In a mathematical sense, the curvature is the reciprocal of the radius, so that a smaller curvature implies a large radius. A curve of large radius, as for a railway, cannot be laid out by using the radius directly. We will see how the problem of laying out a curve of large radius is solved.
In 1983, Motorola released its first commercial mobile phone, known as the Motorola DynaTAC 8000X. The handset offered 30 minutes of talk-time, six hours standby, and could store 30 phone numbers. It also cost Â£2639 ($3995). In the very early days of the mobile space handsets werenât designed with consumers in mind.
1 Bob Greene says April 3 marks the 38th anniversary of the first phone call made on a cell phone. 2  He says Martin Cooper, who helped develop phone for Motorola, made call on NY street. 3  He says phone blessing, curse; makes you always accessible, people come to rely on it. 4  Greene: First phone clunky.