Popular histories often begin with Shockley's postwar research group and then move quickly to Bardeen and Brattain. That makes the material under their contacts look almost passive. The wartime record says otherwise.
High-back-voltage germanium was already an engineered object
Scaff and Theuerer's patent, with a 1945 priority date, describes high-purity germanium, controlled donor impurities, n- and p-type regions, thermal treatment, high-back-voltage n-type zones and practical point-contact rectifiers. This is not later textbook hindsight; it is a direct technical lineage from wartime detector production.
The later Bardeen–Brattain transistor patent explicitly refers to the Scaff/Theuerer process. That substantially weakens any origin argument that relies on suitable high-back-voltage germanium being inexplicably available at Bell.
Purdue is not merely 'prior art'
Purdue's wartime semiconductor program interacted with Bell, Western Electric, MIT and military detector work. Purdue's own history says its high-back-voltage germanium and anomalous germanium observations helped shape the Bell experiments. Because that is an institutional history, its causal language must be audited rather than simply accepted. But the technical network itself is real.
This creates a better question than “was the transistor invented inside Bell?” Knowledge, samples and production practice moved across organizations that had already worked together under wartime conditions. The useful historical unit may be the semiconductor network, with Bell as one especially capable node.
The network can explain convergence without explaining everything
Ordinary common ancestry is currently the strongest explanation for many supposedly mysterious material and process choices. It also gives a restricted-transfer hypothesis a concrete route to test. Those are not the same claim. A shared wartime technique is not evidence of secret transistor information unless a distinctive transistor-relevant item can be shown crossing the boundary.
The decisive documents remain the full NDRC 14-555 and 14-585 reports, plus the correspondence and meeting records that connect the laboratories. We are treating failure to acquire those reports as a bounded acquisition problem, not as evidence that they were suppressed.
Wartime ancestry makes the origin story less isolated. It does not, by itself, make it clandestine.
- Scaff & Theuerer, US2602211A — high-back-voltage germanium rectifier process.
- Purdue, The War Period (1941–1945).
- Purdue, The Post-War Years — useful institutional account with an explicit Purdue-centered bias vector.
- Bardeen & Brattain, US2524035A.