Convert Femtoseconds to Sidereal Years
Convert Femtoseconds (fs) to Sidereal Years (a_sid) instantly and accurately.
Conversion Formula
a_sid = fs × 3.168753579e-23
About Femtoseconds
A femtosecond (fs) = 10⁻¹⁵ s - the timescale of molecular vibrations and chemical reactions. Bond stretching: 10-200 fs; bending: 50-500 fs. Ahmed Zewail won the 1999 Nobel Prize in Chemistry for femtochemistry, capturing transition states in real time. Ti:sapphire lasers produce 10-100 fs pulses; LASIK uses 10-100 fs for precise corneal cuts. At 800 nm, one optical cycle = 2.67 fs. Light travels 300 nm in 1 fs. 1 fs = 10⁻¹⁵ s.
About Sidereal Years
The sidereal year = Earth's orbital period relative to the stars = 365.25636 days = 31,558,149.8 s - about 20 min 24 s longer than the tropical year. The gap arises from precession of the equinoxes (~50 arcsec/year westward drift), which causes the tropical year to end slightly before the sidereal orbit completes. JPL DE440 ephemerides and J2000.0 epoch are anchored to the sidereal frame. 1 a_sid = 365.25636 d.
Quick Reference Table
| Femtoseconds (fs) | Sidereal Years (a_sid) |
|---|---|
| 1 fs | 3.169 × 10-23 a_sid |
| 2 fs | 6.338 × 10-23 a_sid |
| 5 fs | 1.584 × 10-22 a_sid |
| 10 fs | 3.169 × 10-22 a_sid |
| 25 fs | 7.922 × 10-22 a_sid |
| 50 fs | 1.584 × 10-21 a_sid |
| 100 fs | 3.169 × 10-21 a_sid |