Clock drift. Not strictly a Linux question.

Tony Alfrey tonyalfrey
Fri Feb 16 13:39:00 PST 2007


Roger Oberholtzer wrote:
> On Friday 16 February 2007 16:59:15 Tony Alfrey wrote:
>> Roger Oberholtzer wrote:
>>> It's Friday. Time for a weekend-think-about-it question.
>>>
>>> I think I am doing my maths correct. I am checking a PC's clock against a
>>> high-end Trimble receiver (> $2000), using the pulse per second signal.
>>> Unless I am doing something wrong, I seem to see a 0.02 % linear (over
>>> the time I have looked) drift in the PC's clock (via gettimeofday())
>>> compared to the pulse from the GPS.
>> Silly boy, this is clearly a general relativity problem.  The pulse
>> you're getting from the GPS is from a geosynchronous satellite, at a
>> radius of some 25,000 miles, whereas your box is in Sweden (I seem to
>> remember?), where the Earth's crust is particularly thin and so you are
>> close to the mantle.  Therefore, the gravitational field at the location
>> of your box is considerably higher than at the geosynchronous satellite.
>>   And from general relativity, we know that clocks run slower in higher
>> gravitational fields.
>>
>> This is also why Swedes age slower than the rest of us.
> 
> Sweden it is. But if we are so close to the mantle, why is it so damned cold? 
> But I will try this explaination at the next tech meeting. Care to be named 
> as a reference :)
> 

Oh, there's always a skeptic in every crowd.  But we'll see whose right 
when I use my zero-point energy quantum fluctuator to thin the Swedish 
crust still further, causing hot magma to ooze up into the streets of 
Stockholm.  I'll show you guys what global warming really means.



-- 
Tony Alfrey
tonyalfrey at earthlink.net
"I'd Rather Be Sailing"



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