Surprising photographs of things under ultraviolet light

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Surprising photographs of things under ultraviolet light (8/25/06, 11/14/10)

The electromagnetic spectrum encompases all types of "radiation" including that which the human eye can see (visible). Just to the left of this visible layer is UV radiation. The sun actually puts out a lot of this type of radiation and it is the chief reason we get sunburns so easily. This NASA illustration depicts the layout:

Source: Cassini-Mission to Saturn-Operations-Navigation-Uplink/Downlink

Turn of the visible light, leaving just the UV light, and some interesting things can be seen. Under this light some types of materials "floresce" in the visible spectrum. Quinine, found in tonic water, actually lights up quite well:

Emmensely useful, urine also shows up easily, in this case our cat Smudge:

Saved by enzyme cleaners, thankfully. Anyway, next up let's have a look at my face, regular and under UV:

First up, notice the freckles. My face is almost entirely covered in them and they are far more visible under the UV light. I blame MC1R. The lenses in the eye also floresce, which is why those look so weird. Tooth enamel also shows right up, however the material under tooth enamel doesn't:

These are actually congenital birth defects filled with some clear filling but the end result is the same. Green isn't the only florescence though. Lurking behind a molar:

Yeah, that should be an interesting conversation with my dentist. I actually have a crown right next to that so it might be a reflection off of the crown.

Dust, as it happens, lights right up under UV light. It'll completely scare you. This is the dust on a wall. How often do you dust your walls?

Stairways in homes tend to have a board along the bottom of the sides of the stairs. That board is running left to right in this photo, and this is the dust on it. Turn on the light and nothing shows up. It's amazing.

I saved the scariest for last. This is our rug. New rug. After vaccuming it. And yes, the filters were clean. Yeah. See how the dust is just ingrained in it? That's the problem with that urge to get everything extremely clean. Let's use an analogy. The "raw milk" folks like to point out that pasturization kills all of the bacteria in milk, including the good bacteria, which can kill off the bad bacteria. Pasturize it, and everthing is dead. It's a vat of moisture and food just waiting to get invaded by anything that comes along. Raw milk, collected properly, is not only healthier (more vitamins and such) but less risky. It's the "collected properly" part that causes trouble.

So yeah, you don't want too much bad stuff or it'll overpower you, but none of it is a bit of a problem too. Hope this was neat for folks.

Nov. 14, 2010 update: Kyle from OSU wrote in with a question about bones, mushrooms, and blood. Blood looks to be covered well in this pdf. As far as bones and mushrooms, the pics below are, in order, visible light, UVA (368nm), and UVC (Germicidal, 253.7nm). Let's start with Vaseline and Olive Oil:

See how they glow with the UVA one? Oils and fats do that. Next we have a "Beef Jerkey Bone" (left) and a "Beef Knuckle Bone" (right):

I'm fairly certain the parts that are fluorescing in the UVA range are fatty parts of the bones which have been stripped off in the cleaned bone on the right. Lastly, lets look at the mushrooms. In the upper left is Shiitake, upper right is a common Button, and the lower one is a Portabella.

We also have an image of Oyster Mushrooms:

I couldn't really make any fluorescence out with these except on the undersides or when they have been cut in half. Probably not useful for mushroom hunting, and even then, it was very faint.