Time and Elliptical orbits.

All this talk of solstices and sunrise/sunset has got me thinking about
time:

According to relativity, the rate at which clocks "tick" depends upon
their velocity (time dilation and all that). Presumably, then, clocks
on earth change their rate of "ticking" as the linear speed of the
Earth changes in its orbit around the Sun?

So what the hell do we use as a reference or "constant" clock?

--
Stephen Tonkin : UK Amateur Telescope Making Pages
:
http://www.aegis1.demon.co.uk/atm.htm
: (50.9105N 1.829W)

http://groups.google.ie/groups?hl=en....de mon.co.uk

Back 9 years ago that was a very good question so the regulars here
should now be capable of answering it for you.

wrote:

All this talk of solstices and sunrise/sunset has got me thinking about
time:

According to relativity, the rate at which clocks "tick" depends upon
their velocity (time dilation and all that). Presumably, then, clocks
on earth change their rate of "ticking" as the linear speed of the
Earth changes in its orbit around the Sun?

So what the hell do we use as a reference or "constant" clock?

--
Stephen Tonkin : UK Amateur Telescope Making Pages
:
http://www.aegis1.demon.co.uk/atm.htm
: (50.9105N 1.829W)

http://groups.google.ie/groups?hl=en....de mon.co.uk

Back 9 years ago that was a very good question so the regulars here
should now be capable of answering it for you.

Some of the regulars are still here. The relativistic difference between
a stationary terrestrial clock and one in a nearly circular orbit at 1AU
is about 5ppb. The deviation due to the orbital eccentricity of 0.0167
amounts to about 83ppt. These corrections are only really significant
for pulsar research, VLBI and a few other exotic timing experiments. eg

http://www.astro.northwestern.edu/As...ers/burgay.pdf

Jodrell Bank's current choice of hydrogen maser clocks manage to provide
short term frequency stability of 1 part in 10^15 over a typical scan.

To put it into perspective a simple quartz crystal wrist watch will
manage about 1ppm (1 in 10^6) if well trimmed or more likely mass
produced around 6ppm subject to some thermal drift.

NIST have a very nice new site on time and frequency standards:
http://www.boulder.nist.gov/timefreq/general/enc-q.htm

Regards,
Martin Brown
Nezumi Scientific

Martin Brown wrote:
wrote:

All this talk of solstices and sunrise/sunset has got me thinking
about
time:

According to relativity, the rate at which clocks "tick" depends
upon
their velocity (time dilation and all that). Presumably, then,
clocks
on earth change their rate of "ticking" as the linear speed of the
Earth changes in its orbit around the Sun?

So what the hell do we use as a reference or "constant" clock?

--
Stephen Tonkin : UK Amateur Telescope Making
Pages
:
http://www.aegis1.demon.co.uk/atm.htm
: (50.9105N 1.829W)


http://groups.google.ie/groups?hl=en....de mon.co.uk

Back 9 years ago that was a very good question so the regulars here
should now be capable of answering it for you.

Some of the regulars are still here. The relativistic difference
between
a stationary terrestrial clock and one in a nearly circular orbit at
1AU
is about 5ppb. The deviation due to the orbital eccentricity of
0.0167
amounts to about 83ppt. These corrections are only really significant

for pulsar research, VLBI and a few other exotic timing experiments.
eg


I am afraid you are so technically imprecise that it is almost
difficult to reply.'Stationary terrestial clock' has no meaning
whatsoever,the equable pace of hour,minutes and seconds to which the
sum total of a 24 hour clock corresponds is the axial rotation of the
Earth through 360 degrees,the assumption of constant axial rotation and
the Equation of Time format which keep it fixed to terrestial
longitudes.Unless you have'nt noticed there are still 360 deg in a
circle and as a valid event,the axial rotation of the Earth must
correspond to 24 hours exactly,at least if you use any sort of clock.

I can answer Tonkin's question directly,the reference for the constant
24 hour day and the pace to which equable divisions of hours,minutes
and seconds are fixed are based on the assumption that axial rotation
is constant and that other influences vary thepace of a natural day
from one noon to the next.




Go ahead,read Newton's phrasing of the difference between the clock day
and the natural day or what amounts to the same thing ;the Equation of
Time -

"Absolute time, in astronomy, is distinguished from relative, by the
equation or correlation of the vulgar time. For the natural days are
truly unequal, though they are commonly considered as equal and used
for a measure of time; astronomers correct this inequality for their
more accurate deducing of the celestial motions."

http://members.tripod.com/~gravitee/...tions.htm#time

As the Equation of Time is really a mathematical bridge ( addition and
subtraction of minutes and seconds),what part of the Equation of Time
would you care to reject,it is no use saying 'time is not absolute'
like a headless chicken,you have to justify why you determine that the
natural unequal day (relative time) is a great way to model the
structure and motion of celestial objects and why you dislike the
equable 24 hour clock day.

With all due respect,relativists are crazy by virtue of Newtonian
ambiguities and not the ones they impose.






http://www.astro.northwestern.edu/As...ers/burgay.pdf

Jodrell Bank's current choice of hydrogen maser clocks manage to
provide
short term frequency stability of 1 part in 10^15 over a typical
scan.

To put it into perspective a simple quartz crystal wrist watch will
manage about 1ppm (1 in 10^6) if well trimmed or more likely mass
produced around 6ppm subject to some thermal drift.

NIST have a very nice new site on time and frequency standards:
http://www.boulder.nist.gov/timefreq/general/enc-q.htm

Regards,
Martin Brown
Nezumi Scientific

Clocks do not measure a quantity called 'time' even if it is convenient
to imagine they do,astronomically the origins of the 24 hour clock day
is determined by the difference between compound motions of the Earth
on its axis and its motion about the Sun.

The division of the day into equable hours stretches back into remote
antiquity but the gauge for this average day ultimately translates into
constant axial rotation within a heliocentric setting.The Equation of
Time comes from a geocentric era therefore constant axial rotation and
the terrestial longitudes which contain the 360degree/24 hour
equivalency are maintained through an assumption.

When Newton mentions that the 24 hour clock day has no external
reference he is simply stating the obvious,the impossibility of
determining axial rotation in isolation from its compound orbital
motion but the man is confused and confuses his readers in scrambling
an assumption into an observational fact


" It may be, that there is no such thing as an equable motion, whereby
time may be accurately measured."

For an astronomer who is concerned with the equable pace of a 24 hour
day the above sentence is utter nonsense.How you choose to correct it
makes a big difference to astronomy for absolutely nobody is bigger
than the priceless astronomical jewel which facilitates so much through
the Equation of time and certainly not for a peevish ****er like
Newton.

Whatever perverse satisfaction you get out of chucking around the words
absolute and relative,you are doing it at the expense of my
astronomical heritage which was buried to make way for the era of
cataloguer/theorist.

I liked the answer you give the guy on Foucault's pendulum..I wonder
what chance kids have when adults get some perverse satisfaction in
justifying things one way when it suits and then switching to and
alternative value.Unless you have noticed,I have been almost screaming
that no civilisation in sincerity can support two values for axial
rotation through 360 degrees or generalise it when it is convenient.

Go with axial rotation to inertial space/23 hours 56 min 04 sec and you
have the luxury of warped space,multiple universe and whatnot or go
with axial rotation to 360/24 and recover the heritage of
astronomy,human ingenuity and invention and the more comfortable things
that do not lead to absurdities.

I specifically found a website for you -

http://www.draysonbeckett.co.uk/gunn...story.html#top



Colin Rosenthal wrote:

On Mon, 15 Nov 1999 10:26:20 -0000,
Thorsten Brabetz wrote:

Annette Vogels wrote in message
...
Hello,
My name is Laura, and I am doing project for Science class at the
Ithaca
High School (boo, hiss,Thanks, I know I am young).
Another experiment, but one that takes a bit of time, is to use a
pendulum.
If it is a pretty big one that swings for quite some time, you might
be able
to proove the rotation of earth because it will keep its position in
space,
i.e. would turn 360 deg in 24 hours (if I remember right, never
tried it
myself though...).

Exact rotation time depends on your latitude it is exactly 24 hours at
the poles,
and never rotates at all on the equator.

Exactly. Look up the phrase "Foucault Pendulum". It's not, however,
practical to build one yourself.

It isn't all that difficult. The most dodgy part is needing a long
period
pendulum with a very rigid mount and a pretty massive weight. We used
to have 20'
one in the physics dept reception area.
It probably isn't a suitable experiment for high school though.

The coriolis force also has a
direct and significant effect on the flight of artillery shells.

Artillery has always been amusing as gunnery correction tables have
usually been
prepared with wars in the Northern hemisphere in mind. Every S
hemisphere war
using artillery upto and including the Falklands has revealed gunnery
table
faults related to latitude N/S.

Regards,
Martin Brown

http://groups.google.ie/groups?hl=en...40pandora. be

Hi Gerald

what do you do for a living? professor? teacher?

Just wondered as you seem to have much knowledge

Cheers


wrote in message
oups.com...
I liked the answer you give the guy on Foucault's pendulum..I wonder
what chance kids have when adults get some perverse satisfaction in
justifying things one way when it suits and then switching to and
alternative value.Unless you have noticed,I have been almost screaming
that no civilisation in sincerity can support two values for axial
rotation through 360 degrees or generalise it when it is convenient.

Go with axial rotation to inertial space/23 hours 56 min 04 sec and you
have the luxury of warped space,multiple universe and whatnot or go
with axial rotation to 360/24 and recover the heritage of
astronomy,human ingenuity and invention and the more comfortable things
that do not lead to absurdities.

I specifically found a website for you -

http://www.draysonbeckett.co.uk/gunn...story.html#top



Colin Rosenthal wrote:

On Mon, 15 Nov 1999 10:26:20 -0000,
Thorsten Brabetz wrote:

Annette Vogels wrote in message
...
Hello,
My name is Laura, and I am doing project for Science class at the
Ithaca
High School (boo, hiss,Thanks, I know I am young).
Another experiment, but one that takes a bit of time, is to use a
pendulum.
If it is a pretty big one that swings for quite some time, you might
be able
to proove the rotation of earth because it will keep its position in
space,
i.e. would turn 360 deg in 24 hours (if I remember right, never
tried it
myself though...).

Exact rotation time depends on your latitude it is exactly 24 hours at
the poles,
and never rotates at all on the equator.

Exactly. Look up the phrase "Foucault Pendulum". It's not, however,
practical to build one yourself.

It isn't all that difficult. The most dodgy part is needing a long
period
pendulum with a very rigid mount and a pretty massive weight. We used
to have 20'
one in the physics dept reception area.
It probably isn't a suitable experiment for high school though.

The coriolis force also has a
direct and significant effect on the flight of artillery shells.

Artillery has always been amusing as gunnery correction tables have
usually been
prepared with wars in the Northern hemisphere in mind. Every S
hemisphere war
using artillery upto and including the Falklands has revealed gunnery
table
faults related to latitude N/S.

Regards,
Martin Brown


http://groups.google.ie/groups?hl=en...40pandora. be

In article . com,
wrote:
All this talk of solstices and sunrise/sunset has got me thinking about
time:

According to relativity, the rate at which clocks "tick" depends upon
their velocity (time dilation and all that). Presumably, then, clocks
on earth change their rate of "ticking" as the linear speed of the
Earth changes in its orbit around the Sun?

Yes. In addition, as the distance to the Sun (and planets) varies during
the year and the clock is immersed in a varying gravitational potential,
the rate changes because of gravitational redshift. The two effects
together produce an approximately sinusoidal difference between
terrestrial time TT and the coordinate time scale that you would use to
interrogate JPL planetary ephemerides (Teph, similar to TDB), with an
amplitude of 1.6 ms.

An example of an astronomical application that is critically dependent on
taking these effects into account is the prediction of pulse arrival times
from the millisecond pulsars.

So what the hell do we use as a reference or "constant" clock?

Atomic clocks deliver our best quality terrestrial time. If you add the
appropriate fixed offset (exactly 32.184 s) to TAI you get our best
implementation of TT. To get the various coordinate time scales, you
apply mathematical models that take into account the position and speed of
the Earth and the positions of the other solar system bodies.


Patrick Wallace
-------------------------------------------------------------------------

In message , Martin Brown
writes
wrote:

All this talk of solstices and sunrise/sunset has got me thinking about
time:
According to relativity, the rate at which clocks "tick" depends
upon
their velocity (time dilation and all that). Presumably, then, clocks
on earth change their rate of "ticking" as the linear speed of the
Earth changes in its orbit around the Sun?
So what the hell do we use as a reference or "constant" clock?
--
Stephen Tonkin : UK Amateur Telescope Making Pages
:
http://www.aegis1.demon.co.uk/atm.htm
: (50.9105N 1.829W)

http://groups.google.ie/groups?hl=en...yEw2y%40aegis1
.demon.co.uk
Back 9 years ago that was a very good question so the regulars here
should now be capable of answering it for you.

Some of the regulars are still here. The relativistic difference
between a stationary terrestrial clock and one in a nearly circular
orbit at 1AU is about 5ppb. The deviation due to the orbital
eccentricity of 0.0167 amounts to about 83ppt. These corrections are
only really significant for pulsar research, VLBI and a few other
exotic timing experiments. eg

http://www.astro.northwestern.edu/As...ers/burgay.pdf


Isn't GPS the classic example of relativistic effects on clocks
affecting everyday life?
http://www.phys.lsu.edu/mog/mog9/node9.html
--
Support the DEC Tsunami Appeal http://www.dec.org.uk/.
Remove spam and invalid from address to reply.

Jonathan Silverlight wrote:

In message , Martin Brown
writes

Some of the regulars are still here. The relativistic difference
between a stationary terrestrial clock and one in a nearly circular
orbit at 1AU is about 5ppb. The deviation due to the orbital
eccentricity of 0.0167 amounts to about 83ppt. These corrections are
only really significant for pulsar research, VLBI and a few other
exotic timing experiments. eg

http://www.astro.northwestern.edu/As...ers/burgay.pdf

Isn't GPS the classic example of relativistic effects on clocks
affecting everyday life?
http://www.phys.lsu.edu/mog/mog9/node9.html

Yes. Although that is correcting for orbital velocity and height of the
satellite relative to the Earth. Amusingly because electronic engineers
don't understand relativity (and certain electronics rags like Wireless
World recruit editors that publish junk anti-relativity articles) they
had an override to disable the relativistic clock corrections - just in
case. But they were never needed. Modern atomic clocks are good enough
and portable so that one of the RI Christmas lectures has demonstrated it.

Another interesting snippet. When the first double pulsar was discovered
the observations provided such a good test of GR that it found a mistake
in the computer algebra system used to compute the corrections for
Jupiters longitude. Until then we had never had a remote external
precision clock that was studied regularly in so much detail.

Regards,
Martin Brown

Jonathan Silverlight wrote:
In message , Martin Brown
writes
wrote:

All this talk of solstices and sunrise/sunset has got me thinking
about
time:
According to relativity, the rate at which clocks "tick" depends
upon
their velocity (time dilation and all that). Presumably, then,
clocks
on earth change their rate of "ticking" as the linear speed of the
Earth changes in its orbit around the Sun?
So what the hell do we use as a reference or "constant" clock?
--
Stephen Tonkin : UK Amateur Telescope Making
Pages
:
http://www.aegis1.demon.co.uk/atm.htm
: (50.9105N 1.829W)


http://groups.google.ie/groups?hl=en...yEw2y%40aegis1
.demon.co.uk
Back 9 years ago that was a very good question so the regulars
here
should now be capable of answering it for you.

Some of the regulars are still here. The relativistic difference
between a stationary terrestrial clock and one in a nearly circular
orbit at 1AU is about 5ppb. The deviation due to the orbital
eccentricity of 0.0167 amounts to about 83ppt. These corrections are

only really significant for pulsar research, VLBI and a few other
exotic timing experiments. eg

http://www.astro.northwestern.edu/As...ers/burgay.pdf


Isn't GPS the classic example of relativistic effects on clocks
affecting everyday life?
http://www.phys.lsu.edu/mog/mog9/node9.html
--
Support the DEC Tsunami Appeal http://www.dec.org.uk/.
Remove spam and invalid from address to reply.

Ha,ha ha, you are no more mearing answering Tonkin's question than the
other guy but you set the using boring bait that the aetherists fall
for every time.

The reference for the pace of equable
hours,minutes,seconds,nanoseconds, picoseconds and any subdivision of a
24 hour day ultimately is derived from the equivalency between rotation
through 360 degrees at 15 deg per hour giving 24 hours in total.Unless
you have'nt noticed,the longitude values which carry the equivalency
are a total human invention designed around the geometry/geography of
the Earth .



"It may be, that there is no such thing as an equable motion, whereby
time may be accurately measured. All motions may be accelerated and
retarded, but the true, or equable, progress of absolute time is liable
to no change."

http://members.tripod.com/~gravitee/...tions.htm#time



Those great astronomers/geometers who came up with the principles of
the equable 24 hour day and subsequently equable hours,minutes and
seconds recognised that there is no external marker for the equable day
hence the Equation of Time correction which removes the natural
inequality by means of the axial rotation of the Earth to the Sun.

Is there any sane person who can see where the error slips into
Newton's reasoning and that it simply is not a matter of saying 'time
is not absolute'.Is there a single astronomer who can tell the
theorists that they created a fiction with Newtonian relative/absolute
ambiguities that surface every time the value for the rotation rate of
the Earth on its axis is given.

The answer to Tonkin's question is that a clock registers a standard
pace that is permanently fixed to the Earth's geometry/geography in
terms of 360/24 and any amount of subdivisions of that geometry.The GPS
still corrects back to the same principles which make clocks good
rulers of distance just as Harrison's clocks did.

Relativists fooled people into believing that it is all extremely
complicated but anyone who can handle Newton's stupid reworking and
tampering with the Equation of Time and his switch to the sidereal
format will find relativity and relativists hysterically funny.

I guess you did'nt read the article by the inventor of the cesium
clock.

http://www.btinternet.com/~time.lord/Relativity.html

That is the sad part,the theorists manage to assimilate even the life's
work of this man to supporting relativity and the basic Newtonian error
that exists behind the whoe exotic trash.

The only attribute of relativity is that it does focus on the original
error or tampering by Newton in hijacking the existing astronomical
network to support his terrestial ballistics agenda.The relativist
did'nt change Newton,they simply expanded his geocentric/heliocentric
orbital equivalency into outright homocentricity.

A cataloguer could not spot the error but an astronomer could hence any
participant in uk.sci.astronomy knows that he is an astronomer and not
merely a cataloguer.I am still waiting for an astronomer who can pick
up where Roemer left off before the cataloguers/theorists made a mess
of astronomy.