The Kronos Reproducibility Discipline
How the Kronos physics record is built to be checked: pinned code, cold-reproduction runbooks, persistent DOIs, and a two-tier repro standard.
A Record Built to Be Checked
The Kronos designs are simulation and design work, not built machines, so their credibility rests entirely on whether an outside reader can regenerate the numbers. The reproducibility discipline exists to make that possible. Rather than asking readers to trust a figure, the record supplies the code, inputs, and environment needed to reproduce it independently.
Persistent Deposits
Key physics results are deposited in a public repository with persistent DOIs, so each result has a permanent, citable location and a fixed version. A DOI points to an exact snapshot: the code as it was, the inputs as they were, and the outputs they produced. Later revisions get their own identifiers rather than overwriting the record.
Cold Reproduction
- A cold-reproduction runbook regenerates a result on a clean machine, from a fresh environment, with no hidden state.
- The environment is pinned so a reproduction attempt tests the science, not an incidental library change.
- The runbook is itself part of the deposit, so the reproduction instructions are versioned alongside the result.
Two-Tier Reproduction
The discipline distinguishes two standards. Tier one is byte-for-byte reproduction, where the output matches exactly. Tier two is reproduction within a stated numerical tolerance, appropriate when hardware or compiler differences change the last digits without changing the science. Declaring which tier a result meets tells a reader precisely how much to expect.
What It Does and Does Not Establish
This discipline delivers verification-grade checkability and reproducibility. It does not, by itself, establish physical validation: reproducing a simulation confirms the computation, not that the computation matches nature. The record keeps that boundary explicit, and makes no hardware net-gain claim before first-of-a-kind operation. Reproducibility is the foundation on which the separate, ongoing work of physical validation is built.