The Importance of Remembering What You Don't Understand
Fifty-four years ago today, THRESHER was lost. The week following that event, I was analyzing grams called in from all stations; there were no tapes.
As I remember, the DSA backfit was well underway and only a few down-range stations still had the FQQ display system.
An FQQ vernier from Antigua – at a range of 1300 nm – showed not only the energy blast of the THRESHER collapse but also harmonics of a diffuse source that lasted seconds longer than the energy blast.
Although that source - harmonics of a 3.4 Hz spacing up to the 8th – was obviously associated with THRESHER, neither I nor anyone to whom I spoke – including the resident engineer – had any idea what it was. No other gram – even from a range of 30 nm – showed that structure but then the resolution of the FQQ vernier far exceeded that of the DSA broadband. (DSA verniers came later.)
And there my state of ignorance remained for 45 years until in 2008 - while researching SCORPION documents - I read about bubble-pulse energy created when collapse events occurs. Applying the empiric formula that relates bubble-pulse frequency to the volume of a collapsing structure to derive the depth of the event, the collapse-depth of THRESHER was determined to have been an astounding 2400-feet, almost twice test-depth.
That assessment - based on identification of the 3.4 Hz source as bubble-pulse - has been the “Rosetta Stone” for understanding the sequence of events associated with the loss of THRESHER.
I can think of no better example of the importance of remembering – or making a record of – what you don't understand in real-time.