He Grabs 2 Sharpies And Colors In His Smartphone's Flash. The Result? A Useful New Tool
So, if you've learned nothing else from this, at least you know not to use your freshly hacked phone in the bathroom. That's something you just can't un-see. Still, this nifty DIY ultraviolet light has lots of practical (and fun!) uses. Counterfeit bills can be easily detected with a black light. Plastic security threads will appear under UV light in legitimate bills. Additionally, the threads will glow different colors depending on denomination. For instance, a $5 bill will be blue, a $20 bill shows up green and a $100 note glows pink. Your DIY black light can also be helpful if you have any pets. Sometimes accidents happen, and it can be difficult to identify the exact spot. A black light, however, will quickly illuminate the problem.