Alhazen

The eye sees by receiving light, not emitting it.

Mathematical demonstrations are the most certain way to knowledge.

Nature is the greatest book ever written.

To seek truth requires courage and humility.

The rainbow is formed by refraction and reflection of sunlight in raindrops.

Observation and experiment must precede theory.

The mind perceives through the senses, but verifies through reason.

Stars are fixed points of light in the celestial sphere.

Doubt is the key to knowledge.

Light is the purest form of energy.

The camera obscura demonstrates how images are formed.

Truth emerges from the clash of opposing ideas.

The motion of planets follows mathematical laws.

We must test hypotheses against nature's reality.

The eye is the window to the soul, but also to the world.

Refraction bends light at the boundary of mediums.

Seek knowledge even if it takes you to China.

The universe is governed by rational principles.

Magnifying glasses work by converging rays.

Astronomy reveals the order of creation.