Thank you. That’s probably where it came from.

Could it be that the ‘First Lightning’ came about as some kind of an artistic or journalistic metaphor that stuck? I looked at the use of that name in the Soviet books and the 1968 biography of Kurchatov in the famous “ЖЗЛ” series has a chapter named that way, ‘describing’ the production and testing of the RDS-1. The same book has another chapter, called the ‘Second Lightning’, which talks about Soviet thermonuclear weapons. These ‘lightnings’ are only mentioned in the chapter titles, the author does not imply that these are code words.

The link to Google Books: http://books.google.se/books?id=NHcLAAAAMAAJ
The text in Russian: http://lib.rus.ec/b/71207/read

So one hypothesis could be that the ‘First Lightning’ is a Soviet propaganda metaphor that got picked up in the West after the publication in the “ЖЗЛ” series, which had a very wide circulation. This hypothesis can be shown to be wrong if there is the use of the ‘First Lightning’ in the Western literature before 1968.

I suspect that part of the issue with the difference in reported timing and the actual timing had to do with the evolving knowledge base of nuclear isotopes in 1949. Based on what they knew at the time about the various decay chains, they made as good an estimate as possible. Later, as the “Tri-Linear Chart of Nuclear Species” was filled in over the next few years, a better estimate came about.

There’s also the issue that R&D for sampling and lab analysis was done at American tests, where the conditions were more under control and known in advance. I don’t know if they did any analyses via double-blind studies, which might have eliminated the possibility of knowing the timing of the shot affecting the way it was analyzed. The samples of Soviet shots had to be captured “in the wild” so to speak. There was no instantaneous forwarding of the limited acoustic signals, for instance. The tapes had to be forwarded by courier, then analyzed for correlation to other data.

This is in part speculation based on what I do have evidence of, as advanced radio-chemistry is beyond my skill-set. I think a research project that ties the general development of knowledge about various isotopes to the specific ways in which nuclear testing advanced such research would be an interesting history of science research project for someone. i

Whatever the reason was for the timing discrepancy, it’s clear once AFOAT-1′s ad-hoc seismic network became operational in 1950, along with improvements in the Army Signal Corps’-operated acoustic detection network, it quickly made immediate detection of Soviet shot times a routine and accurate matter in most, but not all cases.

It has always astounded me how we were able to accomplish so much, with so little ‘technology’.