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
We don’t see UV as purple. If UV lamps only emitted UV light, it would look as like it was off. We don’t do that for a few distinct reasons.
1. It’s hard to make anything emit only UV, like anything, the lamps emit a spectrum of light, and it sort of bleeds into visible.
2. We could block out the purple that is made, but why should we, it gives a very easy way to tell if your UV lamp is on or not, without doing much harm.
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