... critical angle. Thus, light can be transmitted over long distances by being reflected inward thousands of times with no loss Optical communications date back to the 1790's with French engineer Claude Chappe's "optical telegraph". Chappe's system involved a series of semaphores mounted on towers, where human operators relayed messages from one tower to the next. Of course it was superior to hand ... ...

• Word Count: 1500
• Approx Pages: 6
• Grade Level: Undergraduate