Superluminal Quasar Jets : The Beaming "Explanation" Appears Inadequate

In message , Joseph Lazio
writes
"CO" == Chris O'Riordan writes:

CO There are key cases where it emphatically DOESN'T appear to fit,
CO as I mentioned in
CO http://www.geocities.com/chrisori2000/superjet.htm

There appears to be some link rot here.

CO To recap:-

CO (For the 7 known superluminals in 1983,) the structures did NOT in
CO general appear to be oriented close to the line-of-sight;

CO Mackay, Thompson et al suggested in 1993 that the (outer) jet of
CO quasar 3C273 was nearly PERPENDICULAR, rather than nearly
CO parallel, to the line-of-sight. Superluminal motion of up to
CO ~9.6c has been observed along the (inner) jet;

I can find no paper in ADS with the authors "Mackay" and "Thompson."
Perhaps you could post a reference?

There's a paper in Nature 9 September 1993, vol 365 no 6442
"Internal structure and polarisation of the optical jet of the quasar
3C273" RC Thomson CD MacKay and AE Wright, but I don't have access
online.
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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

Sorry, the correct link is
http://uk.geocities.com/chrisori2000/superjet.htm , which has links to
*some* of the references.

As Jonathan Silverlight below remarks, the Nature article by Thompson,
Mackay and Wright isn't online. It appeared in 1993, and Nature hasn't
got round to putting these online yet. But, basically, the authors say
that the (outer) jet appears to be nearly parallel to the line of sight
because of the way it apparently intersects the surface of a gaseous
halo around the quasar. (Brightening of the jet coincides with
apparent edge-brightening of the halo.)

Joseph Lazio wrote:
"CO" == Chris O'Riordan writes:


CO There are key cases where it emphatically DOESN'T appear to fit,
CO as I mentioned in
CO http://www.geocities.com/chrisori2000/superjet.htm

There appears to be some link rot here.

CO To recap:-

CO (For the 7 known superluminals in 1983,) the structures did NOT in
CO general appear to be oriented close to the line-of-sight;

CO Mackay, Thompson et al suggested in 1993 that the (outer) jet of
CO quasar 3C273 was nearly PERPENDICULAR, rather than nearly
CO parallel, to the line-of-sight. Superluminal motion of up to
CO ~9.6c has been observed along the (inner) jet;

I can find no paper in ADS with the authors "Mackay" and "Thompson."
Perhaps you could post a reference?

All the ADS links I can find for 3c273 since 1995 say that the
observations are entirely consistent with a precessing relativistic jet.
There are oblique references to the discrepancy between what is seen in
VLBI at near the core out way out in the optical. eg.

http://searcht.netscape.com/ns/boomf...t_service.html

CO The jet of the galaxy M87 needs to be at ~19 degrees to the
CO line-of-sight to explain by beaming superluminal motion of up to
CO ~6c in it -- but independent evidence on the jet's orientation
CO suggests it is at ~43 degrees to our line-of-sight.

Doesn't this require independent knowledge of the speed of the ejecta?
Reference?

Again the modellers seem to have things under control. eg
http://searcht.netscape.com/ns/boomf...t_service.html

And being close to us it is well studied at high resolution eg
http://searcht.netscape.com/ns/boomf...t_service.html

Regards,
Martin Brown

wrote:

[snip]

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

No, he indeed was not saying that.

Why do you think he was?


[snip]

Bye,
Bjoern

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

In message .com,
Chris O'Riordan writes
Sorry, the correct link is
http://uk.geocities.com/chrisori2000/superjet.htm , which has links to
*some* of the references.

As Jonathan Silverlight below remarks, the Nature article by Thompson,
Mackay and Wright isn't online. It appeared in 1993, and Nature hasn't
got round to putting these online yet. But, basically, the authors say
that the (outer) jet appears to be nearly parallel to the line of sight
because of the way it apparently intersects the surface of a gaseous
halo around the quasar. (Brightening of the jet coincides with
apparent edge-brightening of the halo.)

There's an ADS abstract at
http://adsabs.harvard.edu/cgi-bin/np...93Natur.365..1
33T&db_key=AST, but having read the paper I'm not entirely
convinced by their argument.
For instance, has anyone confirmed the existence of this shell, whose
radius coincides with knot A1 in the jet? They say
"If this interpretation is correct and the shell feature is real and
edge-brightened, then the jet in 3C273 cannot be aligned nearly parallel
to the line of sight; it must be viewed in the plane of the sky nearly
perpendicular to the line of sight. This follows from the observed
coincidence of knot A1 with the (possibly) edge-brightened shell, which
would then be a remarkable coincidence if the jet were actually aligned
nearly parallel to the line of sight.
Consequently, the optical jet could not be beamed towards us and must be
one-sided".
That sounds a bit circular, and if we aren't seeing a shell, or not
seeing edge-brightening, the coincidence disappears.
And you still have to explain the one sided jet.