Ratings

Entertainment & Gaming

Build a Bridge

By Paul Adams Posted on 2.19.2009 7 Comments

Here we have a fun and frustrating little game that exploits our engineering skills. How to build a stable bridge is what this game is all about. At each level of the game you're given a limited amount of imaginary cash with which to purchase your beams and supports. It's usually just enough to get the job done, if you do it right. Which isn't so easy.

The Environment

The World's 10 Worst Cities

By Abby Seiff Posted on 6.23.2008 12 Comments

You may already know about the pollution plight of Linfen, China. But how about the heavy metals Pittsburghers breathe in on a daily basis? Or the incomparable smog Milanesi put up with? PopSci has culled an eye-opening selection of some of the world's most problematic cities. From the painfully high cancer rates in Sumgayit, Azerbaijan to the acid rain destroying La Oroya, Peru, writer Jason Daley will walk you through the lowest of the low; and explain why, despite it all, there's still hope for these places.

Technology

Robots That Hunt in Packs

By Paul Adams Posted on 11.5.2008 20 Comments

The Department of Defense has put out a call: design a pack of robots. A so-called Multi-Robot Pursuit System would be used to "search for and detect a non-cooperative human subject." Each robot has to weigh 100 kilograms or less, act autonomously (with a human squad leader), negotiate obstacles, and provide immediate feedback. The robots would report back to a human operator, and defer to that human when the robot AI determines that a "difficult decision" is required.

Science

Who Protects The Internet?

By Laura Silver Posted on 3.13.2009 276 Comments

For the past five years, John Rennie has braved the towering waves of the North Atlantic Ocean to keep your e-mail coming to you. As chief submersible engineer aboard the Wave Sentinel, part of the fleet operated by U.K.-based undersea installation and maintenance firm Global Marine Systems, Rennie--a congenial, 6'4", 57-year-old Scotsman--patrols the seas, dispatching a remotely operated submarine deep below the surface to repair undersea cables. The cables, thick as fire hoses and packed with fiber optics, run everywhere along the seafloor, ferrying phone and Web traffic from continent to continent at the speed of light. The cables regularly fail. On any given day, somewhere in the world there is the nautical equivalent of a hit and run when a cable is torn by fishing nets or sliced by dragging anchors. If the mishap occurs in the Irish Sea, the North Sea or the North Atlantic, Rennie comes in to splice the break together.

DIY

Handheld Sunbeam

By Abby Seiff Posted on 1.29.2008 18 Comments

Ralf Ottow was standing in front of his bathroom mirror one morning when he noticed that his forehead was sunburned. He hadnt been out tanning—his homemade flashlight had fried his skin.