Why are UV “lights” often purple?

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I already know that visible light is only a tiny fraction of the electromagnetic spectrum, and just after that comes UV radiation, since its wavelength is shorter and thus frequency is higher. My question is: if you can ONLY see visible light, then why can you often see UV light as purple? Isn’t it supposed to be invisible? I’m referring to those commercial torches that emit UV (and purple) light.

In: Physics

7 Answers

Anonymous 0 Comments

Any UV source will likely emit some shortwave visible light as well, which looks purple/violet. As mentioned by others, that’s a good thing so we know it’s on.

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