CountTip for Android

How much does your meal cost when eating with a group of friends? It’s simple. Launch the built-in calculator app, and push 19 buttons to represent a product of numbers, say 17.90*1.07*1.10*0.9. Hit the equal sign. VoilĂ ! You get 18.96147 and pull out 19 dollars worth of paper money. Pass your phone to the person […]

Where to Buy UV Light?

Following the article on UV Fluorescent security features on banknotes, people have asked on where to purchase a cheap ultraviolet light source. Shops which sell aquarium products and magic supplies often carry ultraviolet lamps, but be warned that they do not come cheap. A small one can set you back by at least $20, and […]

UV Fluorescent Security Features on Banknotes

Placing a banknote under ultraviolet light may reveal some interesting security features. To illustrate this, we have chosen four banknotes from different countries. From top: Peru 5000 Intis (1988), Singapore 100 Dollars (2009), Malaysia 2 Ringgit (1996), South Korea 10000 Won (2007) The most commonly used feature is random flecks which glow brightly under ultraviolet […]