Stephen Hawking, celebrated physicist and award-winning author with strong opinions on Israel, passed away on March 14 (interestingly, on “Pi Day,” as it is known) at the age of 76.

Hawking visited Israel several times, lecturing in Israeli and Arab universities. But he made news for his boycott of a Jerusalem academic conference honoring Israeli President Shimon Peres in 2013 on the advice of Palestinian colleagues.

However, some of Hawking’s most groundbreaking discoveries themselves came as a result of the work of Israeli academics.

In the early 1970s, Hawking challenged, and then later proved, the theory of Israeli Jacob Bekenstein, who theorized that black holes are characterized by entropy—disorder—and therefore have a temperature. Hawking disagreed, saying black holes could not radiate and therefore could not have a temperature.

But in 1974, Hawking proved Bekenstein’s idea through a complicated quantum theory calculation. He initially kept his findings hidden because of his public condemnation of Bekenstein’s ideas. Eventually, he revealed his findings on quantum gravity—considered among his most important—to the public.

Today, the entropy of a black hole is called Bekenstein-Hawking entropy. However, the radiation emitted from a black hole is called Hawking-Bekenstein radiation.

Bekenstein, who donned a kipah, won Israel’s Wolf Prize in 2012.

Hawking said he wanted the Bekenstein-Hawking entropy equation engraved on his tombstone.