Convert Zeptoseconds to Sidereal Years

Convert Zeptoseconds (zs) to Sidereal Years (a_sid) instantly and accurately.

Zeptoseconds (zs)
Sidereal Years (a_sid)

Conversion Formula

a_sid = zs × 3.168753579e-29

About Zeptoseconds

A zeptosecond (zs) = 10⁻²¹ s. In 2020, physicists at Goethe University Frankfurt measured the H₂ photoionisation time at ~247 zs - the first direct event measurement at this timescale. W-boson lifetime ~300 zs; strong-force quark confinement dynamics ~1-3 zs. These timescales are resolved via the energy-time uncertainty relation and lattice-QCD simulations. 1 zs = 10⁻²¹ s = 1,000 ys.

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

Zeptoseconds (zs)Sidereal Years (a_sid)
1 zs3.169 × 10-29 a_sid
2 zs6.338 × 10-29 a_sid
5 zs1.584 × 10-28 a_sid
10 zs3.169 × 10-28 a_sid
25 zs7.922 × 10-28 a_sid
50 zs1.584 × 10-27 a_sid
100 zs3.169 × 10-27 a_sid

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