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If your TOD is to be measured with sub-nanosecond accuracy, where do you
measure from? The TOD of your head? Heart? Fingertips? Feet?
-John
=============
Mark J. Blair wrote:
On Oct 24, 2010, at 1:58 PM, Poul-Henning Kamp wrote:
In message 53601812-FC62-4098-9266-55EDF50AFB2C@nf6x.net, "Mark J.
Blair" wri
tes:
Does anybody know how many bits of precision are used
on tombstones these days?
Most tombstones are engraved with CNC machines and while I have yet
to see a company advertise it as a competitive parameter, your vital
lack of stats will be engraved with better than 1/50mm precision.
Oh, I was mostly concerned with the bits of precision used for the birth
and death timestamps.
I should think that if you have left instructions with your executor,
they can have any arbitrary number of digits engraved, including an
estimate of uncertainty, if needed. You could even have them estimate
the Allan deviation of the various clocks involved, and have the
requisitite plots engraved as well.
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The practicality of TOD depends on who does the proclamation and where
the event occurs.
If no other folks are in attendance at a home setting, actual TOD may be
+/- 1 week
With a attending physician present, TOD will probably be the next day,
so the facility can bill for an additional day. In this case the
tolerance may be up to + 1 day.
What Doc says and what the death certificate says can be 2 different things.
If we looked at a tolerance of TOD based on the persons total life span,
we may achieve better accuracies.
The"time to distribution" of a time nut's collection may depend on when
the local court appoints a executor/trix,
who then has the power to distribute, notwithstanding joint holdings.
Of course, your millage may vary...
Stan, W1LE
Le 24/10/2010 22:50, Mark J. Blair a écrit :
On Oct 24, 2010, at 1:44 PM, Richard H McCorkle wrote:
The disease will continue to progress until
ultimately all of the patients personal time and money are
exhausted or they die.
A nut in the final stages of the disorder would request to be buried
with their clocks . The lab would be sealed for eternity.
One can only hope that the local coroner is also a Time-Nut, so that time of death can be determined with suitable accuracy and precision. Does anybody know how many bits of precision are used on tombstones these days?
On 10/24/2010 11:57 PM, jimlux wrote:
Mark J. Blair wrote:
On Oct 24, 2010, at 1:58 PM, Poul-Henning Kamp wrote:
In message 53601812-FC62-4098-9266-55EDF50AFB2C@nf6x.net, "Mark J.
Blair" wri
tes:
Does anybody know how many bits of precision are used
on tombstones these days?
Most tombstones are engraved with CNC machines and while I have yet
to see a company advertise it as a competitive parameter, your vital
lack of stats will be engraved with better than 1/50mm precision.
Oh, I was mostly concerned with the bits of precision used for the
birth and death timestamps.
I should think that if you have left instructions with your executor,
they can have any arbitrary number of digits engraved, including an
estimate of uncertainty, if needed. You could even have them estimate
the Allan deviation of the various clocks involved, and have the
requisitite plots engraved as well.
Considering that this is a time thing, you want the TDEV rather than the
ADEV plots, alongside an indication of time since last calibration which
is the index into the TDEV plot. This then adds to the TDEV of the chain
giving the calibration along side a separate traceability of systematic
errors in the calibration chain and ...
Proper calibration of time is a beast.
Cheers,
Magnus
Since it's a volume, isn't rather 30k x 30k x 5k = 4.5 Gbit ?
(I ignored the toolholder parameter, I don't understand how to take it into
a ccount)
;-}
----- Original Message -----
From: "Poul-Henning Kamp" phk@phk.freebsd.dk
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Sunday, October 24, 2010 8:58 PM
Subject: Re: [time-nuts] Determining Time-Nut infection severity.
In message 53601812-FC62-4098-9266-55EDF50AFB2C@nf6x.net, "Mark J.
Blair" wri
tes:
Does anybody know how many bits of precision are used
on tombstones these days?
Most tombstones are engraved with CNC machines and while I have yet
to see a company advertise it as a competitive parameter, your vital
lack of stats will be engraved with better than 1/50mm precision.
On one picture I saw at cnczone.com they used approx 10 different
diamondcrusted bits.
Estimating bitcounts we find:
X-axis ~30k [60cm / 1/50mm]
Y-axis ~30k [60cm / 1/50mm]
Z-axis ~5k [10cm / 1/50mm]
Toolholder ~10 [visual estimate]
Total ~65k bits
:-)
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by
incompetence.
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On Oct 24, 2010, at 3:36 PM, mike cook wrote:
A nut in the final stages of the disorder would request to be buried with their clocks . The lab would be sealed for eternity.
In that case, I'd better rush out and patent tombstones with integrated GPS antennas for entombed GPSDOs. I'll make millions on the licensing fees, thus funding the H-maser that I'll be buried with.
--
Mark J. Blair, NF6X nf6x@nf6x.net
Web page: http://www.nf6x.net/
GnuPG public key available from my web page.
On Sun, Oct 24, 2010 at 1:44 PM, Richard H McCorkle
mccorkle@ptialaska.net wrote:
Time-Nuts,
New members to the Time-Nuts list may wonder if the Time-Nut disease
has infected them just by joining the list. A clear indication that
someone has been infected with the Time-Nut disease is they own a
reference that provides accurate time to better than 1us and
frequency to better than 1e-9.
Is there a "cadet" grade? I have a GPS receiver with 1PPS output, but
it only claims microsecond accuracy. I have an OCXO salvaged from an
old Transit satellite navigator, but it claims no better than a few
parts in 1e-8. And I've got a Thunderbolt, but haven't found time to
apply power to it. So I guess I'm not up to the standards of a true
time-nut.
On the other hand, this does suggest a plausible metric for nuttiness:
the negative of the base-10 log of the frequency uncertainty of the
best reference you own. So the scale for fully qualified nuts starts
at 9 and goes upward. Lower numbers are indicative of non-nuts (just
owning a quartz watch puts you at about 5, at least if you care about
its accuracy).
Dave
But some nutty folks (c'est moi!) wear mechanical watches (an Omega
Seamaster in my case) just for the joy of owning an intricate mechanical
device that requires no 'lectricty and has silicon only in the crystal. And
the crystal doesn't oscillate.
BTW, with what accuracy, do you suppose, were the intervals between Hari
Seldon's reappearances determined?
Betcha old Isaac would have had a plausible answer.
On Sun, Oct 24, 2010 at 6:53 PM, David Martindale <dave.martindale@gmail.com
wrote:
On Sun, Oct 24, 2010 at 1:44 PM, Richard H McCorkle
mccorkle@ptialaska.net wrote:
Time-Nuts,
New members to the Time-Nuts list may wonder if the Time-Nut disease
has infected them just by joining the list. A clear indication that
someone has been infected with the Time-Nut disease is they own a
reference that provides accurate time to better than 1us and
frequency to better than 1e-9.
Is there a "cadet" grade? I have a GPS receiver with 1PPS output, but
it only claims microsecond accuracy. I have an OCXO salvaged from an
old Transit satellite navigator, but it claims no better than a few
parts in 1e-8. And I've got a Thunderbolt, but haven't found time to
apply power to it. So I guess I'm not up to the standards of a true
time-nut.
On the other hand, this does suggest a plausible metric for nuttiness:
the negative of the base-10 log of the frequency uncertainty of the
best reference you own. So the scale for fully qualified nuts starts
at 9 and goes upward. Lower numbers are indicative of non-nuts (just
owning a quartz watch puts you at about 5, at least if you care about
its accuracy).
Dave
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and follow the instructions there.
One of the dangers of the TNI is that it can be caught from the
equipment
of the previous victim. No amount of sterilisation will have any effect.
It is bizarre to see how eagerly otherwise healthy individuals will
bid for
the items that will have such a dire consequence.
Over a period of time one good Caesium Unit could take out quite a few
victims.
cheers,
Neville Michie
COnsidering that for many of us, the TOD will be contingent on how
much of our pile of equipment fell on us, and how long it was before
the stink reached the street, causing our discovery. I think month,
day and year would probably suffice.
-Chuck Harris
Stan, W1LE wrote:
The practicality of TOD depends on who does the proclamation and where
the event occurs.
If no other folks are in attendance at a home setting, actual TOD may be
+/- 1 week