I'm thinking about kryptonite radiation and other radiation again. The reason why radiation hurts is generally that the radiation in question is so energetic, i.e., its wavelengths are so short. Visible light has longer wavelengths. Blue and indigo, the visible light with the shortest wavelength, has a wavelength of about 400 nanometers. Red light, the visible light with the longest wavelength, has a wavelength of about 700 nanometers. The shorter the wavelength, the more energetic the light. The wavelengths that really hurt us are much shorter than the shortest visible wavelengths.

Green light has a wavelength of about 500-550 nanometers. The light of the Sun peaks in the green light, i.e., the Sun puts out more green light than red light, more green light than yellow light, more green light than blue light, etcetera. Actually, the Sun might be described as a green star! So why doesn't it look green to us, then? My answer is that it is more practical for us to see sunlight (and therefore daylight) as neutral-colored, or white.

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The light curve of the Sun.

Anyway, it stands to reason that green light wouldn't hurt us humans. If it did, the Sun itself would surely kill every last human on the Earth! (Or else we would be forced to become nocturnal creatures.) Similarly, fireflies give off the kind of light that doesn't hurt us, because it is yellow or greenish-yellow.

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The question is, why would the green light of kryptonite hurt Superman? Obviously the red sun of Krypton would emit less green light than the Sun. The Sun's light curve peaks in green light, but Krypton's sun would peak in red and infrared light. Still, even Krypton's sun would emit some green light. So why would green light hurt Superman so badly? Any theories?

Ann