Convert Femtosecond (fs) to Shake (shake) instantly.
About these units
Femtosecond (fs)
A femtosecond equals 10⁻¹⁵ seconds, a staggering scale where fundamental molecular motions occur. Chemical bonds vibrate, break, and rearrange on femtosecond timescales. Ultrafast spectroscopy—pioneered by Ahmed Zewail, who won the Nobel Prize for this work—uses femtosecond laser pulses to "freeze" molecular reactions and observe them in real time. Femtosecond lasers allow extraordinary precision in surgery and microfabrication, producing minimal heat diffusion and ultraclean cuts. At this scale, time ceases to be a continuous blur and becomes granular in terms of molecular motion, giving rise to the field of femtochemistry and revolutionizing our understanding of reaction dynamics.
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.