[2] On September 5, 2006, at the age of 78, he died of heart failure while camping with his wife in Big Basin Redwoods State Park in California, USA.
In 1964, Leonard Cutler and his colleague Al Bagley invented the first all-solid-state cesium-beam chronometer known as the HP5060A Cesium Beam Clock.
In 1972 and 1976, these same clocks were used in flight tests verifying Albert Einstein's theories of special and general relativity,[4] showing that time does slow down the faster you move or the closer you are to a source of gravity, such as the Earth.
Losing only a second of accuracy every 1.6 million years, it remains the most accurate commercial clock in the world, and accounts for 82% of the data used to keep the International Atomic Time Standard (as of 2006).
[7] Leonard and his colleagues invented and held patents for quartz oscillators and the two-frequency laser inferometer, which is used in fiber optics, integrated circuit manufacturing, physics and many other scientific fields of study today.