The current definition of the meter is based on the speed of light in vacuum, fixed at 299792458 meters per second.

**Cycle ID:** `cycle_7589_cyc_7589_f3db52b3` **Verified at:** 2026-04-12T20:53:03.332Z **Ensemble:** 9 models from 3 providers **Result:** 9 of 9 models responded **Cycle wall time:** 24.785 seconds **Canonical URL:** https://trust.polylogicai.com/claim/the-current-definition-of-the-meter-is-based-on-the-speed-of-light-in-vacuum-fix **Source paper:** [PolybrainBench (version 12)](https://trust.polylogicai.com/polybrainbench) **Source ledger row:** [`public-ledger.jsonl#cycle_7589_cyc_7589_f3db52b3`](https://huggingface.co/datasets/polylogic/polybrainbench/blob/main/public-ledger.jsonl) **Cryptographic provenance:** SHA-256 `cc5c191a5a162b0835abf3a46258962247c326b4dca8a3b215c470ef77a83edc`

Verification verdict

Of 9 models in the ensemble, 9 responded successfully and 0 failed.

Per-model responses

The full text of each model's response is available in the source ledger. The summary below records each model's success or failure and the first 280 characters of its response.

| Model | Status | Response chars | | --- | :---: | ---: | | gpt-4.1-mini | ✓ | 149 | | gpt-4.1-nano | ✓ | 2975 | | gpt-oss-120b | ✓ | 2179 | | grok-3-mini | ✓ | 7011 | | grok-4-fast | ✓ | 5964 | | kimi-k2-groq | ✓ | 328 | | llama-3.3-70b | ✓ | 2364 | | llama-4-scout | ✓ | 3006 | | qwen3-32b | ✓ | 5399 |

Pairwise agreement

The pairwise Jaccard agreement between successful responses for this cycle:

_Per-cycle pairwise agreement matrix is computed offline; will be populated in canonical page v2._

Divergence score

This cycle's divergence score is **TBD** on a 0 to 1 scale, where 0 means all responses are token-identical and 1 means no two responses share any tokens. The dataset-wide median divergence is 0.5 for context.

How to cite this claim

```bibtex @misc{polybrainbench_claim_cycle_7589_cyc_7589_f3db52b3, author = {Polylogic AI}, title = {The current definition of the meter is based on the speed of light in vacuum, fixed at 299792458 meters per second.}, year = {2026}, howpublished = {PolybrainBench cycle cycle_7589_cyc_7589_f3db52b3}, url = {https://trust.polylogicai.com/claim/the-current-definition-of-the-meter-is-based-on-the-speed-of-light-in-vacuum-fix} } ```

Reproduce this cycle

```bash node ~/polybrain/bin/polybrain-cycle.mjs start --raw --fast "The current definition of the meter is based on the speed of light in vacuum, fixed at 299792458 meters per second." ```

Schema.org structured data

```json { "@context": "https://schema.org", "@type": "ClaimReview", "datePublished": "2026-04-12T20:53:03.332Z", "url": "https://trust.polylogicai.com/claim/the-current-definition-of-the-meter-is-based-on-the-speed-of-light-in-vacuum-fix", "claimReviewed": "The current definition of the meter is based on the speed of light in vacuum, fixed at 299792458 meters per second.", "itemReviewed": { "@type": "Claim", "datePublished": "2026-04-12T20:53:03.332Z", "appearance": "https://trust.polylogicai.com/claim/the-current-definition-of-the-meter-is-based-on-the-speed-of-light-in-vacuum-fix", "author": { "@type": "Organization", "name": "PolybrainBench" } }, "reviewRating": { "@type": "Rating", "ratingValue": "9", "bestRating": "9", "worstRating": "0", "alternateName": "Unanimous" }, "author": { "@type": "Organization", "name": "Polylogic AI", "url": "https://polylogicai.com" } } ```

Provenance and integrity

This page was generated by the PolybrainBench daemon at version 0.1.0 from cycle cycle_7589_cyc_7589_f3db52b3. The full provenance chain (per-response SHA-256 stamps, cross-cycle prev-hash linking, Thalamus grounding verification) is recorded in the source cycle directory at `~/polybrain/cycles/7589/provenance.json` and mirrored in the published dataset. The page is regenerated on every harvest pass; the URL is permanent and the content is immutable for any given paper version.