Those of you living in the Bay Area probably already know that on Thursday, April 9, vandals hacked up 10 fiberoptic cables and disabled landline, cell phone, and internet service in Santa Cruz and Santa Clara counties for nearly 24 hours.
The vandals lifted 300-pound manhole covers and climbed down into underground vaults to get at the cables. They cut the cords in two different locations in about two hours. Clearly they thought about this a lot.
There’s been a lot of discussion about whether the communication system is secure enough, how dependent we’ve all become on our cell phones (a few of my classmates went out for lunch after class, and we struggled mightily to figure out how we’d find each other downtown if we couldn’t call), and what’s going to happen to the culprits when they’re caught.
But David Perlman, the 90-year-old science editor at the San Francisco Chronicle and a legend in his own time, used the crisis to teach some science. His article on today’s Chronicle is about the history of fiber-optics. He tracked down the guy who invented fiber-optics in the first place, Narinder Singh Kapany, now 80 and living in Palo Alto, and gave a sharp, vivid description of how it all works:
Today’s fiber-optic cables are bundles of dozens of single hair-thin strands, each fiber made of highly purified glass – often pure silica – and coated in a cladding of impure glass that holds light beams inside. A single cable, about 4 inches thick, has the capability to hold dozens of fibers, which can carry pulses of light signals as far as 200 miles – either curving or in a straight line – at about two-thirds the speed of light. Inside each fiber, the light’s “message” is reflected again and again at an angle against the fiber’s wall as it travels along.
That’s something I never really think about: our society runs on beams of light. Every time I check my email, call my mom, or buy groceries with my debit card, I’m sending a signal down a glowing cylinder that illuminates places no one ever sees. It’s nice to be reminded of the beauty in the mundane.
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