At Christmas time we remember the Star of Bethlehem and put a star ornament on the tree or maybe on the front door, We try to make our star ornament look like a real star in the sky. A real star seems to sparkle with points of light so we put maybe five, six or 12 points on our golden star ornaments. But the fact is that a real star is a round ball of blazing gases with no points at all.

A real, faraway star in the sky only seems to twinkle with points of light. This is because its light must pass through the air above our heads and the air plays tricks with starlight. It makes it seem to dance with glittering points. The real faraway star is round, but it seems to twinkle with two, ten or maybe a hundred darting points.