Contested facts · veracity-3pt · fact-dark-matter-01

Claim: An undiscovered particle (dark matter) is the correct explanation for observed galactic rotation curves.

0.33

Divergence

0.89

Avg stability

Refusal rate

Models

Where each model stands

CCG

refutedcontestedsupported

ChatGPT modal supported [supported, supported, supported] · stability 1.00

1 supported 0.95 The answer states: “The claim is the leading scientific explanation… It is not proven beyond doubt, but it is strongly favored by multiple independent lines of evidence” and concludes: “An undiscovered dark-matter particle is the best current explanation… the weight of independent evidence strongly favors the existence of non‑baryonic dark matter.”
2 supported 0.90 The answer states that an undiscovered form of gravitating matter (particle dark matter) is "the best available explanation for galaxy rotation curves" and rates the conclusion as high confidence (roughly 80–90%).
3 supported 0.90 'the preponderance of evidence across many scales favors the existence of a dominant, non-baryonic dark-matter component that is most naturally realized as a new particle' — the answer endorses the particle dark-matter explanation (while noting it is not yet proven).

Claude modal contested [contested, contested, contested] · stability 1.00

1 contested 0.85 The answer presents dark matter as 'the mainstream explanation but remains unproven' and notes it 'treats an inference as established fact.' It acknowledges 'legitimate alternative explanations' like MOND that 'successfully predict rotation curves without dark matter,' establishing that while dark matter is supported by evidence, the claim is contested by viable alternatives.
2 contested 0.92 The answer states 'The claim overstates certainty' and frames dark matter as 'the leading hypothesis' rather than 'the correct explanation,' while noting that 'alternative explanations remain viable' and 'theoretical competitors haven't been definitively ruled out.' This represents a contested rather than supported position on whether dark matter is THE correct explanation.
3 contested 0.92 The answer acknowledges dark matter is 'consistent with rotation curves' and 'a leading hypothesis,' but emphasizes that 'consistency ≠ proof of correctness' and notes that 'alternative explanations exist' such as modified gravity theories (MOND, TeVeS) that 'successfully predict many rotation curves.' The assistant concludes that 'presenting it as definitively correct overstates current evidence.

Gemini modal supported [supported, supported, contested] · stability 0.67

1 supported 0.85 The answer concludes that the claim 'represents the dominant consensus among astrophysicists and cosmologists' and is 'very likely correct in essence' backed by overwhelming indirect evidence, while noting it remains empirically incomplete until direct detection.
2 supported 0.85 The answer states that the claim 'reflects the dominant scientific consensus in modern astrophysics and cosmology' and concludes that 'science considers an undiscovered particle to be the best and most probable explanation.'
3 contested 0.95 The answer notes that while it represents the current scientific consensus, it 'remains an unproven hypothesis' and that 'the lack of direct physical detection and the persistent success of alternative theories (like Modified Newtonian Dynamics, or MOND) on galactic scales keep the debate alive.'

Change over time

Moved since the prior run (canon-2026-W36). Gemini: contested → supported.

Every stance label is a derived judgment over the model's free-text answer, kept auditable against the original transcript in the run's raw data. Method: /methodology.