Femtosecond Laser

 - Feb 8, 2008
References: inventorspot
Every "get rich quick" schemer would love to turn aluminum into gold. This neat invention is almost the ticket. It can change the colour of any metal, fooling people into thinking it may be a much more valuable one.

By shining an intense light at metal for a split second, the intensity of the beams changes the metal. Tiny structures in the metal reflect the light waves differently, changing the color of the material.

"The scientists can also control how this 'femtosecond laser' forms the metals, in order to make the surfaces respond to incoming light in different ways," InventorSpot explained. "By varying the laser intensity, pulse length, and number of pulses, the researchers can control the etching and therefore control the color. Further, they can etch the metals in such a way as to cause reflected light to interfere differently in different directions. This makes the metal appear different colors depending on the angle it's viewed at, making it iridescent."

It's perfect for the con man, but not anyone who knows their metals, as the only thing that changes is the color.