Forgery detection

A computer-generated hologram technique, a simulation of the pattern of light waves, will detect whether a photograph published in magazines and newspapers is doctored or not, reports the Journal of Optics A. Physicists at the University of Roma Tre in Italy add an invisible ‘watermark’ or a coded stamp to an image, and any subsequent attempt to alter the content of the photograph results in damage to that mark. Forgery can be detected while extracting the watermark with the use of a special software. In a forged picture, it can even identify the object or section which has been tampered with. The specially encrypted watermark can only be decoded by someone who knows the private key to reconstruct it.

Biogas train

Svensk Biogas of Sweden has unveiled the world’s first biogas-powered passenger train, reports AFP. Fitted with two biogas bus engines, this can carry up to 54 passengers with a velocity of 130 km/h. Biogas, produced by decomposing organic material, emits far less carbon dioxide than traditional fossil fuels. The environment-friendly $1,300,000 train can run for 600 km before it needs to refuel. It may eventually replace diesel or electric trains.