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> here on Earth, it will vary from yellow to red If that were true, how would we ever see blue things?
by danellis 6y ago
> here on Earth, it will vary from yellow to red
If that were true, how would we ever see blue things?
- lern_too_spel 6y agoBy looking at things our visual cortex perceives as blue, typically by activating the blue photoreceptors more than others relative to objects that are not blue but also via negative after images and a number of other methods. Look at these blue hearts, for example: https://cdn.cpnscdn.com/static/blog/2015/02/greenblueheartsstriped.jpg https://cdn.cpnscdn.com/static/blog/2015/02/greenblueheartss... You seem to be making the mistake I specifically warned against of defining color by the distribution of wavelengths coming from the object. Once again, the definition of color is ambiguous, and most people will use the human perception definition. Purple things don't have to be composed of pure violet light.
- danellis 6y agoWhat activates blue photoreceptors?
- lern_too_spel 6y agoElectromagnetic radiation with wavelengths between 380 NM and 550 nm. What point are you getting at? It is as yet unclear whether you understood my point.
- danellis 6y agoI'm not making a point; I'm asking a question. If the light from the Sun were "from yellow to red", what would trigger our blue photoreceptors? And no, I don't understand your point. I don't see what it has to do with yellow-red light.