The neutrino mass hierarchy and absolute mass scale are not fully resolved.
Oscillation experiments show mixing but leave ordering and scale uncertain. Next-generation beta-decay and cosmological probes can answer these questions.
World Solve is a public institutional repository for identifying real unresolved problems across science, society, health, governance, economics, and local systems. Each entry is intended to be citable, inspectable, and actionable.
Oscillation experiments show mixing but leave ordering and scale uncertain. Next-generation beta-decay and cosmological probes can answer these questions.
Permanently shadowed craters at the lunar poles reach -240°C, making metals and polymers brittle and prone to shattering. Special cryogenic-resistant alloys and thermal insulation jackets are required.
Sorting algorithms have been optimized extensively, but proving a true absolute lower bound across all possible sorting methods remains an unresolved question in computational theory. This affects the fundamental efficiency limits of computing.
While many invariants help distinguish specific knots, no single finite and fully general method has been proven to work for absolutely every possible pair of knots. This remains a central unresolved question in the mathematical study of knots.
Formal proof systems capture enormous portions of mathematical reasoning, but whether a truly complete and finite rule set exists for absolutely every valid form of proof remains philosophically and technically unresolved. This touches the very foundations of what mathematics is capable of expressing.
Some philosophers argue honesty is an absolute duty, while others believe consequences justify occasional deception, particularly to prevent harm. Real situations in medicine and relationships constantly test where this line actually falls.