The sounds of the rainforest include: the chirps of birds, the buzz of cicadas, the banter of gibbons. But in the background is the almost-always present sound of a chainsaw, from illegal loggers. Engineer Topher White shares a simple, scalable way to stop this brutal deforestation - that starts with your old cell phone.
Metals are what make smartphones so "smart."
An average smartphone may contain up to 62 different
types of metals. One rather obscure group
of metals-the rare-earth metals-plays a vital
role. The rare-earth metals include scandium and
yttrium, as well as elements 57-71. Elements 57-71
are known as the lanthanides, because they begin
with the element lanthanum.