Re: [time-nuts] Time Dilation tinkering

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 >>> >>&g

Re: [time-nuts] Time Dilation tinkering

Rather than commercial passenger flights, it used to be one could get connections and fly along on transport, ferry or private flights, typically for a (no-frills) low fee. There are also flights made for testing equipment at altitude, including radio, satellite, imaging or other sensing

Re: [time-nuts] Time Dilation tinkering

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 "flig

Re: [time-nuts] Time Dilation tinkering

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

Re: [time-nuts] Time Dilation tinkering

- 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

Re: [time-nuts] Time Dilation tinkering

On 22/03/2017 10:56 AM, jimlux wrote: On 3/22/17 4:04 AM, Angus wrote: No tall mountains in Australia, but... Pikes Peak in the US is 14114 ft, 4304m and has a road to the top. Of course the base is at about 5000 ft/1600 m In EU, there's probably a Seilbahn of some sort pretty high up in

Re: [time-nuts] Time Dilation tinkering

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=paci

Re: [time-nuts] Time Dilation tinkering

On Wed, Mar 22, 2017 at 9:39 AM, David C. Partridge wrote: > Aiguille du Midi is 3842m IIRC (cable car base station at about 1000m). > > Dave > > > Pikes Peak in the US is 14114 ft, 4304m and has a road to the top. Of course > the base is at about 5000 ft/1600 m >

Re: [time-nuts] Time Dilation tinkering

Hi, On 03/22/2017 05:55 PM, Attila Kinali wrote: On Wed, 22 Mar 2017 07:56:45 -0700 jimlux wrote: In EU, there's probably a Seilbahn of some sort pretty high up in the Alps, although probably not to 4000m. But almost: https://en.wikipedia.org/wiki/Klein_Matterhorn You

Re: [time-nuts] Time Dilation tinkering

Hi The outer can is at best only “sort of” sealed. Bob > On Mar 22, 2017, at 10:58 AM, jimlux wrote: > > On 3/22/17 4:28 AM, Bob Camp wrote: >> Hi >> >> In this case, the vacuum might work against you. You change the pressure >> outside >> the package and you get a

Re: [time-nuts] Time Dilation tinkering

On Wed, Mar 22, 2017 at 07:52:38AM -0700, jimlux wrote: > I imagine there's a "de minimis" quantity. We didn't declare the cesium in > the CSAC that we hand carried, and I'm pretty sure people have hand carried > SRS Rb sources. The letter they have covers anything up to a gram of Rb.

Re: [time-nuts] Time Dilation tinkering

On 3/21/2017 7:12 PM, Chris Albertson wrote: "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

Re: [time-nuts] Time Dilation tinkering

On 3/22/17 10:07 AM, Arnold Tibus wrote: No tall mountains in Australia, but... Pikes Peak in the US is 14114 ft, 4304m and has a road to the top. Of course the base is at about 5000 ft/1600 m In EU, there's probably a Seilbahn of some sort pretty high up in the Alps, although probably not

Re: [time-nuts] Time Dilation tinkering

Hi, On 03/22/2017 12:02 AM, Tom Van Baak wrote: Scott McGrath wrote: Or perhaps use the Symmetricom CSAC ... Chris Albertson wrote: Get a weather balloon. Or there might already be an amateur group that launches these. Balloons can go much higher than your local mountains. You'll both

Re: [time-nuts] Time Dilation tinkering

Am 22.03.2017 um 15:56 schrieb jimlux: > On 3/22/17 4:04 AM, Angus wrote: >> On Tue, 21 Mar 2017 13:08:56 +0100, you wrote: >> >>> On Tue, 21 Mar 2017 13:38:51 +1100 >>> Hugh Blemings wrote: >>> This got me to wondering if a Rubidium based standard might do the trick

Re: [time-nuts] Time Dilation tinkering

Aiguille du Midi is 3842m IIRC (cable car base station at about 1000m). Dave -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of jimlux Sent: 22 March 2017 14:57 To: time-nuts@febo.com Subject: Re: [time-nuts] Time Dilation tinkering On 3/22/17 4:04 AM

Re: [time-nuts] Time Dilation tinkering

On Wed, 22 Mar 2017 07:56:45 -0700 jimlux wrote: > In EU, there's probably a Seilbahn of some sort pretty high up in the > Alps, although probably not to 4000m. But almost: https://en.wikipedia.org/wiki/Klein_Matterhorn You could start in Sion(500m) or Visp(660m) take the

Re: [time-nuts] Time Dilation tinkering

On 3/22/17 4:28 AM, Bob Camp wrote: Hi In this case, the vacuum might work against you. You change the pressure outside the package and you get a flex. Flex translates to dimensional changes. That gives you a frequency shift. People make absolute pressure sensors this way :) Rb’s are by no

Re: [time-nuts] Time Dilation tinkering

On 3/22/17 12:04 AM, Michael Wouters wrote: Dear Chris, I believe IATA prohibits the carriage of any quantity of rubidium on passenger aircraft. You have to complete a "Dangerous Goods Declaration" and it then has to go by cargo aircraft. I imagine there's a "de minimis" quantity. We didn't

Re: [time-nuts] Time Dilation tinkering

Unhappily, local TSA authorities have--or at least appropriate to themselves--the prerogative to disregard prior approvals from their superiors. A former colleague of mine used to hand carry an ultra-high precision gas dilutor between research sites. She had written approvals from TSA in DC that

Re: [time-nuts] Time Dilation tinkering

I remember a time when some at PBT referred to the HP5065A as their precision pressure sensor Bert Kehren In a message dated 3/22/2017 10:03:58 A.M. Eastern Daylight Time, kb...@n1k.org writes: Hi In this case, the vacuum might work against you. You change the pressure outside the

Re: [time-nuts] Time Dilation tinkering

On 3/22/17 4:04 AM, Angus wrote: On Tue, 21 Mar 2017 13:08:56 +0100, you wrote: On Tue, 21 Mar 2017 13:38:51 +1100 Hugh Blemings wrote: This got me to wondering if a Rubidium based standard might do the trick - the Efratom SLCR-101s seem readily available for ~USD$200

Re: [time-nuts] Time Dilation tinkering

On 3/21/17 10:36 PM, Michael Wouters wrote: Yes, that's what I was quoted by the Microsemi agent and the price on Mouser is similar. The $1568 version was EOL'ed in December 2016; the more expensive unit is the '2nd generation'. Ah probably the one that has a good seal and has a rated

Re: [time-nuts] Time Dilation tinkering

Ive been playing with one for work for the past few weeks and the Nor Easter which blew through NE did not affect short term ADEV with Tau < 1000s and that had a signficant drop in local barometric pressure for several hours As to long term controlled studies no have not had opportunity to do

Re: [time-nuts] Time Dilation tinkering

On Tue, 21 Mar 2017 13:08:56 +0100, you wrote: >On Tue, 21 Mar 2017 13:38:51 +1100 >Hugh Blemings wrote: > >> This got me to wondering if a Rubidium based standard might do the trick >> - the Efratom SLCR-101s seem readily available for ~USD$200 mark. > >As TvB wrote, a

Re: [time-nuts] Time Dilation tinkering

Hi In this case, the vacuum might work against you. You change the pressure outside the package and you get a flex. Flex translates to dimensional changes. That gives you a frequency shift. People make absolute pressure sensors this way :) Rb’s are by no means the only frequency standard

Re: [time-nuts] Time Dilation tinkering

On 3/21/17 7:12 PM, Chris Albertson wrote: "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

Re: [time-nuts] Time Dilation tinkering

Hmm, it appears that Symmetricom has an interpretation from IATA which classifies their rubidium-containing products as non-hazardous. I went through all of this some time ago because we were shipping rubidiums about domestically (Australia) and there was no permissible maximum qty of rubidium

Re: [time-nuts] Time Dilation tinkering

Dear Chris, I believe IATA prohibits the carriage of any quantity of rubidium on passenger aircraft. You have to complete a "Dangerous Goods Declaration" and it then has to go by cargo aircraft. Cheers Michael On Wed, Mar 22, 2017 at 1:12 PM, Chris Albertson wrote:

Re: [time-nuts] Time Dilation tinkering

Hi, My profound thanks to Tom, Bob, Chris, Attila, Scott, Jim, Hal and Michael for such thorough and thoughtful replies to my initial post. I'm fortunate enough to know some of the local amateur high altitude balloon crowd and had contemplated such an endeavour but note this wouldn't be

Re: [time-nuts] Time Dilation tinkering

Yes, that's what I was quoted by the Microsemi agent and the price on Mouser is similar. The $1568 version was EOL'ed in December 2016; the more expensive unit is the '2nd generation'. Cheers Michael On Wed, 22 Mar 2017 at 9:06 am, jimlux wrote: > On 3/21/17 1:40 PM,

Re: [time-nuts] Time Dilation tinkering

On 3/21/17 4:29 PM, Hal Murray wrote: scmcgr...@gmail.com said: However CSAC not subject to barometric effects as Rb units are Does anybody tried to measure CSAC vs pressure? The physics package in a CSAC is a vacuum, so it probably won't make much difference. But, as a practical

Re: [time-nuts] Time Dilation tinkering

On 3/21/17 5:25 PM, Bob Camp wrote: Hi Ummm … e …. it’s a gas cell standard. I’d bet there is a pressure effect. But the gas cell, the laser, etc. is in a vacuum - that's the "wear out" mechanism for a CSAC - the getter fills up, the pressure inside the vacuum package increases, and

Re: [time-nuts] Time Dilation tinkering

On 3/21/17 7:03 PM, Tom Van Baak wrote: Yes, MAC and CSAC do show environmental sensitivity. But that should not be a surprise to anyone that works with precise time & frequency. The factors include voltage, temperature, temperature gradient, pressure, humidity, acceleration, tilt

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

Re: [time-nuts] Time Dilation tinkering

Hi Ummm … e …. it’s a gas cell standard. I’d bet there is a pressure effect. Bob > On Mar 21, 2017, at 7:01 PM, Scott McGrath wrote: > > Noted > > However CSAC not subject to barometric effects as Rb units are > > Content by Scott > Typos by Siri > >> On Mar 21,

Re: [time-nuts] Time Dilation tinkering

scmcgr...@gmail.com said: > However CSAC not subject to barometric effects as Rb units are Does anybody tried to measure CSAC vs pressure? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe,

Re: [time-nuts] Time Dilation tinkering

Scott McGrath wrote: > Or perhaps use the Symmetricom CSAC ... Chris Albertson wrote: > Get a weather balloon. Or there might already be an amateur group that > launches these. Balloons can go much higher than your local mountains. You'll both be interested to hear that CSAC+balloon was

Re: [time-nuts] Time Dilation tinkering

Noted However CSAC not subject to barometric effects as Rb units are Content by Scott Typos by Siri > On Mar 21, 2017, at 4:18 PM, jimlux wrote: > >> On 3/21/17 12:51 PM, Scott McGrath wrote: >> Or perhaps use the Symmetricom CSAC ... >> >> Relatively expensive but

Re: [time-nuts] Time Dilation tinkering

On 3/21/17 1:40 PM, Michael Wouters wrote: These are less stable than a rubidium eg tau=10e-11@1000s and monthly ageing of 9e-10. The price of these has gone up too- they're now about US5000. Really? That's a big increase. I bought some last year (well, in December 2015) and they were

Re: [time-nuts] Time Dilation tinkering

These are less stable than a rubidium eg tau=10e-11@1000s and monthly ageing of 9e-10. The price of these has gone up too- they're now about US5000. Cheers Michael On Wed, 22 Mar 2017 at 7:03 am, Scott McGrath wrote: > Or perhaps use the Symmetricom CSAC ... > >

Re: [time-nuts] Time Dilation tinkering

On 3/21/17 12:51 PM, Scott McGrath wrote: Or perhaps use the Symmetricom CSAC ... Relatively expensive but might work The CSAC is 8E-12 AVAR at 1000 seconds, comparable to a Rb. See also http://tycho.usno.navy.mil/ptti/2011papers/Paper27.pdf which shows a bit better performance (3E-12 @

Re: [time-nuts] Time Dilation tinkering

Or perhaps use the Symmetricom CSAC ... Relatively expensive but might work > On Mar 21, 2017, at 8:08 AM, Attila Kinali wrote: > > On Tue, 21 Mar 2017 13:38:51 +1100 > Hugh Blemings wrote: > >> This got me to wondering if a Rubidium based standard might

Re: [time-nuts] Time Dilation tinkering

Get a weather balloon. Or there might already be an amateur group that launches these. Balloons can go much higher than your local mountains. You al ill want to build an environmental chamber for the Rb clock. The chamber is heated and pressurized. Even for the maintain top experiment you will

Re: [time-nuts] Time Dilation tinkering

On Tue, 21 Mar 2017 13:38:51 +1100 Hugh Blemings wrote: > This got me to wondering if a Rubidium based standard might do the trick > - the Efratom SLCR-101s seem readily available for ~USD$200 mark. As TvB wrote, a single one will not do the trick. You will need a stability

Re: [time-nuts] Time Dilation tinkering

H > On Mar 21, 2017, at 4:58 AM, Tom Van Baak wrote: > > Hi Hugh, > >> If I do the math correctly that's about 14ns difference per 24h the >> clocks are separated by that altitude. [1] > > That's correct. For your 1500m elevation gain, the gravitational redshift, > the

Re: [time-nuts] Time Dilation tinkering

Hi Hugh, > If I do the math correctly that's about 14ns difference per 24h the > clocks are separated by that altitude. [1] That's correct. For your 1500m elevation gain, the gravitational redshift, the df/f frequency change, will be about 1.6e-13. To be able to measure with any confidence