---
title: "Did Achim Leistner's hand-polishing ('atomic feeling') actually outperform machine methods on the Avogadro spheres, and is the account corroborated beyond the Powerhouse Museum caption?"
type: "question"
status: "open"
date_raised: "2026-07-11T00:00:00.000Z"
writer_model: "claude-opus-4-8"
tags: ["metrology","craftsmanship","tactile-cognition","verification","avogadro-constant"]
---


[[claim-leistner-atomic-feeling-hand-polished-avogadro-spheres]] carries an
`[unverified-historical]` flag. The biographical spine (Leistner, Zeiss-Jena
training in 1953, emigration to Australia in 1957, hand-polishing at CSIRO) is
uncontested and fine at Tier 3–4. The problem is the surprising, load-bearing
element: that the manual "atomic feeling" technique "proved superior to purely
machine-based methods" at the nanometer scale. That is a craft-superiority claim
resting on a single Tier-3 source — the Powerhouse Museum's own object record —
which is below the sourcing floor for a surprising claim that is the emotional
core of the note.

## Why it matters

This is the hinge the whole capture turns on, and its bridge into the vault's
tactile-cognition cluster ([[claim-saunderson-palpable-arithmetic-tactile-calculating-device]],
[[claim-blind-mathematicians-independently-reinvented-private-notation]]) is only
as strong as the "hands beat machines" claim. Until it clears the floor, the note
stays seedling and cannot anchor a draft on touch-exceeding-instrumentation.

## What would answer it

- CSIRO's own account (technical report, precision-optics group history, or a
  named CSIRO scientist's statement) of how the final sphere figuring was done
  and what role manual technique versus instrumented/machine polishing played.
- A metrology or optics-journal write-up (Tier 1–2 — e.g. *Metrologia*, IOP, or a
  peer-reviewed Avogadro Project paper) describing the sphere-figuring process and
  whether hand-lapping outperformed machine methods, and in what respect.
- Any primary interview with or obituary of Leistner from a named journalist or
  scientific society (not a museum caption) attesting to the "atomic feeling"
  nickname and the superiority claim.

## Candidate next moves

Start from the Avogadro Project / International Avogadro Coordination publication
list and search *Metrologia* for the silicon-sphere roundness/topography papers,
which would name the polishing method. Cross-check the Wikipedia article on Achim
Leistner (cited in the capture's hop chain but Tier 4) for its own references and
chase those to primary.