@tetrastore is not exactly the same thing, but using two measuring systems (international and imperial) cost to the nasa the mars climate orbiter...two ears.. .
is true and 'only' for a failure to convert data from the base (in n) and those managed by the module (in lbf); There was no effective communication between companies that participated in the project.
question from naive: considering that in practice "only" (it is done to say) canada, united kingdom, united states, birmania and free use the imperial system, how is it possible that they have not yet passed to the metric?
changing habits involving both the productive and economic world requires a lot of time, as an example, it is enough to think that since the introduction of the international system in 1961 the various industrial companies have employed more than 20 years only to change the symbolism in the catalogs (e.g. kgm > nm, hp > kw and rpm > min > min-1) maintaining also for a certain period the double symbolism not to confuse customers.
The British are conservative, for which, even if they had adopted the system paralleled their Anglo-Saxon, a condition necessary to be admitted in the ue, after the brexit, boris johnson took a step back taking away his fellow citizens the obligation to use the double system.
This is still possible because the British economy still suffers little from the influence of the EU market and other countries being still very linked to the United States, Canada and some smaller countries.
It will take a few decades but the process of change has already begun in the United States and Canada as, using imported products, machines and plants and wanting to increase their economic presence in other countries, they are forced to adapt.
I quote as an example the export of transmission organs and other mechanical organs towards the uses for which, up to twenty years ago, it was necessary to build trees and interfaces with measurements in in inches and now, often, are accepted with metric measures instead, now they are forced, to sell in eu, to manage double production.
There remains a speech apart from the voltage and frequency of electric motors as well as some products (type televisions (inch screens), types of threads, etc. and nautical and aviation measuring units that I doubt can change in the near future.
the same applies to countries with a left-wing direction for which change would be very challenging for high costs and, due to the high traffic intensity, the risk of accidents.
