 This is another demonstration video to show you how an x-ray leaves an after image. It is the after image that we are looking at which is the information that we seek. So I've used a piece of glow in the dark paper and you place objects over it, shine a torch onto it. The torch is going to cause all the material which is glow in the dark to glow even stronger. Take the object away and you're left with the after image. Of course the object has scattered or absorbed the light which has caused everything else to glow in the dark and so the image is left. Of course this is using visible light not x-rays but it's an analogous to what's occurring. You saw the blue light in there that's a UV LED torch from AliExpress and yeah it's a lot of fun to play with one of those and any UV light will supercharge anything that glows in the dark. Next great present for birthday parties. Thanks.