The Moving Train
CLC
moving train with a mirror was given. According to SR, the non-moving
observer observes the light leaving the laser at an angle with respect to
the vertical direction. Otherwise the light would not reach the mirror.
However, I do not see any cause and effect here. Why should light decide to
leave the mirror with an angle here? Light does not have any will to to
anything, there must be some cause for this behaviour. What is the law of
physics that causes this behaviour?
If this is standard procedure for SR, then we should expect light from a
laser to create an angle with resepect to the vertical direction in every
moving situation. The faster the moving laser, the greater angle with the
vertical drection. When the velocity of the moving laser increases, light
would be directed more towards the direction of the moving laser. I find
that ludicrous, IMHO.
YBM
Do you have to decide to look smaller when seen at distance ?
Alfred Centauri
Imagine a water hose pointing straight up and a high speed (say 40mph)
stream of water exiting the water pipe straight up. Now, observe this
stream from a car moving at 30mph with respect to the water pipe. What
made the water decide to move at an angle to what you perceive as the
vertical? For that matter, what made the water decide to change speeds
from 40mph to 50mph (30^2 + 40^2)^(1/2)?
The twist that SR adds to all this is that the speed of light you
measure along that perceived diagonal path is c instead of (c^2 +
v^2)^(1/2) (where v is the relative velocity between the observers).
Regards,
Alfred
Martin Hogbin
"CLC" <leg...@spray.se> wrote in message news:pjt8a.2572$ID6....@newsc.telia.net...
> I was looking at the derivation for time dilation, and the example with the
> moving train with a mirror was given. According to SR, the non-moving
> observer observes the light leaving the laser at an angle with respect to
> the vertical direction. Otherwise the light would not reach the mirror.
> However, I do not see any cause and effect here. Why should light decide to
> leave the mirror with an angle here? Light does not have any will to to
> anything, there must be some cause for this behaviour. What is the law of
> physics that causes this behaviour?
I presume you are talking about what is often referred to as the 'light
clock'.
Imagine that, instead of a light beam bouncing off a mirror, there is
a ball being bounced off a wall. In the train the ball travels at right angles
to the direction of motion of the train.
How would a trackside observer see the motion of the ball? It
would be seen to leave the thrower at an angle. No magic
necessary, it is simply due to the motion of the train with respect
to the track. But for one important difference, it is exactly the
same for a light beam.
> If this is standard procedure for SR, then we should expect light from a
> laser to create an angle with respect to the vertical direction in every
> moving situation.
It is standard procedure for just about everything.
> The faster the moving laser, the greater angle with the
> vertical direction. When the velocity of the moving laser increases, light
> would be directed more towards the direction of the moving laser. I find
> that ludicrous, IMHO.
Think about it some more.
Martin Hogbin
CLC
"YBM" <ybm...@nooos.fr> wrote in message
news:3e6263a2$0$3826$79c1...@nan-newsreader-02.noos.net...
>
>
> Do you have to decide to look smaller when seen at distance ?
>
The area of a sphere increases as r^2. The further away, the larger sphere.
The surface of the sphere is then projected to my eyes. Of course objects at
a distance is seen as smaller by using geometrical derivations. This is true
for everyone.
Using logic, the definition of a contradiction is when 'A' and 'not A' are
both claimed to be true. Logic is not restricted to any frame. If light is
not emitted with an angle for the moving observer, and it is emitted with an
angle for another observer, we have a contradiction, and one or more of the
assumptions must be false.
Jon Bell
>I was looking at the derivation for time dilation, and the example with the
>moving train with a mirror was given. According to SR, the non-moving
>observer observes the light leaving the laser at an angle with respect to
>the vertical direction. Otherwise the light would not reach the mirror.
>However, I do not see any cause and effect here. Why should light decide to
>leave the mirror with an angle here? Light does not have any will to to
Suppose that instead of a light beam, you have a ball bouncing between the
floor and the ceiling of the train, and that from the point of view of
someone inside the train, the ball is bouncing straight up and down,
always hitting the same points on the floor and ceiling. From the point
of view of an observer on the ground, the ball is moving in a zigzag path,
always leaving the floor or ceiling at an angle. Why should the ball
decide to leave the floor or roof at an angle? A ball does not have any
will to do anything...
--
Jon Bell <jtbe...@presby.edu> Presbyterian College
Dept. of Physics and Computer Science Clinton, South Carolina USA
YBM
[...]
> Using logic, the definition of a contradiction is when 'A' and 'not A' are
> both claimed to be true. Logic is not restricted to any frame. If light is
> not emitted with an angle for the moving observer, and it is emitted with an
> angle for another observer, we have a contradiction, and one or more of the
> assumptions must be false.
Throw a ball vertically in a train... Its trajectory makes no angle with
the vertical direction, but it makes an angle for an exterior observer.
Football contradicts logic ?
CLC
"Alfred Centauri" <AlfredC...@bellsouth.net> wrote in message
news:3E626C3...@bellsouth.net...
Thanks for your reply, however I must make some remarks. In your example the
speed of the stream of water is 40 mph. Only a very naive moving observer
will believe that the real speed of the stream will increase when the moving
observer passes by in 30 mph. The speed of water will not increase in the
direction of the flow simply by another person passing by.
So if we return to the example with the moving train. Will the constant
speed of light really be violated by someone measuring a speed of (c^2 +
v^2)^(1/2) in the apparent speed of light? If we reduced the apparent speed
of light to c, then the real speed of light would be less than c. But that
would be a violation of the constant speed of light.
/CLC
Alfred Centauri
What do you mean when you say "the real speed of the stream"?
> observer passes by in 30 mph. The speed of water will not increase in the
> direction of the flow simply by another person passing by.
>
For a person passing by at 30mph, the speed of the water in the
direction of the flow is 50mph.
> So if we return to the example with the moving train. Will the constant
> speed of light really be violated by someone measuring a speed of (c^2 +
> v^2)^(1/2) in the apparent speed of light? If we reduced the apparent speed
> of light to c, then the real speed of light would be less than c. But that
> would be a violation of the constant speed of light.
>
> /CLC
>
What do you mean when you say "the real speed of light" verses "the
apparent speed of light"? Is apparent speed synonomous with measured speed?
Regards,
Alfred
dlzc@aol.com (formerly)
"CLC" <leg...@spray.se> wrote in message
news:pjt8a.2572$ID6....@newsc.telia.net...
To infer that any path you perceive cannot be perceived any other way is,
at best, provincial.
What makes any frame special? Only convention.
David A. Smith
Edward Schaefer
> "Alfred Centauri" <AlfredC...@bellsouth.net> wrote:
> >
> > Imagine a water hose pointing straight up and a high speed (say 40mph)
> > stream of water exiting the water pipe straight up. Now, observe this
> > stream from a car moving at 30mph with respect to the water pipe. What
> > made the water decide to move at an angle to what you perceive as the
> > vertical? For that matter, what made the water decide to change speeds
> > from 40mph to 50mph (30^2 + 40^2)^(1/2)?
> >
> > The twist that SR adds to all this is that the speed of light you
> > measure along that perceived diagonal path is c instead of (c^2 +
> > v^2)^(1/2) (where v is the relative velocity between the observers).
> >
>
> Thanks for your reply, however I must make some remarks. In your example the
> speed of the stream of water is 40 mph. Only a very naive moving observer
> will believe that the real speed of the stream will increase when the moving
> observer passes by in 30 mph. The speed of water will not increase in the
> direction of the flow simply by another person passing by.
I think that you have missed something very important about phyics (including
Newtonian physics) in general: All velocities are relative. The observer in
the car is moving at 30mph **with respect to** the water pipe does not change
the fact that the water is moving at 40mph **with repected to** the water pipe.
However, to get the speed of the water **with respect to the car** you have to
combine the two speeds as shown above. (Actually what you do is to combine the
velocities and compute the speed from that, as Alfred did above.)
In short: There is no such thing as an object having an absolute velocity, and
except for c there is no such thing as an absolute speed. Instead speeds and
velocities are meaningful only if they are with respect to something, and may be
modified as one goes from one frame of reference to another.
EMS
Harry
Hi CLC,
You already received some good "bouncing ball" examples, and here is another
that helped me some time ago.
Take a light clock with the light (dashed vertical line) propagating
perpendicular to the movement:
_ mirror
¦
¦
¦ -> v
¦
I laser
Seen from a moving observer:
_ mirror
¦
¦
¦ -> v
¦
I laser
This looks only "wrong" because it lacks resolution! For the light path
INSIDE the laser is ALSO (magnified 4 times):
I
I laser
I
I
It's the same as for a bullet fired from a rifle.
Regards,
Harald
CLC
> CLC wrote:
> > "Alfred Centauri" <AlfredC...@bellsouth.net> wrote in message
> > news:3E626C3...@bellsouth.net...
> >
> >>CLC wrote:
> > Thanks for your reply, however I must make some remarks. In your example
the
> > speed of the stream of water is 40 mph. Only a very naive moving
observer
> > will believe that the real speed of the stream will increase when the
moving
>
> What do you mean when you say "the real speed of the stream"?
>
> > observer passes by in 30 mph. The speed of water will not increase in
the
> > direction of the flow simply by another person passing by.
> >
>
> For a person passing by at 30mph, the speed of the water in the
> direction of the flow is 50mph.
>
> > So if we return to the example with the moving train. Will the constant
> > speed of light really be violated by someone measuring a speed of (c^2 +
> > v^2)^(1/2) in the apparent speed of light? If we reduced the apparent
speed
> > of light to c, then the real speed of light would be less than c. But
that
> > would be a violation of the constant speed of light.
> >
> apparent speed of light"? Is apparent speed synonomous with measured
speed?
>
We can measure the speed of the water stream by measuring its output of
water. 1 liter per second using
an output area of 1 cm^2, means a output velocity of the water with 1000
cm/s = 10 meter per second. This is what I meant by the real speed of the
water, which I thought would not change by anyone passing by, silly of me.
But we can call it output velocity to avoid confusion. This output velocity
could be measured with a rotor of some kind. So when the output veclocity of
light is c, it will still remain c when anyone passes by, but its apparent
or illusory velocity is (c^2 + v^2)^(1/2).
We can get the output velocity of light by measuring the speed when it has a
zero angle with respect to the vertical direction of the laser.
Eric Prebys
> I was looking at the derivation for time dilation, and the example with the
> moving train with a mirror was given. According to SR, the non-moving
> observer observes the light leaving the laser at an angle with respect to
> the vertical direction. Otherwise the light would not reach the mirror.
> However, I do not see any cause and effect here. Why should light decide to
> leave the mirror with an angle here? Light does not have any will to to
> anything, there must be some cause for this behaviour. What is the law of
> physics that causes this behaviour?
>
initial conditions for a laser beam produced in a resonator
which is moving laterally.
Of course, this would be very difficult. The easy way would be
to recognize that Maxwell's equations are Lorentz invariant and
use that to get the answer.
But if you like really hard math, get out your Jackson and go to
work.
> If this is standard procedure for SR, then we should expect light from a
> laser to create an angle with resepect to the vertical direction in every
> moving situation. The faster the moving laser, the greater angle with the
> vertical drection. When the velocity of the moving laser increases, light
> would be directed more towards the direction of the moving laser. I find
> that ludicrous, IMHO.
>
As someone who has spent some time working with lasers in translated
frames, I find your objection "ludicrous".
Seriously , if you have trouble visualizing it, consider a pulsed
laser beam sending out a signle short pulse and the path this
pulse follows.
-Eric
>
--
-------------------------------------------------------------------
Eric Prebys, Fermi National Accelerator Laboratory
Office: 630-840-8369, Email: pre...@fnal.gov
WWW: http://home.fnal.gov/~prebys
-------------------------------------------------------------------
CLC
"Jon Bell" <jtbe...@presby.edu> wrote in message
news:HB52r...@presby.edu...
I understand that the ball will be seen to have a different angle when
observed outside the train. Also the velocity of the ball will stay the same
with respect to the vertical direction both for the observer in the train
and the outside observer. The gedanken experiment with the train is
incorrect in that it does not allow for the same thing to happen with light.
CLC
CLC
"Eric Prebys" <pre...@fnal.gov> wrote in message
news:3E638301...@fnal.gov...
Let us say the laser is moving as in the train. What will be the speed of
light in the vertical direction as observed from an outside frame?
YBM
[...]
> I understand that the ball will be seen to have a different angle when
> observed outside the train. Also the velocity of the ball will stay the same
> with respect to the vertical direction both for the observer in the train
> and the outside observer. The gedanken experiment with the train is
> incorrect in that it does not allow for the same thing to happen with light.
This is exactly the point : experiments show that like does not behave
like a ball, the gedankenexperiment is here to state the consequences
of a hypothesis (light speed constant wich is compatible with such
experiments (namely : Michelson-Morley *and* stellar aberration)
Try not to confuse "difficult to understand at first sight" with
"incorrect"...
Eric Prebys
Assuming the laser is pointed directly "up" in the train,
the vertical velocity measured by a stationary observer
would be u = sqrt(c^2-V^2), where V is the forward velocity
of the train. You can get this with relativistic velocity
addition or just by thinking about it for a minute.
There aren't many trains moving near the speed of light,
but back in the real world, this is not dramatically
different to the kinematics of pi0->gamma+gamma decay
when the gammas decay perpendicular to path of flight.
-Eric
kenseto
You are perfectly correct. It is ludicrous. In real life the what outside
observer will see is as follows: Each photon generated by the source will
keep on moving in the vertical direction and the train will keep on moving
in the horizontal direction. What this mean is that the first batch of
photons will miss the vertical target at the ceiling of the train. The
number of photons missed the target is dependent on the state of motion of
the train.....obviously the higher is the state of motion of the train the
more photons will missed the target. Also, this means that the first photon
that hits the vertical target at the ceiling is not the first photon
generated by the source. It was a photon that was generated at a later time
by the source. Current physics interpreted as time dilation.
For more details about this concept please visit my website:
http://www.erinet.com/kenseto/book.html
Ken Seto
CLC
> CLC a écrit:
> [...]
> > I understand that the ball will be seen to have a different angle when
> > observed outside the train. Also the velocity of the ball will stay the
same
> > with respect to the vertical direction both for the observer in the
train
> > and the outside observer. The gedanken experiment with the train is
> > incorrect in that it does not allow for the same thing to happen with
light.
>
> This is exactly the point : experiments show that like does not behave
> like a ball, the gedankenexperiment is here to state the consequences
> of a hypothesis (light speed constant wich is compatible with such
> experiments (namely : Michelson-Morley *and* stellar aberration)
>
way or another. The MMX experiment showed at most that light is perhaps
constant in a frame for an observer where the observer and the light source
are in the same frame, both at constant distance from each other. It did not
say anything about how light would look like for an outside observer.
I have seen non-relativistic explanations for stellar aberration.
Besides, don't you think that a theory that has existed for almost a hundred
years should have been accepted by everyone by now if it was true?
/CLC
ste...@nomail.com
: Besides, don't you think that a theory that has existed for almost a hundred
: years should have been accepted by everyone by now if it was true?
: /CLC
http://home.twcny.rr.com/ronaldus/hoax.htm
http://www.talkorigins.org/faqs/flatearth.html
Stephen
Alfred Centauri
>
<snip>
> We can measure the speed of the water stream by measuring its output of
> water. 1 liter per second using
> an output area of 1 cm^2, means a output velocity of the water with 1000
> cm/s = 10 meter per second. This is what I meant by the real speed of the
> water, which I thought would not change by anyone passing by, silly of me.
> But we can call it output velocity to avoid confusion. This output
velocity
> could be measured with a rotor of some kind.
Yes, then we will have measured the output speed of the water stream. By
output speed, we mean "the speed of the water relative to the end of the
pipe to which the rotor is attached to". Of course, the speed is unchanged
when someone drives by. If a rotor to measure the speed of the water with
respect to the car gives a different reading, does this alter the reading of
the rotor on the pipe? Of course not. Which rotor reading gives the 'real
speed' of the water - neither do. Which rotor reading gives the measured
speed of the water - both do. None of this is SR so are we actually
debating any of this?
> So when the output veclocity of
> light is c, it will still remain c when anyone passes by
Yup, I agree.
> but its apparent
> or illusory velocity is (c^2 + v^2)^(1/2).
What is illusory velocity? To determine speed (or velocity) requires that a
measurement be made. The speed that is measured is _the_ speed - it is the
measure of the relative motion between the two objects, not the 'real
speed', not the 'apparent speed', nor the 'illusory speed'. SR postulates
that when the speed of light is measured by anyone or anything that is not
accelerated, the measured speed will be c. Others may postulate that the
measured speed will be different. But your references to 'real speed' and
'illusory speed' are meaningless. For example, two cars with 'real speeds'
of 60mph in opposite directions collide head on. Is there anything illusory
about their relative 120mph speed at impact?
> We can get the output velocity of light by measuring the speed when it has
a
> zero angle with respect to the vertical direction of the laser.
>
You are proposing to measure the speed of light emitted by the laser with an
apparatus at rest with respect to the laser, right? Now, imagine that the
apparatus sits 1 meter directly above the laser all the while measuring the
speed of the light passing through it. Imagine that I go whizzing by at
damn near the speed of light to the left. From my perspective, the
apparatus 1 meter above the laser has moved almost 1 meter to the right
during the time the light took to travel from the laser to the apparatus.
Does this mean the laser light missed the apparatus from my perspective?
Don't think so. Does this mean the light took a longer path to the
apparatus from my perspective? Yup, almost sqrt(2) meters. What speed do I
see the apparatus measure for the speed of light? Could it be different
from c? Hmmmm....
YBM
[...]
> I have seen non-relativistic explanations for stellar aberration.
It's why I emphasized the "and" in my response : you can't have the
same non-relativistic explanation for *both* stellar aberration and
MM (without even speaking of hundreds...
> Besides, don't you think that a theory that has existed for almost a hundred
> years should have been accepted by everyone by now if it was true?
It is an non-argument. Stephen pointed out sites "proving" the earth
to be flat, I saw once a huge site, with tons of pseudo-maths, refuting
the existence of satellites and astronomical observation...
Besides, don't you think that "trivial" refutation as you did of a
theory that have been in place for nearly a century, and has been
mathematicaly and physicaly reconstructed from almost every possible
point of view should /at least/ be considered twice before posting
with so much arrogance ? It is a very basic "reality check" !
YBM
Ah ! Seto was missing here. The little stupidity is an attractor for
the huge one...
You didn't explain what "in frame A, light speed is not isotropic
in frame B" is supposed to mean, anyway.
Moreover you didn't say if in frame A, one would see light speed
to be isotropic as B can see it in frame A ? Should I continue ?
CLC
> CLC a écrit:
> [...]
> > I have seen non-relativistic explanations for stellar aberration.
>
> It's why I emphasized the "and" in my response : you can't have the
> same non-relativistic explanation for *both* stellar aberration and
> MM (without even speaking of hundreds...
>
> > Besides, don't you think that a theory that has existed for almost a
hundred
> > years should have been accepted by everyone by now if it was true?
>
> It is an non-argument. Stephen pointed out sites "proving" the earth
> to be flat, I saw once a huge site, with tons of pseudo-maths, refuting
> the existence of satellites and astronomical observation...
>
As I said, perhaps light is constant in a frame with a comoving observer and
lightsource, but I do not think even this can prove time dilation. A
ballistic model of light would also show a null result. Also there can be
several explanations for the null result. Lorentz suggested that the
interferometer contracted in the direction of movement because of an ether.
If a clock moves in a ether that drags light, the clock will go slower. A
local ether, whatever its cause, around the Earth makes sense to me.
These are common sense explanations and SR is definitely not common sense.
Eric Prebys
OK, that has to be the single stupidest argument I've seen in a
newsgroup full of stupid arguments.
-Eric
> /CLC
>
>
>
Dirk Van de moortel
"Eric Prebys" <pre...@fnal.gov> wrote in message news:3E64E234...@fnal.gov...
Definitely ;-)
http://users.pandora.be/vdmoortel/dirk/Physics/ImmortalFumbles.html#Accept
Title: "About accepting theories"
Dirk Vdm
CLC
> >>initial conditions for a laser beam produced in a resonator
> >>which is moving laterally.
> >
of
> > light in the vertical direction as observed from an outside frame?
> >
> >
>
> Assuming the laser is pointed directly "up" in the train,
> the vertical velocity measured by a stationary observer
> would be u = sqrt(c^2-V^2), where V is the forward velocity
> of the train. You can get this with relativistic velocity
> addition or just by thinking about it for a minute.
>
> There aren't many trains moving near the speed of light,
> but back in the real world, this is not dramatically
> different to the kinematics of pi0->gamma+gamma decay
> when the gammas decay perpendicular to path of flight.
>
> -Eric
>
So what are the initial conditions for a laser beam produced in a resonator
which is moving laterally? I am just curious.
/CLC
CLC
This means that it takes the same time for the apparatus to measure the time
it takes for light to travel 1 meter from the perspective of the stationary
observer as sqrt(2) meters from the perspective of the moving observer,
which means that the speed of the observed light increases for the moving
observer. This is the same effect as what happens when you pass by sign
post. From the perspective of a stationary observer at the sign post, the
velocity of the sign post is zero, from the perspective of the moving
observer the speed of the sign post is the same as the speed of the moving
observer. Also called Galilean transformation.
/CLC
Eric Prebys
Well, you'd have to put in the time dependent position of the
plates on either end as light bounced back and forth, superimposed
on the moving atoms of the lasing material. You would find that
to a stationary observer, the resonant condition would have
the light zigzagging back and forth across the resonator just like
in the train gedanken experiment.
Of course, since Maxwell's equations are manifestly Lorentz
invariant, this would be a really stupid way to solve the
problem.
-Eric
> /CLC
>
>
Alfred Centauri
<snip>
> This means that it takes the same time for the apparatus to measure the
time
> it takes for light to travel 1 meter from the perspective of the
stationary
> observer as sqrt(2) meters from the perspective of the moving observer,
> which means that the speed of the observed light increases for the moving
> observer.
Is that the only possibility?
<snip>
CLC
> CLC wrote:
> > "YBM" <ybm...@nooos.fr> wrote in message
> > news:3e639ed0$0$23765$79c1...@nan-newsreader-01.noos.net...
> >
> >>CLC a écrit:
one
> > way or another. The MMX experiment showed at most that light is perhaps
> > constant in a frame for an observer where the observer and the light
source
> > are in the same frame, both at constant distance from each other. It did
not
> > say anything about how light would look like for an outside observer.
> >
> > I have seen non-relativistic explanations for stellar aberration.
> >
> > Besides, don't you think that a theory that has existed for almost a
hundred
> > years should have been accepted by everyone by now if it was true?
> >
>
> OK, that has to be the single stupidest argument I've seen in a
> newsgroup full of stupid arguments.
>
> -Eric
>
Was that the best physical argument you could make? How disappointing. It is
so easy to break your pet theory SR apart by some logical arguments. Really
no sport.
The question was a somewhat provocative, but then, when 100 years had passed
since Newton had presented his theory, it had been accepted by almost
everyone, the same thing has not happened with SR. That is because SR lacks
credibility and common sense.
/CLC
Dirk Van de moortel
"CLC" <leg...@spray.se> wrote in message news:kQt9a.13400$FF4.6...@newsb.telia.net...
>
> "Eric Prebys" <pre...@fnal.gov> wrote in message
> news:3E64E234...@fnal.gov...
> > CLC wrote:
> > > "YBM" <ybm...@nooos.fr> wrote in message
> > > news:3e639ed0$0$23765$79c1...@nan-newsreader-01.noos.net...
> > >
> > >>CLC a écrit:
> > > Time will not change its speed only because light or e-m waves behaves
> one
> > > way or another. The MMX experiment showed at most that light is perhaps
> > > constant in a frame for an observer where the observer and the light
> source
> > > are in the same frame, both at constant distance from each other. It did
> not
> > > say anything about how light would look like for an outside observer.
> > >
> > > I have seen non-relativistic explanations for stellar aberration.
> > >
> > > Besides, don't you think that a theory that has existed for almost a
> hundred
> > > years should have been accepted by everyone by now if it was true?
> > >
> >
> > OK, that has to be the single stupidest argument I've seen in a
> > newsgroup full of stupid arguments.
> >
> > -Eric
> >
>
> Was that the best physical argument you could make?
> How disappointing. It is so easy to break your pet theory
> SR apart by some logical arguments. Really no sport.
Yeah, like that brilliant logical argument of verticality in the
train versus the angle with the vertical of the embankment
observer. Nice logical argument. Really no sport.
>
> The question was a somewhat provocative, but then, when 100
> years had passed since Newton had presented his theory, it
> had been accepted by almost everyone, the same thing has not
> happened with SR. That is because SR lacks credibility and
> common sense.
Another brilliant logical argument.
Glad to have brilliant minds like yours around to keep us on
the right track. What would science do without your logical
arguments?
Dirk Vdm
> /CLC
Eric Prebys
Your "argument" contained no physics or logic, so I answered in kind.
> The question was a somewhat provocative, but then, when 100 years had passed
> since Newton had presented his theory, it had been accepted by almost
> everyone, the same thing has not happened with SR.
I think you're confusing an NG full of kooks with a representative
sample of the rational community. Indeed, SR is certainly "accepted
by almost everyone".
> That is because SR lacks
> credibility and common sense.
>
How "common" is it to travel near the speed of light?
-Eric
> /CLC
>
>
Martin Hogbin
> since Newton had presented his theory, it had been accepted by almost
> everyone, the same thing has not happened with SR. That is because SR lacks
> credibility and common sense.
Surprise, surprise. Another ambush physicist. That makes a change for this
group!
Martin Hogbin
CLC
Well. We will have to agree to disagree here. I do not see any need for
speed to be constant from the perspective of the moving frame.
Alfred Centauri
>
> Well. We will have to agree to disagree here. I do not see any need for
> speed to be constant from the perspective of the moving frame.
>
>
Fair enough.
Regards,
Alfred
Martin Hogbin
"CLC" <leg...@spray.se> wrote in message news:0mO9a.13554$FF4.6...@newsb.telia.net...
>
>
> Well. We will have to agree to disagree here. I do not see any need for
> speed to be constant from the perspective of the moving frame.
Have a look at some of Spaceman's posts. You might have to try a bit to
look that stupid but you could do it if you wanted to.
Martin Hogbin
CLC
radiation from the cesium-133 atoms. Length and light speed c is derived
from this standard unit. It is not the other way around.
CLC
Bill Vajk
> The standard second is is derived from a constant number of periods of
> radiation from the cesium-133 atoms.
Oops! Please rephrase that. The second is the second, therefore the
"second standard is derived....." The second has always been the
second despite more than one historical standard for it.
William J. Vajk
Techny, Illinois
kenseto
"Bill Vajk" <bill9...@hotmail.com> wrote in message
news:3E47A8F3...@hotmail.com...
Does a clock second have the same duration in all inertial frames.
In other words, is a transition of the cesium-133 atom have the same
duration in all inertial frames?
CLC
and c are derived from the definition of a second. Therefore a change in the
how we define a meter does not change the time measurement of a second, but
a change in how we define a second will also change the length of the meter.
CLC