A recent copy of the IEEE Spectrum included this article https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks It isn't as stable as an atomic clock over an extended period but it's short-term accuracy is much better. Each clock period is much closer to being perfectly equal to the last one. And it is an Australian development ... -- Bill Sloman, Sydney
Precison sapphire oscillator
Started by ●August 11, 2021
Reply by ●August 11, 20212021-08-11
On Wed, 11 Aug 2021 01:57:25 -0700 (PDT), Anthony William Sloman <bill.sloman@ieee.org> wrote:>A recent copy of the IEEE Spectrum included this article > >https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks > >It isn't as stable as an atomic clock over an extended period but it's short-term accuracy is much better. Each clock period is much closer to being perfectly equal to the last one. > >And it is an Australian development ...Not surprising the pulsing from the cryocooler caused them some grief. It's too bad there's no practical way yet to get down to < 10K using refrigeration without vibrations and such like. -- Best regards, Spehro Pefhany
Reply by ●August 11, 20212021-08-11
On 2021-08-11 18:33, Spehro Pefhany wrote:> On Wed, 11 Aug 2021 01:57:25 -0700 (PDT), Anthony William Sloman > <bill.sloman@ieee.org> wrote: > >> A recent copy of the IEEE Spectrum included this article >> >> https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks >> >> It isn't as stable as an atomic clock over an extended period but it's short-term accuracy is much better. Each clock period is much closer to being perfectly equal to the last one. >> >> And it is an Australian development ... > > Not surprising the pulsing from the cryocooler caused them some grief. > It's too bad there's no practical way yet to get down to < 10K using > refrigeration without vibrations and such like. >The IEEE Spectrum article is of particularly low quality. It seems to actually make an effort to be as vague and useless as possible. This one is *much* better: <https://www.adelaide.edu.au/ipas/our-research/defence-security/cryogenic-sapphire-oscillator-the-sapphire-clock#publications> Jeroen Belleman
Reply by ●August 12, 20212021-08-12
On Thursday, August 12, 2021 at 3:49:26 AM UTC+10, Jeroen Belleman wrote:> On 2021-08-11 18:33, Spehro Pefhany wrote: > > On Wed, 11 Aug 2021 01:57:25 -0700 (PDT), Anthony William Sloman > > <bill....@ieee.org> wrote: > > > >> A recent copy of the IEEE Spectrum included this article > >> > >> https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks > >> > >> It isn't as stable as an atomic clock over an extended period but it's short-term accuracy is much better. Each clock period is much closer to being perfectly equal to the last one. > >> > >> And it is an Australian development ... > > > > Not surprising the pulsing from the cryocooler caused them some grief. > > It's too bad there's no practical way yet to get down to < 10K using > > refrigeration without vibrations and such like. > > > The IEEE Spectrum article is of particularly low quality. It seems > to actually make an effort to be as vague and useless as possible. > > This one is *much* better: > <https://www.adelaide.edu.au/ipas/our-research/defence-security/cryogenic-sapphire-oscillator-the-sapphire-clock#publications>It is certainly a lot easier to understand. Whether I'd be able to get much out of the publications it lists is an open question. -- Bi;; Sloman, Sydney
Reply by ●August 12, 20212021-08-12
On a sunny day (Wed, 11 Aug 2021 19:49:18 +0200) it happened Jeroen Belleman <jeroen@nospam.please> wrote in <sf12iu$1dnb$1@gioia.aioe.org>:>On 2021-08-11 18:33, Spehro Pefhany wrote: >> On Wed, 11 Aug 2021 01:57:25 -0700 (PDT), Anthony William Sloman >> <bill.sloman@ieee.org> wrote: >> >>> A recent copy of the IEEE Spectrum included this article >>> >>> https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks >>> >>> It isn't as stable as an atomic clock over an extended period but it's short-term accuracy is much better. Each clock period >>> is much closer to being perfectly equal to the last one. >>> >>> And it is an Australian development ... >> >> Not surprising the pulsing from the cryocooler caused them some grief. >> It's too bad there's no practical way yet to get down to < 10K using >> refrigeration without vibrations and such like. >> > >The IEEE Spectrum article is of particularly low quality. It seems >to actually make an effort to be as vague and useless as possible. > >This one is *much* better: ><https://www.adelaide.edu.au/ipas/our-research/defence-security/cryogenic-sapphire-oscillator-the-sapphire-clock#publications>ThE qUesTion noW bEcomEs at 10^-15 relative to what is it moving and when brought back to down under after being tested at NIST for verification will it still give the right date ;-??? I mean all is relative is it not? 1 second in 40 million years with earth flying around a sun that flies in a galaxy that flies away from the Big Ben sorry Big Bang in an other universe where a second equals an hour of coffee zipping, so confused. And does cooling it that much cause glow ball worming?
Reply by ●August 12, 20212021-08-12
On Thursday, August 12, 2021 at 5:36:01 PM UTC+10, Jan Panteltje wrote:> On a sunny day (Wed, 11 Aug 2021 19:49:18 +0200) it happened Jeroen Belleman > <jer...@nospam.please> wrote in <sf12iu$1dnb$1...@gioia.aioe.org>: > >On 2021-08-11 18:33, Spehro Pefhany wrote: > >> On Wed, 11 Aug 2021 01:57:25 -0700 (PDT), Anthony William Sloman > >> <bill....@ieee.org> wrote: > >> > >>> A recent copy of the IEEE Spectrum included this article > >>> > >>> https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks > >>> > >>> It isn't as stable as an atomic clock over an extended period but it's short-term accuracy is much better. Each clock period > >>> is much closer to being perfectly equal to the last one. > >>> > >>> And it is an Australian development ... > >> > >> Not surprising the pulsing from the cryocooler caused them some grief. > > > >> It's too bad there's no practical way yet to get down to < 10K using > >> refrigeration without vibrations and such like. > > > >The IEEE Spectrum article is of particularly low quality. It seems > >to actually make an effort to be as vague and useless as possible. > > > >This one is *much* better: > ><https://www.adelaide.edu.au/ipas/our-research/defence-security/cryogenic-sapphire-oscillator-the-sapphire-clock#publications> > > ThE qUesTion noW bEcomEs at 10^-15 relative to what is it moving > and when brought back to down under after being tested at NIST for verification > will it still give the right date ;-???The travelling clock experiment showed that it wouldn't. https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment That was in 1971, with cesium beam atomic clocks and going around the world eastward and westward produced a roughly 300nsec time difference. The differences are predictable.> I mean all is relative is it not?Of course it is.> 1 second in 40 million years with earth flying around a sun that flies in a galaxy that flies away from the Big Ben sorry Big Bang > in an other universe where a second equals an hour of coffee zipping, so confused.Not so much confused as wrong, but Jan gets lots of stuff wrong.> And does cooling it that much cause glow ball worming?It takes energy, and if it was produced by burning fossil carbon (as it mostly is at the moment) it will have produced a little bit more global warming. The electricity companies are going over to producing their power from renewable sources as much as they can - they are cheaper - but it is a slow process, and they are going to have get more grid storage (pumped hydro and big batteries) than they have at the moment, but that's coming on too. -- Bill Sloman, Sydney
Reply by ●August 12, 20212021-08-12
Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> wrote in news:sf2j0q$3up$4 @gioia.aioe.org:> And does cooling it that much cause glow ball worming?Only if you painted them with Radium paste. The little glow worms really like that stuff. There is a vas defrens between that and unpainted, non glowing balls.
Reply by ●August 12, 20212021-08-12
On Wed, 11 Aug 2021 12:33:43 -0400, Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> wrote:>On Wed, 11 Aug 2021 01:57:25 -0700 (PDT), Anthony William Sloman ><bill.sloman@ieee.org> wrote: > >>A recent copy of the IEEE Spectrum included this article >> >>https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks >> >>It isn't as stable as an atomic clock over an extended period but it's short-term accuracy is much better. Each clock period is much closer to being perfectly equal to the last one. >> >>And it is an Australian development ... > >Not surprising the pulsing from the cryocooler caused them some grief. >It's too bad there's no practical way yet to get down to < 10K using >refrigeration without vibrations and such like.The usual atomic clock disciplines a quartz crystal oscillator with a very slow feedback loop. Short-term (as in seconds at least) jitter is from the crystal oscillator. In a really good source, you're paying for a double ovenized SC-cut crystal more than for the rubidium thing. -- Father Brown's figure remained quite dark and still; but in that instant he had lost his head. His head was always most valuable when he had lost it.
Reply by ●August 12, 20212021-08-12
"the concepts "male" and "female" are essentially social constructions" (Bill Sloman) Bozo the Clown... -- Anthony William Sloman <bill.sloman@ieee.org> wrote:> X-Received: by 2002:a37:9d3:: with SMTP id 202mr3294622qkj.369.1628755327412; Thu, 12 Aug 2021 01:02:07 -0700 (PDT) > X-Received: by 2002:a05:620a:d54:: with SMTP id o20mr3261776qkl.326.1628755327203; Thu, 12 Aug 2021 01:02:07 -0700 (PDT) > Path: eternal-september.org!reader02.eternal-september.org!weretis.net!feeder8.news.weretis.net!proxad.net!feeder1-2.proxad.net!209.85.160.216.MISMATCH!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail > Newsgroups: sci.electronics.design > Date: Thu, 12 Aug 2021 01:02:07 -0700 (PDT) > In-Reply-To: <sf2j0q$3up$4@gioia.aioe.org> > Injection-Info: google-groups.googlegroups.com; posting-host=14.202.161.14; posting-account=SJ46pgoAAABuUDuHc5uDiXN30ATE-zi- > NNTP-Posting-Host: 14.202.161.14 > References: <59308434-8513-4f1f-bd5e-98df9b588bdfn@googlegroups.com> <0ru7hgdomm85n0d1nhm4lgftb1nvevkjir@4ax.com> <sf12iu$1dnb$1@gioia.aioe.org> <sf2j0q$3up$4@gioia.aioe.org> > User-Agent: G2/1.0 > MIME-Version: 1.0 > Message-ID: <5bd4d360-3a93-4697-8861-e00ee15e164en@googlegroups.com> > Subject: Re: Precison sapphire oscillator > From: Anthony William Sloman <bill.sloman@ieee.org> > Injection-Date: Thu, 12 Aug 2021 08:02:07 +0000 > Content-Type: text/plain; charset="UTF-8" > Content-Transfer-Encoding: quoted-printable > Xref: reader02.eternal-september.org sci.electronics.design:640145 > > On Thursday, August 12, 2021 at 5:36:01 PM UTC+10, Jan Panteltje wrote: >> On a sunny day (Wed, 11 Aug 2021 19:49:18 +0200) it happened Jeroen Belle > man >> <jer...@nospam.please> wrote in <sf12iu$1dnb$1...@gioia.aioe.org>: >> >On 2021-08-11 18:33, Spehro Pefhany wrote: >> >> On Wed, 11 Aug 2021 01:57:25 -0700 (PDT), Anthony William Sloman >> >> <bill....@ieee.org> wrote: >> >> >> >>> A recent copy of the IEEE Spectrum included this article >> >>> >> >>> https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines- > even-the-best-atomic-clocks >> >>> >> >>> It isn't as stable as an atomic clock over an extended period but it' > s short-term accuracy is much better. Each clock period >> >>> is much closer to being perfectly equal to the last one. >> >>> >> >>> And it is an Australian development ... >> >> >> >> Not surprising the pulsing from the cryocooler caused them some grief. > >> > >> >> It's too bad there's no practical way yet to get down to < 10K using > >> >> refrigeration without vibrations and such like. >> > >> >The IEEE Spectrum article is of particularly low quality. It seems >> >to actually make an effort to be as vague and useless as possible. >> > >> >This one is *much* better: >> ><https://www.adelaide.edu.au/ipas/our-research/defence-security/cryogeni > c-sapphire-oscillator-the-sapphire-clock#publications> >> >> ThE qUesTion noW bEcomEs at 10^-15 relative to what is it moving >> and when brought back to down under after being tested at NIST for verifi > cation >> will it still give the right date ;-??? > > The travelling clock experiment showed that it wouldn't. > > https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment > > That was in 1971, with cesium beam atomic clocks and going around the world eastward and westward produced a roughly 300nsec time difference. > > The differences are predictable. > >> I mean all is relative is it not? > > Of course it is. > >> 1 second in 40 million years with earth flying around a sun that flies in > a galaxy that flies away from the Big Ben sorry Big Bang >> in an other universe where a second equals an hour of coffee zipping, so > confused. > > Not so much confused as wrong, but Jan gets lots of stuff wrong. > >> And does cooling it that much cause glow ball worming? > > It takes energy, and if it was produced by burning fossil carbon (as it mostly is at the moment) it will have produced a little bit more global warming. > > The electricity companies are going over to producing their power from renewable sources as much as they can - they are cheaper - but it is a slow process, and they are going to have get more grid storage (pumped hydro and big batteries) than they have at the moment, but that's coming on too. > > -- > Bill Sloman, Sydney > >
Reply by ●August 12, 20212021-08-12
"the concepts "male" and "female" are essentially social constructions" (Bill Sloman) Bozo the Clown... -- Anthony William Sloman <bill.sloman@ieee.org> wrote:> X-Received: by 2002:a0c:eb0a:: with SMTP id j10mr2109820qvp.28.1628672245887; Wed, 11 Aug 2021 01:57:25 -0700 (PDT) > X-Received: by 2002:a37:a00b:: with SMTP id j11mr26980219qke.457.1628672245723; Wed, 11 Aug 2021 01:57:25 -0700 (PDT) > Path: eternal-september.org!reader02.eternal-september.org!news.mixmin.net!proxad.net!feeder1-2.proxad.net!209.85.160.216.MISMATCH!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail > Newsgroups: sci.electronics.design > Date: Wed, 11 Aug 2021 01:57:25 -0700 (PDT) > Injection-Info: google-groups.googlegroups.com; posting-host=14.202.161.14; posting-account=SJ46pgoAAABuUDuHc5uDiXN30ATE-zi- > NNTP-Posting-Host: 14.202.161.14 > User-Agent: G2/1.0 > MIME-Version: 1.0 > Message-ID: <59308434-8513-4f1f-bd5e-98df9b588bdfn@googlegroups.com> > Subject: Precison sapphire oscillator > From: Anthony William Sloman <bill.sloman@ieee.org> > Injection-Date: Wed, 11 Aug 2021 08:57:25 +0000 > Content-Type: text/plain; charset="UTF-8" > Xref: reader02.eternal-september.org sci.electronics.design:640047 > > A recent copy of the IEEE Spectrum included this article > > https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks > > It isn't as stable as an atomic clock over an extended period but it's short-term accuracy is much better. Each clock period is much closer to being perfectly equal to the last one. > > And it is an Australian development ... > > -- > Bill Sloman, Sydney > > > > >
