On 22/08/2020 18:34, Max Demian wrote:
On 22/08/2020 17:45, NY wrote:
"Chris Hogg" wrote in message
...
On Sat, 22 Aug 2020 14:58:08 +0100, "NY" wrote:

What is the Zanzibar effect? I can't find anything on Google so it's
evidently not a widely-known term.

Zanzibar time : https://tinyurl.com/suqbk29

Basically, a circular calibration process. A calibrates his instrument
against an instrument owned by B, who unbeknown to A, calibrates his
instrument against A's.

Interesting that googling for the phrase as quoted "zanzibar effect"
does not produce any matches. Lots of matches for the country of that
name, but nothing else. Even googling for "zanzibar time" or "zanzibar
effect time" doesn't produce any matches.

I can understand the problem of circular calibration, but I'd never
have been able to discover or even guess what it was from the phrase,
assuming I hadn't already heard of it.

"Zanzibar effect" (with the quotes) gives (me) this as the first result:
https://metrology.wordpress.com/stat...-traceability/


"The famous story of the retired sea-captain on the island who takes his
time from the watchmaker in town only to find out that the watchmaker
uses the sea-captains cannon shots at 12 noon each day to set his own
clocks! [Attributed to Harrison (MIT) by Petley.]"

Without the quotes it's a bit further down the list. But I agree it's
not easy to find.

that is not even the watchmaker involved ...that shop is on some Spanish
island ....