H-Units: A Complete Hydrogen-Based
Measurement System for Post-Terrestrial Physics

Time • Length • Temperature • Mass • Quantum constants
All derived from the 21-cm hydrogen line, the speed of light, and the cosmic microwave background.

H-Clock (Live)
000000
H-Seconds since Epoch: 0

Epoch: 30 Sep 2025 00:00 UTC • No leap seconds • 4-year cycles

The Complete Series — November 20, 2025

Part I

H-Units: Time & Length Standard

Part II

The Cosmic Kelvin
(Temperature)

Part III

H-Units in the Quantum Domain
(Planck’s Constant & Scales)

Part IV — NEW

H-Mass: The H-kilogram
(Completing the System)

The Four Cosmic Foundations

H-Second

1.5×10⁹ hydrogen cycles
≈ 1.056036 s

H-Meter

c × 1 H-s / 3×10⁸
≈ 1.055306 m

H-Kelvin

CMB peak = exactly 1 H-K
≈ 2.72548 K

H-kilogram

Hydrogen Compton wavelength
= exactly 20.000 H-m

With these four papers (20 November 2025),
H-units now provide cosmic, reproducible definitions for:

  1. Time → H-second
  2. Length → H-meter
  3. Temperature → H-Kelvin
  4. Mass → H-kilogram
  5. The quantum of action → hH

Electric current (ampere) and amount of substance (mole) follow immediately from existing constants in H-units.
Only luminous intensity (candela) remains unchanged or awaits an optional cosmic redefinition.

Six of the seven SI base units are now free of all Earth artifacts.
The seventh is trivial.