. But it is possible to create a colourspace that completely contains the gamut of perceivable colours using only three dimensions.
  • slavik81 6y ago
    Our video technology is designed to capture and reproduce what humans can see. If all humans were red-green colourblind, we would only have designed our videos to capture green-blue images, and our TVs would only output green-blue images. To us, they would look like perfect reproductions of the world. In that world, you would be arguing there are only two colours. Yet, the image on those green-blue TVs would obviously not be an accurate reproduction if viewed by a person with normal RGB colour vision from our world. Similarly, compared to Geordi La Forge, we are all colourblind. He can distinguish thousands of different wavelengths of light independently, and to him our current RGB videos look nothing like the reality they attempt to depict, due to all the colours they throw away.
• sudosysgen 6y ago
  Colour does have three dimensions, though. You cannot describe human colour perception without three dimensions - frequency and magnitude is sufficient for pure waves, but saturation is needed to match colour perception of the impurity of a given tone. So colour as perceived by humans is indeed three-dimensional.
  • andrewla 6y ago
    Human color perception is three-ish-dimensional I think would be more accurate. There are no three colors that can be mixed to produce the whole gamut of colors that humans can perceive. That is, there are shades that are visibly distinct that can not be produced by the closest pigments we have to primary cyan/magenta/yellow, and similar cannot be produced by mixing of monochromatic light. Our perception is a window into the infinite dimensional space of frequency/intensity that can be very well-described by three parameters, but that is not adequate to completely describe colors even as perceived by humans.
    • sudosysgen 6y ago
      While you cannot produce all colours humans can perceive using a mix of monochromatic light (indeed, some perceivable colours are entirely impossible to be perceived without afterimages), the colourspace of human colour perception is entirely three-dimensional. This is, fundamentally, because we have three types of receptors. Pigment maps into our perception of colour are possible in theory, but it is impossible to make an ideal pigment in practice nor an ideal substrate, which is why you see the issues you do when trying to produce them in practice.
    • 6gvONxR4sf7o 6y ago
      Not only that, some people have four receptors.
  • jcranmer 6y ago
    Modern color perception theory is actually way more than 3-dimensional. That's because human perception of color isn't driven by the absolute amount of light hitting our various color receptor cells, but by the relative amounts we see in the various parts of the image, and white balance and fatigue enters the perception as well.
• BurningFrog 6y ago
  One important fact is that we hear sound frequencies MUCH better than we see light frequencies. With sound, what we hear is pretty much all the frequency information within our range. With light, the huge frequency complexity gets reduced down to our three base colors. This is why a certain "color" can be produced with an uncountable number of frequency combinations.
  • layer8 6y ago
    Part of the reason may be that the visible light spectrum only covers one "octave".
    • OscarCunningham 6y ago
      Also, if we had more types of cones then each type would have to be more spread out over the retina, so we would lose resolution. In some sense the eyes and ears are at opposite ends of a spectrum. The eyes give you lots of information about the direction light is coming from, but barely any information about its spectrum (only three types of cone), whereas the ears give you lots of information about sound's frequency spectrum, but barely any information about its direction (only two ears). Come to think of it, this could be phrased as a tradeoff between resolution in position and resolution in frequency. It's the uncertainty principle!
      • BurningFrog 6y ago
        That actually clarifies things for me. Thanks!
• andi999 6y ago
  Quite a number of humans are tetrachromat:https://en.wikipedia.org/wiki/Tetrachromacy https://en.wikipedia.org/wiki/Tetrachromacy