Lots of people (e.g. [0], [1], [2]) have blogged the Feynman technique, which seems to have been first documented in Gleick’s biography [3]. The various descriptions identify the following four steps:

* write down the name of a concept

* write down an explanation of the concept in plain English, identifying the bits you don’t know

* review the explanation, going back to source material if there is something that you haven’t yet explained, and repeat step 2

* simplify the language and rewrite bits where you have paraphrased the source material

[0] https://collegeinfogeek.com/feynman-technique/

[1] https://mattyford.com/blog/2014/1/23/the-feynman-technique-m...

[2] https://mystudentvoices.com/feynman-technique-learn-and-reta...

[3] https://www.amazon.com/gp/product/0679747044

The first soviet atomic bomb was detonated in 1949[1] so this was nearly 10 years after that fact.

His association to Klaus Fuchs[2] was probably more suspect than Oppenheimer (despite how suspicious they were of him) given he was allegedly an actual spy (I say allegedly because I know how suspicious of the FBI people are around here, and not without reason in some cases).

According to the Feynman Bio I'm reading right now [3], Fuchs was said to have joked (when Feynman wasn't around) that he would be the most likely person to be a spy because of how often he left the base alone to visit his sick wife (or so he said).

[1] http://www.atomicheritage.org/history/soviet-atomic-program-... [2] https://en.wikipedia.org/wiki/Klaus_Fuchs [3] https://www.amazon.com/Genius-Life-Science-Richard-Feynman/d...