1001 Space Earth Nature History Human World Science and Technology Chemistry Materials Force and Energy Heat and Light Electricity and Magnetism Industry Machines Electronics and Computers Cars and Trucks Railways Ships Aircraft Fishing and Agriculture Undersea Exploration

Choose a Page:How did people pump water in ancie...How does a robot arm work?What is the simplest machine?What is a crawler-transporter used...How does a steam locomotive work?Which were the first machines not ...How did early gramophones work?Who invented the motorcar engine?When was the first bicycle made?*What are lasers used for?*Who invented the jet aeroplane?How do a bicycle's gears work?Is it possible to make a perpetual...How does a roller coaster work? What are lasers used for? Lasers produce a narrow beam of high-energy light that is all exactly the same colour. A laser beam can be used for welding metals and cutting cloth. Three-dimensional pictures, called holograms, are produced using lasers. But perhaps the most important uses are in communications. For example, in a CD or CD-ROM player, a laser beam 'reads' the information on the compact disc. Laser beams also carry information along fibre optic cables. The beam from a laser is made of intense light of the same wavelengths.   Previous: Back Book: 1001 Section: Science and Technology Chapter: Machines