Rare earth minerals have been referred to as "the vitamin of industry". Chances are, it's everywhere around you - in your television, mobile phone and the car you drive. And China has more than half of the world's rare earth mineral reserves. But rather than simply export raw material, one savvy businessman used it to develop a very practical and important product -- illuminated signposts. His business boomed as the result of a very tragic event- the terrorist attacks of September 11. Now, his signposts can be found around the world, ready to assist in the case of emergency.
Signposts are a common part of everyday life. As children, we're taught that their purpose is to give directions. But the Beijing subway system is home to a collection of signs that are quite different from the norm.
Every day, millions of passengers filter through the capital's extensive subway system. Those paying attention will notice the small stainless steel signs that run along the floors and walls of various metro stations. But do passengers give these signs more than a passing glance?
How do the signposts come to life when darkness strikes?
These inconspicuous signs are designed to help in emergencies, and they're only activated when the metro station falls into complete darkness. In normal situations, while the station is ablaze with light, the signs remain dormant. So how exactly do they come to life when darkness strikes?
The signs are designed by Zhang Mings Sunfor Light Company. In the past, traditional emergency evacuation signals relied on power supply to be activated. But Zhang Ming adopted new technology when designing his signs...