From: "Tom Van Baak" <[EMAIL PROTECTED]> Subject: Re: [time-nuts] Time Nuts at PTTI this past week Date: Sat, 9 Dec 2006 07:43:41 -0800 Message-ID: <[EMAIL PROTECTED]>
> Hal, Tom, > > What's the calculated value? Lassen isn't very high. Are the campgrounds > > higher than Denver/Boulder? > > It was Mt Rainier, near here in Seattle, WA. We > went up to the 5400' level where the clocks ran on > the order of 500 ps/hour faster than at my home lab > at 1000'. We stayed up there about 40 hours. The > calculated time dilation, based on GPS logs of our > position, was around 23 ns. I assume you told the kids that yes, time does goes faster when you are having fun! Good practicaly physics lecturer you had there. > > For that matter, how hard is it to do this experiment with just two clocks > at > > different elevations? Do cesium clocks have an adjustment knob that > easily > > covers any elevation offsets? > > Yes and no. One could use the C-field adjustment, > as many of us have. With modern locking techniques, the C-field is being steered for the feature separations. It does not concerns itself with altitude as result of GR as far as I know. Did you log the C-field control loop during this trip? > But better results can be had > using an external phase microstepper, or just making > corrections in software, treating the cesium more as > a paper clock. > > For this relativity experiment I didn't adjust any of the > clocks - the whole point was to let them run at their > natural frequency and see how far off they had dilated > in time when they got back home. Indeed. > With the differential elevation gain I had available here > (between home and Mt Rainier is 1340 meters) the > predicted relativistic effect on the mountain was about > 1.5e-13. Remember that while you are 1340 meters up, the mountains gravity pull creates a local compensation to a small degree, so you will not fully experience the full altitude difference. It would have been a different exercise if you took a hotair balloon more or less straight up from your home. It might however be a challenge to stay up there for long enought to be comparable. Cheers, Magnus _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
