Internet Ocean

Say you’re curious about giraffes.

- Colette Weil Parrinello

You do a web search and click on a link that looks interesting. The information on the web page comes from another computer far away. That computer sends it to yours along a hopping path. Most of its journey is through cables—some under the sea.

How does the internet get under the sea?

1 Make a Glass Cable

Cables that carry the internet on land and under the sea are made of super-clear glass, spun into strands thinner than a hair. Several hundred strands are bundled together. Then they’re covered with layers of metal and plastic to make a cable that’s tough, flexible, and waterproof.

Computer signals travel along the glass threads as pulses of light. Computers read these signals and translate them into web pages, or movies, or the sound of a voice. Light beams are so thin that a single hair-sized fiber can carry over 25,000 phone calls at the same time.

How fast do these signals go? Take a breath. In one second, a light signal could travel five times around the earth. That’s two-thirds the speed of light (186,000 miles a second).