Worlds Smallest Petrol Engine:           Scientists have created the smallest petrol engine in the world ( less  than a centimeter long not even half an inch ), small enough to power a  watch or any small gadget. The mini-motor, which runs for two years on a  single squirt of lighter fuel, is set to revolutionize world  technology.It generates 700 times more energy than a conventional  battery. It could be used to operate  laptops and mobile phones for months doing away with the need for  charging. Experts believe it could be phasing out batteries in such  items within just six years. The engine, minute enough to be balanced on  a fingertip, has been produced by engineers at the University of  Birmingham.  At present, charging an ordinary battery to deliver one  unit of energy involves putting 2,000 units into it. The little engine,  because energy is produced locally, is far more effective. One of the  main problems faced by engineers who have tried to produce micro motors  in the...