[meteorite-list] Earth time dilation: minimal latitude-dependence
From: MexicoDoug <mexicodoug_at_meteoritecentral.com>
Date: Thu, 21 Jul 2016 17:45:55 -0400
> I'm now working through the math to figure
> out the latitude on earth where you age the
> slowest. ;-)
Hi Rob, and fellow time pirates,
That's one interesting calculation and I'd have thought the latitude was slam-dunk 90 N, because that's over 20 km closer to the center of gravity all surface points on the equator according to the shapes that fit the spinning oblate globe!
Time dilation at the north pole factory, and near-light speed travel (like over 99.9999% the speed of light) could help explain how Santa's factory churns out all those toys in such a short time and easily delivers them, plus NORAD keeps a very close eye on him:
However given the speed he travels at, I would think Santa's waistline would be ablated after the run, and he would leave ionic trails. Not to mention, Rudolf's nose would be blue-shifted beyond UV the spectrum of visible light. (Which means the above NORAD video describes an inefficient tracking procedure) ... so maybe they have ulterior motives.
How to define "aging"? A loss of a few unhealthy isotopes? Biological clocks are as complicated a finding the Fountain of Youth here in Florida (though it may exist in a deep sinkhole somewhere) ... and have a temperature dependence.
A meteoroid on the other hand can weather (suspended on autopilot) 4.57 billion years and be fresh aside from the isotope composition, unless it meets some heat, radiation, reactants such as oxygen, and/or solvents like water.
And even further back to meteorites: Rob's comment that Earth's core is around a year or two younger helps motivate ballpark limits of aging in the context of the original discussion on meteorite age. If the core of Earth is limited to be calculated as 2.5 years younger than the crust, this is the order of magnitude of the limit we are dealing with for time dilation for most meteoroids.
We can compare that to the age of the Solar System, which is peer reviewed from a refractory inclusion in NWA 2364 (CV3) that give the age as 4,568.2 million years. Without looking up if they covered their error bars in the determination, just consider the significant figures alone they quote which leave us with an uncertainty of 100,000 years. So before we have to worry about time dilation for native small Solar System objects forcing a time adjustment, we will have to know the age of the Solar System to within say, 10 years or so. Not that Rome was built in a day ;-)
From: Matson, Rob D. <ROBERT.D.MATSON at leidos.com>
To: MexicoDoug <mexicodoug at aol.com>; meteorite-list <meteorite-list at meteoritecentral.com>
Sent: Thu, Jul 21, 2016 4:13 pm
Subject: Earth time dilation: minimal latitude-dependence
> I'm now working through the math to figure out the latitude on earth where you
> age the slowest.
Turns out the combination of 1/r GR effect from mass, a latitude-dependent quadrupole
component, and the centripetal term (special relativity) due to the earth's rotation nearly
compensate for one another in such a way that there is very little change in clock speeds
at the earth's surface as a strict function of latitude. Clocks run slowest at the equator,
marginally faster at midlatitudes, and then slower again at the poles (but not quite as
slow as at the equator). Local changes in gravitational field strength probably dominate
over changes with latitude. And altitude plays a much stronger roll at any latitude.
Received on Thu 21 Jul 2016 05:45:55 PM PDT