In a recent episode of MacGyver, an improvised ultraviolet light was created from an LED. How would this work and what is a blacklight?

Don't let poor lighting ruin an otherwise great photo. A portable LED fill light can add the extra dash of illumination you need, and if you don't want to pony up for a new one, you can make your ...

You'll require paper, preferably something colourful and stiff, and a wooden skewer to form the stem of your flower. You'll also need an LED light, a three-volt "coin cell" battery and conductive ...