Tire placard pressure is often much lower than listed on the tire sidewall. Air pressure given by the vehicle maker was based on the tires supplied with the vehicle. They design many newer replacement tires to give a good ride, with much more pressure.
Fresnel lens. A Fresnel lens is a type of lens invented by Augustin-Jean Fresnel. Originally developed for lighthouses, the design enables the construction of lenses of large size and short focal length without the weight and volume of material which would be required in a lens of conventional design. Detailed information.
Photos: The Fresnel lens exhibit at Think Tank, the science museum in Birmingham, England. The silvery thing at the bottom is the electric turntable that makes the whole lamp and lens assembly rotate very slowly. Lenses work by bending (refracting) light beams.