NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Choice of timepiece
From: Frank Reed
Date: 2009 Nov 13, 20:34 -0800
From: Frank Reed
Date: 2009 Nov 13, 20:34 -0800
Lu, you wrote: "but I'm looking at heavens-above.com and its display is about seven seconds slower than time.gov. I suspect that while, as they claim, they have very accurate time-keeping on their server, they're not compensating for propagation delay across the Internet." Interesting! Seven seconds is a big error. I just experimented with three different browsers (Internet Explorer, Google Chrome, and Firefox, all running under Windows Vista). I was able get de-synchronizations of the various time displays of up to half a second by minimizing and then restoring the browser windows (which is to be expected since the animated time display is just a javascript function), but when I refreshed the page, they were all back within an indistinguishable fraction of a second compared to WWV. And I think we *have* to believe that they are compensating for Internet propagation delay when the page first loads. I don't have any special pipeline to that web site! . . . I just spent five minutes away from my computer and have come back to see how they're doing. The javascript displays in the three browsers have de-synched by about a quarter of a second. -FER --~--~---------~--~----~------------~-------~--~----~ NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList+@fer3.com -~----------~----~----~----~------~----~------~--~---
