The dimensions of the head are impressive. With a width of less than a hundred nanometers and a thickness of about ten, it flies above the platter at a speed of up to 15,000 RPM, at a height that’s the equivalent of 40 atoms. If you start multiplying these infinitesimally small numbers, you begin to get an idea of their significance.
Consider this little comparison: if the read/write head were a Boeing 747, and the hard-disk platter were the surface of the Earth:
- The head would fly at Mach 800
- At less than one centimeter from the ground
- And count every blade of grass
- Making fewer than 10 unrecoverable counting errors in an area equivalent to all of Ireland.
All the elements of the head are fabricated very much the same way as processors are. They are formed from wafers, using photolithography and deposition of appropriate materials.