eli5 On projectors, why does the screen show only on the wall, rather than being carried out like a laser?

Question

eli5 On projectors, why does the screen show only on the wall, rather than being carried out like a laser?

In: Technology

Answer 1

A laser emits far more light in a far more concentrated area than a projector. The few flecks of dust that are in the air in the lasers path will deflect some of that laser light, which makes it into your eye, giving you the idea of seeing the lasers path.

With a projector, the light is so much weaker that any small part bouncing off the dust is so dim that you don’t really see anything.