It's yellow in the pictures they paint for books, or when it's low in the sky, but sunlight's actual color temperature is about 5800 degrees K, an almost perfect white.BuddTX said:Yea, but just look at how YELLOW the SUN is...
Precisely! - Right on. It's funny how most people think the light from the sun is yellow, and then you shine an incan light and an LED light onto a piece white paper in full sunshine showing how the LED is colorless and the incan is yellow. The reason the sun "looks" yellow is probably because of the blue sky that surrounds it. Human eye "white balance control" at the works here.nerdgineer said:It's yellow in the pictures they paint for books, or when it's low in the sky, but sunlight's actual color temperature is about 5800 degrees K, an almost perfect white.
I thank that's because we evoloved under it, so our eyes are optimized to see it as a perfect white...
The spectral output of the sun is closer to 100 lumens per watt -- most blackbody radiators that we are used to (incandescent lamps, for example) operate at a fairly low temperature, so the "peak" wavelength is usually in the infrared -- this means that only a small fraction of the energy is released as visible light, usually with an efficiacy of around 10-25 lumens per watt for incandescent. In the case of the sun though, its surface temperature is about 5700K, which means that the "peak" wavelength is actually in the green portion of the spectrum -- which coincides with the eye's sensitivity peak. If a filament material existed that would operate at 5700k, we could have incan lamps with 100 lm/W efficicacy, and perfect color rendering. (don't count on it -- tungtsen is already the metal with the highest melting point, around 3400k, and running it near that point results in very very short life).The 1 Watt LS is ~18 lumens per watt, so 6840000000000000000000000000 lumens....
If you can put something equivalent in a portable flashlight, I'll give you a dollar.
Yep, most people consider the sun to be "yellow" and the moon to be more "blue", when in fact that moon is a poor reflector of blue light, so its apparent color temperature is actually lower (more yellow) at about 4000k. I suppose it does look bluish though compared to the typical high pressure sodium lamps (1900K) most people have to compare it to...Precisely! - Right on. It's funny how most people think the light from the sun is yellow, and then you shine an incan light and an LED light onto a piece white paper in full sunshine showing how the LED is colorless and the incan is yellow. The reason the sun "looks" yellow is probably because of the blue sky that surrounds it. Human eye "white balance control" at the works here.
A hypernova is going to emit all of its energy as high intensity gamma rays, so considering it "bright" is somewhat of a misnomer -- the only way we've been able to "see" them is that the gamma rays sometimes hit something else, which in turn re-emits light in the visible range.Want bright? Try a hypernova.