300 years before Harvey, Ibn al-Nafis accurately described the blood circulation from the heart to the lungs for oxygenation, refuting Galen's errors.

Centuries before Bacon, Ibn al-Haytham established that scientific theories must be proven through systematic observation, hypothesis, and experimentation, not just philosophy.

In his Book of Animals, Al-Jahiz described the mechanisms of "natural selection," the struggle for survival, and how animals adapt to their environments, 1,000 years before Darwin.

Ibn al-Haytham stated that a moving body continues in its movement unless stopped by an external force. This is the exact definition of Newton's First Law.

In Kitab al-Shifa, Ibn Sina described how mountains form from the piling up of layers and the petrification of aquatic clay, introducing the concept of deep geological time.

Al-Kindi invented Frequency Analysis, the method used to break encrypted codes by analyzing how often letters appear. This is the foundation of modern cryptography.

While Aristotle believed light was instantaneous, Al-Biruni correctly theorized that light travels immensely fast but has a finite speed, faster than sound.

Al-Razi was the first to clinically distinguish between Smallpox and Measles as two different diseases, writing the definitive book Al-Judari wa al-Hasbah.

Euclid and Ptolemy believed the eye emits rays to see. Ibn al-Haytham proved mathematically that light enters the eye from the object, founding modern optics.

Nasir al-Din al-Tusi established trigonometry as an independent discipline rather than just a tool for astronomy, formulating the famous Sine Law for spherical triangles.

While Europe treated the mentally ill as possessed, Al-Razi established the first dedicated psychiatric wards in Baghdad, treating patients with dignity and therapy.

Al-Biruni recorded that Al-Sijzi built an Astrolabe based on the assumption that the Earth rotates, not the sky—centuries before Copernicus popularized heliocentrism.