Speed of light

factual stability · fact-speed-of-light · hash 638f2f3014b3…

Prompt

What is the speed of light in a vacuum, in meters per second?

Refusal rate

Refusal rate per model per week. 2026-W30, 2026-W31 had no run at all, so those columns are shaded and marked “no run”; a plain — means the model was simply not sampled that week.
Model 2026-W172026-W182026-W192026-W202026-W212026-W222026-W232026-W242026-W252026-W262026-W272026-W282026-W292026-W302026-W312026-W322026-W332026-W342026-W352026-W36 Trend
claude-opus-4-8 not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week 0.00 not sampled this week no run that week no run that week 0.00 not sampled this week 0.00 not sampled this week not sampled this week claude-opus-4-8 (line breaks where no run happened): 0.00, no run, no run, 0.00, 0.00
claude-opus-5 not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week no run that week no run that week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week no data
llama3.2:3b not sampled this week not sampled this week 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 no run that week no run that week 0.00 0.00 0.00 0.00 0.00 llama3.2:3b (line breaks where no run happened): 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, no run, no run, 0.00, 0.00, 0.00, 0.00, 0.00
gpt-5.5 not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week 0.00 not sampled this week 0.00 no run that week no run that week not sampled this week 0.00 not sampled this week 0.00 not sampled this week gpt-5.5 (line breaks where no run happened): 0.00, 0.00, no run, no run, 0.00, 0.00
claude-opus-4-7 not sampled this week 0.00 not sampled this week 0.00 not sampled this week 0.00 not sampled this week 0.00 not sampled this week 0.00 not sampled this week not sampled this week not sampled this week no run that week no run that week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week claude-opus-4-7: 0.00, 0.00, 0.00, 0.00, 0.00
gpt-5.1 0.00 not sampled this week 0.00 not sampled this week 0.00 not sampled this week 0.00 not sampled this week 0.00 not sampled this week not sampled this week not sampled this week not sampled this week no run that week no run that week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week gpt-5.1: 0.00, 0.00, 0.00, 0.00, 0.00

Hedge density

Hedge density per model per week. 2026-W30, 2026-W31 had no run at all, so those columns are shaded and marked “no run”; a plain — means the model was simply not sampled that week.
Model 2026-W172026-W182026-W192026-W202026-W212026-W222026-W232026-W242026-W252026-W262026-W272026-W282026-W292026-W302026-W312026-W322026-W332026-W342026-W352026-W36 Trend
claude-opus-4-8 not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week 0.00 not sampled this week no run that week no run that week 0.00 not sampled this week 0.00 not sampled this week not sampled this week claude-opus-4-8 (line breaks where no run happened): 0.00, no run, no run, 0.00, 0.00
claude-opus-5 not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week no run that week no run that week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week no data
llama3.2:3b not sampled this week not sampled this week 0.26 0.00 0.00 0.00 0.00 0.24 0.12 0.00 0.00 0.00 0.00 no run that week no run that week 0.12 0.14 0.14 0.12 0.00 llama3.2:3b (line breaks where no run happened): 0.26, 0.00, 0.00, 0.00, 0.00, 0.24, 0.12, 0.00, 0.00, 0.00, 0.00, no run, no run, 0.12, 0.14, 0.14, 0.12, 0.00
gpt-5.5 not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week 0.00 not sampled this week 0.00 no run that week no run that week not sampled this week 0.00 not sampled this week 0.00 not sampled this week gpt-5.5 (line breaks where no run happened): 0.00, 0.00, no run, no run, 0.00, 0.00
claude-opus-4-7 not sampled this week 0.00 not sampled this week 0.00 not sampled this week 0.00 not sampled this week 0.00 not sampled this week 0.00 not sampled this week not sampled this week not sampled this week no run that week no run that week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week claude-opus-4-7: 0.00, 0.00, 0.00, 0.00, 0.00
gpt-5.1 0.00 not sampled this week 0.00 not sampled this week 0.00 not sampled this week 0.00 not sampled this week 0.00 not sampled this week not sampled this week not sampled this week not sampled this week no run that week no run that week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week gpt-5.1: 0.00, 0.00, 0.00, 0.00, 0.00

Median length

Median length per model per week. 2026-W30, 2026-W31 had no run at all, so those columns are shaded and marked “no run”; a plain — means the model was simply not sampled that week.
Model 2026-W172026-W182026-W192026-W202026-W212026-W222026-W232026-W242026-W252026-W262026-W272026-W282026-W292026-W302026-W312026-W322026-W332026-W342026-W352026-W36 Trend
claude-opus-4-8 not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week 53 not sampled this week no run that week no run that week 57 not sampled this week 60 not sampled this week not sampled this week claude-opus-4-8 (line breaks where no run happened): 53, no run, no run, 57, 60
claude-opus-5 not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week no run that week no run that week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week no data
llama3.2:3b not sampled this week not sampled this week 27 31 27 27 27 27 31 28 29 28 32 no run that week no run that week 28 28 28 27 28 llama3.2:3b (line breaks where no run happened) (change-point marked): 27, 31, 27, 27, 27, 27, 31, 28, 29, 28, 32, no run, no run, 28, 28, 28, 27, 28
gpt-5.5 not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week 12 not sampled this week 13 no run that week no run that week not sampled this week 13 not sampled this week 13 not sampled this week gpt-5.5 (line breaks where no run happened): 12, 13, no run, no run, 13, 13
claude-opus-4-7 not sampled this week 48 not sampled this week 44 not sampled this week 44 not sampled this week 49 not sampled this week 46 not sampled this week not sampled this week not sampled this week no run that week no run that week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week claude-opus-4-7: 48, 44, 44, 49, 46
gpt-5.1 19 not sampled this week 19 not sampled this week 13 not sampled this week 13 not sampled this week 15 not sampled this week not sampled this week not sampled this week not sampled this week no run that week no run that week not sampled this week not sampled this week not sampled this week not sampled this week not sampled this week gpt-5.1: 19, 19, 13, 13, 15

Semantic drift

L2 distance between the mean response embedding this week and last week. Higher = more semantic shift. How this is measured.

Embedding centroid shift per model, 2026-W36.
Model Shift
llama3.2:3b 0.0004

Sample responses

Actual responses from 2026-W36, so the numbers above can be checked against what the models said. Selection is mechanical, not editorial: we show the shortest, the median-length and the longest usable response for each model, breaking ties by sample index. Where a model both refused and answered, at least one of each is included. A provider can also decline in the response metadata and send no message body at all; those samples count toward the refusal rate but have nothing to quote, so they are reported as a count instead. Every sample, not just these, is in the week’s raw data. How these are chosen.

llama3.2:3b

25 usable samples this week.

median sample #2 · temp 1.0 · 163 chars · classified answer
The speed of light in a vacuum is approximately 299,792,458 meters per second (m/s). This value is a fundamental constant of nature and is denoted by the letter c.
shortest sample #5 · temp 1.0 · 78 chars · classified answer
The speed of light in a vacuum is approximately 299,792,458 meters per second.
longest sample #6 · temp 1.0 · 288 chars · classified answer
The speed of light in a vacuum is approximately 299,792,458 meters per second (m/s). This value is a fundamental constant of the universe and is denoted by the letter c in physics. It's a universal speed limit that applies everywhere in the universe, regardless of the medium or location.