Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- From: "Androcles" <Androcles@ MyPlace.org>
- Date: Mon, 04 Jul 2005 23:59:44 GMT
"bz" <bz+sp@xxxxxxxxxxxxxxxxxxxx> wrote in message
news:Xns9689588D98886WQAHBGMXSZHVspammote@xxxxxxxxxxxxxxxxx
> "Androcles" <Androcles@ MyPlace.org> wrote in
> news:h4%xe.105275$Vj3.46075
> @fe2.news.blueyonder.co.uk:
>
>>
>> "bz" <bz+sp@xxxxxxxxxxxxxxxxxxxx> wrote in message
>> news:Xns96889858C4E94WQAHBGMXSZHVspammote@xxxxxxxxxxxxxxxxx
>>> "Androcles" <Androcles@ MyPlace.org> wrote in
>>> news:UeWxe.696$d75.627@xxxxxxxxxxxxxxxxxxxxxxxxx:
>>>
>>>>
>>>> "bz" <bz+sp@xxxxxxxxxxxxxxxxxxxx> wrote in message
>>>> news:Xns9687EDE449726WQAHBGMXSZHVspammote@xxxxxxxxxxxxxxxxx
>>>>> "Arthur Dent" <jp006t2227@xxxxxxxxxxxxxxxx> wrote in
>>>>> news:1120334272.118942.112390@xxxxxxxxxxxxxxxxxxxxxxxxxxxx:
>>>>>
>>>>>>
>>>>>>
>>>>>> bz wrote:
>>>>>>> "Arthur Dent" <jp006t2227@xxxxxxxxxxxxxxxx> wrote in
>>>>>>> news:1120291898.963571.290740@xxxxxxxxxxxxxxxxxxxxxxxxxxxx:
>>>>>>>
>>>>>>> >> > Just speed up the light, then :-)
>>>>>>> >>
>>>>>>> >> kinda hard to do, at will, otherwise there would be no point
>>>>>>> >> in
>>>>>>> >> our
>>>>>>> >> discussion.
>>>>>>> >
>>>>>>> > Actually it's as simple as bat and ball, at least in
>>>>>>> > principle,
>>>>>>> > but
>>>>>>> > trying to do it in air is like playing tennis underwater.
>>>>>>>
>>>>>>> I am afraid that would be 'kinda a drag'. Photons don't seem to
>>>>>>> slow
>>>>>>> down while passing through vacuum [and not much through air].
>>>>>>
>>>>>> Enough air and even brilliant sunshine turns red.
>>>>>
>>>>> Because blue light is scattered by our atmosphere. [thats why the
>>>>> sky
>>>>> is
>>>>> blue]
>>>> It isn't scattered in space, that's why the sky is black
>>>
>>> At night, the sky is microwave colored. The distant echo of the big
>>> bang.
>>>
>> If you had radiation from some supposed "Big Bang", it would either
>> have
>> occurred right here where we are
>
> It does. It is just hard to see here. It is here, it is there, it is
> everywhere.
We are at the exact place where the original explosion occurred, the
dead centre of the Universe? Wow!
(If ever I've heard a subjective point of view, that one takes the
cream. The universe is geocentric after all.)
>> or it would have a direction.
>
> It is essentially isotropic.
>
>> There is
>> no evidence to support a big bang.
>
> There are a lot of scientists that would disagree with you.
>
>> The CMBR is BACKGROUND radiation and
>> it is everywhere. Red shift is NOT evidence of an expanding universe,
>> it
>> is evidence that the FURTHER AWAY a source of light is, the redder
>> the
>> shift, and that is ALL that it is.
>
> I wish you were right. Personally, I like the tired light theory, but
> it
> fails some important tests.
Only because you base those tests on a theory that also fails some
important tests. The empirical data is: red shift is a function of
distance.
Concluding red shift is ONLY a function of velocity leads to the
conclusion
that the velocity is a function of distance, that the further away the
emission comes from, the faster the source is moving away. That implies
acceleration, a kind of negative gravity.
> I would like to say that the combined
> gravitational effects have slowed down the light by just the right
> amount to
> give the observed red shift.
We are at the exact centre of the Universe, by your isotropic CMBR. The
further away a galaxy is, the greater its velocity. Being at the centre
of the Universe, the combined gravity of the rest of the Universe is
concentrated right here and all the light we see from distant sources
should be accelerating toward us and BLUE shifted. I don't like your
theory very much, and if a lot of other scientists agree with you I
don't like their theories very much either, however many lots they are.
BTW, I'm discussing the subject with you, not with lots of other
scientists. Lots of other scientists think Einstein was right, but I
don't. Lots of other scientists have been wrong ever since Copernicus
showed lots of other scientists were wrong. Please don't invoke lots of
other scientists as your argument, it isn't convincing. Individuals make
discoveries, lots of other scientists cling to established and ancient
theory. Nature is not a democracy, she is a dictator, and she doesn't
care what lots of
other scientists think.
>
> Unfortunately, this would mean that there must be MUCH more mass
> behind the
> light than is in front of the light (because it GAINS energy falling
> TOWARD
> mass. That would mean that we have to be 'in a thin spot' of the
> universe.
> Since the matter seems to be 'more or less' the same in all
> directions, the
> theory of tired light must fall.
Seems to me that we'd have to be in thin spot in the universe with the
mass concentrated at the rim. Why doesn't the mass behind us balance the
mass ahead?
>
> In two dimensional analogy, if the enemy had to climb to reach us,
> from all
> directions, then that means we must occupy the high ground. But that
> would
> mean that the universe is not homogenous on a large scale.
Fine. It wasn't me that claimed the CMBR is evidence of the big bang.
It's your high ground.
>
>> If Planck's equation E = hf has any validity, then energy is directly
>> proportional to the frequency. The energy from any given source is
>> finite and the energy we perceive is a function of the inverse square
>> law. The greater the distance, the greater the distribution of
>> energy,
>> the lower the frequency.
>> Therefore we EXPECT light to be red-shifted as a function of
>> distance.
>>
>>>> , why there is
>>>> no aether, why there is no "one atom per cc" as Sue thinks because
>>>> it
>>>> said so on a web page. :-)
>>>> As I said, BaT isn't a friction model, whereas your blue sky is.
>>>
>>> Sounds like a 'blue sky' pronouncement.
>>>
>>>>>>> Once they do slow down for the media, they don't continue to
>>>>>>> lose
>>>>>>> velocity, which they should do if BaT were valid.
>>>>>>
>>>>>> Whether you were right or wrong, it would have nothing to do with
>>>>>> the
>>>>>> speed of light in nothing.
>>>>>> The ballistic theory of light isn't a friction theory.
>>>>>
>>>>> The proposal was that light is slowed by passing near matter.
>>>>
>>>> No it wasn't.
>>>
>>> Henri's proposal was that light is slowed by passing near matter.
>> What does Henri know?
>> BaT is purely and simply the principle of relativity, as Einstein
>> calls
>> his first postulate.
> [quote]
> the same laws of electrodynamics and optics will be valid for all
> frames of
> reference for which the equations of mechanics hold good.
> [unquote]
[quote]
Examples of this sort....
[unquote]
and the example he gives is that of Galilean relativity,
[quote]
Take, for example, the reciprocal electrodynamic action of a magnet and
a conductor.
[unquote]
> He does not say what those laws are.
Of course not, he's about to deny Galilean relativity (being the vector
addition of velocities), in favour of his second postulate and his
personal
definition of time. He doesn't dare say what those laws are at this
stage in his development.
[quote]
Thus the law of the parallelogram of velocities is valid according to
our theory only to a first approximation.
[unquote]
> He just says that they will hold for all
> frames of reference for which the equations of machanics hold.
Galilean relativity holds good for mechanics and the vector addition
of velocities, as given by the example of the reciprocal electrodynamic
action of the magnet and conductor. He later says the first postulate is
only an approximation. How can a law be both correct and only an
approximation?
When the magnet moves past the conductor at c, what happens?
> He follows this closely with his second postulate.
> [quote]
> 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.
> [unquote]
For which there is no evidence, only a subjective point of view.
MMX uses air as the medium, so that wouldn't apply anyway.
Shooting the moon with a laser from a source that is moving
relative to the moon hasn't been done yet.
His first and second postulates are irreconcilable, and his attempt
at reconcilation is to reject the first as "only an approximation".
BaT hold the first true and rejects the second as only an approximation.
The evidence for that is doppler shift, which Einstein has to modify.
As I've told you before, to derive the Lorentz transforms he makes USE
of the vector addition of velocities in the form x'/(c-v) and x'/(c+v)
(which are only the one-way first approximations for the time of flight
of the ray that he says are equal) and then claims they can be used to
show that the vector addition of velocities is only a first
approximation. That's illogical and circular.
Make the time of flight = x'/(c-v)/(1-v/c) as he claims it should be,
now no longer an approximation, and you cannot derive the Lorentz
transforms.
>>>>> BaT light has no minimum velocity.
>>>>> It would continue to slow until it stopped moving.
>>>>
>>>> Light leaving water and entering air is sped up, not slowed down.
>>>
>>> It goes at c after leaving the water.
>> No it doesn't, it goes at c/n.
>
> Assuming a different n than for water. n_air, rather than n_water.
Right (well, almost, see below).
> Why doesn't it go at c'=(c+v)/n, like it was supposedly going before
> it
> entered the water.
The definition of n is found for TWO media, not one. All too often
we talk about the refractive index of water with air taken as the other
medium by default.
The refraction of light at an oil-water interface doesn't have a
refractive index of n_oil or of n_water. It is n_oil/water.
http://scienceworld.wolfram.com/physics/SnellsLaw.html
>>> Not at c'=c+v.
>>
>> Yes it does, all velocities are relative.
>> The velocity of light in water is relative to the shark.
>> Proof:
>> A shark swims toward an underwater source of light.
>> Relative to the water, the velocity of the shark is v.
>> It takes less time for the light to reach the shark than it does
>> to reach the reef the shark left, given that the speed of light in
>> water
>> is finite.
>
> That just shows that the time for the light to travel depends on the
> distance. Proves nothing wrt velocity.
The time for the light to travel from source to shark is less than
the time it takes to travel from shark to source, the shark moves as
the light moves.
Light moves D, shark moves d.
Source <-----------D------------->|<--d--> Shark/reef.
Light meets shark at >|<.
Velocity = distance/time.
(D+d)/t = D/t+d/t = c+v.
OR, if you want to do this in a vacuum and have the shark's watch
slow down,
D/t + d/tau ~= c+v.
Notice that if tau = 0 relative to t (the clock slowed to zero because
of the high speed of shark, tau = t* sqrt( 1-c^2/c^2), d > 0, v is
infinite. The shark moves a distance d at high speed in zero time.
>>
>>> Why would it speed
>>> back up if c'=c+v was operative?
>> The speed of light in a medium is c/n. I don't pretend to know why.
>> "Why?" is cause for investigation.
>
> Science doesn't answer 'why' questions. It answers 'how' questions. I
> shouldn't have asked 'why'.
Then "How?" is cause for investigation, but we'll never get to solve it
if we continue with Einstein's gibberish.
> What I was trying to find out is why you think that the light would
> speed
> back up. Should it speed up to c+v or just c? If just c, what happens
> to the
> excess energy?
>
> Suppose a photon from a light moving at .999 c has the velocity
> c'=c+.999 or
> 1.999 c. It passes through my eyeglasses.
More like your sun-visor as you spacewalk. The photon speed has already
dropped to c/n in air before it reaches your eyeglass.
It slows down to c/n in the glass.
Yep. Then back up to c/n_air on leaving the glass and going to your eye
inside your helmet, then c/n_cornea.
> Its path should get bent a lot more than a photon of the same color
> that is
> just moving at c.
It won't be the same colour as a photon of the same frequency in vacuum.
It will have a LONGER wavelength. 1.999 times longer.
Then when it hit the glass, the wavelength will suddenly shorten and
you'll perceive a higher frequency. The NUMBER of wave crests will not
change. they all have to count, but will appear to arrive faster. Now
you have blue shift, as expected.
1.999c = (1.999 *lambda) * frequency
1c = (lambda / 1.999) * (frequency * 1.999)
It will be out of focus.
Yep. Wrong colour, too. The wavelength has doubled.
> But what happens when it emerges
> from the glass? Is it moving at 1.999c or c?
c/n_air, or, if entering vacuum, c. The original
frequency will have changed.
That's a lot of the problem with c being thought as
constant. The speed changes instantaneously
right in your cornea or the diffraction grating just before you see it.
>
> If there are c+v photons, a refracting telescope should see a much
> different
> picture than a telescope that uses front surface mirrors ONLY to
> handle the
> light.
Sure, but since v<<c, then c+v is (to a first approximation), c.
It's just a matter of deciding which of Einstein's two incompatible
postulates are the approximation.
> If we look at a Androcoles/Henri Cepheid with both telescopes (from
> the ISS),
> we should see very different views of the Cepheid. The mirror scope
> should
> focus all photons at the same time. The refractor should show
> different focii
> for photons of different speeds.
Sure, but since v<<c, v+c is, to a first approximation, c. How different
is "very"?
>>> It is because it travels at c in the water also.
>>
>> Relative to the water, it travels at c/n.
>
> That is 'c' for water. I was using c the way mach is used wrt sound.
Ok.
>
> Mach varies with the altitude and temperature of the air(or other
> medium).
>
>> Relative to the shark, c/n +v.
>> ALL velocities are relative.
>
> Apparently all light travels at c/n relative to every apparatus used
> to
> measure light velocity.
Until you get above atmosphere, what apparatus are you talking about?
The apparatus I use is the spectrometer.
>
>>> It just was slowed down by
>>> absorbtion/re-emission as it traveled along its way. Between
>>> absorbtion/emission events, it travels at c.
>> When photon hits an atom, it kicks an electron into a higher energy
>> state
>> and stops dead.
>
> If it has the right energy. Those jumps are quatitized.
Correct. So we'll know when absorption and re-emission has taken place,
and it isn't "along its way". If it doesn't have the right energy, there
is no absorption and reemission and that's one more myth dispensed with.
>
>> It may even ionize.
>
> If it has enough energy.
Correct. By now the whole of space should be full of ionized atoms
in 1 cm cubes, swimming in a sea of electrons, there's been x and gamma
radiation in uncountable photons reaching us for a few million years.
:-)
>
>> The electron will then emit one or
>> more photons as returns to its ground state, and is not intantaneous.
>
> This is true for ionization and for quantum leaps.
>
>> The direction the photon(s) is/are emitted is NOT known. Absorption
>> and
>> re-emission with the light still going in the same direction with the
>> same frequency isn't sensible.
>
> This is true for quantum leaps, atomic absorbtion/reemission.
Since you already know this, why did you raise the spectre of absorption
and re-emission? We don't see it, it doesn't happen.
> It is NOT true for the propagation of most light in transparent media.
>
> [quote http://www.answers.com/topic/photon-2]
> In a material,
Were are not really discussing media, we are discussing Einstein's
crackpot idea of light being always c in a vacuum, as CLAIMED measured.
> photons couple to the excitations of the medium and
> behave
> differently. These excitations can often be described as
> quasi-particles
> (such as phonons and excitons); that is, as quantized wave- or
> particle-like
> entities propagating though the matter. "Coupling" means here that
> photons
> can transform into these excitations (that is, the photon gets
> absorbed and
> medium excited, involving the creation of a quasi-particle) and vice
> versa
> (the quasi-particle transforms back into a photon, or the medium
> relaxes by
> re-emitting the energy as a photon). However, as these transformations
> are
> only possibilities, they are not bound to happen and what actually
> propagates
> through the medium is a polariton; that is, a quantum-mechanical
> superposition of the energy quantum being a photon and of it being one
> of the
> quasi-particle matter excitations.
> [unquote]
>
>
>> Scattering is.
>> (Why the sky is blue.)
>>
>>
>>> This seems consistent with the very slow light experiments.
>>> http://www.news.harvard.edu/gazette/1999/02.18/light.html
>>> http://www.msnbc.com/news/242698.asp?cp1=1
>>>
>>>>>>> They certainly don't stop. Tennis balls do.
>>>>>>
>>>>>> The medium governs the speed of light both in the medium and
>>>>>> relative
>>>>>> to the medium. Move the medium at v and the speed of light is
>>>>>> added
>>>>>> to
>>>>>> the speed of the medium, v, and becomes c/n+v.
>>>>>> You've got three choices.
>>>>>> 1) The speed of light is source dependent.
>>>>>> 2) the speed of light is observer dependent.
>>>>>> 3) the speed of light is medium dependent.
>>>
>>> These were not intended as choices. They were corrections to the
>>> above
>>> statements. They ALL apply.
>>>
>>>>> 1) the speed of light is independent of source.
>>>>> 2) the speed of light is independent of observer.
>>>>> 3) the speed of light is medium dependent.
>>>>> 4) there is no medium in a vacuum.
>>>>
>>>> Your 4) is a superfluous statement, not a choice, and vacuum is by
>>>> definition free of any matter whatsoever and isn't an option that
>>>> excludes the other 3.
>>>
>>> I am sorry I wasn't clear, they were corrections, not choices.
>>
>> I was very clear. You have three choices, and I do not accept your
>> "corrections".
>
> Why must I choose between your three doors?
>
> I am afraid that light doesn't care what choices you give me.
>
>> The speed of light (c/n) is medium dependent except in
>> the absence of a medium, in which case it is source dependent. It is
>> c/n +v with respect to an observer. n = 1 in a vacuum.
>
> The problem is that your three choices leave out Einsteins postulate,
> entirely.
Which one? The first, which is just an approximation, or the second
which is exact (supposedly)?
Why must I choose one of YOUR options rather than
> Einstein's?
Because that is all the choices there are. There is nothing in a vacuum
to serve as a reference and all velocities are relative to something.
>
>>>> 3) takes care of MMX.
>>>>
>>>> That leaves us with your 1) and 2) .
>>>> They are not mutually exclusive. Both could be valid.
>>>> That makes it difficult to reach any kind of conclusion.
>>>
>>> ALL of mine apply [per SR/GR/EEP]
>>>>> 1) the speed of light is independent of source.
>>
>> There is no evidence for that.
>
> There is no evidence against it, either.
Yes there is, red and blue shift.
> All evidence, to date, is consistent with this [Einsteins second
> postulate].
Red and blue shift are not consistent with Einstein's second postulate,
but more importantly his first postulate is not consistent with his
second.
The laws of mechanics hold good (even in non-inertial frames).
>
> There is no unambiguous evidence for c'=c+v either.
Agreed, it is possible to make data appear ambiguous, but only by
invoking impossibilities like time dilation or aether.
> There is evidence that IF c'=c+vk, k must be very small.
No there isn't. The introduction of k is pure obfuscation, typical of
the faithful relativist. c' = ck + v and k is very close to one.
>> A medium will invalidate it, but the
>> issue is what 'c' is relative to in the absence of a medium.
>
> Light moves at c wrt source and wrt destination as far as all
> experiments
> performed to date.
No experiments with a source moving along at high v in a vacuum have
been
performed to date. That's why such an experiment has been proposed, to
whit, shoot the moon with a laser from the ISS.
This is consistent will all available data from all
> sources.
Consistent with none at all, you have no available data.
>>>>> 2) the speed of light is independent of observer.
>>
>> Of course it is. Redshift/blueshift easily demonstrates it, with or
>> without a medium. It is always c/n +v with respect to the observer.
>
> With the removal of the 'v' term, I would agree.
Oh, so the observer isn't allowed to move?
> Experiments seem to indicate that if c'=c/n+vk, the k must be very
> small.
Assertion carries no weight.
>>>>> 3) the speed of light is medium dependent.
>> Yep.
>>
>>>>> 4) there is no medium in a vacuum.
>> That defines "vacuum". Nothing in it.
>
> right. Just making clear that I don't believe in LET.
Good. Then you are reduced to two choices for the speed of light
in a vacuum, c relative to source or c relative to observer, because we
can devise an experiment where that is all there is. The source, the
observer and the light, a tape measure and a stopwatch.
>>>
>>>> My way of thinking:
>>>> 1) The way to our destination is to turn left at the next
>>>> T-junction.
>>>> 2) The way to our destination is to turn right at the next
>>>> T-junction.
>>>>
>>>> Your way of thinking:
>>> ....you misread because I was not clear.
>>>
>>>> Try to formulate options that are relevant and will lead to a
>>>> conclusion.
>>>> You've got THREE choices.
>>>> 1) The speed of light is source dependent.
>>>> 2) the speed of light is observer dependent.
>>>> 3) the speed of light is medium dependent.
>>>
>>> I don't agree with 1. I restated it.
>> Ok. Tell me what governs the speed of light, c.
>> Not what it isn't relative too, but what it IS relative to.
>
> It is c, relative to every object that has rest mass.
So you assert. Where's your math to support it?
>
>>> I don't agree with 2. I restated it.
>>> Although 3 is true it doesn't apply to a vacuum.
>>> all the following apply:
>>> 1) the speed of light is independent of source. It is c wrt source
>>> 2) the speed of light is independent of observer. It is c wrt
>>> observer
>>> 3) the speed of light is medium dependent. It is c wrt medium
>>
>> Would you care to reread 1) and 3) as you have written them?
> See below.
>
>> 1) INdependent A, c wrt A.
>>> 1) the speed of light is independent of source. It is c wrt source
> your 1 and my 1 are indentical. Independent of motion of source.
> [not c'=c+v]
I fire a bullet from a moving gun, the speed of the bullet is dependent
on the speed of the gun. If I subsequently move the gun, then the speed
of the bullet becomes independent, but it certainly leaves the gun at
gunspeed
plus muzzle velocity. That's what I mean by c+v. Moving the gun may be
what you mean by independent.
>> 3) dependent B, c wrt B.
>>> 3) the speed of light is medium dependent. It is c wrt medium
> when moving through solid, liquid or gas [medium] the speed is
> dependent upon
> the medium. The speed is c wrt the medium.
>
> That is what I meant to say.
Ok, so now we are done with media.
>
>> Maybe it was a copy/paste error, I've done that myself sometimes.
>>
>>> 4) there is no medium in a vacuum. It is c wrt vacuum.
>> Nope. There is no reference for nothing.
>
> You are correct, I can't say 'it is c wrt vacuum'. Restated:
>
> 4) there is no [other] "medium" in a vacuum. The speed of light is
> c wrt
> every object when the 'medium' between the objects is the vacuum.
> [there is no aether].
I want something to support that, it looks like fiction to me.
The objects include the source and the observer, and the observer is
moving relative to the source.
[quote]
Thus the law of the parallelogram of velocities is valid according to
our theory only to a first approximation.
[unquote]
What Einstein calls the parallelogram of velocities I call the vector
addition of velocities, and it is at least approximately true. How are
you going to make
v vanish entirely? With time dilation? Make the observer's clock slow
down with increasing v?
Run directly at a source at c and it stops altogether?
[quote]
It follows from these results that to an observer approaching a source
of light with the velocity c, this source of light must appear of
infinite intensity.
[unquote]
Infinite intensity in no time.
If time stopped, the light would be unable to move at all.
[quote]
the velocity of light in our theory plays the part, physically, of an
infinitely great velocity.
[unquote]
"All the evidence to date", and "lots of scientists" agree, the speed of
light is finite and approximately 300,000 km/sec. "This is consistent
will all available data from all sources."
How's that for convincing you, when I use your own words?
Do you still believe the velocity of light is infinite? It is in
Einstein's theory.
When he says c he doesn't mean 300,000 km/sec, he means infinite.
That's why I consider him a crackpot.
>>>
>>>>>> In MMX all three apply since source, medium and observer are all
>>>>>> relatively at rest.
>>>>>
>>>>> If there were an aether, the medium would not have been at rest.
>>>>>
>>>>>> Take away the medium and you are down to two choices, the
>>>>>> subjective
>>>>>> speed of is light is c for you personally and speed of light is
>>>>>> objectively source dependent.
>>>>>
>>>>> SR/GR/EEP says "it ain't 'subjective'" and it is independent of
>>>>> source.
>>>>
>>>> Thieves usually plead not guilty when charged.
>>>
>>> Strawman and as an analogy has nothing to do with situation.
>>
>> It doesn't matter how much SR/GR/EEP CLAIMS not to be subjective,
>> guilty
>> as charged.
>
> Which 'subjective' do you mean? There doesn't appear to be a
> definition for
> physics. http://en.wikipedia.org/wiki/Subjective
>
> It sounds like you are not being objective.
The following are examples of subjective experiences:
a.. What the color green looks like to me;
b.. What a musical tone sounds like to me;
c.. What pleasure and pain feel like to me.
And their corresponding objective analogues:
a.. The green surface;
b.. The musical instrument producing oscillations in air;
c.. The things that induce pleasure or pain.
"The observer sees the speed of light is c for him" is subjective.
Objectively, we use the "law of the parallelogram of velocities", which
is NOT
an approximation.
>>>> I say that the speed of light being c WRT the observer is purely
>>>> subjective, by definition of subjective.
>>>
>>> Every measurement made, to date, says it is objectively true.
>>
>> When did anyone go into space and do the measurement?
>
> One doesn't have to go into space to measure the speed.
True, we can do it from the Doppler shift. However, since that is
ambiguous
to your model and mine, we need to shoot the moon and that means going
out into space to measure the speed of light by timing it over a fixed
distance.
> Many
> experiments have
> been made that should have shown different results if c'=c+v were
> valid.
You do love all this vague rhetoric to demonstrate your beliefs, don't
you?
Please learn to debate without talking about "many experiments". That
means nothing to me, I have no idea what experiments you are talking
about.
Give me a specific example, not some vague "many", and we'll discuss it.
>> That's why I proposed shooting the moon. The number of measurements,
>> to date, is precisely zero, I don't care how objective no
>> measurements
>> say they are.
>
> I have no objection to shooting the moon. However, many closer
> satellites are
> available, every day. They move at much higher velocities. There
> should be
> greater c'=c+v effects.
Oh, here we go with the "should be" again.
How many satellites do you know of that have a velocity in OUR direction
and don't pass their signal through atmosphere?
Of course the ISS has a much higher velocity relative to the moon, but
it has practically no velocity relative to an observer on Earth. You
could watch it moving overheard and take minutes from horizon to
horizon.
Heck, a geostationary satellite for communications and TV doesn't move
at all (in the frame of the Earth), you can point your dish at it, and
even a geosynchronous satellite only moves a few degrees a day
North/South.
>>>>>> We see red/blue shift, and there is no
>>>>>> aether.
>>>>>
>>>>> Agreed.
>>>
>>>> Good. So the amount of shift is dependent on the speed of the
>>>> source,
>>>> there is no aether so we can't use Doppler's f' = f.c/(c-v) (which
>>>> WOULD
>>>> hold for aether), that leaves Doppler's f' = f.(c+v)/c and the
>>>> speed
>>>> of
>>>> light is source dependent. Or maybe you think Doppler was wrong.
>>>
>>> I think the Einstein formulation of the doppler effect is correct.
>>
>> Really... As I said, I can't reason against faith.
>
> I place my faith in no theory.
So why have you claimed above that you believe
"It is c, relative to every object that has rest mass."
If that isn't faith, I don't know what else to call it.
>> You ducked out of
>> analyzing Einstein's paper with me, said you'd have to look at the
>> math.
>
> I am still reading his book and looking at the math there and in his
> paper.
> Want to go through it with me, step by step?
I don't know what book you mean and I wouldn't have a copy unless it is
online, but his paper, sure, I'd be glad to, right up until you make an
unsubstantiated assertion and won't retract.
>> Now you think it's correct. If that isn't blind faith, show your
>> reasoning. I want to know where the sqrt(1-v^2/c^2) was found before
>> it
>> was applied to modify Doppler.
>
> it comes from the equations of transformation that he developed
> earlier, that
> match the lorentz transforms.
Yes, I know. I'm challenging the derivation of the Lorentz transforms,
without which his Doppler argument fails along with the rest of his
theory.
>
> It represents the lorentz/einstein contraction of anything parallel to
> the
> direction of motion of the FoR.
>
> Further, deponent knowest not.
>
>>> The doppler effect depends on the RELATIVE velocity between source
>>> and
>>> observer.
>>
>> Too right it does, but Einstein wants c in the vacuum as though it
>> were
>> a medium. That's his second postulate.
>
> His second postulate "light is always propagated in empty space with a
> definite velocity c which is independent of the state of motion of the
> emitting body" says nothing about a medium. He made no assumption of a
> medium. To the contrary. He assumed there was NO medium. He then
> showed that
> he could develop the same transforms, without a medium, that Lorentz
> had
> derived by assuming a medium.
"In empty space" ,c.
All velocities are relative, so light's speed c is relative to the
"empty space". There is nothing in the empty space to refer to, except
aether. He is treating the empty space as he would a medium. Recall the
reciprocal electrodynamic action of the conductor and the magnet. Look
out the window of the aircraft, the world is moving past you. In empty
space, the empty space is moving past you. Relative to the photon the
empty space is whizzing past at c. Only there is nothing there to do the
whizzing.
As I said previously, he can't derive those transforms, not to the
satisfaction of a mathematician or scientist. He fails at the
high-school level.
Here's a little analysis of the LTs, inspired by McCullough.
It can save you trying to plow through Einstein's paper with me.
Sam, Joe, a mosquito and a ladder.
by Androcles
Much of this story is credited to Daryl McCullough, only the ladder
and the story was added by me. It explains the origins of Einstein's
Special Relativity scaled for those having difficulty grasping the
subject.
Scale 1 ft : 60,000 km
Sam and Joe are housepainters, and are walking along the street at 3 fps
in still air carrying a 32 ft long ladder between them, Joe leading the
way. Sam is carrying some paint cans and Joe has the brushes and
rollers.
At some point along their journey a mosquito named Albert buzzes past
Sam's ear. Sam swats at it, but drops a can of red paint as he does so.
Albert the mosquito flies along the ladder from Sam to Joe at a constant
speed
of 5 fps. When it reaches Joe, Joe also swats at it, but drops a paint
roller. Albert, still hungry but not liking the smell of Joe's cigar,
flies back along the ladder toward Sam, again with a constant speed of
5 fps in the still air. Upon reaching Sam, once again Sam tries to swat
the wee beastie but drops a can of green paint. He yells as the mosquito
bites him and this startles Joe, who drops a paint brush.
Now it's your turn. I'll give the answers further down, but take a
moment
to do the calculations for yourself.
1) How many seconds did it take for Albert to fly from Sam to Joe?
2) How many seconds did it take for Albert to fly from Joe to Sam?
3) How far is it between the red paint can and the roller?
4) How far is it between the green paint can and the roller?
(Answers below)
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
Assume the speed of the mosquito is c = 5 fps.
The speed of Sam and Joe is v = 3 fps, given.
We then must have a distance along the road for Joe of
32ft + vt, and for the mosquito, a distance of ct.
Solving for t,
ct = 32 + vt
ct - vt = 32
t(c-v) = 32
t = 32 /(c-v) = 32/(5 - 3) = 16 seconds
So the answer to Q.1) is 16 seconds.
The mosquito coming back is going to meet Sam going forward,
so it flies along the 32 feet of the ladder in time
t = 32/(c+v) = 32/8 = 4 seconds.
The answer to Q.2) is therefore 4 seconds.
The distance from the dropped red paint can to the dropped roller
is just ct, or 5 * 16 = 80 feet, so the answer to Q.3) is 80 ft.
Or we could do it by vt + 32 = 3 * 16 + 32 = 80, once again.
(Remember Joe had a 32 ft head start over the mosquito)
Coming back, Albert again flies at 5 fps but this time
for only 4 seconds, so it reaches the green paint can 20 feet
from the roller, which is the answer to Q.4)
So, as Sam sees it, Albert takes 16 seconds to reach Joe, flying at
5-3 = 2 fps, and 4 seconds to return, flying along the ladder at
5+3 = 8 fps.
Now we think like Einstein with his mosquito brain. Sam wants to know
when the mosquito reached Joe.
He isn't able to see the mosquito, its too small at 32 feet away,
so he guesses that since it went 32 ft each way, and took 20 seconds to
fly
away and back again, it must have reached Joe after 10 seconds = ½ of
20.
So we explain it carefully. First we label the red paint can "A" and the
dropped roller "B". We write:
If at the point A of space there is a clock, an observer called Sam at
the
red paint can will determine the time values of events in the immediate
proximity of the red paint can by finding the positions of the hands
which
are simultaneous with these events. If there is at the point B of space
another clock in all respects resembling the one at the red paint can,
it
is possible for an observer Joe at the dropped roller to determine the
time
values of events in the immediate neighbourhood of the roller at B. But
it
is not possible without further assumption to compare, in respect of
time,
an event at A with an event at the dropped roller, B. We have so far
defined only an "A time" and a "B time." We have not defined a common
"time" for the red paint can and the dropped roller, for the latter
cannot
be defined at all unless we establish by *definition* that the "time"
required by a mosquito to travel from the red paint can to the dropped
roller equals the "time" it requires to travel from B to the red paint
can,
A.
Note the *definition*. Remember this is hypothetical, not real. The
definition is very important.
Now, we want to do this algebraically, because tomorrow Joe and Sam
might
be carrying a different length of ladder, running at a different speed,
whatever, and we want a general solution.
So we write:
If we place x'=x-vt, it is clear that a point at rest in the system
ladder
must have a system of values x', y, z, independent of time.
What that means is the ladder's length is x', so that 32 = 80 - 3 *
16,
and doesn't change as time passes. Did you think it would? Well, we'll
have
to see. Maybe if we water it, it might grow.
According to Albert, we are to assume the speed of the mosquito is
independent of the speed of Sam (which is fair enough) and also we are
to
assume that the time for the mosquito to make the round trip (20
seconds)
when divided by 2 is equal to the time it took to reach Joe, 16 seconds,
by Albert's DEFINITION.
We don't know yet about the 16 seconds, we can only write it
algebraically
and pretend it is 10 seconds.
It is actually written as x'/(c-v) [or 32/(5-3) in real numbers].
Now we say:
>From the origin of system ladder (Sam's end) let a mosquito be emitted
at the time tau0 along the ladder to x' (Joe's end), and at the time
tau1
be reflected thence (that just means go back) to the origin of the
co-ordinates (which we are deliberately vague about as to whether we
mean Sam on the ladder or the red paint can), arriving there at the time
tau2; we then must have (don't you just love that phrase, "then must
have" ?)
½(tau0 + tau2) = tau1,
or ½([midmorning + 0] + [midmorning + 20]) = [midmorning + 16], which is
curious to say the least, since Sam and Joe could be doing this in the
late afternoon for all the difference it would make.
But ok, Einstein wanted to be complete, so I guess its fine.
But our hero and physics wizard isn't satisfied with this. Oh no, we
need
to include the length of the ladder as well, or we won't have any
spacetime
to prattle on about later so that people will see just how smart we are.
It is very important to include the length of the ladder into the
equation.
You'll see why later.
Here is Einstein's equation:
½[tau(0,0,0,t)+tau(0,0,0,t+x'/(c-v)+x'/(c+v))] = tau(x',0,0,t+x'/(c-v))
You can read about it at
http://www.fourmilab.ch/etexts/einstein/specrel/www/
(in Section 3)
Putting in the mosquito numbers,
½[tau(0,0,0,t)+tau(0,0,0,t+32/(5-3)+32/(5+3))] = tau(32,0,0,t+32/(5-3))
½[tau(0,0,0,t)+tau(0,0,0,t+20)] = tau(32,0,0,t+16)
In agreement with experience (gotta love that phrase!) clearly!
(0,0,0,t)
is pretty meaningless, and we can drop the "t+" since we really don't
care
if Sam and Joe are walking in the midmorning or late afternoon.
So, (by the vector addition of (0,0,0,0) + (0,0,0,20) !)
½ * tau(0,0,0,20) = tau(32,0,0,16).
Now do you see why we need to include the length of the ladder into the
evaluation of time? We can't just say ½ * 20 = 16 without it. Even my
grandson would say that wasn't right, and he's not learning algebra yet.
There's some differentiation by Einstein to make himself look smart and
important, he has to show off all his skills if not his common sense,
because "common sense is the collection of prejudices acquired by age
eighteen", or so he tells us, and he eventually arrives at
tau = (t-vx/c^2) / sqrt( 1 - v^2/c^2 )
xi = (x-vt) / sqrt( 1 - v^2/c^2 )
eta = y
zeta = z.
This is is the procedure so far:
1)
Define t = x'/(c-v) = x'/(c+v)
because the time for light to go from A to B equals the time it takes
to travel from B to A
2)
½[tau(0,0,0,t)+tau(0,0,0,t+x'/(c-v)+x'/(c+v))] = tau(x',0,0,t+x'/(c-v))
3)
½[1/(c-v)+1/(c+v)] * dtau/dt = dtau/dx' + 1/(c-v) * dtau/dt
4)
dtau/dx' + v/(c^2-v^2) * dtau/dt = 0
5)
tau = a * ( t - (vx' / (c^2-v^2)))
6)
tau = (t-vx/c^2) / sqr(1-v^2/c^2)
That is what you get when you treat time as if it were a vector and mix
in
some distance. Time is NOT a vector quantity, it has no inverse. There
is no identity, no minus time to when you were.
We can forget y and z, the mosquito didn't fly up into a tree or into
the
ditch at the side.
We apply this to the equations derived:
tau = (16 - 3 * 80 / 25) / sqrt (1 - 3^2/5^2)
= (6.4) / 0.8
= 8 seconds
xi = 32 / sqrt (1 - 9 / 25)
= 40 feet
Sanity check:
c = 40 ft / 8 seconds = 5 fps. Yep, that's the right speed for Albert.
So...
We are standing at the roadside watching Sam and Joe carry a 32 ft
ladder
that they think is a 40 ft ladder, because the speed of mosquitoes is 5
fps
in all inertial frames of reference, and ½ * 20 * 0.8 = 8 seconds
without
batting an eyelid.
There is a slight hitch, though. In the roadside frame, where is A, at
the red paint can or the green paint can? We still want half the time
to travel from A to B to be equal to the time to travel the round trip,
and the distance from the red paint can to the roller is 80 ft, and back
to the green paint can is 20 ft.
Which is the "origin of the coordinates"?
This is best satisfied by beefing up Albert's speed to infinity, and as
Einstein says,
the velocity of light... err... mosquitoes in out theory plays the part,
physically, of an infinitely great velocity."
It must be right, its only algebra after all is said and done.
So now you should be able to fully understand Special Relativity, all
you need do is replace the speed of the mosquito with the speed of
light,
have Sam and Joe run at the relativistic speed of 0.6c, the algebra is
perfect, and who needs common sense anyway?
Just remember that 32 ft ladders stretch to 40 ft ladders when you run
with
them at 180,000 km/sec, and you'll be as smart as Einstein the cretin.
For myself, I'll keep the collection of prejudices I acquired by the
time I was eighteen, since that defines common sense.
>>>>>> The subjective speed of light c for the observer would mean the
>>>>>> irrationality of time dilation. I send a beam of light from A to
>>>>>> B,
>>>>>> a
>>>>>> distance of 1 light-year, reflect it back from B to A for a total
>>>>>> time
>>>>>> of 2 years, and in the meantime I buzz around in any direction,
>>>>>> any
>>>>>> speed and return once again to A. If my clock slowed as I did so
>>>>>> I'd
>>>>>> be
>>>>>> forced to conclude the speed of light from A to B and back again
>>>>>> was
>>>>>> greater than c, which is a contradiction and irrational.
>>>>>
>>>>> The only thing irrational is to think that you can do anything
>>>>> during
>>>>> the
>>>>> experiment without changing its results.
>>>>>
>>>>> If you leave your clock behind, when you come back and check the
>>>>> speed, it
>>>>> will be correct. You can't take the clock with you
>>>>
>>>> Why can't I take a clock with me? I take my wrist watch with me
>>>> most
>>>> of
>>>> the time, and I've yet to see a RATIONAL reason for it changing as
>>>> a
>>>> function
>>>> of my velocity.
>>>
>>> Because it is not a valid measure of the speed of light. In any
>>> scientific
>>> experiment you keep everything constant that you possibly can keep
>>> constant
>>> except for the thing you want to measure. Taking your clock with you
>>> introduces additional factors into the experiment.
>>
>> The thing I want to measure is the time for light to travel from A to
>> B
>> and back to A, which are one light-year apart.
>
> TWLS. Henri won't like that. :)
Einstein should love it. :-)
>
>> Why would my going down
>> the pub for a pint (speed unspecified) affect the two years it takes
>> for
>> the light to come back?
>
> It doesn't, unless you take the clock with you.
Ok, so it's two years on the money.
>
> In order for the FoR to be a valid inertial FoR, it must maintain
> constant
> velocity. No acceleration allowed. So, if you move the clock, you
> break its
> connection with the FoR wrt which you wish to measure the light speed.
All evidence, to date, is consistent with you not being able to get
a pint without accelerating, and a lot of scientists agree. :-)
>
> You could leave a clock and resync the clocks when you get back.
Why would I need to resync?
>
>> I can get back in plenty of time to be there 10
>> minutes before the end of the experiment.
>> If my clock ran slow I'd find the light went faster than c, wouldn't
>> I?
>
> faster wrt what?
'A', of course.
You have traveled through many FoR during your bar
> hopping.
> I bet that IF you properly transform your coordinates on each hop and
> compute
> t''''''' of your clock wrt the original FoR, correct your clock for
> all those
> effects and THEN measure the TWLS, you will still get c.
I bet you would, too. And two years by my clock :-)
Did I tell you it was a 61 foot long fat candle, and has been burning 1
inch a day?
After 2 * 365 days, there is nothing left of the original 60.833 ft.
If it had run slow, there'd be a foot or two still remaining. I'd have
notice the flame a little dimmer than the candle I left at A as well.
>>> As for your watch, I doubt that your watch has sufficient accuracy
>>> for
>>> you to know whether or not it gained or lost time during any trips
>>> you
>>> have taken during your lifetime.
>>
>> Probably not, but that doesn't change my thought experiment, which is
>> all Einstein had anyway. When I get back to A my watch has to read 2
>> years exactly, or I've measured a value of c different to yours. You
>> can
>> stay at A and keep time, you'll miss out on the beer. (I was buying,
>> too.)
>>
>
> Let me take the trip and I'll buy you all the beer you want.
How many 8-packs can you carry home?
>>
>>>>>> Performing an experiment with light IN THE VICINITY of matter is
>>>>>> essentially the same as light in a medium, only the distance from
>>>>>> the
>>>>>> photon to the atom has changed.
>>>>>
>>>>> All light is in the vicinity of matter. Especially if we perform
>>>>> an
>>>>> experiment of any kind.
>>>>
>>>> It leaves the vicinity of matter ( a star) and travels a heck of a
>>>> long
>>>> way though space near nothing at all. That's very different to
>>>> going
>>>> down a waveguide or accelerator tube.
>>>
>>> If you can't show c'=c+v photons in a laboratory, you are going to
>>> play heck convincing anyone that they exist.
>>
>> A moon shot will do it. We don't need a brick building full of test
>> tubes to perform an experiment.
>
> Wood would do.
Nah... Fire hazard. My clock is a candle and measures time by the length
remaining. Perhaps Einstein never heard of such old fashioned devices,
but Newton had one.
>>> Take a look at http://members.cox.net/astro7/binstar.html
>>> Download the Starlight Pro program and play with it.
>>>
>>> It gives an interesting view, data on a bunch of stars and some
>>> useful
>>> light curves simulations. Perhaps it will be useful to you.
>>> I would love to be able to compare its results with your program's
>>> results.
>>
>> http://www.physics.sfasu.edu/astro/ebstar/ebstar03.gif
>> and
>> http://www.physics.sfasu.edu/astro/ebstar/ebstar07.gif
>> demonstrates the problem with Algol.
> I am not sure what your point is with the two references.
>
> Beta Per (239) is in the catalogue the program has.
>
>> If you move the blue and red stars any further apart than about 4
>> times
>> the radius of the red star, you can't eclipse for 10 hours in 70, or
>> 52
>> degrees.
>> The program sucks, I was unable to change the separation between the
>> stars
>
> You change the separation by changing the radii of the stars. Radii
> are
> relative to the separation.
>
> See the 'Help'.
>
>> and I got a divide by zero when I set the radius of one star to 1,
>> even
>> though I was trying to set to 0.1
>
> Not too surprising, you just made the stars coincide.
That should have been trapped by the programmer. Sloppy user inteface.
>
>> The real Algol doesn't show much of a dip in the curve at half phase.
>
> The photometric curve may not be to scale.
Let's face it, it's a crude model written in BASIC and isn't up
to the quality you get with
http://zone.msn.com bankshot billiards. :-)
Androcles.
.
- References:
- Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- From: Arthur Dent
- Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- From: bz
- Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- From: Arthur Dent
- Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- From: bz
- Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- From: Arthur Dent
- Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- From: bz
- Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- From: Arthur Dent
- Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- From: bz
- Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- From: Androcles
- Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- From: bz
- Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- From: Androcles
- Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- From: bz
- Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- Prev by Date: Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- Next by Date: Re: 100 years today!
- Previous by thread: Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- Next by thread: Re: Will Somebody PleaseTell bz What an Inertial Frame is.
- Index(es):
Relevant Pages
|
Loading
