On Wednesday, 10 November 2021 at 14:23:48 UTC+1, Al Coe wrote:
> On Wednesday, November 10, 2021 at 2:40:47 AM UTC-8, bodk...@gmail.com wrote:
> > >> An observer in a circular path is not at rest in any inertial reference frame.
> > >
> > > As noted previously, such a person is always momentarily at rest in an inertial frame,
> > > What you meant to say is he is not continuously at rest in any single inertial reference
> >
> > By “at rest in” I meant over any nonzero interval of time...
>
> Right, that's what I explained you really meant (see above), but that's not what you said, hence the correction with charitable explanation. This has been carefully explained previously when the OP made the same misstatement, so your misstatement(s) needed to be corrected to avoid backsliding the discussion into that conceptual error.
> > over which an observer could measure speed by distance covered
> > over elapsed time.
> That's another of the OP's misconceptions. The speed of an object in terms of any specified system of coordinates can be empirically determined, regardless of our state of motion. It is not necessary for a person to be at rest in the specified system (in fact, usually we are not at rest in terms of the coordinate systems we use).
> > An observer at rest in an inertial reference frame only momentarily, might
> > be able to make a hypothetical statement about what the speed of light
> > should be in that momentarily visited frame...
>
> See above. You are falling prey to all of the OP's misconceptions. The speed of light being 1 in terms of the inertial coordinates in which the traveler is at rest at any given instant is not a "hypothetical statement", it is an objective, empirically verifiable fact. In fact, the speed of light is 1 in terms of those coordinates even is he is never at rest in those coordinates at all, and this too is a verifiable fact.

In the meantime in the real world, however, forbidden by
your moronic religion GPS clocks keep measuring t'=t,
just like all serious clocks always did. And this too is a
verifiable fact.

Maciej Wozniak wrote:

>> An observer at rest in an inertial reference frame only momentarily,
>> might be able to make a hypothetical statement about what the speed of
>> light should be in that momentarily visited frame, but would not be
>> able to confirm it directly by watching light cover some distance in
>> that frame, over an interval of time in that frame. Obviously.
>
> In the meantime in the real world, however, forbidden by your moronic
> religion GPS clocks keep measuring t'=t,
> just like all serious clocks always did.

yes sure, but your ass will be freezing in EU, begging for cheap gas from
Russia. What a shame. Take those immigrants from freezing and give them
to Holland, which as yesterday said they want you out of europe.

Al Coe <coeal5136@gmail.com> wrote:
> On Wednesday, November 10, 2021 at 2:40:47 AM UTC-8, bodk...@gmail.com wrote:
>>>> An observer in a circular path is not at rest in any inertial reference frame.
>>>
>>> As noted previously, such a person is always momentarily at rest in an inertial frame,
>>> What you meant to say is he is not continuously at rest in any single inertial reference
>>
>> By “at rest in” I meant over any nonzero interval of time...
>
> Right, that's what I explained you really meant (see above), but that's not what you said,

Well, yes it was. It was not a misconception, it was not a misuse. It was a
deliberate and careful choice to use a term as my correspondent understands
it. Most people will take “at rest” to mean “at the same place in
successive moments for at least some period of time.” You, on the other
hand, have a correct and precise meaning (zero instantaneous velocity)
which is a jargon definition that will be lost on the casual or untrained
audience, as David is. That is why, when YOU use the term “at rest”, you
have to carefully distinguish “momentarily at rest” and “continually at
rest”, which is a pedantic distinction that only those trained would care
about. This is the difference between pedantry and pedagogy, where the
latter often means taking steps toward where the learner presently is,
rather than standing firmly on the spot where YOU are and repeatedly
asking, “NOW do you understand?” This is why I have commented at least a
few times that you are woefully inadequate as a pedagogue, as evidenced by
the fact that you get nowhere with your correspondents, which you then
incorrectly blame them for. It also exhibits a disability with empathy and
interpersonal relations, which is why I wondered if you had been diagnosed
as being on the autistic spectrum.

> hence the correction with charitable explanation. This has been
> carefully explained previously when the OP made the same misstatement, so
> your misstatement(s) needed to be corrected to avoid backsliding the
> discussion into that conceptual error.
>
>> over which an observer could measure speed by distance covered
>> over elapsed time.
>
> That's another of the OP's misconceptions. The speed of an object in
> terms of any specified system of coordinates can be empirically
> determined, regardless of our state of motion. It is not necessary for a
> person to be at rest in the specified system (in fact, usually we are not
> at rest in terms of the coordinate systems we use).
>
>> An observer at rest in an inertial reference frame only momentarily, might
>> be able to make a hypothetical statement about what the speed of light
>> should be in that momentarily visited frame...
>
> See above. You are falling prey to all of the OP's misconceptions. The
> speed of light being 1 in terms of the inertial coordinates in which the
> traveler is at rest at any given instant is not a "hypothetical
> statement", it is an objective, empirically verifiable fact. In fact,
> the speed of light is 1 in terms of those coordinates even is he is never
> at rest in those coordinates at all, and this too is a verifiable fact.
> This has nothing to do with "visiting" frames. It's vitally important
> for the OP and you to understand that vague and sloppy phrases like "as
> measured by Dave", which actually have no definite meaning (and mislead
> newbies into thinking your state of motion somehow *forces* you to
> measure things in terms of a certain basis), are just used as shorthand
> for "in terms of inertial coordinates in which Dave is at rest".
>
>> I chose simpler terms.
>
> Our terms should be as simple as possible, but no simpler, and we
> especially should not make statements that echo and reinforce the OP's misconceptions.
>

--
Odd Bodkin -- maker of fine toys, tools, tables

On Wednesday, November 10, 2021 at 6:45:30 AM UTC-8, bodk...@gmail.com wrote:
> >>>> An observer in a circular path is not at rest in any inertial reference frame.
> >>>
> >>> As noted previously, such a person is always momentarily at rest in an inertial frame,
> >>> What you meant to say is he is not continuously at rest in any single inertial reference
> >>
> >> By “at rest in” I meant over any nonzero interval of time...
> >
> > Right, that's what I explained you really meant (see above), but that's not what you said,
>
> Well, yes it was.

Nope, you said "An observer in a circular path is not at rest in any inertial reference frame", which is not true, because such an observer is always at rest in an inertial frame, albeit only momentarily in any given one. This was carefully explained earlier in the thread, and it's best not to backslide.

Al Coe <coeal5136@gmail.com> wrote:
> On Wednesday, November 10, 2021 at 6:45:30 AM UTC-8, bodk...@gmail.com wrote:
>>>>>> An observer in a circular path is not at rest in any inertial reference frame.
>>>>>
>>>>> As noted previously, such a person is always momentarily at rest in an inertial frame,
>>>>> What you meant to say is he is not continuously at rest in any single
>>>>> inertial reference
>>>>
>>>> By “at rest in” I meant over any nonzero interval of time...
>>>
>>> Right, that's what I explained you really meant (see above), but that's
>>> not what you said,
>>
>> Well, yes it was.
>
> Nope, you said "An observer in a circular path is not at rest in any
> inertial reference frame", which is not true, because such an observer is
> always at rest in an inertial frame, albeit only momentarily in any given one.

See my carefully articulated meaning for “at rest”, which you have ignored
in deference to your own pedantic jargon meaning, which then requires
qualification as either “momentarily” or “continually”. If you do not wish
to meet people at their commonly shared meanings, then this is illustrative
of your pedagogical failures and your comfort with pedantry. All of which
has been called out by many people on this forum directly to you. Sniff all
you like, if it makes you feel better.

> This was carefully explained earlier in the thread, and it's best not to backslide.
>
>

--
Odd Bodkin -- maker of fine toys, tools, tables

On Wednesday, November 10, 2021 at 7:28:18 AM UTC-8, bodk...@gmail.com wrote:
> See my carefully articulated meaning for “at rest”, which you have ignored
> in deference to your own pedantic jargon meaning...

Don't you have that backwards? I think the definition of "at rest" that I'm using is quite standard, certainly in physics discussions, whereas your proposed re-definition of "at rest" to mean "continuously (perpetually?) at rest" is "your own". You can slide into Fontenot territory and start coining terms like "perpetually inertial observer" (PIO), because of course no finite amount of time would suffice to cover all distances, but it's usually not a good idea to tacitly apply your own home brewed definitions of terms..

And it doesn't save any time to use the abbreviated phrase "at rest" to mean "continuously at rest for some suitable duration of time", because you need to mention that you are doing this, and by that time it would have been just as easy to say "continuously at rest".

In any case, this was all carefully explained earlier in the thread, using the normal meanings of words, and it's best not to backslide.

Al Coe <coeal5136@gmail.com> wrote:
> On Wednesday, November 10, 2021 at 7:28:18 AM UTC-8, bodk...@gmail.com wrote:
>> See my carefully articulated meaning for “at rest”, which you have ignored
>> in deference to your own pedantic jargon meaning...
>
> Don't you have that backwards? I think the definition of "at rest" that
> I'm using is quite standard,

Standard for what audience?

For people trained and practiced in physics, yes. For people who have
studied a number of textbooks and are comfortable with the jargon practiced
in them, yes.

For people who have only shallow contact with physics and who are curious
but untrained amateurs, definitely not.

As mentioned numerous times, persistently using precise jargon language,
without any effort to bridge the gap, is ineffective pedagogy (and in fact
is simply giving up on teaching) and has the primary result of talking over
the audience’s heads and only in the end serves to show that YOU know what
you’re talking about even if your audience doesn’t.

> certainly in physics discussions, whereas your proposed re-definition of
> "at rest" to mean "continuously (perpetually?) at rest" is "your own".

No, it is not my own. It is a common, colloquial understanding of what “at
rest” means. Whether you choose to acknowledge it, or whether you scoff at
it as being “incorrect” is the lack of empathy I mentioned before. It does
not escape my attention that you firmly believe that meeting the audience
where they are is “backsliding”. A lot of empathy there….not.

> You can slide into Fontenot territory and start coining terms like
> "perpetually inertial observer" (PIO), because of course no finite amount
> of time would suffice to cover all distances, but it's usually not a good
> idea to tacitly apply your own home brewed definitions of terms.
>
> And it doesn't save any time to use the abbreviated phrase "at rest" to
> mean "continuously at rest for some suitable duration of time", because
> you need to mention that you are doing this, and by that time it would
> have been just as easy to say "continuously at rest".
>
> In any case, this was all carefully explained earlier in the thread,
> using the normal meanings of words, and it's best not to backslide.
>

--
Odd Bodkin -- maker of fine toys, tools, tables

On Wednesday, November 10, 2021 at 9:23:39 AM UTC-8, bodk...@gmail.com wrote:
> >> See my carefully articulated meaning for “at rest”, which you have ignored
> >> in deference to your own pedantic jargon meaning...
> >
> > Don't you have that backwards? I think the definition of "at rest" that
> > I'm using is quite standard, certainly in physics discussions, whereas
> > your proposed re-definition of "at rest" to mean "continuously (perpetually?)
> > at rest" is "your own".

> Standard for what audience?

As I said, it's standard in discussions of physics, so the audience is anyone wanting to discuss physics. Naturally a mortician usually means something different by "at rest now" than a physicist does.

> It is not my own. It is a common, colloquial understanding of what “at
> rest” means.

Many terms are used in contexts with specialized tacit meanings, such as in popular expositions that limit themselves to inertial objects, i.e., objects that are at rest in a particular frame for the duration of the phenomena under discussion. Indeed the word "observer" in special relativity expositions is usually taken to be synonymous with "an inertial coordinate system", but when you are in a discussion with someone who wants to talk about "accelerating observers", well, you have a contradiction in terms relative to the popular expositional use of "observer" as tacitly not accelerating. There's no way to clarify such a discussion without making the explicit basic distinctions between things like being unaccelerated and being momentarily at rest in a given frame... and between observers and coordinate systems, etc. If this distinction is beyond your ... er, I mean your friend Average Joe's ... mental capacity, then you, I mean he, are/is simply not equipped to understand the subject. But most people can grasp these distinctions.... unless they are determined not to.

On Wednesday, 10 November 2021 at 18:23:39 UTC+1, bodk...@gmail.com wrote:
> Al Coe <coea...@gmail.com> wrote:
> > On Wednesday, November 10, 2021 at 7:28:18 AM UTC-8, bodk...@gmail.com wrote:
> >> See my carefully articulated meaning for “at rest”, which you have ignored
> >> in deference to your own pedantic jargon meaning...
> >
> > Don't you have that backwards? I think the definition of "at rest" that
> > I'm using is quite standard,
> Standard for what audience?
>
> For people trained and practiced in physics, yes. For people who have
> studied a number of textbooks and are comfortable with the jargon practiced
> in them, yes.
>
> For people who have only shallow contact with physics and who are curious
> but untrained amateurs, definitely not.
>
> As mentioned numerous times, persistently using precise jargon language,
> without any effort to bridge the gap, is ineffective pedagogy (and in fact
> is simply giving up on teaching) and has the primary result of talking over
> the audience’s heads and only in the end serves to show that YOU know what
> you’re talking about even if your audience doesn’t.
> > certainly in physics discussions, whereas your proposed re-definition of
> > "at rest" to mean "continuously (perpetually?) at rest" is "your own".
> No, it is not my own. It is a common, colloquial understanding of what “at
> rest” means. Whether you choose to acknowledge it, or whether you scoff at
> it as being “incorrect” is the lack of empathy I mentioned before. It does
> not escape my attention that you firmly believe that meeting the audience
> where they are is “backsliding”. A lot of empathy there….not.

Well well, who would ever think that poor idiot Odd is
going to defend colloquial understanding against
the insane newspeak of his moronic church.

On Wednesday, November 10, 2021 at 9:45:30 AM UTC-5, bodk...@gmail.com wrote:

My 2 cents, in support of...

> >>>> An observer in a circular path is not at rest in any inertial reference frame.

True [ using the common use of the meaning of that sentence in these contexts].

> You, on the other
> hand, have a correct and precise meaning (zero instantaneous velocity)
> which is a jargon definition that will be lost on the casual or untrained
> audience, as David is. That is why, when YOU use the term “at rest”, you
> have to carefully distinguish “momentarily at rest” and “continually at
> rest”, which is a pedantic distinction that only those trained would care
> about.

True.

Al Coe <coeal5136@gmail.com> wrote:
> On Wednesday, November 10, 2021 at 9:23:39 AM UTC-8, bodk...@gmail.com wrote:
>>>> See my carefully articulated meaning for “at rest”, which you have ignored
>>>> in deference to your own pedantic jargon meaning...
>>>
>>> Don't you have that backwards? I think the definition of "at rest" that
>>> I'm using is quite standard, certainly in physics discussions, whereas
>>> your proposed re-definition of "at rest" to mean "continuously (perpetually?)
>>> at rest" is "your own".
>
>> Standard for what audience?
>
> As I said, it's standard in discussions of physics, so the audience is
> anyone wanting to discuss physics. Naturally a mortician usually means
> something different by "at rest now" than a physicist does.

No, that’s too general. Even physicists write differently on the SAME
subject, depending on whether their audience is fellow professional
physicists, or a group of freshman students, or the lay public. The reason
they choose different language is that they want to reach their audience
and communicate effectively with it, and they recognize (unlike you) that
different assumptions need to be made about vocabulary and conceptual
preparedness for different audiences.

>
>> It is not my own. It is a common, colloquial understanding of what “at
>> rest” means.
>
> Many terms are used in contexts with specialized tacit meanings, such as
> in popular expositions that limit themselves to inertial objects, i.e.,
> objects that are at rest in a particular frame for the duration of the
> phenomena under discussion. Indeed the word "observer" in special
> relativity expositions is usually taken to be synonymous with "an
> inertial coordinate system", but when you are in a discussion with
> someone who wants to talk about "accelerating observers", well, you have
> a contradiction in terms relative to the popular expositional use of
> "observer" as tacitly not accelerating. There's no way to clarify such a
> discussion without making the explicit basic distinctions between things
> like being unaccelerated and being momentarily at rest in a given
> frame... and between observers and coordinate systems, etc. If this
> distinction is beyond your ... er, I mean your friend Average Joe's ...
> mental capacity, then you, I mean he, are/is simply not equipped to
> understand the subject. But most people can grasp these distinctions...
> unless they are determined not to.

Again, you are confusing willingness to meet an audience where they are,
with being conceptually unequipped. The point here is that YOU make a
choice to use precise jargon even when your audience does not have the same
grasp of it. You insist that this is the only correct practice, and that
anyone who might make a different choice simply does not have the mental
capacity to do what you do.

The arrogance of that stance, the insatiable need to be the only right one
where there is a disagreement, and a profound lack of empathy for your
correspondents, are all things you are well known for here. You have no
regret about any of these traits, apparently, which is also noted by
several here. As a reminder, as people disengage with you, the reason does
not have to do with their deficiencies.

>

--
Odd Bodkin -- maker of fine toys, tools, tables

rotchm <rotchm@gmail.com> wrote:
> On Wednesday, November 10, 2021 at 9:45:30 AM UTC-5, bodk...@gmail.com wrote:
>
>
> My 2 cents, in support of...
>
>>>>>> An observer in a circular path is not at rest in any inertial reference frame.
>
> True [ using the common use of the meaning of that sentence in these contexts].
>
>> You, on the other
>> hand, have a correct and precise meaning (zero instantaneous velocity)
>> which is a jargon definition that will be lost on the casual or untrained
>> audience, as David is. That is why, when YOU use the term “at rest”, you
>> have to carefully distinguish “momentarily at rest” and “continually at
>> rest”, which is a pedantic distinction that only those trained would care
>> about.
>
> True.
>

And I’ll just mention, “Al Coe”, that this is an example of my observations
about you not being limited to me.

Perhaps you respond with “I don’t care what anybody else thinks about this.
I’m right anyway.” That would be yet another symptom.

--
Odd Bodkin -- maker of fine toys, tools, tables

On Wednesday, November 10, 2021 at 11:07:29 AM UTC-8, bodk...@gmail.com wrote:
> Even physicists write differently on the SAME subject, depending on
> whether their audience is fellow professional physicists, or a group of
> freshman students, or the lay public.

The issue isn't generically whether people tailor their words to different audiences, the issue is whether, in a discussion of the distinction between inertial coordinate systems and accelerating travelers, and the various measures of duration, distance, and speed, etc., we can avoid making a careful distinction between inertial coordinate systems and accelerating travelers. This is the very essence of what is being discussed. Without making these distinctions, we are not actually explaining the thing.

Another example is when Ed Lake was told how relativistic aberration resolves his pulsar paradox, and you jumped in to say "Yeah! that's the ticket.... it's just like raindrops on your windshield!". Well, no, the resolution of the paradox was not the raindrop effect, which Ed was perfectly capable of seeing. The paradox is resolved only by the relativity of simultaneity involved in relativistic aberration (not present with the raindrops), and the discussion is derailed by you jumping in with your misguided comment. If Ed was to say to you: "Your explanation doesn't resolve my paradox", he would be perfectly correct. Now, you may be pleased with yourself that at least he understood what you were saying, but what you were saying was wrong, so I don't think you should be so pleased with yourself. Speaking simply is not a virtue if what you're saying is wrong.

On 11/10/21 11:06 AM, Al Coe wrote:
> [...]

This discussion about "at rest" is downright silly. Coe is deliberately
manufacturing an argument where none exists.

When a physicist says "object A is at rest in inertial frame K", they
mean it applies for the duration of the discussion. That is how these
words are actually used. Coe's ill-informed attempt to include
"instantaneously at rest" in the meaning of "at rest" is just not how
those words are used -- the modifier cannot be omitted, because it
fundamentally changes the meaning of the phrase.

> I think the definition of "at rest" that I'm using is quite
> standard,

Nope. A pointlike object in circular motion is indeed not at rest in any
inertial frame. But it is always instantaneously at rest in some
inertial frame.

Note that Coe's original objection is not actually correct: Bodkin
originally applied that to an observer. As has been pointed out,
"observer" is often/usually used to stand in for a coordinate system,
which is inherently an extended object. For extended objects, it is
often the case that there is never any inertial frame in which it is
instantaneously at rest (e.g. if it is rotating).

[Yes, this is a picayune argument like Coe's. Unless someone
brings up a substantial point, I won't continue.]

Tom Roberts

On Friday, 12 November 2021 at 17:37:40 UTC+1, tjrob137 wrote:

> Note that Coe's original objection is not actually correct: Bodkin
> originally applied that to an observer. As has been pointed out,
> "observer" is often/usually used to stand in for a coordinate system,
> which is inherently an extended object. For extended objects, it is
> often the case that there is never any inertial frame in which it is
> instantaneously at rest (e.g. if it is rotating).

Note that in the meantime in the real world, forbidden
by your moronic religion GPS clocks keep measuring
t'=t, just like all serious clocks always did. Your insane
screams that we're FORCED - simply didn't work.

On Friday, November 12, 2021 at 8:37:40 AM UTC-8, tjrob137 wrote:
> When a physicist says "object A is at rest in inertial frame K", they
> mean it applies for the duration of the discussion.

This was all explained previously. Again, in many popular expositions the author confines himself to inertially moving objects, and indeed the word "observer" is often used as shorthand for "inertial coordinate system". In other words, when someone says "as measured by Bob" they mean "in terms of inertial coordinates in which Bob is at rest (for a sufficient duration to cover the phenomena in question". This was all explicitly explained previously. But in this discussion with Barnpole Dave he is talking about an "accelerating observer", and he is trying to speak about such an observer in the same way that popular expositions speak about "observers". But the latter are tacitly referring to inertial coordinates, which of course doesn't apply to an accelerating person.

Now, at this point Dave says "Are you saying those expositions are wrong for an accelerating observer?" And the answer is that, no, they are not wrong (albeit perhaps sloppy), because it is perfectly correct that Dave's accelerating observer is always at rest in terms of a co-moving inertial coordinate system, and the speed of light is indeed c in terms of that system. So if you want to carry forward the definition of "observer" as "in terms of inertial coordinates in which Bob is at rest", then it still applies perfectly well, you just have to understand that our accelerating Bob is only momentarily at rest in each of the co-moving frames.

This is a perfectly correct and carefully presented explanation that responds to Dave's (as usual) convoluted verbal confusions. The only reason the usual dog pack responds as one mind (or 3/4 of a mind) is personal, not conceptual.

> Coe's ill-informed attempt to include "instantaneously at rest" in the
> meaning of "at rest" is just not how those words are used...

As always, you have it backwards. It is the dog pack that is attempting to include "continuously at rest" in the meaning of "at rest". My point is that "at rest" just means "at rest", and if the discussion requires distinguishing between momentarily or continuously, then a grown-up person makes that distinction.

On Friday, 12 November 2021 at 21:40:38 UTC+1, Al Coe wrote:
> On Friday, November 12, 2021 at 8:37:40 AM UTC-8, tjrob137 wrote:
> > When a physicist says "object A is at rest in inertial frame K", they
> > mean it applies for the duration of the discussion.
> This was all explained previously. Again, in many popular expositions the author confines himself to inertially moving objects, and indeed the word "observer" is often used as shorthand for "inertial coordinate system". In other words, when someone says "as measured by Bob" they mean "in terms of inertial coordinates in which Bob is at rest

Poor idiot Al know what they mean, and they won't dare meaning
anything else.

How do we measure a light wave in an accurate way?
How do we know where it will arrive?
How do we measure emission or absorption directly?
We are not doing that.