California's earthquake revolution: Early-warning systems make strides, issuing more than 5 million alerts
Most Californians know that sinking feeling.
Most Californians know that sinking feeling.
Environment
Aug 12, 2024
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30
An automated computational approach to the optical lens design of imaging systems promises to provide optimal solutions without human intervention, slashing the time and cost usually required. The result could be improved ...
Optics & Photonics
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108
Isabella Pires first noticed what she calls the "gradual apathy pandemic" in eighth grade. Only a handful of classmates registered for service projects she helped organize at her Massachusetts school. Even fewer actually ...
Education
Aug 25, 2024
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0
The telephone (from the Greek: τῆλε, tēle, "far" and φωνή, phōnē, "voice") is a telecommunications device that transmits and receives sound, most commonly the human voice. It is one of the most common household appliances in the developed world, and has long been considered indispensable to business, industry and government. The word "telephone" has been adapted to many languages and is widely recognized around the world.
The device operates principally by converting sound waves into electrical signals, and electrical signals into sound waves. Such signals when conveyed through telephone networks — and often converted to electronic and/or optical signals — enable nearly every telephone user to communicate with nearly every other worldwide. Graphic symbols used to designate telephone service or phone-related information in print, signage, and other media include ℡, ☎, ☏, and ✆.
This text uses material from Wikipedia, licensed under CC BY-SA