Convert Shake (shake) to Year (Sidereal) (y (sidereal)) instantly.
About these units
Shake (shake)
A shake is a playful but scientifically important unit equal to 10 nanoseconds. It originated in the Manhattan Project, where physicists needed a convenient term for very short intervals in nuclear chain reactions. A nuclear fission event occurs on the order of a few shakes, making the unit ideal for modeling neutron capture, reaction propagation, and weapon physics. Today, the shake appears in nuclear engineering literature, plasma physics, and astrophysics—any field involving extremely rapid events. Despite its whimsical name, the shake represents a meaningful scientific compromise: short enough for nuclear events, yet still relatable and easy to calculate.
Year (Sidereal) (y (sidereal))
A sidereal year is the time it takes Earth to complete one full orbit relative to distant fixed stars, lasting approximately 365.25636 days. This is the "true" orbital period of Earth in space, unaffected by precession-related shifts of the equinoxes. Sidereal years are used in celestial mechanics, spacecraft navigation, and modeling solar system dynamics. The slight difference between the tropical and sidereal year (about 20 minutes) reveals how Earth's wobbling axis alters how we perceive time, creating two distinct astronomical year definitions.