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    Re: Susceptibility of GPS to CME, Rationale for CN?
    From: Robert VanderPol II
    Date: 2018 Sep 30, 20:17 -0700


    Per Francis' original description, the thermos was not the Faraday cage, it was a thermal insulator to flatten out temperature swings..  The faraday cage was the metal box the thermos was in.  He did not include an electrical insulating layer in the description so it sounds like there is still room for improvement.

    Regarding Francis' question about a CME affecting quartz watches.  I can see the CME affecting the earth's geomagnetism which may have a minor effect on the rate of quartz watches.  No evidence for that just my gut feeling there is a very small effect if any.  I found several links discussing magnetic resistance in watches. The following seemed like the best discussion.:


    The bigger issue of CMEs would be the effect on ground based infrastructure, namely the electrical and communication grids.  Electrical is almost certainly more susceptible, a lot of the communication grid being fiber optic, though the communication grid depends on power from the electrical grid.  The Carrington event caused significant problems with the telegraph systems of the day.  Today there are orders of magnitude more and longer runs of conductors in place for the electrical grid.  I would expect most of the electrical grids world wide to go down.  Very small ones might stay up.  The big question is how resilient is the electrical grid for the countries with positioning systems on orbit.  Would the event blow breakers that can be reset or would it fry transformers.  The lead time on delivery for very large transformers is on the over of a year or more.  If a lot of transformers blew at once then we are looking at years long return to service for big chuncks of the grid.  

    In the short term the ground side of the GPS and other systems will have backup generation to keep operating.  In the medium to long term there will need to be a commitment by the controlling governments to fuel the backup generation.  I suspect that the ground system is limited enough and the service valuable enough that most countries would assign scarce resources to that maintenance.

    I suspect that WAAS and similar will not be maintained in the short term, use would depend on both the electrical grid and communication network being restored.

    Now you have a bunch of guesses on my part.

    Bob II

    Re: Susceptibility of GPS to CME, Rationale for CN?
    From: Brad Morris
    Date: 2018 Sep 30, 21:38 -0400

    Hi Francis

    As Bob indicated, the watches should be in an insulator, and then enclosed in the metal faraday cage.  
    Is the top of the thermos plastic?  Then the faraday cage isn't complete.  Are the watches touching any metal of the thermos?  Then the insulator just isn't.
    On Sun, Sep 30, 2018, 9:29 PM Francis Upchurch <NoReply_Upchurch@fer3.com> wrote:

    Does CME affect quartz watches? I keep my 4 cheap backups in a thermos flask stowed in a metal box ("Faraday cage").Should be safe?
    I knew I might  find a practical use for my mechanical Invicta watch (cheap Rolex Submariner copy)  which keeps regular time + 4-8 secs per day over the last 2 years.
    On the philosophy of time. Enjoy life and do it now. It is later than you think!
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