The information age has been facilitated by the exponentially growing capacity of such storage media as magnetic disks. As demand has soared, the information‐storage industry has crammed more and more bits into ever shrinking areas. Significant innovations have already pushed magnetic storage densities well beyond the limits forecast by pundits just a few years ago. Developments now on the horizon promise to raise the densities from values of 30‐50 gigabits per square inch(Gb/in2),which are typical today, to double or triple those values in the near future, and eventually to densities as high as 1 terabit (Tb) per square inch. (See the box on page 16.)