Superluminal Quasar Jets : The Beaming "Explanation" Appears Inadequate

Dear Jonathan Silverlight:

"Jonathan Silverlight"
wrote in message ...
In message kPkTd.81133$Yu.56373@fed1read01, "N:dlzc D:aol T:com (dlzc)"
writes
Dear Chris O'Riordan:

"Chris O'Riordan" wrote in message
groups.com...
The conventional explanantion for the superluminal motions observed in
many quasar-type jets is that it is an optical illusion due to the jets
being oriented at a fairly narrow angle to our line of sight.
...

If the jets are truly superlumenal, how is it that we can see light from
them? Since we *do* see light from them, and their spectra are
"reasonable", the rest is "tricks of geometry". If they were
superlumenal,
the light could never leave...

We could see Cerenkov radiation (it's been looked for in searches for
tachyons) but presumably the spectrum from a jet doesn't match what's
expected for Cerenkov radiation, so that's not the answer.

My point was, if they are moving towards us in any sense, faster than c,
then the particle/body/object will outrun the light. We could *see*
nothing coming towards us. And the faster it is, the closer it would have
to be to "motion at 90 deg to line of sight" to keep from outrunning light
that leaves towards us.

I agree, Cerenkov radiation places limits on ions, and even on sources of
thermally-based light emission (which liberates charges).

David A. Smith

"NDT" == N:dlzc D:aol T:com \(dlzc\) N writes:

NDT My point was, if they are moving towards us in any sense, faster
NDT than c, then the particle/body/object will outrun the light. We
NDT could *see* nothing coming towards us. And the faster it is,
NDT the closer it would have to be to "motion at 90 deg to line of
NDT sight" to keep from outrunning light that leaves towards us.

Yes, but the model isn't that the ejecta is moving faster than the
speed of light. Consider ejecta moving at 0.999c and moving toward
you.

--
Lt. Lazio, HTML police | e-mail:
No means no, stop rape. | http://patriot.net/%7Ejlazio/
sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html

Dear Joseph Lazio:

"Joseph Lazio" wrote in message
...
"NDT" == N:dlzc D:aol T:com \(dlzc\) N writes:

NDT My point was, if they are moving towards us in any sense, faster
NDT than c, then the particle/body/object will outrun the light. We
NDT could *see* nothing coming towards us. And the faster it is,
NDT the closer it would have to be to "motion at 90 deg to line of
NDT sight" to keep from outrunning light that leaves towards us.

Yes, but the model isn't that the ejecta is moving faster than the
speed of light. Consider ejecta moving at 0.999c and moving toward
you.

The concern appears to be "what if they are superlumenal". The standard
model doesn't have the problem I described. He has so far ignored the
"normal spectrum", which also limits the jet to sublumenal speed.

Maxwell provides the conundrum I describe, since light travels at c for all
observers, yet light leaves "forward" from an object travelling at c. He
seems to be running towards Fizeau next...

David A. Smith

N:dlzc D:aol T:com (dlzc) wrote:
Dear Joseph Lazio:

"Joseph Lazio" wrote in message
...
"NDT" == N:dlzc D:aol T:com \(dlzc\) N writes:

NDT My point was, if they are moving towards us in any sense,
faster
NDT than c, then the particle/body/object will outrun the light.
We
NDT could *see* nothing coming towards us. And the faster it is,
NDT the closer it would have to be to "motion at 90 deg to line of
NDT sight" to keep from outrunning light that leaves towards us.

Yes, but the model isn't that the ejecta is moving faster than the
speed of light. Consider ejecta moving at 0.999c and moving toward
you.

The concern appears to be "what if they are superlumenal". The
standard
model doesn't have the problem I described. He has so far ignored
the
"normal spectrum", which also limits the jet to sublumenal speed.

Maxwell provides the conundrum I describe, since light travels at c
for all
observers, yet light leaves "forward" from an object travelling at c.
He
seems to be running towards Fizeau next...

Then wasn't Maxwell saying c'=c+v , and thus in direct conflict with
AE?

How is the increasing length per time (velocity) of these jets
measured?
SR believers might claim that the only legitimate measurement would be
that of a traveller on the jet! Otherwise, SR is decapitated right
here, with the obvious and trivial observation that velocity has NOT
shrunken the moving body!

Jim G
c'=c+v

wrote in message
oups.com...

N:dlzc D:aol T:com (dlzc) wrote:

Maxwell provides the conundrum I describe, since light travels at c for
all
observers, yet light leaves "forward" from an object travelling at c. He
seems to be running towards Fizeau next...

Then wasn't Maxwell saying c'=c+v

David said "light travels at c for all observers"
hence c'=c.

http://www.fnal.gov/pub/inquiring/mo...ght_page9.html

, and thus in direct conflict with AE?

See section 6 of Einstein's original paper:

http://www.fnal.gov/pub/inquiring/mo...ght_page9.html

How is the increasing length per time (velocity) of these jets measured?

Length isn't too meaningful as the jets are a
continuous flow so there is no clear end to the
jet. Measuring the speed depends on non-uniformity
in the flow by following the progress of 'knots'
of matter. For example:

http://www.stsci.edu/ftp/science/m87/m87.html

and in particular this set of frames:

http://www.stsci.edu/ftp/science/m87/bw3.gif

Or look at the attached radio map he

http://www.phy.duke.edu/~kolena/superluminalmotion.html

You might also practice your maths by trying
to answer the questions on that page ;-)

SR believers might claim that the only legitimate measurement would be
that of a traveller on the jet!

SR provides a set of rules for converting
measurements in one frame into another frame.
Both measurements are "legitimate" in their
respective frames.

Otherwise, SR is decapitated right
here, with the obvious and trivial observation that velocity has NOT
shrunken the moving body!

It has. Someone riding on the jet would measure
a greater distance between the same knots than
an observer at rest wrt the source and viewing
the jet perpendicular to its motion.

George

George Dishman wrote:
wrote in message
oups.com...

N:dlzc D:aol T:com (dlzc) wrote:

Maxwell provides the conundrum I describe, since light travels at
c for
all
observers, yet light leaves "forward" from an object travelling at
c. He
seems to be running towards Fizeau next...

Then wasn't Maxwell saying c'=c+v

David said "light travels at c for all observers"
hence c'=c.

If c'=c for ALL observers, does not l'=l for those SAME observers?

http://www.fnal.gov/pub/inquiring/mo...ght_page9.html

, and thus in direct conflict with AE?

See section 6 of Einstein's original paper:

http://www.fnal.gov/pub/inquiring/mo...ght_page9.html

How is the increasing length per time (velocity) of these jets
measured?

Length isn't too meaningful as the jets are a
continuous flow so there is no clear end to the
jet. Measuring the speed depends on non-uniformity
in the flow by following the progress of 'knots'
of matter. For example:

The view is of a train coming out of a tunnel; select a carriage (=
knot)
and measure to engine. Length is carriage - engine velocity is
carriage
- tunnel mouth / time

http://www.stsci.edu/ftp/science/m87/m87.html

and in particular this set of frames:

http://www.stsci.edu/ftp/science/m87/bw3.gif

Or look at the attached radio map he

http://www.phy.duke.edu/~kolena/superluminalmotion.html

You might also practice your maths by trying
to answer the questions on that page ;-)

SR believers might claim that the only legitimate measurement would
be
that of a traveller on the jet!

SR provides a set of rules for converting
measurements in one frame into another frame.
Both measurements are "legitimate" in their
respective frames.

If we applied SR to the observed velocity length which we are seeing,
then the jet would vanish! (Travelling at c it reduces to nil)

We can see the speed of the jet by way of the increasing angle between
the source and the "top", if we have a fair idea of the distance from
here.
The passenger on the jet has NO angle to observe, and so he continues
to be mistaken in his belief that he is closer to the top than he
measures. :-)

Otherwise, SR is decapitated right
here, with the obvious and trivial observation that velocity has
NOT
shrunken the moving body!

It has. Someone riding on the jet would measure
a greater distance between the same knots than
an observer at rest wrt the source and viewing
the jet perpendicular to its motion.

similar to above

Cheers
Jim G
c'=c+v

Special Relativity applies.

wrote in message
ups.com...

George Dishman wrote:
wrote in message
oups.com...

Then wasn't Maxwell saying c'=c+v

David said "light travels at c for all observers"
hence c'=c.

If c'=c for ALL observers, does not l'=l for those SAME observers?

You know better than that Jim. Remember our email
discussions

IF
speed = c
THEN
....
ENDIF

http://www.fnal.gov/pub/inquiring/mo...ght_page9.html

, and thus in direct conflict with AE?

See section 6 of Einstein's original paper:

http://www.fnal.gov/pub/inquiring/mo...ght_page9.html

How is the increasing length per time (velocity) of these
jets measured?

Length isn't too meaningful as the jets are a
continuous flow so there is no clear end to the
jet. Measuring the speed depends on non-uniformity
in the flow by following the progress of 'knots'
of matter. For example:

The view is of a train coming out of a tunnel; select a
carriage (= knot) and measure to engine. Length is
carriage - engine velocity is carriage - tunnel
mouth / time

The engine passed long ago and is now out of sight
but you can choose any two carriages to get the
same effect.

http://www.stsci.edu/ftp/science/m87/m87.html

and in particular this set of frames:

http://www.stsci.edu/ftp/science/m87/bw3.gif

Or look at the attached radio map he

http://www.phy.duke.edu/~kolena/superluminalmotion.html

You might also practice your maths by trying
to answer the questions on that page ;-)

SR believers might claim that the only legitimate measurement
would be that of a traveller on the jet!

SR provides a set of rules for converting
measurements in one frame into another frame.
Both measurements are "legitimate" in their
respective frames.

If we applied SR to the observed velocity length which we are seeing,
then the jet would vanish! (Travelling at c it reduces to nil)

The jet is travelling at less than c, and what
we see is the reduced length, if measured on the
jet it would be longer.

We can see the speed of the jet by way of the increasing angle between
the source and the "top", if we have a fair idea of the distance from
here.
The passenger on the jet has NO angle to observe, and so he continues
to be mistaken in his belief that he is closer to the top than he
measures. :-)

Otherwise, SR is decapitated right
here, with the obvious and trivial observation that velocity has NOT
shrunken the moving body!

It has. Someone riding on the jet would measure
a greater distance between the same knots than
an observer at rest wrt the source and viewing
the jet perpendicular to its motion.

similar to above

Similar but the other way round.

George

wrote:

[snip]


If c'=c for ALL observers, does not l'=l for those SAME observers?

If you mean "length" here, then no. Why should it?


[snip]

Bye,
Bjoern

"j" == jgreen writes:

j The view is of a train coming out of a tunnel; select a carriage (=
j knot) and measure to engine. Length is carriage - engine velocity
j is carriage tunnel mouth / time

O.k., suppose you make this measurement. Say you get 2
milliarcseconds. Suppose you also know the distance to the quasar, so
that you can convert the angular distance (in milliarcseconds) to a
linear distance (in parsecs).

Now what? You have one measurement. We don't know the velocity of
the material in the jet (other than it is probably close to c), and
you cannot necessarily use the motion of the knots, because they might
be shock waves within the jets and not reflecting the actual motion of
the material in the jet.

--
Lt. Lazio, HTML police | e-mail:
No means no, stop rape. | http://patriot.net/%7Ejlazio/
sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html