In explaining how an ellipse evolves into a parabola, for example, Mr. Seife suggests gradually tilting a flashlight as its beam spreads upon a wall.

The beam will spread that far.

The beams spread; one glimmering ray shone suddenly upon a weaving figure that stopped like a frozen statue.

Even so, the beam spreads slowly so that it is more than 4 miles wide at the Moon and 12 miles wide upon return.

In poor visibility, or at short range, a narrow beam is not much use, and a wider beam spreads the light over a more useful area.

I catch sight of myself in the mirror again - and a huge, exhilarated beam has spread itself over my face.

Now the beam will spread as it leaves the grid.

Defense called Dr. Harry McCavity, who testified that from the nature of the wound the beam must have spread abnormally.

More beams spread into the pit.

The inherent disadvantage of the radar beam riding system is that the beam spreads as it travels outward from the broadcaster.