The Islamic Golden Age saw many scientists like Ibn al-Nafis (1213 – 1288), also called the ‘father of circulatory physiology,' and Hassan Ibn al-Haitham (965 – 1040), considered one of the founders of modern optics, rise to prominence. 

Fast forward to modern times, Arab scientists continue to climb new heights... But sometimes their life missions are cut short by sudden and mysterious death. 

Here are five Arab scientists whose deaths remain ambiguous to this very day:

1. Samir Najib (Egypt)

Considered a top-notch atomic scientist during his time, Najib graduated from the University of Cairo before heading to the U.S. to further his studies

At 33 years of age, he was already assisting nuclear scientists and physicists, even finishing his Ph.D. thesis one year before its due date. 

Out of 200 applicants, Najib was chosen by the University of Detroit to be the institution's assistant professor of biology. Despite the many academic and financial opportunities he received, he set his mind on returning to Egypt.

On Aug. 18, 1967, the day he was meant to travel back to Cairo, Najib was killed in a hit-and-run crash.

2. Nabil Al Kallini (Egypt)

Realizing how fast the Earth's natural resources were being depleted, Al Kallini concluded that one KG of uranium contains up to three million times the energy equivalent of oil and coal.  

A graduate of the University of Cairo, Al Kallini was sent to what was then Czechoslovakia (Czech Republic) to develop his research. 

According to reports, Al Kallini left his apartment on Jan. 27, 1975  after receiving a phone call, never to be seen or heard from again. 

Local media reports said a body resembling his was found in a river. It was cremated two weeks later without further investigation.

His disappearance remains a mystery to this day.

3. Hassan Kamel Al Sabbah (Lebanon)

Born in Nabatieh, Lebanon, in 1894, Hassan Al Sabbah was an electrical and electronic engineer.

A graduate of the American University of Beirut, Al Sabbah taught mathematics both at Imperial College Damascus and AUB. He then moved to the U.S. where he continued his studies at the Massachusetts Institute of Technology (MIT) and the University of Illinois.  

Al Sabbah's experiments and research at General Electric in New York yielded the innovator some 50 patents and 52 inventions.  

His inventions were vastly known and praised, including a pressure monitor that allows one to check the amount of electricity needed for a device to work, and a battery that works on solar energy.

Al Sabbah died on Mar. 31, 1935 in a sudden car accident.

4. Ali Mostafa Moshrefa (Egypt)

Also known as “The Einstein of Arabs,” Moshrefa was born in Egypt in 1898 to a well-off family. 

He was sent by the Egyptian Ministry of Education to the University of Nottingham, England where he obtained a BSc (Honors). He then went on to earn a Ph.D. in sciences from London's King’s College. He was awarded the degree of Doctor of Science, making him the first Egyptian and the 11th scientist to hold this degree at the time.

He returned to Egypt where he became a professor of applied mathematics and a dean of the Faculty of Science of the University of Cairo at the age of 38. He also worked closely with Albert Einstein. 

Moshrefa died on Jan. 15, 1950 of an alleged heart attack. While some have claimed the Israeli Mossad was behind his death, no evidence proved the rumors to be correct.

5. Samia Abdel Rahim Maimani (Saudi Arabia)

Born in Saudi Arabia, Maimani fought to become the kingdom's first female neurosurgeon after her father died in a car accident that fractured his skull. 

She was admitted into the University of Charles R. Drew of science and medicine, U.S, where she worked on finding a cure for brain strokes.

One of her most known findings is the "Aneurysm clip applier and remover for use with neuroendoscopes and steriotactic systems," which helps doctors access areas in the brain without craniotomy (bone flap removal).  

Maimani's body, which had signs of strangulation, was found in an empty refrigerator on the street.