thickness

The new procedure involves inserting a tiny 2mm-square photovoltaic microchip, with the thickness of a human hair, under the retina.

Further evidence for a north-to-south impact came from studying the moon's topography, crustal thickness, and surface chemistry.

Super spikes, however, have an actual sole—the thickness of a deck of cards made out of high-tech, energy-returning foam—plus a springy carbon-fiber plate.

Historically, it has been done by spreading the sunscreen on 10 people at the same thickness, then timing how long it takes for their skin to start burning both with and without the product applied.

The largest bar is about the size and thickness of a mobile phone.