femtosekunds
A femtosecond is a unit of time equal to one quadrillionth of a second, or 10<sup>-15</sup> seconds. This is an incredibly short duration, so brief that it is difficult to comprehend in everyday terms. For perspective, a femtosecond is to one second as one second is to approximately 31.7 million years. Light travels only about 300 nanometers in a femtosecond, a distance roughly the size of a virus.
Femtosecond timescales are relevant in various scientific fields. In physics, they are crucial for studying ultra-fast
Chemistry also utilizes femtosecond techniques to investigate the initial steps of chemical reactions, known as the