Leistner's hand-polishing of the Avogadro spheres is independently corroborated beyond the Powerhouse Museum record — the 'atomic feeling' nickname is not

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claim-leistner-atomic-feeling-hand-polished-avogadro-spheres originally rested the hand-polishing narrative on a single Tier-3 source, the Powerhouse Museum's object record, and was flagged pending independent corroboration at question-verify-leistner-atomic-feeling-superior-to-machines. Two more independent, named-journalist sources have since turned up the same practice without paraphrasing the museum. Jonathon Keats, reporting for Wired in 2011, describes Achim Leistner spinning the silicon sphere "inside a pair of funnels — like a scoop of ice cream held between two cones — until he can feel the molecular structure of the cubic silicon crystal itself with his fingertips." Devin Powell, writing in New Scientist in July 2008 — days after the spheres were discussed at the SPIE Astronomical Telescopes and Instrumentation conference in France, and some months after CSIRO presented them to the Avogadro Project in April — reports that "opticians manipulated two spinning rotors to grind the surface by hand," and quotes Leistner directly on the result. Both are on-the-record accounts by named journalists carrying their own reporting, not restatements of the museum's wording.

This is uncontested biographical/historical material, for which the sourcing floor accepts Tier 3–4, and it is now met twice over in two different venues by two different reporters. The hand-polishing practice, and the narrative of a craftsman feeling the crystal structure through his fingertips, can be treated as corroborated.

The nickname itself cannot. The phrase "atomic feeling" appears in neither of these two sources, and it does not appear in the Powerhouse Museum object record that the vault originally credited for it. Its traceable home is the English Wikipedia article on Achim Leistner — Tier 4, usable as a pointer and not as evidence — which attributes the phrase to BBC Four's documentary Precision: The Measure of All Things, episode 2, "Mass and Moles" (4 July 2014). No vault note has read that documentary. The nickname circulates; what corroborates it has not been located.

What also remains unresolved is the separate, stronger claim that the technique measurably outperformed machine methods — that claim carries its own higher sourcing floor and is tracked at claim-leistner-hand-beats-machines-claim-lacks-tier1-primary.