What could explain the gallium anomaly?
Anomalous results from gallium-based neutrino experiments are raising the possibility of “sterile” neutrinos — hypothetical particles that don’t interact via the known forces and could reshape models of neutrino physics and dark matter. Commenters weigh how well sterile neutrinos fit existing cosmology, contrast them with more mundane explanations such as nuclear or chemical effects in liquid gallium, and note how hard it is to rule out experimental error. The thread also touches on the ethics and pragmatics of ongoing U.S.–Russian scientific collaboration during the war in Ukraine, using this neutrino experiment as a case study.
Radiation-detecting fish and other bioindicators
- Photo of fish as radiation sentinels prompts comparison to canaries in coal mines and rabbits for nerve-gas labs.
- Some speculate fish could accumulate alpha emitters in water where external detectors struggle; others argue modern scintillators/solid-state detectors are superior.
- One comment notes a practical advantage: if fish move, they’re working; with instruments, silent failure is harder to notice.
- Related examples: clams/mussels used in US/EU as water-quality bioindicators, with systems tracking shell-opening behavior.
Space pens, pencils, and markers
- Thread corrects the myth that NASA spent heavily to develop a pen while Soviets used pencils.
- Explanation: Fisher Pen developed the space pen privately; NASA and later the USSR simply bought them.
- Pencils are criticized as dangerous in spacecraft due to conductive, flammable graphite dust.
- Markers (Sharpies, Duro) reportedly work in space but dry quickly and lack precision; crayons are seen as too wide and faint.
Gallium anomaly, neutrinos, and sterile states
- Clarification that gallium is the target; neutrinos come from a radioactive source and convert Ga-71 to Ge-71 by absorbing an electron neutrino and emitting an electron.
- Only ~80% of expected conversions are seen. One possibility: oscillation of electron neutrinos into sterile states that don’t trigger the reaction.
- Discussion of chirality vs helicity: observed neutrinos are left-chiral; a truly “sterile” neutrino could be right-chiral and weakly/non-interacting.
- Some point out that oscillations don’t change total neutrino mass budget; others note heavy sterile neutrinos are popular dark-matter and baryon-asymmetry candidates.
Alternative, more “chemical” explanations
- One proposal: liquid gallium may form structured electronic environments (analogous to hydrogen bonding in water) that “shield” nuclei or alter reaction rates.
- Pushback: neutrinos traverse Earth with minimal interaction; extra electrons around gallium are unlikely to matter much.
- Others allow that subtle effects via electron capture and local electronic structure might exist but are usually assumed negligible; cited work claims cross-section miscalculation has already been ruled out, though details are unclear in the thread.
Scale and unit-conversion side discussion
- Participants estimate that 57 tonnes of liquid gallium is roughly a 2×2×2 m cube, or on the order of a few dozen 55-gallon drums.
- There’s meta-discussion about Google vs Wolfram Alpha unit handling and how “almost right” automated answers can mislead.
Geopolitics and scientific collaboration
- Some welcome ongoing US–Russia collaboration on BEST/ISS as stabilizing contact between nuclear powers and an expression of scientific “purity” above politics.
- Others argue any cooperation with Russia (beyond ISS safety necessities) is morally unacceptable given the war in Ukraine and that ordinary Russians should feel stronger consequences.
- Counterarguments stress realpolitik (MAD, need for communication channels) and note similar dilemmas about cooperating with China.