Question for Spaceman
Jason P
If you use the word "time" in the above definition, please define "time" as well.
Thanks.
Jason
Franz Heymann
"Jason P" <pawl...@aol.com> wrote in message
news:51566c78.02111...@posting.google.com...
> What is the definition of "clock"?
A clock is a device which executes a perfectly repeatable periodic
motion.
Objects in an ensemble of different kinds of object which are suspected
of being clocks may be sorted into the category "clock" by grouping
together all those which keep in step. By a pair keeping in step I mean
that if B completes b cycles whenever A completes a cycles, then b/a is
a conserved quantity.
Elapsed time is proportional to the nimber of cycles of motion completed
by a clock. Any arbitrary one of a collection of clocks may be chosen
to be the one for which the constant of proportionality is deemed to be
1. From then on, that specimen defines the units in which time is
measured.
How''s that for a trial?
> If you use the word "time" in the above definition, please define
"time" as well.
Franz Heymann
Spaceman
>What is the definition of "clock"?
A device that counts and displays such a count, via a ratio.
It is a counting device, (limited to it's constant counting ability).
and nothing more than such.
James M Driscoll Jr
Spaceman
http://www.realspaceman.com
Spaceman
>A clock is a device which executes a perfectly repeatable periodic
>motion.
and counts such motions as ratios.
and...
Only when kept in a "constant surroundings and settings".
The atomic clock goofs up such "perfectly repeatable periodic motion"
when it is moved beyond the clocks ability to keep itself constant.
Gregory L. Hansen
Franz Heymann <Franz....@btopenworld.com> wrote:
>
>"Jason P" <pawl...@aol.com> wrote in message
>news:51566c78.02111...@posting.google.com...
>> What is the definition of "clock"?
>
>A clock is a device which executes a perfectly repeatable periodic
>motion.
Well, it doesn't *have* to be periodic, it just has to be something that
happens, a standard we decide to use. How could you say it's periodic
unless you had another clock to compare it to?
In practice we like clocks that make motion simple; an unaccelerated
object goes equal distances in equal time intervals. And we can look at
acceleration independently of our definition of time by, e.g., looking at
a mass-and-spring accelerometer attached to it.
We like our rulers the same way; the interval between each pair of hash
marks is equal so that you can slide two rulers past each other and match
up the hash marks at each interval. We don't *have* to use rulers like
that, but it would be pretty silly not to.
--
"A nice adaptation of conditions will make almost any hypothesis agree
with the phenomena. This will please the imagination but does not advance
our knowledge." -- J. Black, 1803.
puppe...@hotmail.com
> "Jason P" <pawl...@aol.com> wrote in message
> news:51566c78.02111...@posting.google.com...
> > What is the definition of "clock"?
>
> A clock is a device which executes a perfectly repeatable periodic
> motion.
Put in "adequately" rather than "perfectly." After all, knowing
that something is perfectly repeatable is not possible, but it
is possible to know that it is adequate. It's just a bow in the
direction of "all measurements are estimates."
A wristwatch is still a clock, and adequate to purposes such as
getting to work in the morning. It's just not good enough to do
things like detect the effects of relativity at 800 kph.
> Objects in an ensemble of different kinds of object which are suspected
> of being clocks may be sorted into the category "clock" by grouping
> together all those which keep in step. By a pair keeping in step I mean
> that if B completes b cycles whenever A completes a cycles, then b/a is
> a conserved quantity.
>
> Elapsed time is proportional to the nimber of cycles of motion completed
> by a clock. Any arbitrary one of a collection of clocks may be chosen
> to be the one for which the constant of proportionality is deemed to be
> 1. From then on, that specimen defines the units in which time is
> measured.
>
> How''s that for a trial?
>
> > If you use the word "time" in the above definition, please define
> "time" as well.
Franz did not define time. Time is directly experienced by humans,
but not in a quantitatively commensurate way. We experience time
as before and after, longer and shorter durations, at the same time
as, and similar things. Time is made commensurate, through the use
of a clock, by requiring motion to be simple. That is, if we see
something moving along and not being sped up or slowed down, we
require time to be such that this motion is uniform.
There's a lovely explanation of this in one of those "boxes" in
the book _Gravitation_ by Misner, Thorne, and Wheeler.
Socks
Franz Heymann
"Franz Heymann" <Franz....@btopenworld.com> wrote in message
news:ar0351$m0q$1...@sparta.btinternet.com...
>
> news:51566c78.02111...@posting.google.com...
> > What is the definition of "clock"?
>
> A clock is a device which executes a perfectly repeatable periodic
> motion.
> Objects in an ensemble of different kinds of object which are
suspected
> of being clocks may be sorted into the category "clock" by grouping
> together all those which keep in step. By a pair keeping in step I
mean
> that if B completes b cycles whenever A completes a cycles, then b/a
is
> a conserved quantity.
>
> Elapsed time is proportional to the number of cycles of motion
completed
> by a clock. Any arbitrary one of a collection of clocks may be chosen
> to be the one for which the constant of proportionality is deemed to
be
> 1. From then on, that specimen defines the units in which time is
> measured.
>
> How''s that for a trial?
On second thoughts, my trial definition is weak. It omitted to say that
the ensemble of objects must be at the same place and in the same state
of motion when the sorting is done. It is also feeble because it does
not make clear that in the case of a pendulum oscillating in a
gravitational field, the clock is not the pendulum, but the pendulum +
earth combination.
>
> > If you use the word "time" in the above definition, please define
> "time" as well.
>
> Franz Heymann
Franz Heymann
Franz Heymann
"Gregory L. Hansen" <glha...@steel.ucs.indiana.edu> wrote in message
news:ar0dev$krt$2...@hood.uits.indiana.edu...
> In article <ar0351$m0q$1...@sparta.btinternet.com>,
> Franz Heymann <Franz....@btopenworld.com> wrote:
> >
> >"Jason P" <pawl...@aol.com> wrote in message
> >news:51566c78.02111...@posting.google.com...
> >> What is the definition of "clock"?
> >
> >A clock is a device which executes a perfectly repeatable periodic
> >motion.
>
> Well, it doesn't *have* to be periodic,
I would distinguish between a clock and an aperiodic time indicator
somewhat analogously to the way I distingish between a spectrometer and
a spectroscope.
> it just has to be something that
> happens, a standard we decide to use. How could you say it's periodic
> unless you had another clock to compare it to?
Gregory, I hate to have to have to say it: You did not read the rest of
my humble offering. If you had, you would have seen how I proposed to
establish the property of "periodicity".
>
> In practice we like clocks that make motion simple; an unaccelerated
> object goes equal distances in equal time intervals. And we can look
at
> acceleration independently of our definition of time by, e.g., looking
at
> a mass-and-spring accelerometer attached to it.
>
> We like our rulers the same way; the interval between each pair of
hash
> marks is equal so that you can slide two rulers past each other and
match
> up the hash marks at each interval. We don't *have* to use rulers
like
> that, but it would be pretty silly not to.
>
Franz Heymann
Gregory L. Hansen
Franz Heymann <Franz....@btopenworld.com> wrote:
>
>"Gregory L. Hansen" <glha...@steel.ucs.indiana.edu> wrote in message
>news:ar0dev$krt$2...@hood.uits.indiana.edu...
>> In article <ar0351$m0q$1...@sparta.btinternet.com>,
>> Franz Heymann <Franz....@btopenworld.com> wrote:
>> >
>> >"Jason P" <pawl...@aol.com> wrote in message
>> >news:51566c78.02111...@posting.google.com...
>> >> What is the definition of "clock"?
>> >
>> >A clock is a device which executes a perfectly repeatable periodic
>> >motion.
>>
>> Well, it doesn't *have* to be periodic,
>
>I would distinguish between a clock and an aperiodic time indicator
>somewhat analogously to the way I distingish between a spectrometer and
>a spectroscope.
Well, I'd say any time standard could do, but we prefer certain types of
time standards. Time standard, clock, same thing.
>
>> it just has to be something that
>> happens, a standard we decide to use. How could you say it's periodic
>> unless you had another clock to compare it to?
>
>Gregory, I hate to have to have to say it: You did not read the rest of
>my humble offering. If you had, you would have seen how I proposed to
>establish the property of "periodicity".
You're right, my mind wandered a little there.
Still, in the ensemble you could imagine a bunch of clocks whose rate of
ticking changes together. If any arbitrary one of them is reset to zero,
to some standard initial condition, and then continues ticking with the
rest, we have periodicity.
Pmb
A better question for him is "What is the definition of a good clock?"
I recall somewhere that someone got the wrong idea regarding clocks by
using a poor example. They used the idea of a pendulum clock. While
the pendulum in a g-field goes through cycles and can be used for a
clock the person got the wrong idea that if you bring the clock up to
the mountains where the gravity is lower or to the moon etc then an
identical clock 'runs' slower. Also a 'poor' clock might be damaged by
acceleration.
Pmb
Randy Poe
>>From: pawl...@aol.com (Jason P)
>
>
>>What is the definition of "clock"?
>
>
> A device that counts and displays such a count, via a ratio.
>
> It is a counting device, (limited to it's constant counting ability).
> and nothing more than such.
So if I'm counting a crowd with a hand-held
clicker, I'm a clock?
So a Geiger counter is a clock?
- Randy
Sam Wormley
>
> What is the definition of "clock"?
>
> If you use the word "time" in the above definition, please define "time" as well.
>
ту
Actually this is not a good question for Spaceman, as he
obviously needs his "clock" cleaned.
History of clocks:
http://physics.nist.gov/GenInt/Time/time.html
http://www.google.com/search?q=%22history+of+clocks%22
Does a clock's acceleration affect its timing rate?
http://math.ucr.edu/home/baez/physics/Relativity/SR/clock.html
USNO Atomic Clock Development
http://clockdev.usno.navy.mil/default.htm
Some dictionary definitions of the word "clock":
http://www.dictionary.com/search?q=clock
Related resources about time:
http://scienceworld.wolfram.com/astronomy/Time.html
http://www.edu-observatory.org/gps/time.html
me...@cars3.uchicago.edu
>In article <ar0351$m0q$1...@sparta.btinternet.com>,
>Franz Heymann <Franz....@btopenworld.com> wrote:
>>
>>"Jason P" <pawl...@aol.com> wrote in message
>>news:51566c78.02111...@posting.google.com...
>>> What is the definition of "clock"?
>>
>>A clock is a device which executes a perfectly repeatable periodic
>>motion.
>
>Well, it doesn't *have* to be periodic, it just has to be something that
>happens, a standard we decide to use. How could you say it's periodic
>unless you had another clock to compare it to?
>
measurement and comparison (which is proto-measurement). A periodic
process is the equivalent of measuring rod.
Mati Meron | "When you argue with a fool,
me...@cars.uchicago.edu | chances are he is doing just the same"
Franz Heymann
<puppe...@hotmail.com> wrote in message
news:c7976c46.02111...@posting.google.com...
> "Franz Heymann" <Franz....@btopenworld.com> wrote in message
news:<ar0351$m0q$1...@sparta.btinternet.com>...
> > "Jason P" <pawl...@aol.com> wrote in message
> > news:51566c78.02111...@posting.google.com...
> > > What is the definition of "clock"?
> >
> > A clock is a device which executes a perfectly repeatable periodic
> > motion.
>
> Put in "adequately" rather than "perfectly." After all, knowing
> that something is perfectly repeatable is not possible, but it
> is possible to know that it is adequate. It's just a bow in the
> direction of "all measurements are estimates."
I see your point. I am happy to refer to my definition of a clock as an
"ideal clock"
Socks has made a valuable contribution to this thread.
Franz Heymann
Gregory L. Hansen
<me...@cars3.uchicago.edu> wrote:
>In article <ar0dev$krt$2...@hood.uits.indiana.edu>,
>glha...@steel.ucs.indiana.edu (Gregory L. Hansen) writes:
>>In article <ar0351$m0q$1...@sparta.btinternet.com>,
>>Franz Heymann <Franz....@btopenworld.com> wrote:
>>>
>>>"Jason P" <pawl...@aol.com> wrote in message
>>>news:51566c78.02111...@posting.google.com...
>>>> What is the definition of "clock"?
>>>
>>>A clock is a device which executes a perfectly repeatable periodic
>>>motion.
>>
>>Well, it doesn't *have* to be periodic, it just has to be something that
>>happens, a standard we decide to use. How could you say it's periodic
>>unless you had another clock to compare it to?
>>
>Well, you do need something periodic to establish the concept of time
>measurement and comparison (which is proto-measurement). A periodic
>process is the equivalent of measuring rod.
Equal intervals between ticks is nice, but you just need some standard.
me...@cars3.uchicago.edu
>In article <nQQA9.44$P4....@news.uchicago.edu>,
> <me...@cars3.uchicago.edu> wrote:
>>In article <ar0dev$krt$2...@hood.uits.indiana.edu>,
>>glha...@steel.ucs.indiana.edu (Gregory L. Hansen) writes:
>>>In article <ar0351$m0q$1...@sparta.btinternet.com>,
>>>Franz Heymann <Franz....@btopenworld.com> wrote:
>>>>
>>>>"Jason P" <pawl...@aol.com> wrote in message
>>>>news:51566c78.02111...@posting.google.com...
>>>>> What is the definition of "clock"?
>>>>
>>>>A clock is a device which executes a perfectly repeatable periodic
>>>>motion.
>>>
>>>Well, it doesn't *have* to be periodic, it just has to be something that
>>>happens, a standard we decide to use. How could you say it's periodic
>>>unless you had another clock to compare it to?
>>>
>>Well, you do need something periodic to establish the concept of time
>>measurement and comparison (which is proto-measurement). A periodic
>>process is the equivalent of measuring rod.
>
>Equal intervals between ticks is nice, but you just need some standard.
>
The concept of length starts wioth an observation that you've object
which have spatial extent and it *appears* that said property of
spatial extent is not changing when the object is moved from one place
to another. Then you can pick an arbitrary object of the sort, call
it "standard", move it around and compare it with various other
objects.
When it comes to time, we observe that spatial location doesn't
provide full information about things and that there is "something
else" that needs to be specified (this is a proto-notion, thus not
fully defineable). So, how can we establish a standard here. The
standard should involve only a change of time, else we measure some
mix of properties. Well, we observe that there are processes which
are cyclic, meaning that starting from some state and going through
various intermediate state we arrive back at what appears to be same
state. If they do it over and over again, we can assume that since
you're going through the same sequence of states, each loop takes same
amount of time. Then we can take the elapsed time of a loop as a
"time standard" and compare other times to it.
So, the notion of repeated cycle is essential here, without it you
can't even start with the process of time measurements. Once you
started then, of course, you can calibrate other, not necessary
periodic processes to you standard and use them as convenient. But
the periodicity of the standard is essential, else you've no basis for
comparison.
Ken Muldrew
> <me...@cars3.uchicago.edu> wrote:
>>glha...@steel.ucs.indiana.edu (Gregory L. Hansen) writes:
>>>Well, it doesn't *have* to be periodic, it just has to be something that
>>>happens, a standard we decide to use. How could you say it's periodic
>>>unless you had another clock to compare it to?
>>Well, you do need something periodic to establish the concept of time
>>measurement and comparison (which is proto-measurement). A periodic
>>process is the equivalent of measuring rod.
>Equal intervals between ticks is nice, but you just need some standard.
What does it mean to have a "standard" unless you have a periodic
phenomenon that is at least assumed to have equal ticks?
Ken Muldrew
kmul...@ucalgary.ca
Gregory L. Hansen
Well, I disagree. Your length standard needn't have uniform intervals all
the way down. But you'd need some convention with an origin. Then take
your one meter at Sevres standard at Sevres and it becomes a two meter
standard in New York or a 2.5 meter standard in Tokyo. It doesn't make
sense to do it that way, but as long as we have a standard that everyone
agrees on we could scale the standard and the object we compare it to the
same way. The origin needn't be fixed, would might measure with a
logarithmic scale on our tape rulers. Sliding axes around become more
difficult than f(x)->f(x-a), and our standard meter would have to be
understood as measured from the zero on a logarithmic tape ruler rather
than from any arbitrary point to any other arbitrary point one meter
farther. The equation of motion for a particle in uniform motion would
no longer be simply x=vt.
None of that is practical. But on a philosophical level, which allows any
manner of impractical but consistent application, there's no reason not
to.
A non-periodic time standard would be just the same. To compare the
ticking of two clocks would couldn't allow (t2-t1)=(s2-s1). We'd have to
make some correction for origin, (f(t2)-f(t1))=(g(s2)-g(s1)) or somesuch.
That's already done when the "ticks" of an atomic clock or a quartz clock
or other clock is scaled into so many ticks per second, so the functions
f() and g() become simple multiplication by a scalar.
Again it's not something you'd actually want to endorse except in
philosophical argument. But as long as you have clearly defined
standards, it could be done that way.
Gregory L. Hansen
Suppose, compared to a periodic timepeice, you choose as your standard
something whose period increases so that t'=t^2. And then you must
specify when "zero" is, you can't just slide it around like
f(t)->f(t-t0).
But whatever funny standard you use can be converted into periodic ticks.
Which means you can invert that, and any equations depending on periodic
ticks can be converted to equations that depend on non-periodic ticks.
You'd need some method of interpolating time between ticks. Right now we
just scale it linearly--halfway between ticks means half the time between
ticks has passed. The funky standard should follow some smooth curve for
that reason.
me...@cars3.uchicago.edu
It doesn't have *any* intervals except for its full length. Beginning
of stick to end of stick.
>
>A non-periodic time standard would be just the same. To compare the
>ticking of two clocks would couldn't allow (t2-t1)=(s2-s1).
Again, What you need is a standard tick. That's all. And the
standard tick cannot be "the tick that occured yesterday" because you
cannot go back and compare with it.
Franz Heymann
"Spaceman" <agents...@aol.combination> wrote in message
news:20021114092646...@mb-dh.aol.com...
> >From: pawl...@aol.com (Jason P)
>
> >What is the definition of "clock"?
>
> A device that counts and displays such a count, via a ratio.
>
> It is a counting device, (limited to it's constant counting ability).
> and nothing more than such.
I live in sheep farming country. The local farmers constantly count
their sheep and display the count on a piece of paper.
Franz Heymann
Franz Heymann
"Pmb" <pm...@hotmail.com> wrote in message
news:8ac61757.0211...@posting.google.com...
The clock is not the bare pendulum. It is the system consisting of the
earth and the pendulum.
Franz Heymann
Spaceman
>I live in sheep farming country.
That was a thought I had,
thanks for the proof.
<LOL>
Richard
This is an astute observation, really, from which follows that changing
the altitude of the pendulum wrt the Earth constitutes a change in the
physical structure of the clock itself, that is, its change in ticking
rate with altitude constitutes only a change in the rate of its physical
processes. OTOH the same argument applies to every clock, regardless of
type, the difference being only a quantitative one. Hmmm. Some argument
Franz, whose side you on anyway! But thanks just the same;-)
--
Richard
http://www.cswnet.com/~rper
--The dissenter is every human being at those moments of his life when
he resigns momentarily from the herd and thinks for himself.
--Archibald MacLeish
Pmb
> > > I recall somewhere that someone got the wrong idea regarding clocks by
> > > using a poor example. They used the idea of a pendulum clock. While
> > > the pendulum in a g-field goes through cycles and can be used for a
> > > clock the person got the wrong idea that if you bring the clock up to
> > > the mountains where the gravity is lower or to the moon etc then an
> > > identical clock 'runs' slower. Also a 'poor' clock might be damaged by
> > > acceleration.
> >
> > The clock is not the bare pendulum. It is the system consisting of the
> > earth and the pendulum.
Symantics - The comment clearly meant this - i.e. the post for a 'good
clock' - i.e. its not a good clock for the reason you stated. The
pendulum is not a good clock of just that reason.
> This is an astute observation, really, from which follows that changing
> the altitude of the pendulum wrt the Earth constitutes a change in the
> physical structure of the clock itself, that is, its change in ticking
> rate with altitude constitutes only a change in the rate of its physical
> processes. OTOH the same argument applies to every clock, regardless of
> type, the difference being only a quantitative one. Hmmm. Some argument
> Franz, whose side you on anyway! But thanks just the same;-)
Pmb
Ken Muldrew
> Ken Muldrew <kmul...@ucalgary.ca> wrote:
> >glha...@steel.ucs.indiana.edu (Gregory L. Hansen) wrote:
> >>Equal intervals between ticks is nice, but you just need some standard.
> >
> >What does it mean to have a "standard" unless you have a periodic
> >phenomenon that is at least assumed to have equal ticks?
>
> Suppose, compared to a periodic timepeice, you choose as your standard
> something whose period increases so that t'=t^2. And then you must
> specify when "zero" is, you can't just slide it around like
> f(t)->f(t-t0).
Well here you have a periodic timepiece *and* a standard. Since your
standard is derived from your periodic timepiece, why bother adding
complications?
> But whatever funny standard you use can be converted into periodic ticks.
> Which means you can invert that, and any equations depending on periodic
> ticks can be converted to equations that depend on non-periodic ticks.
I still don't see how non-periodic ticks can make any sense at all
without presupposing periodic ticks.
Franz Heymann
"Spaceman" <agents...@aol.combination> wrote in message
> >From: "Franz Heymann" Franz....@btopenworld.com
>
> >I live in sheep farming country.
>
> That was a thought I had,
> thanks for the proof.
> <LOL>
The second half of my contribution, which Space mannikin removed by
judicious snipping, was
"The local farmers constantly count their sheep and display the count on
a piece of paper."
I guess Spacemoron found that too close to the bone to leave unsnipped?
Naughty, naughty.
Franz Heymann
Spaceman
>The second half of my contribution, which Space mannikin removed by
>judicious snipping, was
snipping twisted irrelevant comparisons is OK,
and you are an idiot too.
>"The local farmers constantly count their sheep and display the count on
>a piece of paper."
Big deal,
Is it a "constant without changing rate of count"
Fuch Offf Franz,
you still refuse to learn the basics of clocks.
They are just "constant rate counting machines"
>I guess Spacemoron found that too close to the bone to leave unsnipped?
>Naughty, naughty.
I guess Franz is also still too stupid to learn how to copy and paste my
Nickname.
(Must be a troll infection he has and does not know it)
<LOL>
Franz,
Go back to counting sheep,
It' about as safe a job I would give you,
I would feel sorry for the sheep though.
and I would know the wolf must love you.
Sam Wormley
>
What is it that you think you accomplish with you
posting behavior in news:sci.physics constantly being
made a fool of? What's your purpose Driscoll?
Spaceman
Posting behavior?
Oh!
you mean posting facts..
My purpose is to spread the truth
and not the bologna spread with crap dressing.
Still refuse to research "all clocks" huh Sam?
Sad..
just sad.
What is your purpose?
Scam backer?
Sam Wormley
>
>
> My purpose is to spread the truth
> and not the bologna spread with crap dressing.
>
My purpose--
First I'm a learner...
Spaceman
>My purpose--
> First I'm a learner...
Than learn about "the faults of GR,SR and even QM"
clock malfunctions are "not" time changing rate.
The End of learning about SR,GR or QM unless you can "fix them"
:)
So c,mon,
fix,
don't parrot.
:)
Spaceman
>Which faults are you referring to, specifically? I need
>examples.
Time dilations having a circular cause for the biggest one.
Sam Wormley
>
>
> Than learn about "the faults of GR,SR and even QM"
Which faults are you referring to, specifically? I need
examples.
Sam Wormley
>
>
> Still refuse to research "all clocks" huh Sam?
>
all clocks: http://www.ericweisstein.com/encyclopedias/books/Timekeeping.html
Spaceman
>all clocks: http://www.ericweisstein.com/encyclopedias/books/Timekeeping.html
>
>
<ROFLOL>
and that is about as much research you wil ever do huh?
Sam,
you are no longer in the race.
You have stopped for "food" and never started running again since huh?
Poor fattening, mass increasing, length contracting, time changing, parrot!
<LOL>