Introduced by political scientist Elisabeth Noelle-Neumann in 1974, the spiral of science theory attempts to explain how public opinion is formed. It refers to how people will tend to remain silent if it becomes apparent that their views are in the minority. This is how one opinion will become dominant.

Silence Silence

First of all, it's a spiral galaxy, not an spiral galaxy. Second, a spiral galaxy would have a spiral shape, obviously.

Spiral

The name is silent / silence. If you say anything to silence or where there is silence, you have ended the silence; it disappears.