The cut surface of the disk shows the central soft nucleus pulposus and the tougher annulus fibrosus surrounding it. (marvistavet.com)
Once the spinning stops, the stagnation zone disappears and imperfections in the surface of the disk cause the rapid, non-uniform movement of bacteria away from the origin of rotation. (sciencedaily.com)
The flying height of this fast - moving head is as low as 2 nanometers from the surface of the disk, some 50,000 times less than the width of a human hair. (sciencedaily.com)