Once upon a time Ultraviolet(UV) or "black" Light was reserved for clubs, theaters and science labs.
With the arrival of cold cathode lamps and LEDs we can all have some fun.
Step 1: The Science Bit
Ultraviolet light forms part of the Electromagnetic Spectrum (first proposed by James Clerk Maxwell: Respect) which comprises (in order of increasing wavelength) Gamma Rays, X-Rays, Ultraviolet Light, Visible Light, Infrared Light Microwaves, Radio Waves.
Ultraviolet is divided into three ranges:
•UVA - “ black light“ Harmless
•UVB – causes Suntan, makes the skin produce vitamin D, Most dangerous as it can cause burns and skin cancer
•UVC – Used to Sterilize things - Not a hazard as not much occurs naturally.
Fluorescence is when some substances absorb the normally invisible UV and re-radiate it as visible light.
Step 2: Security Features in Bank Notes.
UK bank notes feature the denomination printed in Fluorescent ink. They glow with a vibrant yellow and red under UV Light.
Step 3: Credit Cards and Driving Licences.
I have blurred out the left hand image for obvious reasons . The center image is a UK driving License. The right hand shows the "MC" sprinted on all MasterCards.
Step 4: My Teeth.
Over the years I have had endless trouble with my teeth. I have had a lot of (very expensive and uncomfortable) dental prosthetic work over the last 35 years or so. Over the years the materials and technology have changed. Some of my crowns glow under UV light some don't.
Step 5: Odds and Ends
On the left is a glass of tonic water which contains quinine. Originally used by ex-pats in the British Empire as a medicine to protect against Malaria. It glows blue.
The middle picture shows Turmeric spilled on a chair. Also visible are some bits of lint glowing white.
On the right is a green circuit board which glows blue.
Step 6: Paper
Most white paper contains fluorescent dyes to make it look whiter in daylight. The picture on the left show a poster in natural light against a cream painted wall. Under UV light the wall disappears and the poster glows.
Step 7: And Finally..
I was discussing with a fellow maker (Hi Kerry) at Coventry Maker-space that Urine fluoresces. When I got home I was about to have a bath when I saw that my wretched cat Smith Pussy had obligingly done a wee on the bathroom floor. this can be seen glowing yellow as urine contains phosphorus. I shows up better when it is dry, but who wants to let cat wee dry on the bathroom floor?
I now have two new furry white slippers.*
*No cats were harmed in preparing this instructable. Yet