12th September 2005, 4:24 PM
Blue on the light scale is a high wave length, so something has to be hot in order to release blue light, relative to red light.
However, it doesn't need to be hot to reflect blue light. The sun is hot enough that it releases a lot of blue light, as well as red and green, and everything below that, and a few above blue as well. But, blue paint doesn't do anything except absorb the two other colors our eyes can detect; green and red.
The other option is filtration instead of reflection. Hence, why a lot of lights can look blue even if they release the whole spectrum from blue down. LEDs are nice, they don't produce very much heat at all. Remember, blue light is high energy, but that doesn't need to be heat. In the case of an LED, it's electrical. The heat there just comes from the resistance in the circuit. Certain underwater fish have a very efficient system. They can produce light of many visible wavelengths with another energy source, chemical. There is no detectable heat from this reaction. It's chemical to light.
That's all I know about this though.
And yeah, it's hard to really nail down what's causing that image without more info, but I'm going with more probable stuff. What lazy said is most probable because he's actually been trained in photography.
However, it doesn't need to be hot to reflect blue light. The sun is hot enough that it releases a lot of blue light, as well as red and green, and everything below that, and a few above blue as well. But, blue paint doesn't do anything except absorb the two other colors our eyes can detect; green and red.
The other option is filtration instead of reflection. Hence, why a lot of lights can look blue even if they release the whole spectrum from blue down. LEDs are nice, they don't produce very much heat at all. Remember, blue light is high energy, but that doesn't need to be heat. In the case of an LED, it's electrical. The heat there just comes from the resistance in the circuit. Certain underwater fish have a very efficient system. They can produce light of many visible wavelengths with another energy source, chemical. There is no detectable heat from this reaction. It's chemical to light.
That's all I know about this though.
And yeah, it's hard to really nail down what's causing that image without more info, but I'm going with more probable stuff. What lazy said is most probable because he's actually been trained in photography.
"On two occasions, I have been asked [by members of Parliament], 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able to rightly apprehend the kind of confusion of ideas that could provoke such a question." ~ Charles Babbage (1791-1871)