View full lesson: http://ed.ted.com/lessons/how-do-hard-drives-work-kanawat-senanan The modern hard drive is an object that can likely hold more information ...
========== Imagine an airplane flying
one millimeter above the ground and circling the Earth
once every 25 seconds while counting every blade of grass. Shrink all that down so that it fits
in the palm of your hand, and you'd have something equivalent
to a modern hard drive, an object that can likely hold
more information than your local library. So how does it store so much information
in such a small space? At the heart of every hard drive
is a stack of high-speed spinning discs with a recording head
flying over each surface. Each disc is coated with a film
of microscopic magnetised metal grains, and your data doesn't live there
in a form you can recognize. Instead, it is recorded
as a magnetic pattern formed by groups of those tiny grains. In each group, also known as a bit, all of t...