Re: Superluminal Quasar Jets : The Beaming "Explanation" Appears Inadequate

From: George Dishman (george_at_briar.demon.co.uk)
Date: 02/28/05 

Date: Mon, 28 Feb 2005 00:14:57 -0000

<jgreen@seol.net.au> wrote in message
news:1109545483.934581.52550@l41g2000cwc.googlegroups.com...
>
> George Dishman wrote:
>> <jgreen@seol.net.au> wrote in message
>> news:1109461004.939277.271580@f14g2000cwb.googlegroups.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/more/light/light_page9.html
>>
>> > , and thus in direct conflict with AE?
>>
>> See section 6 of Einstein's original paper:
>>
>> http://www.fnal.gov/pub/inquiring/more/light/light_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 here:
>>
>> 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

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