Flashes of light below the dripping faucet: an optical signal from capillary oscillations of water drops
Bibliographic record
Abstract
Falling water drops from a dripping faucet, illuminated from above, exhibit a row of bright strips of light, a few centimeters apart at a fixed distance below the faucet. Flash photographs of the drops show that they are oblate in shape when the flashes occur, and the bright flashes of light originate from the edge of the drop that is on the opposite of the overhead light source. Here we show that the spots result from the same internal reflection that gives rise to the rainbow in a cloud of spherical drops. The periodic flashes reflect the capillary oscillations of the liquid drop between alternating prolate and oblate shapes, and the dramatic enhancement in the oblate phase results from a combination of several optical effects. Ray tracing analysis shows that the flashes occur when the rainbow angle is 42 ° in spherical drops but sweeps over a wide range between 35 ° and 65 ° for typical ellipsoidal drops, and the intensity of the caustic is strongly enhanced in the oblate phase. This phenomenon can be seen in all brightly lit water sprays with millimeter size drops and is responsible for their white color.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".