It's not getting one past the airport authorities that's the issue. It's getting one that's powered up past them. ;)
Written from about 10,000'. :) > On Mar 22, 2017, at 20:15, Tom Van Baak <t...@leapsecond.com> wrote: > > Chris Albertson wrote: >> Why drive up a mountain? > > "Because it's there" ;-) And because there's a paved road, and it's free, > and there's a place to stay overnight, and the mountain doesn't move. Plus a > car makes a good portable time lab; you can share the experience with family > or students or visiting time nuts; and a number of technical reasons. > > But most importantly: you can remain at altitude as long as you want -- in > order to accumulate just enough nanoseconds of time dilation to meet your > experiment's S/N goal -- without running into (or much worse, going beyond) > the flicker floor of your clocks. > > There are several different ways to measure time dilation with atomic clocks. > Some notes here: > http://leapsecond.com/pages/atomic-tom/ > > >> Take the clock with you inside the pressurized cabin of a commercial airliner > > Yes, and this has been done many times. The first (1971) and most famous of > all traveling clock relativity experiments is: > https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment > > For vintage hp flying clock articles see: > https://www.febo.com/pipermail/time-nuts/2013-January/073743.html > > Two modern examples are described here: > > "Time flies" > http://www.npl.co.uk/news/time-flies > > "Demonstrating Relativity by Flying Atomic Clocks" > http://www.npl.co.uk/upload/pdf/metromnia_issue18.pdf > > /tvb > > ----- Original Message ----- > From: Chris Albertson > To: Tom Van Baak ; Discussion of precise time and frequency measurement > Sent: Tuesday, March 21, 2017 7:12 PM > Subject: Re: [time-nuts] Time Dilation tinkering > > "flight" there is the word. Why drive up a mountain? Take the clock with > you inside the pressurized cabin of a commercial airliner next time you are > on one of those 10 hour trans=pacific flights. You be taller then any > mountain and it is actually cheaper then a weather balloon. > > Can you get a Rb clock past the TSA x-ray machine. Maybe if you ask first. > There must be a way to hand cary specialized equipment. > > On Tue, Mar 21, 2017 at 7:03 PM, Tom Van Baak <t...@leapsecond.com> wrote: > > But attached is one of the first plots where I put a SA.32m in a home-brew > vacuum chamber and pulled down to a few inches of Hg for a few hours to > simulate the low pressure of a flight up to 50 or 90,000 ft. For a high > altitude relativity experiment -- where you'd like your clock to remain > stable to parts in e-13 and not accumulate too many stray ns -- it's not a > good sign when your clock changes by 2e-11 (that's more than 1 ns per minute) > just because of ambient pressure changes. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.