On Wed, Jun 6, 2018 at 11:26 PM, Brent Meeker <meeke...@verizon.net> wrote:
> *> hasn't the Sun been getting hotter, which would mean moving from yellow > toward green rather than the other way. And it's still still more a yellow > than green store. * There are intensely red stars and there are pale blue stars but there are no green stars; the reason has to do with the fact that curve of blackbody radiation energy output verses color of an object at a given temperature is NOT symmetrical. It also has to do with the fact that the eye has 3 different receptors for color, one for the red, green and blue. A star that gives off the peak of its energy in the red will still give off a substantial amount of energy in the infrared but the eye can't see that, and due to the non-symmetrical blackbody curve the energy drops off rapidly in the green and blue part of the spectrum, so only (or almost only) the red receptor in the eye is stimulated so we see it as intensely red. A hotter star that gives off most of its energy in the blue would still give off a lot in the red and green so all 3 receptors would be stimulated and we'd see it as white, or if it was very very hot a bluish white (the output would drop off rapidly in the ultraviolet but we can’t see that so it doesn’t matter). Due to the shape of the blackbody curve there is no temperature that would give off its radiant energy in the green but none in the red or blue so that only the green receptor is stimulated. You can have green lasers but unlike stars that light is not produced by blackbody radiation, and because only the green receptor is stimulated it looks intensely green. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
