I can't follow you Jesse.
Thanks for the discusion anyway.
Hope it was valuable to you.
Mitch Raemsch -- Light

Nick wrote:

I can't follow you Jesse.
Thanks for the discusion anyway.
Hope it was valuable to you.
Mitch Raemsch -- Light




It's not really that complicated. Remember the situation I talked about
earlier, where you have two ships moving together, then one decelerates
until it is at rest in absolute space? Well, this is just like that
situation, except that instead of two ships you have a ship and a planet
that are moving together, and then the ship fires its rockets and
decelerates until it is at rest in absolute space, while the planet
continues to move at the same speed. From the point of view of people on
the planet, won't it look like the ship is flying away from them, even
though it is "really" the planet that is moving and the ship that is
coming to rest?

Jesse

This is my parting shot: some things are moving through
space some are not.
Goodbye Jesse.

Nick wrote:

This is my parting shot: some things are moving through
space some are not.
Goodbye Jesse.




Even if that's true, you have no basis for claiming it's the rocket
that's moving rather than the planet--that was the point I was making.

Jesse

nightbat wrote

Randy Poe wrote:

Nick wrote:
Randy Poe wrote:

You don't think the earth is moving?
Not toward the spaceship Randy!!!

No? If I were plotting an Earth to Mars trip, I would
definitely take advantage of the Earth's motion so that
I would make sure that the earth WAS traveling toward
the ship.

It's a journey of months. The earth moves in its orbit
about 78 million km per month. You'd be an idiot
not to plan things to take advantage of that motion,
so that the earth is moving toward the spaceship.

Get it straight Ninkumpoop.

That's nimcompoop. Don't use big words if you don't know
how to spell them.

- Randy

nightbat

Actually Mr. Poe it's spelled nincompoop, ha, ha, ha, for it may
take an apparent simpleton to apparently understand the Universe. One
who isn't troubled by the spelling of things just how they really work.
Simple solution just get a good post spell checker, it helps. Anyway we
have star race beautiful Darla now so who needs to worry about spelling
or where the planets vector are with a far advanced stellar or cosmic
body position handling super quantum computer and 1st contact incoming
star ship hopefully soon at our mutual access? So forget trying to out
run mosquitoes, limited Earth physics, and the genius of the absolute.
Net science elect Officers stay alert, our benevolent, overseeing, and
profound net star traveler, Darla, is about to possibly grace us all.
Yes, where finally perhaps geniuses and presumed idiots happily together
will have an equal chance to hopefully truly reach the stars.

ponder on,
the nightbat

"Randy Poe" wrote in message
oups.com...

The monkey won.

You have learnt the hard way. In future be as crude and rude as I am
when discoursing with monkeys like Androcles..
Their only use in this ng is to serve as clowns to be lampooned.

Franz

"Jesse Mazer" wrote in message
...


Androcles wrote:

"Jesse Mazer" wrote in message
...

Androcles wrote:


"Jesse Mazer" wrote in message
...


Androcles wrote:



"Jesse Mazer" wrote in message
...



Androcles wrote:


Do me a favour.
Einstein wrote

"light is always propagated in empty space with a definite
velocity c which is independent of the state of motion of the
emitting body"
Reference :
http://www.fourmilab.ch/etexts/einstein/specrel/www/

Then he wrote:
"But the ray moves relatively to the initial point of k, when
measured in the stationary system, with the velocity c-v, so that
x'/(c-v) = t."



I don't know what the context of this is. I assume he's not talking
about how fast the light is moving in a given frame, but rather how
fast the light is moving away from some other object, as seen not
in the object's own frame but in a frame where the object itself is
moving at velocity v. In this case, although light will still
travel at c in this frame, the distance between the light ray and
the object moving at velocity v will be seen to grow at the rate
(c-v) in this frame. In the object's own frame, though, the
distance between itself and the light ray would grow at the rate c,
as relativity predicts.


You didn't reply to this part of my post--can you provide me with the
context of that statement by Einstein?


I've given you the reference.


Ah, I didn't notice that you were quoting from a website, sorry. But
that's a pretty long article, which section did you get the quote
involving the equation x'/(c-v) = t from?

Section 3. It wouldn't refer to it as an "article" though. It's the
original
paper that Einstein wrote in 1905 creating special relativity.



You are one of those that starts at the Lorentz
Transforms, proceeds to lecture on what you imagine I'm not aware of,
then conclude you are right.


You didn't really read my post, so how do you know this?
I didn't read it in depth, no. I quickly glanced down and saw some
equations I recognised as wasn't prepared to comment on, since they
cannot be derived in any sensible manner.


In fact, I didn't assume the Lorentz transformations were correct
without argument, I pointed out that all the current known laws of
physics are Lorentz-invariant,
Sorry, but I do not agree the laws of physics are illogical. The PoR
stood the test of time until Einstein who corrupted it in favour of his
own
insistence concerning the speed of light, which he stated in 1905 was
"only apparently irreconcilable" and in 1920 recognized was
irreconcilable. He
rejected the PoR in favour of c = (c+v)/(1+v/c). Trouble is, he used
c+v to derive the composition of velocities.


thus *if* these laws are correct, the laws must remain unchanged under
a Lorentz transformation but not under other types of coordinate
transformations, which shows that the Lorentz transformation is the
most natural type of coordinate transformation to use if these laws
are correct (and any physical rulers and clocks which obey
Lorentz-invariant laws must also show length contraction and time
dilation).

If you are arguing that physicists have got the laws of physics wrong,
that they should actually use modified laws which are
Galilei-invariant rather than Lorentz-invariant, that's fine, but it's
incumbent on you to show some evidence that existing laws are wrong
and these modified laws are correct.

No it isn't. The burden of proof is upon the claimant, and Einstein
failed to prove
his case. All I have to show is the error in his math/logic.



If you think my understanding of his meaning is incorrect, could you
explain why?


I do not know what you understanding is.


I just explained it in the post you responded to--here it is again: "I
assume he's not talking about how fast the light is moving in a given
frame, but rather how fast the light is moving away from some other
object, as seen not in the object's own frame but in a frame where the
object itself is moving at velocity v.

You admit you are making assumption. Im not in the assumption game.
Einstein makes many assumptions, many invalid.

This is the worst one.
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))

Where does that ½ come from?
Consider McCullough's silly little puzzle, which I'll embellish
slightly.
Sam and Joe are walking along carrying a 32 ft ladder between
them, at 3 fps. A mosquito flies from Sam to Joe and back to
Sam again at 5 fps, ground frame. How long does it take the
mosquito to make the round trip?
x' is the 32 ft ladder, c the speed of the mosquito and v the speed
of Sam and Joe.

Answer. 16 seconds to reach Joe and 4 seconds to return.
So (16+4)/2 = 16 ?
I don't think so. Einstein tries to justify it by saying Sam cannot
know when the mosquito reaches Joe, so he'll simply use the ½.
That is assumption, not mathematics.




In this case, although light will still travel at c in this frame, the
distance between the light ray and the object moving at velocity v
will be seen to grow at the rate (c-v) in this frame. In the object's
own frame, though, the distance between itself and the light ray would
grow at the rate c, as relativity predicts."


As far as I'm concerned we never
get to the Lorentz Transforms, hence I have no interest in them.
Insofar as
Einstein's 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"
Reference :
http://www.fourmilab.ch/etexts/einstein/specrel/www/
there is no justification for it. What we would expect to happen if
slow, earlier emitted light were to be passed along the way by later
emitted faster light
is exactly what we do see.
http://www.androc1es.pwp.blueyonder....ctual_data.htm


So if we look at light from a given star at two points in the earth's
orbit, the first when the earth is moving away from the star and the
second when it's moving towards it, why isn't any difference in the
speed of light measured?

It is. You'll see as doppler-shift.
Androcles.






Jesse

Androcles wrote:

"Jesse Mazer" wrote in message
...


Androcles wrote:



"Jesse Mazer" wrote in message
...



Androcles wrote:




"Jesse Mazer" wrote in message
...




Androcles wrote:





"Jesse Mazer" wrote in message
...





Androcles wrote:




Do me a favour.
Einstein wrote

"light is always propagated in empty space with a definite
velocity c which is independent of the state of motion of the
emitting body"
Reference :
http://www.fourmilab.ch/etexts/einstein/specrel/www/

Then he wrote:
"But the ray moves relatively to the initial point of k, when
measured in the stationary system, with the velocity c-v, so that
x'/(c-v) = t."





I don't know what the context of this is. I assume he's not talking
about how fast the light is moving in a given frame, but rather how
fast the light is moving away from some other object, as seen not
in the object's own frame but in a frame where the object itself is
moving at velocity v. In this case, although light will still
travel at c in this frame, the distance between the light ray and
the object moving at velocity v will be seen to grow at the rate
(c-v) in this frame. In the object's own frame, though, the
distance between itself and the light ray would grow at the rate c,
as relativity predicts.




You didn't reply to this part of my post--can you provide me with the
context of that statement by Einstein?



I've given you the reference.



Ah, I didn't notice that you were quoting from a website, sorry. But
that's a pretty long article, which section did you get the quote
involving the equation x'/(c-v) = t from?



Section 3. It wouldn't refer to it as an "article" though. It's the
original
paper that Einstein wrote in 1905 creating special relativity.



I see my interpretation was correct, then. He is saying that you have
two reference frames, K and k, and that in K's reference frame, the
distance between the origin of k and a ray of light is growing at the
rate (c-v). This does not mean that the ray of light is moving at
velocity (c-v) in k's reference frame; in both K and k, the light is
moving at velocity c.





You are one of those that starts at the Lorentz
Transforms, proceeds to lecture on what you imagine I'm not aware of,
then conclude you are right.



You didn't really read my post, so how do you know this?


I didn't read it in depth, no. I quickly glanced down and saw some
equations I recognised as wasn't prepared to comment on, since they
cannot be derived in any sensible manner.


They can be derived from the fact that all the fundamental laws of
physics display the property of "Lorentz invariance". This is a
mathematical property which can be verified simply by examining the
equations. Do you understand what it means to say a given equation shows
Lorentz invariance? If not, I can go into more detail.

However, if it is true that all the fundamental laws of nature obey
Lorentz invariance, it must be true that if different observers in
motion with relation to one another all use the same procedure to define
the coordinates of events in their frame--building a network of rulers
and clocks which are at rest with respect to themselves, and
synchronizing the clocks using the assumption that light moves at the
same speed in all directions in their frame--then the Lorentz
transformation equations will indeed be the correct way to transform
measurements made with one set of rulers and clocks into measurements
made with another set. From your comments I gather you probably believe
that existing laws are not really fundamental, and that when we find the
real fundamental laws they will not be Lorentz-invariant...but would you
at least agree that *if* the fundamental laws are Lorentz-invariant,
then the Lorentz transformation will be the correct way to transform
between measurements on different observers' rulers and clocks?







In fact, I didn't assume the Lorentz transformations were correct
without argument, I pointed out that all the current known laws of
physics are Lorentz-invariant,


Sorry, but I do not agree the laws of physics are illogical.


Are you saying there is something inherently illogical about the idea
that I will see rulers shrink as they move faster, and clocks slow down?
Again, you are free to believe there is a true Absolute Space and that
only rulers and clocks at rest in this space measure distance and time
correctly, and rulers and clocks moving in Absolute Space are
"objectively" shorter and slower. Even if you don't believe this is how
things actually work, are you saying it is *logically impossible* that
they could work this way (ie, that this hypothesis involves a logical
contradiction?) Or are you just using "illogical" to mean "implausible"?


The PoR
stood the test of time until Einstein who corrupted it in favour of his
own
insistence concerning the speed of light, which he stated in 1905 was
"only apparently irreconcilable" and in 1920 recognized was
irreconcilable. He
rejected the PoR in favour of c = (c+v)/(1+v/c). Trouble is, he used
c+v to derive the composition of velocities.


In relativity it is true that if I see you moving in one direction with
velocity v, and I see a light beam moving in the opposite direction with
velocity c, then the distance between you will grow at the rate (c+v),
in my reference frame. But this is not a problem, since you will *not*
measure the light beam to be moving at velocity (c+v) relative to yourself.







thus *if* these laws are correct, the laws must remain unchanged under
a Lorentz transformation but not under other types of coordinate
transformations, which shows that the Lorentz transformation is the
most natural type of coordinate transformation to use if these laws
are correct (and any physical rulers and clocks which obey
Lorentz-invariant laws must also show length contraction and time
dilation).

If you are arguing that physicists have got the laws of physics wrong,
that they should actually use modified laws which are
Galilei-invariant rather than Lorentz-invariant, that's fine, but it's
incumbent on you to show some evidence that existing laws are wrong
and these modified laws are correct.



No it isn't. The burden of proof is upon the claimant, and Einstein
failed to prove
his case. All I have to show is the error in his math/logic.


But it is easy to prove that if all the fundamental laws of physics are
Lorentz-invariant, then if observers use rulers and clocks at rest
relative to themselves and synchronize the clocks using Einstein's
procedure, then the Lorentz transformations will give the correct rule
for transforming between different observer's measuring system. It is
also an objective fact that the laws of electromagnetism exhibit
Lorentz-invariance, as do all our current fundamental laws (like quantum
field theory). So unless someone like you can come up with some new
fundamental laws which don't exhibit Lorentz-invariance, this is
sufficient to prove that the Lorentz transformation will give the
correct rule for transforming between the measurements of different
networks of rulers and clocks.






If you think my understanding of his meaning is incorrect, could you
explain why?



I do not know what you understanding is.



I just explained it in the post you responded to--here it is again: "I
assume he's not talking about how fast the light is moving in a given
frame, but rather how fast the light is moving away from some other
object, as seen not in the object's own frame but in a frame where the
object itself is moving at velocity v.



You admit you are making assumption. Im not in the assumption game.
Einstein makes many assumptions, many invalid.

This is the worst one.
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))

Where does that ½ come from?
Consider McCullough's silly little puzzle, which I'll embellish
slightly.
Sam and Joe are walking along carrying a 32 ft ladder between
them, at 3 fps. A mosquito flies from Sam to Joe and back to
Sam again at 5 fps, ground frame. How long does it take the
mosquito to make the round trip?
x' is the 32 ft ladder, c the speed of the mosquito and v the speed
of Sam and Joe.


Wait, first you said the mosquito flew at 5 fps, then you said at
c...are you assuming the speed of light is 5 fps in this
thought-experiment, or do you no mean c to be the speed of light?

In either case, I'd solve it like this. In the ground frame, the end of
the ladder starts out at position x=32 feet, moving at 3 fps, and the
mosquito starts out at x=0 feet, and moves at 5 fps, so in this frame
you'd calculate the time t for them to meet using the equation:

0 + 5t = 32 + 3t

which gives t=16 seconds, meeting at position x=80. Then the mosquito
flies backwards from that position at velocity -5 fps, and meanwhile the
other end of the ladder starts at x=48 feet and moves forward at 3 fps,
so to find where they meet you could use this equation:

80 - 5t = 48 + 3t

which gives t = 4 seconds. So, the total time is 20 seconds. Notice that
I calculated everything from the ground frame, without ever switching to
the mosquito's frame or the ladder's frame.


Answer. 16 seconds to reach Joe and 4 seconds to return.
So (16+4)/2 = 16 ?
I don't think so. Einstein tries to justify it by saying Sam cannot
know when the mosquito reaches Joe, so he'll simply use the ½.
That is assumption, not mathematics.


What are you talking about? Einstein would agree with my analysis above,
even if the speed of light was 5 feet per second; notice that I always
assumed the mosquito was travelling at 5 fps in the ground frame, I
never switched to a different frame.



So if we look at light from a given star at two points in the earth's
orbit, the first when the earth is moving away from the star and the
second when it's moving towards it, why isn't any difference in the
speed of light measured?



It is. You'll see as doppler-shift.
Androcles.


A doppler-shift is just a change in the wavelength, not in the velocity.

Jesse

"Jesse Mazer" wrote in message
...


Androcles wrote:

"Jesse Mazer" wrote in message
...

Androcles wrote:


"Jesse Mazer" wrote in message
...


Androcles wrote:



"Jesse Mazer" wrote in message
...



Androcles wrote:




"Jesse Mazer" wrote in message
.. .




Androcles wrote:



Do me a favour.
Einstein wrote

"light is always propagated in empty space with a definite
velocity c which is independent of the state of motion of the
emitting body"
Reference :
http://www.fourmilab.ch/etexts/einstein/specrel/www/

Then he wrote:
"But the ray moves relatively to the initial point of k, when
measured in the stationary system, with the velocity c-v, so
that x'/(c-v) = t."




I don't know what the context of this is. I assume he's not
talking about how fast the light is moving in a given frame, but
rather how fast the light is moving away from some other object,
as seen not in the object's own frame but in a frame where the
object itself is moving at velocity v. In this case, although
light will still travel at c in this frame, the distance between
the light ray and the object moving at velocity v will be seen to
grow at the rate (c-v) in this frame. In the object's own frame,
though, the distance between itself and the light ray would grow
at the rate c, as relativity predicts.



You didn't reply to this part of my post--can you provide me with
the context of that statement by Einstein?


I've given you the reference.


Ah, I didn't notice that you were quoting from a website, sorry. But
that's a pretty long article, which section did you get the quote
involving the equation x'/(c-v) = t from?


Section 3. It wouldn't refer to it as an "article" though. It's the
original
paper that Einstein wrote in 1905 creating special relativity.


I see my interpretation was correct, then. He is saying that you have
two reference frames, K and k, and that in K's reference frame, the
distance between the origin of k and a ray of light is growing at the
rate (c-v).

For some duration of time.
For another duration of time the rate is v+c.
These durations are not equal.
Time is not a vector, it has no additive inverse.




This does not mean that the ray of light is moving at velocity (c-v)
in k's reference frame; in both K and k, the light is moving at
velocity c.


I don't believe in magic. If c = c+v and c = c-v, then v = 0.
If V = (c+v)/(1+v/c) then use that to derive the LTs.
If the system of equations is linear as Einstein claims, it shoud be
no trouble.




You are one of those that starts at the Lorentz
Transforms, proceeds to lecture on what you imagine I'm not aware
of, then conclude you are right.


You didn't really read my post, so how do you know this?

I didn't read it in depth, no. I quickly glanced down and saw some
equations I recognised as wasn't prepared to comment on, since they
cannot be derived in any sensible manner.


They can be derived from the fact that all the fundamental laws of
physics display the property of "Lorentz invariance".

Bull****.


This is a mathematical property which can be verified simply by
examining the equations. Do you understand what it means to say a
given equation shows Lorentz invariance? If not, I can go into more
detail.

Go on then, explain circularity .... err .... Lorentz invariance to me.




However, if it is true that all the fundamental laws of nature obey
Lorentz invariance,
it must be true that if different observers in motion with relation
to one another all use the same procedure to define the coordinates of
events in their frame--building a network of rulers and clocks which
are at rest with respect to themselves, and synchronizing the clocks
using the assumption that light moves at the same speed in all
directions in their frame--

It seemeth impossible for it to be, for if I walk away from a candle set
by the wall and you walk toward the same candle, we then have some
motion between us. If we then divide that motion equally between us, and
impart it to the candle such that it appeareth to be at rest upon the
floor upon which we walk, how then doth the light divide it's motion
between us, that we may both observe it to be the same?

And if I place another candle on the other side of us beside the
opposing wall, such that it is at rest with respect to the first candle,
how then shall I determine the light I approach and the light I recede
from, that they be of equal motion to me?
And yet one more candle, be it placed between us in the room, at centre,
that we may both recede from it and still determine that the motion of
light from all candles be the same?

I am but a simple man, and sorely perplexed by these deliberations, for
it is truly astounding that these assertions be true. Explain this
wondrous concept any sensible way you can, but gently, for it shall
surely confound me and cause my head to ache.



then the Lorentz transformation equations will indeed be the correct
way to transform measurements made with one set of rulers and clocks
into measurements made with another set.

I do not see any justification for magic or incorrect assumption.



From your comments I gather you probably believe that existing laws
are not really fundamental, and that when we find the real fundamental
laws they will not be Lorentz-invariant...

Quite so, the Lorentz Transforms do not exist.


but would you at least agree that *if* the fundamental laws are
Lorentz-invariant, then the Lorentz transformation will be the correct
way to transform between measurements on different observers' rulers
and clocks?

If you can use
1/2[tau(0,0,0,t)+tau(0,0,0,t+x'/V+x'/V)] = tau(x',0,0,t+x'/V)
since "the velocity of light c cannot be altered by composition with a
velocity less than that of light. For this case we obtain V =
(c+w)/(1+w/c) = c."
to derive the Lorentz Transforms, I'll take another look.

Go ahead. I'm amenable to reason.
Explain to me how the two velocities of light, c-v and c+v, measured
over a single distance, are really only one, c.




In fact, I didn't assume the Lorentz transformations were correct
without argument, I pointed out that all the current known laws of
physics are Lorentz-invariant,

Sorry, but I do not agree the laws of physics are illogical.


Are you saying there is something inherently illogical about the idea
that I will see rulers shrink as they move faster, and clocks slow
down?

Yes.
v = 3, t = 16, c = 5.
(Fixed font needed now)

S[----------]M moving frame, t = 0.
O---32----

Sam and Mike are carrying a ladder. You are going to shrink the ladder.

S[-----------]M moving frame, t = 16.
O---48----|----32---|X

Start mapping O in the stationary frame to S,
and X in the stationary frame to M. Linearly.

S[-----------]M moving frame, t = 20.
O----60----|----32---|X
E

Now show that half of 92 is 60 and half of 20 is 16, because the light
has
traveled from S to M and back again at speed 2 out and 8 back in the
moving frame, and from O to E via M (at t=16) in the stationary frame.

Again, you are free to believe there is a true Absolute Space and that
only rulers and clocks at rest in this space measure distance and time
correctly, and rulers and clocks moving in Absolute Space are
"objectively" shorter and slower. Even if you don't believe this is
how things actually work, are you saying it is *logically impossible*
that they could work this way (ie, that this hypothesis involves a
logical contradiction?) Or are you just using "illogical" to mean
"implausible"?

I mean illogical.




The PoR
stood the test of time until Einstein who corrupted it in favour of
his own
insistence concerning the speed of light, which he stated in 1905 was
"only apparently irreconcilable" and in 1920 recognized was
irreconcilable. He
rejected the PoR in favour of c = (c+v)/(1+v/c). Trouble is, he used
c+v to derive the composition of velocities.


In relativity it is true that if I see you moving in one direction
with velocity v, and I see a light beam moving in the opposite
direction with velocity c, then the distance between you will grow at
the rate (c+v), in my reference frame. But this is not a problem,
since you will *not* measure the light beam to be moving at velocity
(c+v) relative to yourself.

That is your assertion. Assertions carry no weight. If I approach a
source
of sound I'll certainly measure 731.4 m/s +v. Doppler shift will be
evident also.
If I approach a source of light, likewise. Are you saying I'd see no
shift?

No it isn't. The burden of proof is upon the claimant, and Einstein
failed to prove
his case. All I have to show is the error in his math/logic.


But it is easy to prove that if all the fundamental laws of physics
are Lorentz-invariant, then if observers use rulers and clocks at rest
relative to themselves and synchronize the clocks using Einstein's
procedure, then the Lorentz transformations will give the correct rule
for transforming between different observer's measuring system.

It is also an objective fact that the laws of electromagnetism exhibit
Lorentz-invariance, as do all our current fundamental laws (like
quantum field theory). So unless someone like you can come up with
some new fundamental laws which don't exhibit Lorentz-invariance, this
is sufficient to prove that the Lorentz transformation will give the
correct rule for transforming between the measurements of different
networks of rulers and clocks.





If you think my understanding of his meaning is incorrect, could
you explain why?


I do not know what you understanding is.


I just explained it in the post you responded to--here it is again:
"I assume he's not talking about how fast the light is moving in a
given frame, but rather how fast the light is moving away from some
other object, as seen not in the object's own frame but in a frame
where the object itself is moving at velocity v.


You admit you are making assumption. Im not in the assumption game.
Einstein makes many assumptions, many invalid.

This is the worst one.
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))

Where does that ½ come from?
Consider McCullough's silly little puzzle, which I'll embellish
slightly.
Sam and Joe are walking along carrying a 32 ft ladder between
them, at 3 fps. A mosquito flies from Sam to Joe and back to
Sam again at 5 fps, ground frame. How long does it take the
mosquito to make the round trip?
x' is the 32 ft ladder, c the speed of the mosquito and v the speed
of Sam and Joe.


Wait, first you said the mosquito flew at 5 fps, then you said at
c...are you assuming the speed of light is 5 fps in this
thought-experiment, or do you no mean c to be the speed of light?

I've clearly stated "c the speed of the mosquito", which is 5 fps.

In either case, I'd solve it like this. In the ground frame, the end
of the ladder starts out at position x=32 feet, moving at 3 fps, and
the mosquito starts out at x=0 feet, and moves at 5 fps, so in this
frame you'd calculate the time t for them to meet using the equation:

0 + 5t = 32 + 3t

which gives t=16 seconds, meeting at position x=80. Then the mosquito
flies backwards from that position at velocity -5 fps, and meanwhile
the other end of the ladder starts at x=48 feet and moves forward at 3
fps, so to find where they meet you could use this equation:

80 - 5t = 48 + 3t

which gives t = 4 seconds. So, the total time is 20 seconds. Notice
that I calculated everything from the ground frame, without ever
switching to the mosquito's frame or the ladder's frame.

Well, carry on, then. This is only algebra, prove that time for the
mosquito
is less, the ladder is shorter and that the speed of the mosquito is 5
fps in the moving frame. You can do (c+v)/(1+v/c) when you come to § 5
"with the help of the equations of transformation developed in § 3 "-
Einstein.

Introduction.
Section 1
Section 2
Section 3 Use c+v, c - v. Derive LT.
Section 4
Section 5 c= (c+v)/(1+v/c) from section 3.

The speeds of the mosquito in the moving frame are 8 and 3.
This makes the speed of the mosquito 5 in the moving frame
(Lorentz invariant)
I don't call that logical or consistent, but you do. We cannot agree
on what is logical.
The problem as I see it is that the time for the moquito to travel
from 0 to 80 and back to 60 at 5 fps = 100/5 = 20 is the same
time as in the moving frame, a distance of 32 at 8 fps + 32 at 2 fps,
and Einstein has used ½ of 20 seconds in the stationary frame
for the one way trip taking 16 seconds in the moving frame.
I call that assinine. The light never gets back to the origin of the K
frame, there is no half to consider.


Answer. 16 seconds to reach Joe and 4 seconds to return.
So (16+4)/2 = 16 ?
I don't think so. Einstein tries to justify it by saying Sam cannot
know when the mosquito reaches Joe, so he'll simply use the ½.
That is assumption, not mathematics.


What are you talking about?

I'm talking about the statement
"From the origin of system k let a ray be emitted at the time tau0 along
the X-axis to x', and at the time tau1 be reflected thence to the origin
of the co-ordinates,
arriving there at the time tau2; we then must have ½(tau0+tau2) = tau1.

Why MUST we have that? I would only be true if the speed of the mosquito
was 5 in the moving frame, and we have already stated it to be 2 and 8.
It doesn't become 5 until section 5, and a priori, we haven't reached
that section.
I say (16/20) * (0+20) = 16, not ½(tau(0,0) +tau(0, 20)) = tau(32, 16).


Einstein would agree with my analysis above,
even if the speed of light was 5 feet per second; notice that I always
assumed the mosquito was travelling at 5 fps in the ground frame, I
never switched to a different frame.

I expect Einstein would. I don't.
As far as I'm concerned the light never gets back to the origin in
the stationary frame, so there is no half to consider.





So if we look at light from a given star at two points in the earth's
orbit, the first when the earth is moving away from the star and the
second when it's moving towards it, why isn't any difference in the
speed of light measured?


It is. You'll see as doppler-shift.
Androcles.


A doppler-shift is just a change in the wavelength, not in the
velocity.

Doppler's equation is (for one axis)
(c+v)
f' = f. ---------
(c+u)

where u is the velocity of the source and v the velocity of the
observer.
Where there is no medium, this reduces to
f' = f. (c+v)/c.
The wavelength does not change.

Androcles.

Androcles wrote:

"Jesse Mazer" wrote in message
...


Androcles wrote:



"Jesse Mazer" wrote in message
...



Androcles wrote:




"Jesse Mazer" wrote in message
...




Androcles wrote:





"Jesse Mazer" wrote in message
...





Androcles wrote:






"Jesse Mazer" wrote in message
. ..






Androcles wrote:





Do me a favour.
Einstein wrote

"light is always propagated in empty space with a definite
velocity c which is independent of the state of motion of the
emitting body"
Reference :
http://www.fourmilab.ch/etexts/einstein/specrel/www/

Then he wrote:
"But the ray moves relatively to the initial point of k, when
measured in the stationary system, with the velocity c-v, so
that x'/(c-v) = t."






I don't know what the context of this is. I assume he's not
talking about how fast the light is moving in a given frame, but
rather how fast the light is moving away from some other object,
as seen not in the object's own frame but in a frame where the
object itself is moving at velocity v. In this case, although
light will still travel at c in this frame, the distance between
the light ray and the object moving at velocity v will be seen to
grow at the rate (c-v) in this frame. In the object's own frame,
though, the distance between itself and the light ray would grow
at the rate c, as relativity predicts.





You didn't reply to this part of my post--can you provide me with
the context of that statement by Einstein?




I've given you the reference.




Ah, I didn't notice that you were quoting from a website, sorry. But
that's a pretty long article, which section did you get the quote
involving the equation x'/(c-v) = t from?



Section 3. It wouldn't refer to it as an "article" though. It's the
original
paper that Einstein wrote in 1905 creating special relativity.



I see my interpretation was correct, then. He is saying that you have
two reference frames, K and k, and that in K's reference frame, the
distance between the origin of k and a ray of light is growing at the
rate (c-v).



For some duration of time.
For another duration of time the rate is v+c.
These durations are not equal.
Time is not a vector, it has no additive inverse.






This does not mean that the ray of light is moving at velocity (c-v)
in k's reference frame; in both K and k, the light is moving at
velocity c.




I don't believe in magic. If c = c+v and c = c-v, then v = 0.


Nowhere has anyone said that c = c-v. Rather, the idea here is that if
you measure the speed that the distance between k and the light ray is
growing using K's rulers and clocks, it is growing at the rate (c-v);
but if you measure the speed that the distance between k and the light
ray is growing using k's rulers and clocks, it is growing at the rate c.
Since K and k use different rulers and clocks, then *if* you believe
that rulers shrink and clocks dilate, it shouldn't be so surprising that
K's rulers and clocks will give a different answer than k's rulers and
clocks. I know you don't actually believe that, but the point is that
advocates of relativity do, so clearly they are not saying anything so
silly as c = c-v, rather they are saying:
speed measured by K's rulers and clocks = c-v
speed measured by k's rulers and clocks = c

If V = (c+v)/(1+v/c) then use that to derive the LTs.
If the system of equations is linear as Einstein claims, it shoud be
no trouble.


Where are you getting V = (c+v)/(1+v/c)? That's not an equation I can
remember seeing.








You are one of those that starts at the Lorentz
Transforms, proceeds to lecture on what you imagine I'm not aware
of, then conclude you are right.




You didn't really read my post, so how do you know this?



I didn't read it in depth, no. I quickly glanced down and saw some
equations I recognised as wasn't prepared to comment on, since they
cannot be derived in any sensible manner.



They can be derived from the fact that all the fundamental laws of
physics display the property of "Lorentz invariance".



Bull****.




This is a mathematical property which can be verified simply by
examining the equations. Do you understand what it means to say a
given equation shows Lorentz invariance? If not, I can go into more
detail.



Go on then, explain circularity .... err .... Lorentz invariance to me.


Well, first I'll describe Galilei invariance since it's mathematically a
bit simpler, then I'll explain Lorentz invariance. Here are the Galilei
transformations for transforming between inertial reference frames in
Newtonian physics:

x'=x - vt
y'=y
z'=z
t'=t

x=x' + vt'
y=y'
z=z'
t=t'

To say a certain physical equation is "Galilei-invariant" just means the
form of the equation is unchanged if you make these substitutions. For
example, suppose at time t you have a mass m1 at position (x1, y1, z1)
and another mass m2 at position (x2, y2, z2) in your reference frame.
Then the Newtonian equation for the gravitational force between them
would be:

F = Gm1m2/[(x1 - x2)^2 + (y1 - y2)^2 + (z1 - z2)^2]

Now, suppose we want to transform into a new coordinate system moving at
velocity v with respect to the first one. In this coordinate system, at
time t' the mass m1 has coordinates (x1', y1', z1') and the mass m2 has
coordinates (x2', y2', z2'). Using the Galilei transformations, we can
figure how the force would look in this new coordinate system, by
substituting in x1 = x1' + vt', x2 = x2' + vt', y1 = y1', y2 = y2', and
so forth. With these substitutions, the above equation becomes:

F = Gm1m2/[(x1' + vt' - (x2' + vt'))^2 + (y1' - y2')^2 + (z1' - z2')^2]

and you can see that this simplifies to:

F = Gm1m2/[(x1' - x2')^2 + (y1' - y2')^2 + (z1' - z2')^2]

In other words, the equation has exactly the same form in both
coordinate systems. This is what it means to be "Galilei invariant".
More generally, if you have *any* physical equation which computes some
quantity (say, force) as a function of various space and time
coordinates, like f(x,y,z,t) [of course it may have more than one of
each coordinate, like the x1 and x2 above, and it may be a function of
additional variables as well, like m1 and m2 above] then for this
equation to be "Galilei invariant", it must satisfy:
f(x'+vt,y',z',t') = f(x',y',z',t')

From this, it's pretty simple to see what it must mean for a given
physical equation to be "Lorentz invariant" as well. Here are the
Lorentz transformation equations:

x'=gamma(x - vt)
y'=y
z'=z
t'=gamma(t - vx/c^2)

x=gamma(x' + vt')
y=y'
z=z'
t=gamma(t' + vx'/c^2)

where gamma = 1/squareroot(1-v^2/c^2)

So, if you have some physical equation f(x,y,z,t), then for it to be
"Lorentz-invariant" it just must have the following property:

f(gamma(x'+vt'),y',z',gamma(t'+vx'/c^2)) = f(x',y',z',t')

This is just a mathematical property of a given equation or set of
equations, it is just a matter of calculation to check if the equation
satisfies it (the equation for Newtonian gravity would not have this
property, so it would not be Lorentz-invariant). And it is a fact that
Maxwell's laws do have this property of Lorentz-invariance, as do all
the most fundamental laws currently known (such as the laws of quantum
field theory).






However, if it is true that all the fundamental laws of nature obey
Lorentz invariance,
it must be true that if different observers in motion with relation
to one another all use the same procedure to define the coordinates of
events in their frame--building a network of rulers and clocks which
are at rest with respect to themselves, and synchronizing the clocks
using the assumption that light moves at the same speed in all
directions in their frame--



It seemeth impossible for it to be, for if I walk away from a candle set
by the wall and you walk toward the same candle, we then have some
motion between us. If we then divide that motion equally between us, and
impart it to the candle such that it appeareth to be at rest upon the
floor upon which we walk, how then doth the light divide it's motion
between us, that we may both observe it to be the same?

Because you and I use different rulers and clocks to measure this
motion. Even if we lived in a Newtonian universe where rulers and clocks
wouldn't *naturally* appear to shrink and slow down, suppose I bought
you some phony gag rulers and clocks from the novelty shop, with the
markings on the rulers too short by a factor of squareroot(1-v^2/c^2),
and each tick of the clock longer then it should be by a factor of
1/squareroot(1-v^2/c^2). Suppose I also made different clocks of yours
be out-of-sync, by using the (false, in a Newtonian universe) assumption
that a beam of light emitted from the midpoint of two clocks (by a
source at rest relative to me, if you believe light's velocity depends
on the source velocity, although in classical E&M it should actually
depend on the rest frame of the aether) should strike both clocks at the
same time, even if one clock is moving towards the point the light was
emitted and one is moving away from it.

If you are moving away from me at velocity v, and you are using these
gag rulers and clocks (which have been synchronized using this incorrect
procedure, in the Newtonian universe we're living in) to measure things,
do you agree that *as measured by your incorrect rulers and clocks*,
then if I measure the light to be moving at c, you will also measure it
to be moving at c? Do you agree that if I want to find some equations to
transform between my correct measurements and your incorrect
measurements, the correct equations will be the Lorentz transformation
equations?

then the Lorentz transformation equations will indeed be the correct
way to transform measurements made with one set of rulers and clocks
into measurements made with another set.



I do not see any justification for magic or incorrect assumption.


This is not an assumption, it's just a logical consequence of the idea
that all the fundamental equations of physics exhibit the mathematical
property of "Lorentz invariance" which I described above. You may not
believe that in our final Theory of Everything, the fundamental laws
really *will* all be Lorentz-invariant ones, but do you agree that *if*
all the fundamental laws were Lorentz-invariant, then if different
observers all used the same procedure to measure distance and time
(excluding procedures that rely on external reference points--imagine
each observer must construct his measuring system in a windowless box,
with no knowledge of how fast the box is moving in relation to the rest
of the universe), that necessarily implies that the correct way to
transform between different observers' coordinate systems will be the
Lorentz transformation?







From your comments I gather you probably believe that existing laws
are not really fundamental, and that when we find the real fundamental
laws they will not be Lorentz-invariant...



Quite so, the Lorentz Transforms do not exist.


They are just equations for transforming one set of coordinates to
another, so I don't see how they could fail to "exist". The empirical
question is whether they would correctly transform between different
observers' measurements on rulers and clocks, but even in a Newtonian
universe where they wouldn't do so if each observer designs his network
of rulers and clocks in a "natural" way, it would still be possible to
artificially create distorted rulers and clocks such that they would
correctly transform between the normal set and the distorted one, as I
described above in my "novelty shop scenario".







but would you at least agree that *if* the fundamental laws are
Lorentz-invariant, then the Lorentz transformation will be the correct
way to transform between measurements on different observers' rulers
and clocks?



If you can use
1/2[tau(0,0,0,t)+tau(0,0,0,t+x'/V+x'/V)] = tau(x',0,0,t+x'/V)
since "the velocity of light c cannot be altered by composition with a
velocity less than that of light. For this case we obtain V =
(c+w)/(1+w/c) = c."
to derive the Lorentz Transforms, I'll take another look.

Go ahead. I'm amenable to reason.
Explain to me how the two velocities of light, c-v and c+v, measured
over a single distance, are really only one, c.


Is this equation from section 3 of that Einstein paper? I didn't see it
there, and I need to know the context before I can answer this question.









In fact, I didn't assume the Lorentz transformations were correct
without argument, I pointed out that all the current known laws of
physics are Lorentz-invariant,



Sorry, but I do not agree the laws of physics are illogical.



Are you saying there is something inherently illogical about the idea
that I will see rulers shrink as they move faster, and clocks slow
down?



Yes.
v = 3, t = 16, c = 5.
(Fixed font needed now)

S[----------]M moving frame, t = 0.
O---32----

Sam and Mike are carrying a ladder. You are going to shrink the ladder.

S[-----------]M moving frame, t = 16.
O---48----|----32---|X

Start mapping O in the stationary frame to S,
and X in the stationary frame to M. Linearly.

S[-----------]M moving frame, t = 20.
O----60----|----32---|X
E

Now show that half of 92 is 60 and half of 20 is 16, because the light
has
traveled from S to M and back again at speed 2 out and 8 back in the
moving frame, and from O to E via M (at t=16) in the stationary frame.


Ok, so you're saying that in my frame, the ladder is moving 3 ft/sec.,
and the ladder is 32 feet long. At t=0, light is emitted by Sam towards
Mike, and in my frame it reaches Mike at t=16 sec. Then Mike sends some
light back, and it reaches Sam at t=20 sec. in my frame.

The key to understanding how Sam and Mike measure the light to have
travelled the same speed in both directions is to realize that their
clocks will appear out-of-sync in my frame--in this case, Mike's clock
is always 4.8 seconds behind Sam's, from my point of view. So if Sam's
clock reads t'=0 at the same moment that my clock reads t=0, then at the
same moment (in my frame) Mike's clock will read t'=-4.8 (I derived this
using the Lorentz transformation equation, I can show you how if you
like). In my frame, both clocks will also appear slowed down by a factor
of 0.8 (or squareroot[1-v^2/c^2]). So, when my clock reads t=16, Sam's
clock reads t'=(16)(0.8)+0=12.8, and Mike's clock reads
t'=(16)(0.8)-4.8=8. Therefore, in Sam&Mike's frame, the light took 8
seconds to travel from Sam to Mike. And in their frame, the ruler's
length must be 32/0.8 = 40 feet. So, the light travelled at 40/8=5 feet
per second in their frame.

Then when my clock reads t=20, Sam's clock reads t'=(20)(0.8)+0=16. So
in their frame the light left Sam at t=0, arrived at Mike's position at
t=8, and returned back to Sam at t=16. Since the ruler is 40 feet long
in their frame, it travelled 5 feet/second both ways.





Again, you are free to believe there is a true Absolute Space and that
only rulers and clocks at rest in this space measure distance and time
correctly, and rulers and clocks moving in Absolute Space are
"objectively" shorter and slower. Even if you don't believe this is
how things actually work, are you saying it is *logically impossible*
that they could work this way (ie, that this hypothesis involves a
logical contradiction?) Or are you just using "illogical" to mean
"implausible"?



I mean illogical.


Well, you're wrong--see above. Even in a Newtonian universe, if Sam and
Mike use a gag ruler that says 40 feet even though it's "really" only 32
feet long, and if they both use gag clocks that tick at 0.8 the correct
rate, and if Mike's clock is set so that it is "really" behind Sam's
clock by 4.8 seconds, then if they have been fooled into thinking their
clocks and rulers run at the correct rate, and that their clocks are
perfectly synchronized, then according to their measurements the flash
of light will have moved at 5 feet/second in both directions, just as it
did according to my (correct) measurements.

So if you grant this, then I think you have to grant that if rulers
really do appear to shrink and clocks really do appear to slow down
(naturally, with no need for a trip to the novelty shop), and if
observers in different reference frames synchronize their clocks by
*assuming* light travels at the same speed in both directions relative
to themselves (which means that each observer will see the clocks of
other observers to be out-of-sync), then the Lorentz transformation
equations will be the correct way to relate one observer's measurements
to another. Again, you don't have to believe that each observer's
measurements are equally valid--you're free to believe in "Absolute
Space", and that only an observer at rest in absolute space will measure
things correctly, with all other observers having "objectively" shrunken
rulers and slowed-down, out-of-sync clocks. But as long as all the laws
of physics have the mathematical property of Lorentz-invariance, there
will be no experiment anyone can do to determine which frame actually is
the rest frame of Absolute Space, since the laws of physics will have
exactly the same form in each observer's measuring system.







The PoR
stood the test of time until Einstein who corrupted it in favour of
his own
insistence concerning the speed of light, which he stated in 1905 was
"only apparently irreconcilable" and in 1920 recognized was
irreconcilable. He
rejected the PoR in favour of c = (c+v)/(1+v/c). Trouble is, he used
c+v to derive the composition of velocities.



In relativity it is true that if I see you moving in one direction
with velocity v, and I see a light beam moving in the opposite
direction with velocity c, then the distance between you will grow at
the rate (c+v), in my reference frame. But this is not a problem,
since you will *not* measure the light beam to be moving at velocity
(c+v) relative to yourself.



That is your assertion. Assertions carry no weight. If I approach a
source
of sound I'll certainly measure 731.4 m/s +v. Doppler shift will be
evident also.
If I approach a source of light, likewise. Are you saying I'd see no
shift?


No it isn't. The burden of proof is upon the claimant, and Einstein
failed to prove
his case. All I have to show is the error in his math/logic.



But it is easy to prove that if all the fundamental laws of physics
are Lorentz-invariant, then if observers use rulers and clocks at rest
relative to themselves and synchronize the clocks using Einstein's
procedure, then the Lorentz transformations will give the correct rule
for transforming between different observer's measuring system.





It is also an objective fact that the laws of electromagnetism exhibit
Lorentz-invariance, as do all our current fundamental laws (like
quantum field theory). So unless someone like you can come up with
some new fundamental laws which don't exhibit Lorentz-invariance, this
is sufficient to prove that the Lorentz transformation will give the
correct rule for transforming between the measurements of different
networks of rulers and clocks.







If you think my understanding of his meaning is incorrect, could
you explain why?




I do not know what you understanding is.




I just explained it in the post you responded to--here it is again:
"I assume he's not talking about how fast the light is moving in a
given frame, but rather how fast the light is moving away from some
other object, as seen not in the object's own frame but in a frame
where the object itself is moving at velocity v.



You admit you are making assumption. Im not in the assumption game.
Einstein makes many assumptions, many invalid.

This is the worst one.
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))

Where does that ½ come from?
Consider McCullough's silly little puzzle, which I'll embellish
slightly.
Sam and Joe are walking along carrying a 32 ft ladder between
them, at 3 fps. A mosquito flies from Sam to Joe and back to
Sam again at 5 fps, ground frame. How long does it take the
mosquito to make the round trip?
x' is the 32 ft ladder, c the speed of the mosquito and v the speed
of Sam and Joe.



Wait, first you said the mosquito flew at 5 fps, then you said at
c...are you assuming the speed of light is 5 fps in this
thought-experiment, or do you no mean c to be the speed of light?



I've clearly stated "c the speed of the mosquito", which is 5 fps.



In either case, I'd solve it like this. In the ground frame, the end
of the ladder starts out at position x=32 feet, moving at 3 fps, and
the mosquito starts out at x=0 feet, and moves at 5 fps, so in this
frame you'd calculate the time t for them to meet using the equation:

0 + 5t = 32 + 3t

which gives t=16 seconds, meeting at position x=80. Then the mosquito
flies backwards from that position at velocity -5 fps, and meanwhile
the other end of the ladder starts at x=48 feet and moves forward at 3
fps, so to find where they meet you could use this equation:

80 - 5t = 48 + 3t





which gives t = 4 seconds. So, the total time is 20 seconds. Notice
that I calculated everything from the ground frame, without ever
switching to the mosquito's frame or the ladder's frame.



Well, carry on, then. This is only algebra, prove that time for the
mosquito
is less, the ladder is shorter and that the speed of the mosquito is 5
fps in the moving frame. You can do (c+v)/(1+v/c) when you come to § 5
"with the help of the equations of transformation developed in § 3 "-
Einstein.

Introduction.
Section 1
Section 2
Section 3 Use c+v, c - v. Derive LT.
Section 4
Section 5 c= (c+v)/(1+v/c) from section 3.

The speeds of the mosquito in the moving frame are 8 and 3.
This makes the speed of the mosquito 5 in the moving frame
(Lorentz invariant)
I don't call that logical or consistent, but you do. We cannot agree
on what is logical.
The problem as I see it is that the time for the moquito to travel
from 0 to 80 and back to 60 at 5 fps = 100/5 = 20 is the same
time as in the moving frame, a distance of 32 at 8 fps + 32 at 2 fps,
and Einstein has used ½ of 20 seconds in the stationary frame
for the one way trip taking 16 seconds in the moving frame.
I call that assinine. The light never gets back to the origin of the K
frame, there is no half to consider.




Answer. 16 seconds to reach Joe and 4 seconds to return.
So (16+4)/2 = 16 ?
I don't think so. Einstein tries to justify it by saying Sam cannot
know when the mosquito reaches Joe, so he'll simply use the ½.
That is assumption, not mathematics.



What are you talking about?



I'm talking about the statement
"From the origin of system k let a ray be emitted at the time tau0 along
the X-axis to x', and at the time tau1 be reflected thence to the origin
of the co-ordinates,
arriving there at the time tau2; we then must have ½(tau0+tau2) = tau1.


Yes, but now he's analyzing things from within k's reference frame. In
terms of the ladder scenario, this would be equivalent to analyzing
things in the ladder's reference frame, while my analysis above was
actually in the reference frame of the observer on the ground.

Anyway, I've covered the same problem in the Sam&Mike scenario above--I
showed how the light (or mosquito moving at light speed) could be
measured to go at 5 feet/sec. both in terms of the ground-observer's
rulers and clocks *and* in terms of Sam&Mike's rulers and clocks.