El miércoles, 30 de marzo de 2022 a las 18:03:11 UTC-3, det...@outlook..com escribió:
> On Wednesday, March 30, 2022 at 12:38:43 PM UTC-5, Paparios wrote:

> >
> > > You are talking about two different statements in two different parts of the paper
> > > referring to two different situations.
> > >
> > They both refer to the same situation (as the name of the paper says "On the Electrodynamics of Moving Bodies"), where one body is moving (at constant speed v) relative to another body. Both statements are known as the principle of constancy of the speed of light.

> There is no second body in the first quote. All it says is that "light is always
> propagated in empty space with a definite velocity c which is independent
> of the state of motion of the emitting body." NO SECOND BODY.
>

You clearly do not understand what Einstein wrote. When he writes "independent of the state of motion of the emitting body", you have to qualify what that state of motion is. He clearly is talking about either one of two conditions:

a) The emitting body is stationary.
b) The emitting body is moving.

In both cases you need a different body to identify which condition applies.. For instance, if the emitting body is fixed on the ground, the emitting body is stationary RELATIVE to the ground (the second body). If the emitting body is on a moving platform (moving at 20 mph RELATIVE to the ground), then the emitting body is moving.

If you do not have a reference, the state of motiom of a body can not be defined.

> In the second quote, Einstein is talking about "stationary systems," which is NOT
> relevant to the first quote. Don't you understand what "independent of the
> state of motion of the emitting body" means????
>

The second quote says exactly the same: "whether the ray be emitted by a stationary or by a moving body"!!!!

> > > Nonsense. Neither statement mentions any "observer" RECEIVING
> > > light. Both are just about how a photon moves once it is EMITTED.
> > Again, by the geometry and symmetry of the situation, a stationary or a moving receiver will also receive that incoming light at speed c. This is verified every day by the astronomical observatories around the world, where we can only receive the light of stars.

> Nonsense. Light from every star travels at c, but c is the speed of light
> PER SECOND, and the length of a second could be different at EVERY STAR.
>

That is nonsense. The second is defined as:
"The second is equal to the duration of 9192631770 periods of the radiation corresponding to the transition between the hyperfine levels of the unperturbed ground state of the 133Cs atom".

The meter is actually defined as a function of the second:
"The metre is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second".

The light coming from stars arrives at the observatories at speed c, where c=wavelength/frequency.

Le 30/03/2022 à 22:27, Michael Moroney a écrit :

> That's impossible, since when A sees B's clock ticking slower due to
> motion, B sees A's clock ticking slower. This is impossible to resolve
> from any actual slower ticking by any clock, but in SR it's possible
> since it is a geometric effect, and these aren't the same measurements
> anyway.

That's absolutely correct.

This is called the relativity of chronotropy.

When two watches are moving relative to each other, each considers that
the other has a lower chronotropy.

It works for uniform media, it also works for accelerated media.

The relativity equation of chronotropy is known to everyone.

To=Tr/sqrt(1-vo²/c²)

This well-known and real phenomenon, however, poses a logical problem if
one does not understand what one is saying.

We then speak of "Langevin's paradox" and we say: "If during ALL the
course, each of the watches, both on the way out and on the way back,
really beats faster than the one it observes, there is necessarily an
absurdity finally".

No, there is no absurdity.

The twin remained on earth at really 30 years old, and the other 18 years
old (in the example given) although their reciprocal chronotropy was
exactly the same, each watch considering that the other watch beats
constantly less quickly.

Simply, we forget one thing, and that is the hardest thing for human
beings to swallow, there is not only one phenomenon involved, ie
chronotropy.

Another phenomenon occurs at the same time: anisotropy.

The initial equation relating to chronotropy must then be modified by a
second factor.

And this becomes reciprocally:
To=Tr(1+cosµ.v/c)/sqrt(1-v²/c²)

The anisochronous effect is in the numerator, the chronotropic effect in
the denominator.

Digital Application:
- on the outward journey for land To=27 years Tr=9 years
- Returning for land To=3 years Tr=9 years.

- On the outward journey for the cosmonaut Tr=9 years To=3 years
- On return Tr=9 years To=27 years.

It is a prodigious mathematical evidence.

For the elasticity of distances and lengths, the same equation must be
applied.

If we stupidly apply x'=x.sqrt(1-v²/c²), the whole intellectual
structure collapses.

Again, apply x'=x.sqrt(1-v²/c²)/(1+cosµ.v/c)

Thank you for your attention.

R.H.

On 3/30/2022 5:18 PM, Ed Lake wrote:
> On Wednesday, March 30, 2022 at 12:51:19 PM UTC-5, Michael Moroney wrote:
>> On 3/30/2022 11:12 AM, Ed Lake wrote:
>>> On Tuesday, March 29, 2022 at 5:02:40 PM UTC-5, rotchm wrote:
>>>> On Tuesday, March 29, 2022 at 5:17:09 PM UTC-4, wrote:
>>>>> On Tuesday, March 29, 2022 at 2:57:02 PM UTC-5, rotchm wrote:
>>>>
>>>>>>> The first one says that light is ALWAYS EMITTED at c ...
>>>>>>
>>>>>> Just in that sentence, who is the 'observer' , the one noting that the
>>>>>> speed is c?
>>>>> The emitter is the only "observer."
>>>> OK. However, to those who can read English, those who can understand what is written (or the intention thereof),
>>>> the above not only means that the 'observer' is the emitter, but that the observer can be any (inertial) observer.
>>>
>>> No, that is what is called "making a false assumption." It is twisting the
>>> statement to make it fit some argument that you want to make.
>>>
>>>>
>>>> But yes, some may interpret the above that the only observer is the emitter.
>>>> Those people (you?) should investigate more the meaning of that sentence to see if they understood it correctly.
>>>>>>> Light is emitted at c whether the emitter is moving or stationary, accelerating or
>>>>>>> decelerating.
>>>>>> Again, who is the observer that is noting that the speed is c in those cases?
>>>>> The emitter is the only "observer."
>>>> In the now above, it is much more clear that the author meant that any (inertial) observer is/are the ones
>>>> declaring that it is 'c'; that the emitter is NOT 'the' observer. Anyone who understands English, would have understood/interpreted it like that. Do you agree with my comments in this reply?
>>>
>>> No, of course not.
>> Throughout the paper Einstein does NOT assume that only the emitter is
>> the observer. Your claim makes no sense.
>
> You make no sense. You seem to believe that if Einstein is talking about
> one thing on page 1, he must be talking about the same thing all pages.

If the only thing he talks about in the second postulate is the speed of
light relative to the emitter, but throughout the paper he talks about
the speed of light relative to various observers, why even mention that
unused postulate?
>
>>>
>>>>> The emitter emits photons at c and
>>>>> c is the speed PER SECOND at the location of the emitter.
>>>> He (inertial) who choses to measure the speed of that photon is the Observer. And this Observer will get the value of c.
>>>> That is what is meant (English) by E's postulate. That is how a good reader would understand it.
>>>
>>> No, that is how MATHEMATICIANS twist things to make Einstein's words
>>> fit their beliefs.
>> You need to get help regarding these "mathematician" boogeymen you see
>> everywhere. This is all physics, no mathematicians to be seen anywhere.
>
> If all you understand is mathematics, you are a MATHEMATICIAN, not a
> physicist and NOT a scientist.

I am so-so with math, I understand physics better. Definitely no
mathematician 🧟‍♂️. And I do understand that physics has lots of math,
like it or not. Fortunately my math is good enough for physics.
>
>>>
>>> If I am moving through space and emit a photon, that photon will travel at c
>>> as c is defined at MY location. I.e., the photon will travel at 299,792,458 meters
>>> PER SECOND as a second is measured at MY location. That is all that
>>> Einstein's Second Postulate says.
>> Yet Einstein uses other observers (NOT the emitter) seeing the light as c.
>
> When he wants to make a point about other observers, he uses other observers.

And (your version of) the Second Postulate doesn't apply to them.
>
>>> What some OTHER observer might see
>>> or measure when he sees the photon I emitted has NOTHING to do with
>>> the Second Postulate.
>> Why would he even have made it? Nowhere does he use the emitter
>> measuring the light as c. The whole first section involves observers
>> measuring light as c.
>
> He is setting up a POSTULATE. A "postulate" is an ASSUMPTION that
> something is true in order to develop or propose an IDEA or theory.
>
> The rest of the paper develops and explains that IDEA. The IDEA is that
> time varies with velocity.

But he doesn't even use (your version of) the postulate! Remember, you
said that the postulate ONLY states the speed of light is c relative to
the emitter. Not to any other observer, the emitter ONLY.
>
>>>
>>> The point Einstein is making is that c will be different depending upon how
>>> fast I am moving. It will ALWAYS be 299,792,458 meters PER SECOND,
>>> but the LENGTH OF A SECOND at my location will vary depending upon
>>> the speed at which I am traveling.
>> Nowhere is that a postulate of the SR paper. You just made that up, to
>> justify your mistaken beliefs.
>
> It is the IDEA that Einstein is proposing in his paper. His postulate sets up
> the idea and the paper explains the idea that Time varies with velocity.

But he doesn't even use (your version of) the postulate!
>
>>>
>>> What someone else is doing is not relevant.
>>>
>> ????? The substantial part of the paper involves what others observe!
>
> Right. But the Second Postulate is NOT about what others observe.
> The rest of the paper may be, but the Second Postulate is NOT.

So you admit that (your version of) the second Postulate isn't used!
>
> Ed

On Wednesday, March 30, 2022 at 5:03:11 PM UTC-4, det...@outlook.com wrote:
> On Wednesday, March 30, 2022 at 12:38:43 PM UTC-5, Paparios wrote:

> There is no second body in the first quote.

Yes there is. See below.

> All it says is that "light is always
> propagated in empty space with a definite velocity c which is independent
> of the state of motion of the emitting body." NO SECOND BODY.

Consider "Light is always propagated in empty space with a definite velocity c."
Just that, means that there is someone (something) measuring the speed of light, and that someone is getting the result c.
To declare a velocity, implicitly means there is an "observer".
Do you agree that the above sentence means/imply that? (to this point, it's just a question of English language).

Now, adding to that sentence "which is independent of the state of motion of the emitting body." does not change the first clause.
In fact, "which is independent of the state of motion of the emitting body." is redundant, since just
"Light is always propagated in empty space with a definite velocity c." means that no matter who measures it, they will get c, be it the emitting body, or some other body (another observer). This is just a matter of the logic of the English language, the meaning of the words used.

On Wednesday, March 30, 2022 at 4:55:10 PM UTC-5, Paparios wrote:
> El miércoles, 30 de marzo de 2022 a las 18:03:11 UTC-3, escribió:
> > On Wednesday, March 30, 2022 at 12:38:43 PM UTC-5, Paparios wrote:
>
> > >
> > > > You are talking about two different statements in two different parts of the paper
> > > > referring to two different situations.
> > > >
> > > They both refer to the same situation (as the name of the paper says "On the Electrodynamics of Moving Bodies"), where one body is moving (at constant speed v) relative to another body. Both statements are known as the principle of constancy of the speed of light.
>
> > There is no second body in the first quote. All it says is that "light is always
> > propagated in empty space with a definite velocity c which is independent
> > of the state of motion of the emitting body." NO SECOND BODY.
> >
> You clearly do not understand what Einstein wrote. When he writes "independent of the state of motion of the emitting body", you have to qualify what that state of motion is. He clearly is talking about either one of two conditions:
>
> a) The emitting body is stationary.
> b) The emitting body is moving.
>
> In both cases you need a different body to identify which condition applies. For instance, if the emitting body is fixed on the ground, the emitting body is stationary RELATIVE to the ground (the second body). If the emitting body is on a moving platform (moving at 20 mph RELATIVE to the ground), then the emitting body is moving.
>
> If you do not have a reference, the state of motiom of a body can not be defined.

No, Einstein was NOT talking about either one of those two conditions.
He was stating that light is emitted at c REGARDLESS of whether the
emitter is moving or stationary. In other words: Light is ALWAYS EMITTED AT c.
PERIOD.

> > In the second quote, Einstein is talking about "stationary systems," which is NOT
> > relevant to the first quote. Don't you understand what "independent of the
> > state of motion of the emitting body" means????
> >
> The second quote says exactly the same: "whether the ray be emitted by a stationary or by a moving body"!!!!

I REPEAT: The second quote is about "stationary systems." The first quote is NOT.

> > > > Nonsense. Neither statement mentions any "observer" RECEIVING
> > > > light. Both are just about how a photon moves once it is EMITTED.
> > > Again, by the geometry and symmetry of the situation, a stationary or a moving receiver will also receive that incoming light at speed c. This is verified every day by the astronomical observatories around the world, where we can only receive the light of stars.
>
> > Nonsense. Light from every star travels at c, but c is the speed of light
> > PER SECOND, and the length of a second could be different at EVERY STAR..
> >
> That is nonsense. The second is defined as:
> "The second is equal to the duration of 9192631770 periods of the radiation corresponding to the transition between the hyperfine levels of the unperturbed ground state of the 133Cs atom".
>
> The meter is actually defined as a function of the second:
> "The metre is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second".
>
> The light coming from stars arrives at the observatories at speed c, where c=wavelength/frequency.

Nonsense. Light coming from stars arrives at c+v or c-v depending upon
the earth's motion v. PLUS, c could be different for every star, since every
star has a different mass and moves through space at a different speed.

Ed

On Wednesday, March 30, 2022 at 7:05:07 PM UTC-5, Michael Moroney wrote:
> On 3/30/2022 5:18 PM, Ed Lake wrote:
> > On Wednesday, March 30, 2022 at 12:51:19 PM UTC-5, Michael Moroney wrote:
> >> On 3/30/2022 11:12 AM, Ed Lake wrote:
> >>> On Tuesday, March 29, 2022 at 5:02:40 PM UTC-5, rotchm wrote:
> >>>> On Tuesday, March 29, 2022 at 5:17:09 PM UTC-4, wrote:
> >>>>> On Tuesday, March 29, 2022 at 2:57:02 PM UTC-5, rotchm wrote:
> >>>>
> >>>>>>> The first one says that light is ALWAYS EMITTED at c ...
> >>>>>>
> >>>>>> Just in that sentence, who is the 'observer' , the one noting that the
> >>>>>> speed is c?
> >>>>> The emitter is the only "observer."
> >>>> OK. However, to those who can read English, those who can understand what is written (or the intention thereof),
> >>>> the above not only means that the 'observer' is the emitter, but that the observer can be any (inertial) observer.
> >>>
> >>> No, that is what is called "making a false assumption." It is twisting the
> >>> statement to make it fit some argument that you want to make.
> >>>
> >>>>
> >>>> But yes, some may interpret the above that the only observer is the emitter.
> >>>> Those people (you?) should investigate more the meaning of that sentence to see if they understood it correctly.
> >>>>>>> Light is emitted at c whether the emitter is moving or stationary, accelerating or
> >>>>>>> decelerating.
> >>>>>> Again, who is the observer that is noting that the speed is c in those cases?
> >>>>> The emitter is the only "observer."
> >>>> In the now above, it is much more clear that the author meant that any (inertial) observer is/are the ones
> >>>> declaring that it is 'c'; that the emitter is NOT 'the' observer. Anyone who understands English, would have understood/interpreted it like that. Do you agree with my comments in this reply?
> >>>
> >>> No, of course not.
> >> Throughout the paper Einstein does NOT assume that only the emitter is
> >> the observer. Your claim makes no sense.
> >
> > You make no sense. You seem to believe that if Einstein is talking about
> > one thing on page 1, he must be talking about the same thing all pages.
> If the only thing he talks about in the second postulate is the speed of
> light relative to the emitter, but throughout the paper he talks about
> the speed of light relative to various observers, why even mention that
> unused postulate?

> But he doesn't even use (your version of) the postulate! Remember, you
> said that the postulate ONLY states the speed of light is c relative to
> the emitter. Not to any other observer, the emitter ONLY.

> But he doesn't even use (your version of) the postulate!

> So you admit that (your version of) the second Postulate isn't used!

You clearly do not understand what a postulate is. Let me see if I can
summarize for you Einstein's 1905 paper on special relativity:

He says, Experiments with magnets and conductors indicate that if we
ASSUME that two things are true, then we get a THEORY that does not
require a luminiferous ether in order to measure motion. Those two
ASSUMPTIONS (also known as "postulates") are: (1) All experiments
work the same way in a closed inertial system, and (2) Light is always
emitted at c regardless of the speed of the emitter. Those two
ASSUMPTIONS may appear to be contradictory, but the THEORY to be
described will show that they are NOT contradictory.

Then Einstein begins describing his theory in TEN different sections.
each describing a part of the THEORY. I'll just mention a few of them.

In the first section he describes "simultaneity" and how things may
sometimes seem simultaneous when in reality they are not. It all
depends upon how you view time.

The second section is about lengths and times. The faster you travel,
the less time it takes to get from point A to point B.

In the fourth section he describes why "a balance-clock at the equator
must go more slowly, by a very small amount, than a precisely similar
clock situated at one of the poles under otherwise identical conditions."
It is because time ticks at a slower rate at the faster moving equator.
In the tenth section he describes how an electron gains mass when it
is forced to move. That force slows down time for the electron. And
there isn't enough force in the universe to make the photon travel at
the speed of light.

I could explain the other sections, too, but the point is: a postulate is
an ASSUMPTION used to develop a THEORY. The THEORY is about how
light and time work. There are NO POSTULATES described in the theory,
the theory describes how things work IF the postulates are true.

Ed

El jueves, 31 de marzo de 2022 a las 12:56:03 UTC-3, det...@outlook.com escribió:
> On Wednesday, March 30, 2022 at 4:55:10 PM UTC-5, Paparios wrote:

> > > There is no second body in the first quote. All it says is that "light is always
> > > propagated in empty space with a definite velocity c which is independent
> > > of the state of motion of the emitting body." NO SECOND BODY.
> > >
> > You clearly do not understand what Einstein wrote. When he writes "independent of the state of motion of the emitting body", you have to qualify what that state of motion is. He clearly is talking about either one of two conditions:
> >
> > a) The emitting body is stationary.
> > b) The emitting body is moving.
> >
> > In both cases you need a different body to identify which condition applies. For instance, if the emitting body is fixed on the ground, the emitting body is stationary RELATIVE to the ground (the second body). If the emitting body is on a moving platform (moving at 20 mph RELATIVE to the ground), then the emitting body is moving.
> >
> > If you do not have a reference, the state of motiom of a body can not be defined.

> No, Einstein was NOT talking about either one of those two conditions.
> He was stating that light is emitted at c REGARDLESS of whether the
> emitter is moving or stationary. In other words: Light is ALWAYS EMITTED AT c.
> PERIOD.

You are not making any sense. When he writes "the state of motion of the emitting body" he clearly means (as you write above) "the emitter is moving or stationary". For that to be true you have to know if the emitter is stationary or is moving, which requires a system of coordinates.

Einstein did use frames of reference in the page 1, where he wrote: "They suggest rather that, as has already been shown to the first order of small quantities, the same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good".

> > > In the second quote, Einstein is talking about "stationary systems," which is NOT
> > > relevant to the first quote. Don't you understand what "independent of the
> > > state of motion of the emitting body" means????
> > >
> > The second quote says exactly the same: "whether the ray be emitted by a stationary or by a moving body"!!!!

> I REPEAT: The second quote is about "stationary systems." The first quote is NOT.

This is clearly wrong as "whether the ray be emitted by a stationary or by a moving body" shows.

> > > Nonsense. Light from every star travels at c, but c is the speed of light
> > > PER SECOND, and the length of a second could be different at EVERY STAR.
> > >
> > That is nonsense. The second is defined as:
> > "The second is equal to the duration of 9192631770 periods of the radiation corresponding to the transition between the hyperfine levels of the unperturbed ground state of the 133Cs atom".
> >
> > The meter is actually defined as a function of the second:
> > "The metre is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second".
> >
> > The light coming from stars arrives at the observatories at speed c, where c=wavelength*frequency.

> Nonsense. Light coming from stars arrives at c+v or c-v depending upon
> the earth's motion v. PLUS, c could be different for every star, since every
> star has a different mass and moves through space at a different speed.
>

More nonsense. Light from stars arrive at speed c, where c=fλ

On Wednesday, March 30, 2022 at 9:03:13 PM UTC-5, rotchm wrote:
> On Wednesday, March 30, 2022 at 5:03:11 PM UTC-4, wrote:
> > On Wednesday, March 30, 2022 at 12:38:43 PM UTC-5, Paparios wrote:
>
> > There is no second body in the first quote.
> Yes there is. See below.
> > All it says is that "light is always
> > propagated in empty space with a definite velocity c which is independent
> > of the state of motion of the emitting body." NO SECOND BODY.
> Consider "Light is always propagated in empty space with a definite velocity c."
> Just that, means that there is someone (something) measuring the speed of light, and that someone is getting the result c.
> To declare a velocity, implicitly means there is an "observer".
> Do you agree that the above sentence means/imply that? (to this point, it's just a question of English language).

We can ASSUME there is an "observer," since without an "observer" we
see and know and observe nothing.
>
> Now, adding to that sentence "which is independent of the state of motion of the emitting body." does not change the first clause.
> In fact, "which is independent of the state of motion of the emitting body." is redundant, since just
> "Light is always propagated in empty space with a definite velocity c." means that no matter who measures it, they will get c, be it the emitting body, or some other body (another observer). This is just a matter of the logic of the English language, the meaning of the words used.

TOTAL NONSENSE!!!!!!!!!!!!!! ONLY THE EMITTER will measure the light to travel at c.
You are twisting things to fit your mistaken beliefs. The quote CLEARLY says
NOTHING about what other observers will see. And we know from experiments that
a moving observer will NOT see oncoming light as traveling at c. The light will arrive
at c+v where v is the speed of the observer. That is the PRINCIPLE BEHIND RADAR GUNS.

Ed

Ed Lake <detect@outlook.com> wrote:
> On Wednesday, March 30, 2022 at 4:55:10 PM UTC-5, Paparios wrote:
>> El miércoles, 30 de marzo de 2022 a las 18:03:11 UTC-3, escribió:
>>> On Wednesday, March 30, 2022 at 12:38:43 PM UTC-5, Paparios wrote:
>>
>>>>
>>>>> You are talking about two different statements in two different parts of the paper
>>>>> referring to two different situations.
>>>>>
>>>> They both refer to the same situation (as the name of the paper says
>>>> "On the Electrodynamics of Moving Bodies"), where one body is moving
>>>> (at constant speed v) relative to another body. Both statements are
>>>> known as the principle of constancy of the speed of light.
>>
>>> There is no second body in the first quote. All it says is that "light is always
>>> propagated in empty space with a definite velocity c which is independent
>>> of the state of motion of the emitting body." NO SECOND BODY.
>>>
>> You clearly do not understand what Einstein wrote. When he writes
>> "independent of the state of motion of the emitting body", you have to
>> qualify what that state of motion is. He clearly is talking about either
>> one of two conditions:
>>
>> a) The emitting body is stationary.
>> b) The emitting body is moving.
>>
>> In both cases you need a different body to identify which condition
>> applies. For instance, if the emitting body is fixed on the ground, the
>> emitting body is stationary RELATIVE to the ground (the second body). If
>> the emitting body is on a moving platform (moving at 20 mph RELATIVE to
>> the ground), then the emitting body is moving.
>>
>> If you do not have a reference, the state of motiom of a body can not be defined.
>
> No, Einstein was NOT talking about either one of those two conditions.
> He was stating that light is emitted at c REGARDLESS of whether the
> emitter is moving or stationary. In other words: Light is ALWAYS EMITTED AT c.
> PERIOD.

Nope, Ed, that’s not what it says.

It says that an observer who is measuring the speed of light will measure
that speed to be c, regardless whether the emitter is stationary relative
to the observer, or whether the emitter is moving relative to the observer.

This also means, as a directly corollary, that if you have a single source
and there two different observers, where one observer is stationary
relative to the emitter and the other observer is moving relative to the
emitter, then both observers will measure the speed of light from that
source to be c.

>
>>> In the second quote, Einstein is talking about "stationary systems," which is NOT
>>> relevant to the first quote. Don't you understand what "independent of the
>>> state of motion of the emitting body" means????
>>>
>> The second quote says exactly the same: "whether the ray be emitted by a
>> stationary or by a moving body"!!!!
>
> I REPEAT: The second quote is about "stationary systems." The first quote is NOT.
>
>>>>> Nonsense. Neither statement mentions any "observer" RECEIVING
>>>>> light. Both are just about how a photon moves once it is EMITTED.
>>>> Again, by the geometry and symmetry of the situation, a stationary or
>>>> a moving receiver will also receive that incoming light at speed c.
>>>> This is verified every day by the astronomical observatories around
>>>> the world, where we can only receive the light of stars.
>>
>>> Nonsense. Light from every star travels at c, but c is the speed of light
>>> PER SECOND, and the length of a second could be different at EVERY STAR.
>>>
>> That is nonsense. The second is defined as:
>> "The second is equal to the duration of 9192631770 periods of the
>> radiation corresponding to the transition between the hyperfine levels
>> of the unperturbed ground state of the 133Cs atom".
>>
>> The meter is actually defined as a function of the second:
>> "The metre is the length of the path travelled by light in vacuum during
>> a time interval of 1/299 792 458 of a second".
>>
>> The light coming from stars arrives at the observatories at speed c, where
>> c=wavelength/frequency.
>
> Nonsense. Light coming from stars arrives at c+v or c-v depending upon
> the earth's motion v. PLUS, c could be different for every star, since every
> star has a different mass and moves through space at a different speed.
>
> Ed
>

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

On Thursday, March 31, 2022 at 11:39:25 AM UTC-5, Paparios wrote:
> El jueves, 31 de marzo de 2022 a las 12:56:03 UTC-3, escribió:
> > On Wednesday, March 30, 2022 at 4:55:10 PM UTC-5, Paparios wrote:
>
> > > > There is no second body in the first quote. All it says is that "light is always
> > > > propagated in empty space with a definite velocity c which is independent
> > > > of the state of motion of the emitting body." NO SECOND BODY.
> > > >
> > > You clearly do not understand what Einstein wrote. When he writes "independent of the state of motion of the emitting body", you have to qualify what that state of motion is. He clearly is talking about either one of two conditions:
> > >
> > > a) The emitting body is stationary.
> > > b) The emitting body is moving.
> > >
> > > In both cases you need a different body to identify which condition applies. For instance, if the emitting body is fixed on the ground, the emitting body is stationary RELATIVE to the ground (the second body). If the emitting body is on a moving platform (moving at 20 mph RELATIVE to the ground), then the emitting body is moving.
> > >
> > > If you do not have a reference, the state of motiom of a body can not be defined.
>
> > No, Einstein was NOT talking about either one of those two conditions.
> > He was stating that light is emitted at c REGARDLESS of whether the
> > emitter is moving or stationary. In other words: Light is ALWAYS EMITTED AT c.
> > PERIOD.
> You are not making any sense. When he writes "the state of motion of the emitting body" he clearly means (as you write above) "the emitter is moving or stationary". For that to be true you have to know if the emitter is stationary or is moving, which requires a system of coordinates.

You have to know if the emitter is stationary or moving in order to do the MATH,
but light is always EMITTED at c regardless of whether the emitter is stationary or moving.
That is a FACT that does not involve math.

>
> Einstein did use frames of reference in the page 1, where he wrote: "They suggest rather that, as has already been shown to the first order of small quantities, the same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good".

Yes, but he's not "using" a frame of reference. He is DEFINING a frame of reference.

(snip opinions)

Ed

On Thursday, March 31, 2022 at 11:46:24 AM UTC-5, bodk...@gmail.com wrote:
> Ed Lake wrote:
> > On Wednesday, March 30, 2022 at 4:55:10 PM UTC-5, Paparios wrote:
> >> El miércoles, 30 de marzo de 2022 a las 18:03:11 UTC-3, escribió:
> >>> On Wednesday, March 30, 2022 at 12:38:43 PM UTC-5, Paparios wrote:
> >>
> >>>>
> >>>>> You are talking about two different statements in two different parts of the paper
> >>>>> referring to two different situations.
> >>>>>
> >>>> They both refer to the same situation (as the name of the paper says
> >>>> "On the Electrodynamics of Moving Bodies"), where one body is moving
> >>>> (at constant speed v) relative to another body. Both statements are
> >>>> known as the principle of constancy of the speed of light.
> >>
> >>> There is no second body in the first quote. All it says is that "light is always
> >>> propagated in empty space with a definite velocity c which is independent
> >>> of the state of motion of the emitting body." NO SECOND BODY.
> >>>
> >> You clearly do not understand what Einstein wrote. When he writes
> >> "independent of the state of motion of the emitting body", you have to
> >> qualify what that state of motion is. He clearly is talking about either
> >> one of two conditions:
> >>
> >> a) The emitting body is stationary.
> >> b) The emitting body is moving.
> >>
> >> In both cases you need a different body to identify which condition
> >> applies. For instance, if the emitting body is fixed on the ground, the
> >> emitting body is stationary RELATIVE to the ground (the second body). If
> >> the emitting body is on a moving platform (moving at 20 mph RELATIVE to
> >> the ground), then the emitting body is moving.
> >>
> >> If you do not have a reference, the state of motiom of a body can not be defined.
> >
> > No, Einstein was NOT talking about either one of those two conditions.
> > He was stating that light is emitted at c REGARDLESS of whether the
> > emitter is moving or stationary. In other words: Light is ALWAYS EMITTED AT c.
> > PERIOD.
> Nope, Ed, that’s not what it says.
>
> It says that an observer who is measuring the speed of light will measure
> that speed to be c, regardless whether the emitter is stationary relative
> to the observer, or whether the emitter is moving relative to the observer.

Nope. That is you twisting things to fit your mistaken beliefs.

The ONLY observer in the postulate is the EMITTER. The postulate says
nothing about any other observers. Plus, the postulate does not work
for other observers.

> This also means, as a directly corollary, that if you have a single source
> and there two different observers, where one observer is stationary
> relative to the emitter and the other observer is moving relative to the
> emitter, then both observers will measure the speed of light from that
> source to be c.

FALSE. Radar guns demonstrate that guns EMIT photons at c, but the
target (outside observer) receives the photons at c+v or c-v.

Other experiments show the same thing.

Ed

Ed Lake <detect@outlook.com> wrote:
> On Wednesday, March 30, 2022 at 7:05:07 PM UTC-5, Michael Moroney wrote:
>> On 3/30/2022 5:18 PM, Ed Lake wrote:
>>> On Wednesday, March 30, 2022 at 12:51:19 PM UTC-5, Michael Moroney wrote:
>>>> On 3/30/2022 11:12 AM, Ed Lake wrote:
>>>>> On Tuesday, March 29, 2022 at 5:02:40 PM UTC-5, rotchm wrote:
>>>>>> On Tuesday, March 29, 2022 at 5:17:09 PM UTC-4, wrote:
>>>>>>> On Tuesday, March 29, 2022 at 2:57:02 PM UTC-5, rotchm wrote:
>>>>>>
>>>>>>>>> The first one says that light is ALWAYS EMITTED at c ...
>>>>>>>>
>>>>>>>> Just in that sentence, who is the 'observer' , the one noting that the
>>>>>>>> speed is c?
>>>>>>> The emitter is the only "observer."
>>>>>> OK. However, to those who can read English, those who can understand
>>>>>> what is written (or the intention thereof),
>>>>>> the above not only means that the 'observer' is the emitter, but
>>>>>> that the observer can be any (inertial) observer.
>>>>>
>>>>> No, that is what is called "making a false assumption." It is twisting the
>>>>> statement to make it fit some argument that you want to make.
>>>>>
>>>>>>
>>>>>> But yes, some may interpret the above that the only observer is the emitter.
>>>>>> Those people (you?) should investigate more the meaning of that
>>>>>> sentence to see if they understood it correctly.
>>>>>>>>> Light is emitted at c whether the emitter is moving or stationary, accelerating or
>>>>>>>>> decelerating.
>>>>>>>> Again, who is the observer that is noting that the speed is c in those cases?
>>>>>>> The emitter is the only "observer."
>>>>>> In the now above, it is much more clear that the author meant that
>>>>>> any (inertial) observer is/are the ones
>>>>>> declaring that it is 'c'; that the emitter is NOT 'the' observer.
>>>>>> Anyone who understands English, would have understood/interpreted it
>>>>>> like that. Do you agree with my comments in this reply?
>>>>>
>>>>> No, of course not.
>>>> Throughout the paper Einstein does NOT assume that only the emitter is
>>>> the observer. Your claim makes no sense.
>>>
>>> You make no sense. You seem to believe that if Einstein is talking about
>>> one thing on page 1, he must be talking about the same thing all pages.
>> If the only thing he talks about in the second postulate is the speed of
>> light relative to the emitter, but throughout the paper he talks about
>> the speed of light relative to various observers, why even mention that
>> unused postulate?
>
>> But he doesn't even use (your version of) the postulate! Remember, you
>> said that the postulate ONLY states the speed of light is c relative to
>> the emitter. Not to any other observer, the emitter ONLY.
>
>> But he doesn't even use (your version of) the postulate!
>
>> So you admit that (your version of) the second Postulate isn't used!
>
> You clearly do not understand what a postulate is. Let me see if I can
> summarize for you Einstein's 1905 paper on special relativity:
>
> He says, Experiments with magnets and conductors indicate that if we
> ASSUME that two things are true, then we get a THEORY that does not
> require a luminiferous ether in order to measure motion. Those two
> ASSUMPTIONS (also known as "postulates") are: (1) All experiments
> work the same way in a closed inertial system,

Ed, just to make a small point here: jotting down what a postulate says,
from some source you looked up, doesn’t mean much if you don’t know what
the words mean.

Here, I’m going to take the easy gamble that you don’t actually know what
“closed system” means and what “inertial system” means. Guessing here would
not be a good idea.

> and (2) Light is always
> emitted at c regardless of the speed of the emitter. Those two
> ASSUMPTIONS may appear to be contradictory, but the THEORY to be
> described will show that they are NOT contradictory.
>
> Then Einstein begins describing his theory in TEN different sections.
> each describing a part of the THEORY. I'll just mention a few of them.
>
> In the first section he describes "simultaneity" and how things may
> sometimes seem simultaneous when in reality they are not. It all
> depends upon how you view time.
>
> The second section is about lengths and times. The faster you travel,
> the less time it takes to get from point A to point B.
>
> In the fourth section he describes why "a balance-clock at the equator
> must go more slowly, by a very small amount, than a precisely similar
> clock situated at one of the poles under otherwise identical conditions."
> It is because time ticks at a slower rate at the faster moving equator.
>
> In the tenth section he describes how an electron gains mass when it
> is forced to move. That force slows down time for the electron. And
> there isn't enough force in the universe to make the photon travel at
> the speed of light.
>
> I could explain the other sections, too, but the point is: a postulate is
> an ASSUMPTION used to develop a THEORY. The THEORY is about how
> light and time work. There are NO POSTULATES described in the theory,
> the theory describes how things work IF the postulates are true.
>
> Ed
>

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

Ed Lake <detect@outlook.com> wrote:
> On Thursday, March 31, 2022 at 11:46:24 AM UTC-5, bodk...@gmail.com wrote:
>> Ed Lake wrote:
>>> On Wednesday, March 30, 2022 at 4:55:10 PM UTC-5, Paparios wrote:
>>>> El miércoles, 30 de marzo de 2022 a las 18:03:11 UTC-3, escribió:
>>>>> On Wednesday, March 30, 2022 at 12:38:43 PM UTC-5, Paparios wrote:
>>>>
>>>>>>
>>>>>>> You are talking about two different statements in two different parts of the paper
>>>>>>> referring to two different situations.
>>>>>>>
>>>>>> They both refer to the same situation (as the name of the paper says
>>>>>> "On the Electrodynamics of Moving Bodies"), where one body is moving
>>>>>> (at constant speed v) relative to another body. Both statements are
>>>>>> known as the principle of constancy of the speed of light.
>>>>
>>>>> There is no second body in the first quote. All it says is that "light is always
>>>>> propagated in empty space with a definite velocity c which is independent
>>>>> of the state of motion of the emitting body." NO SECOND BODY.
>>>>>
>>>> You clearly do not understand what Einstein wrote. When he writes
>>>> "independent of the state of motion of the emitting body", you have to
>>>> qualify what that state of motion is. He clearly is talking about either
>>>> one of two conditions:
>>>>
>>>> a) The emitting body is stationary.
>>>> b) The emitting body is moving.
>>>>
>>>> In both cases you need a different body to identify which condition
>>>> applies. For instance, if the emitting body is fixed on the ground, the
>>>> emitting body is stationary RELATIVE to the ground (the second body). If
>>>> the emitting body is on a moving platform (moving at 20 mph RELATIVE to
>>>> the ground), then the emitting body is moving.
>>>>
>>>> If you do not have a reference, the state of motiom of a body can not be defined.
>>>
>>> No, Einstein was NOT talking about either one of those two conditions.
>>> He was stating that light is emitted at c REGARDLESS of whether the
>>> emitter is moving or stationary. In other words: Light is ALWAYS EMITTED AT c.
>>> PERIOD.
>> Nope, Ed, that’s not what it says.
>>
>> It says that an observer who is measuring the speed of light will measure
>> that speed to be c, regardless whether the emitter is stationary relative
>> to the observer, or whether the emitter is moving relative to the observer.
>
> Nope. That is you twisting things to fit your mistaken beliefs.

I’m sorry, Ed, but the only one who is twisting things here is you.

Just to put some emphasis on this point, Einstein lived 50 years past the
publication of this article. He therefore had 50 years to assess whether
his peers in the professional physics community were correctly
understanding what he was saying. What it is that I wrote is what
professional physicists, all of Einstein’s peers, understood by the
statements in a paper aimed at that community of peers.

You, on the other hand, are saying that YOU, who are NOT qualified to be a
member of the intended audience of that paper, are the one that is
correctly understanding Einstein and that Einstein’s peers did NOT
understand him correctly. And moreover, you are saying that for 50 years,
Einstein did not detect that his peers (with whom he was in constant
contact and communication) did not understand him correctly.

Now ask yourself, Ed, whether this is a truly viable claim you are making.

>
> The ONLY observer in the postulate is the EMITTER. The postulate says
> nothing about any other observers. Plus, the postulate does not work
> for other observers.
>
>> This also means, as a directly corollary, that if you have a single source
>> and there two different observers, where one observer is stationary
>> relative to the emitter and the other observer is moving relative to the
>> emitter, then both observers will measure the speed of light from that
>> source to be c.
>
> FALSE. Radar guns demonstrate that guns EMIT photons at c, but the
> target (outside observer) receives the photons at c+v or c-v.
>
> Other experiments show the same thing.
>
> Ed
>

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

On Thursday, 31 March 2022 at 18:56:03 UTC+2, bodk...@gmail.com wrote:

> Ed, just to make a small point here: jotting down what a postulate says,
> from some source you looked up, doesn’t mean much if you don’t know what
> the words mean.

To know that you must be a skilled woodworker.

Maciej Wozniak <maluwozniak@gmail.com> wrote:
> On Thursday, 31 March 2022 at 18:56:03 UTC+2, bodk...@gmail.com wrote:
>
>> Ed, just to make a small point here: jotting down what a postulate says,
>> from some source you looked up, doesn’t mean much if you don’t know what
>> the words mean.
>
> To know that you must be a skilled woodworker.
>

Nah. What it does require is reading the works of physicists, because it’s
language devised by them for purpose. Whether you don’t care for it is
irrelevant. If you don’t want to discuss physics intelligently, then
there’s absolutely no pressure to learn any physics. If you do want to
discuss physics intelligently, though, it’s going to be a requirement.

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

On 3/30/2022 7:39 PM, Richard Hachel wrote:
> Le 30/03/2022 à 22:27, Michael Moroney a écrit :
>
>> That's impossible, since when A sees B's clock ticking slower due to
>> motion, B sees A's clock ticking slower.  This is impossible to
>> resolve from any actual slower ticking by any clock, but in SR it's
>> possible since it is a geometric effect, and these aren't the same
>> measurements anyway.
>
> That's absolutely correct.
>
> This is called the relativity of chronotropy.
>
No, it is not. Skip the made-up words.

On Thursday, 31 March 2022 at 20:52:21 UTC+2, bodk...@gmail.com wrote:
> Maciej Wozniak <maluw...@gmail.com> wrote:
> > On Thursday, 31 March 2022 at 18:56:03 UTC+2, bodk...@gmail.com wrote:
> >
> >> Ed, just to make a small point here: jotting down what a postulate says,
> >> from some source you looked up, doesn’t mean much if you don’t know what
> >> the words mean.
> >
> > To know that you must be a skilled woodworker.
> >
> Nah. What it does require is reading the works of physicists, because it’s
> language devised by them for purpose.

For the purpose of brainwashing new generations
of the morons like themself; sure. But that no way
means they know what the words mean. Sorry.

> Whether you don’t care for it is
> irrelevant. If you don’t want to discuss physics intelligently, then
> there’s absolutely no pressure to learn any physics. If you do want to
> discuss physics intelligently, though, it’s going to be a requirement.

Well, you're an idiot, sure, but I think you're still able to
guess how much I care for your requirements.

On 3/31/2022 12:41 PM, Ed Lake wrote:
> On Wednesday, March 30, 2022 at 9:03:13 PM UTC-5, rotchm wrote:
>> On Wednesday, March 30, 2022 at 5:03:11 PM UTC-4, wrote:
>>> On Wednesday, March 30, 2022 at 12:38:43 PM UTC-5, Paparios wrote:
>>
>>> There is no second body in the first quote.
>> Yes there is. See below.
>>> All it says is that "light is always
>>> propagated in empty space with a definite velocity c which is independent
>>> of the state of motion of the emitting body." NO SECOND BODY.
>> Consider "Light is always propagated in empty space with a definite velocity c."
>> Just that, means that there is someone (something) measuring the speed of light, and that someone is getting the result c.
>> To declare a velocity, implicitly means there is an "observer".
>> Do you agree that the above sentence means/imply that? (to this point, it's just a question of English language).
>
> We can ASSUME there is an "observer," since without an "observer" we
> see and know and observe nothing.

And that observer observes "Light is always propagated in empty space
with a definite velocity c." Doesn't "Light is always propagated in
empty space with a definite velocity c." mean light is always observed at c?
>
>>
>> Now, adding to that sentence "which is independent of the state of motion of the emitting body." does not change the first clause.
>> In fact, "which is independent of the state of motion of the emitting body." is redundant, since just
>> "Light is always propagated in empty space with a definite velocity c." means that no matter who measures it, they will get c, be it the emitting body, or some other body (another observer). This is just a matter of the logic of the English language, the meaning of the words used.
>
> TOTAL NONSENSE!!!!!!!!!!!!!! ONLY THE EMITTER will measure the light to travel at c.

Your opinion is irrelevant.

> You are twisting things to fit your mistaken beliefs. The quote CLEARLY says
> NOTHING about what other observers will see.

The quote CLEARLY states "Light is always propagated in empty space with
a definite velocity c." You agreed that there must be an observer to
observe "Light is always propagated in empty space with a definite
velocity c.", correct?

> And we know from experiments that
> a moving observer will NOT see oncoming light as traveling at c.

Nope, we know from experiments that ALL observers observe light moving
at c. Remember, this was known BEFORE Einstein came along. Physicists
puzzled over the constant speed of light, and kept trying to tweak the
ether theories to account for this.

> The light will arrive
> at c+v where v is the speed of the observer.

Nope. The speed of light from stars in the ecliptic plane are unaffected
by earth's orbital motion.

> That is the PRINCIPLE BEHIND RADAR GUNS.
>
Your opinion on how radar guns work is irrelevant.

On Thursday, 31 March 2022 at 21:56:40 UTC+2, Michael Moroney wrote:

> And that observer observes "Light is always propagated in empty space
> with a definite velocity c."

Stupid Mike, even your idiot guru was unable to stick to this
nonsense for a long time and his GR shit had to abandon it.

> Nope, we know from experiments that ALL observers observe light moving
> at c.

No, stupid Mike, I don't, for instance.

> Remember, this was known BEFORE Einstein came along.

Remember, only such an idiot can believe such an impudent
lie.

Maciej Wozniak <maluwozniak@gmail.com> wrote:
> On Thursday, 31 March 2022 at 20:52:21 UTC+2, bodk...@gmail.com wrote:
>> Maciej Wozniak <maluw...@gmail.com> wrote:
>>> On Thursday, 31 March 2022 at 18:56:03 UTC+2, bodk...@gmail.com wrote:
>>>
>>>> Ed, just to make a small point here: jotting down what a postulate says,
>>>> from some source you looked up, doesn’t mean much if you don’t know what
>>>> the words mean.
>>>
>>> To know that you must be a skilled woodworker.
>>>
>> Nah. What it does require is reading the works of physicists, because it’s
>> language devised by them for purpose.
>
> For the purpose of brainwashing new generations
> of the morons like themself; sure. But that no way
> means they know what the words mean. Sorry.

Of course it does. Jargon is created by the members of the community for
their internal communication. What the world outside that community uses is
irrelevant to that, and they don’t have to communicate with the physics
community if they don’t want to.

>
>> Whether you don’t care for it is
>> irrelevant. If you don’t want to discuss physics intelligently, then
>> there’s absolutely no pressure to learn any physics. If you do want to
>> discuss physics intelligently, though, it’s going to be a requirement.
>
> Well, you're an idiot, sure, but I think you're still able to
> guess how much I care for your requirements.
>

Well, since you are not part of the physics community, they don’t care what
you think anyway. So that’s fine. You won’t communicate intelligently about
physics because you don’t know physics language and that’s just dandy.

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

On Thursday, March 31, 2022 at 11:56:03 AM UTC-4, det...@outlook.com wrote:
> On Wednesday, March 30, 2022 at 4:55:10 PM UTC-5, Paparios wrote:

> > The light coming from stars arrives at the observatories at speed c...
> Nonsense. Light coming from stars arrives at c+v or c-v depending upon
> the earth's motion v.

No, that is not true. The speed of the light from many stars has been measured. In every instance the speed of all those photons, of all that light, always gave the same value of C.

On Thursday, March 31, 2022 at 12:41:02 PM UTC-4, det...@outlook.com wrote:
> On Wednesday, March 30, 2022 at 9:03:13 PM UTC-5, rotchm wrote:

> > To declare a velocity, implicitly means there is an "observer".
> > Do you agree that the above sentence means/imply that? (to this point, it's just a question of English language).

> We can ASSUME there is an "observer," since without an "observer" we
> see and know and observe nothing.

OK. So you agree that to do physics, to do actual measurements, we need an "observer"...right?
So when we see sentences as " the speed is...", there is implicitly and observer, right?
In other words, we need a reference frame (some may call it a coordinate system).
Are you aware that "observer" and "reference frame" are synonyms (in physics and especially in relativity)?

> > Now, adding to that sentence "which is independent of the state of motion of the emitting body." does not change the first clause.

Agree or not?

> > In fact, "which is independent of the state of motion of the emitting body." is redundant, since just
> > "Light is always propagated in empty space with a definite velocity c." means that no matter who measures it,
> > they will get c, be it the emitting body, or some other body (another observer). This is just a matter of the
> > logic of the English language, the meaning of the words used.

> TOTAL NONSENSE!!!!!!!!!!!!!!

Okay, so the problem here is one language. You do not agree or interpret what Einstein wrote as the way we understand or interpret it.
This is why I am trying to take a step back, and use simpler sentences.

> The quote CLEARLY says
> NOTHING about what other observers will see.

It doesn't need to be that specific, since it is obvious to the intended readers but that is what was meant.
And as a proof of that, if you read the rest of Einstein's work, you will see that he does specify that it is independent of The Observers.

> And we know from experiments that
> a moving observer will NOT see oncoming light as traveling at c.

That is untrue. Actual experiments show otherwise. Are you now a reality denier? That you deny the results of peer-reviewed experiments and papers?

On Thursday, March 31, 2022 at 12:55:10 PM UTC-4, det...@outlook.com wrote:
> On Thursday, March 31, 2022 at 11:46:24 AM UTC-5, bodk...@gmail.com wrote:

> > It says that an observer who is measuring the speed of light will measure
> > that speed to be c, regardless whether the emitter is stationary relative
> > to the observer, or whether the emitter is moving relative to the observer.
> Nope. That is you twisting things to fit your mistaken beliefs.

Again, it's your understanding of what Einstein wrote, versus everyone else's common understanding.
Do you agree to this?

If so, ask yourself why do we all agree to a common understanding, and you do not.
And does this imply that we are all wrong and you are right? Or that perhaps we are all right and you are wrong?
And one step further, how can we figure out who is right?

Is it possible that, what someone writes, be ambiguous?
Is it possible not what E wrote, be ambiguous?
And if it is ambiguous, how can one figure out what was the intended meaning?

On March 30, rotchm wrote:
> "Light is always propagated in empty space with a definite velocity c."
> means that no matter who measures it, they will get c, be it the emitting
> body, or some other body. This is just a matter of the logic of the English language

"A wave is always propagated in calm water with a definite velocity d."
means that no matter who measures it, they will get d, be it the emitting
body, or some other body. This is just a matter of the logic of the English language.

--
Rich

On Thursday, March 31, 2022 at 4:04:36 PM UTC-5, rotchm wrote:
> On Thursday, March 31, 2022 at 12:41:02 PM UTC-4, wrote:
> > On Wednesday, March 30, 2022 at 9:03:13 PM UTC-5, rotchm wrote:
>
> > > To declare a velocity, implicitly means there is an "observer".
> > > Do you agree that the above sentence means/imply that? (to this point, it's just a question of English language).
>
> > We can ASSUME there is an "observer," since without an "observer" we
> > see and know and observe nothing.
> OK. So you agree that to do physics, to do actual measurements, we need an "observer"...right?
> So when we see sentences as " the speed is...", there is implicitly and observer, right?

Okay, I think I'm done posting here for awhile. We're just arguing over
words and phrasing.

I never should have said that you need an "observer" to see an event.
There are countless "events" that happen in the universe without any
observer there to SEE them.

Einstein's Second Postulate does NOT involve any observer. All it says is
"light is always propagated in empty space with a definite velocity c which
is independent of the state of motion of the emitting body."

That is true and happens whether there is anyone around to see it happen
or not. When you add an observer to the situation, you have to state where
the observer is located. If the observer is located with the emitter, then the
photon will travel at c away from that observer. If the observer is somewhere
else, then what the observer will see (and measure) depends upon a lot of
factors.

> > And we know from experiments that
> > a moving observer will NOT see oncoming light as traveling at c.
> That is untrue. Actual experiments show otherwise. Are you now a reality denier? That you deny the results of peer-reviewed experiments and papers?

NAME THE EXPERIMENTS!

Here is a list of experiments which say what I just said:
http://www.ed-lake.com/Variable-Speed-of-Light-Experiments.html

Ed