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.
The First Cellphone Went on Sale 30 Years Ago for $4,000. Somewhere in either Chicago, Baltimore or Washington, someone plunked down $3,995 to buy the Motorola DynaTAC 8000X, the first handheld cellphone, on March 13, 1984 â 30 years ago today. We don't know who that first cellphone buyer was. At the time, the occasion didn't register as historically auspicious. After all, in 1984, the terms cellphone and mobile phone didn't refer to handheld phones; those terms referred to car phones, which had been around since the mid-1940s.