It can range in size from invisible microscopic particles to grains of sand.

However, at the time, the atomic theory was considered more complex because it implied the existence of invisible particles which had not been directly detected.

Both are only a cloud formation of the same invisible, whirling particles.

Metal dust and insulation fibers are typical examples of invisible particles.

A stream of invisible particles shot from the barrel of the disrupter.

We serious allergy sufferers have given much thought to invisible particles, though not the anthrax sort.

Death pointedly picked invisible particles off the edge of his scythe.

A widely supported theory, of hypothetical invisible particles known as cold dark matter, was dealt a serious blow this year.

If the missing mass was composed of invisible exotic particles, this might explain the gravitational forces required to shape the present universe.

Neil smiled as the invisible particles rained down on him.