🚀 go-pugleaf

On Tue, 13 May 2008 14:33:32 +0100, "Androcles" <Headmaster@Hogwarts.physics>
wrote:

>
>"Dr. Henri Wilson" <HW@....> wrote in message 
>news:6j6i241dbneq6tdg9d02jlt2rmk2vn0e89@4ax.com...

>| >| My equation is for the rotating frame in which both rays appear to move 
>at
>| >c
>| >| wrt the source/detector.
>| >| ct = 2piR + alphaR
>| >
>| >In the rotating frame the "observer" (what or whomever that may be) 
>doesn't
>| >move at all, he goes along with the rotating frame. You don't move with
>| >respect
>| >to the city of Sydney, but you do move around the Sun by one degree a day
>| >(alpha).
>| >As far as you are concerned the speed of light from your home to downtown
>| >Sydney
>| >is c and the distance is ct.  It is NOT ct-alpha.R, you have to be off 
>the
>| >Earth to make
>| >that determination. You can't frame hop, Wilson.
>|
>| Look, I've tried to explain this to relativists but they're too dumb to
>| understand. You are more intelligent so can probably see what's going on. 
>Read
>| carefully.
>
>Ok, then read my replies carefully.
>
>
>| Consider you are on the ring and rotating with it at v.
>| Next to you is another ring that is NOT rotating.
>
>If this second ring is concentric with the rotating ring then it IS rotating 
>in the
>opposite direction in frame of reference, and if not then it is orbiting my 
>ring,
>crossing my sky as I turn just as the sun does. Indeed, the Earth and Sun 
>are
>two such rings.
>  I've intelligently read carefully and find you have not made adequate 
>definition
>for me to understand your intent at this stage.

Of course the second ring is concentric. it is right next to the gyro ring.


>| At  certain instant, you emit two pulses of light in opposite directions 
>around
>| the ring. You also place a mark on the nonrotating ring.
>|
>| What happens to the mark?
>| Answer: it appears to move away from you at v.
>
>Not at all, it moves away at v.sin(t), eventually returning.

The movement is only a couple of light wavelengths at the most. 
You can assume the movement is in a straight line and is just vt..

>| By the time the pulses return, the mark has moved a distance vt away.
>
>The pulses never return, they travel directly away from me in opposite
>directions and continue forever.

We are discussing a ring gyro in which total internal reflection occurs. As far
as this argument is concerned the rays move in straight lines.

>You are not doing a very good job here with your specialising in teaching
>physics to engineers and mathematicians... or perhaps you are, this
>is typical of the kind of undefined crap we've come to expect of
>physicists. It is also why your programs are loaded down with constants,
>you fail to define them at the beginning, inventing them as you need them.
>That's a very poor programming technique, you have only to make
>a typographical error in "3.14259265" somewhere and you'll never spot it,
>whereas by writing "pi = 3.14159265" at the beginning it is defined 
>throughout.
>I never write 3.141592653589790
> as a value in excel, I use pi() instead.
>
>
>Grandpa doesn't ride the carousel, Wilson, only the kids do that.
>  http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/gifs/coriolis.mov

In a ring gyro, the detector rides the ring.

>| Of course YOU have no way of knowing that the mark represents the original
>| position of the emission point or that you are rotating with a peripheral 
>speed
>| of v. You have every reason to believe that both pulses move away from you 
>at c
>| and travel the same distance, 2piR in the same time. You are therefore
>| mystified by the fact that they are not in phase when they reunite.
>
>I'm not mystified at all, Wilson, but you are.
>When two kids pace their way around the carousel matching step for step
>they arrive "in phase" back at the start point. Only when they step off
>and one rides the moving sidewalk and the other does not do they get
>"out of phase" because one is travelling faster than the other.

In a ring gyro stuck in an aeroplane, the kids don't ever get off.

>Here's some pictures of it:
>  http://www.androcles01.pwp.blueyonder.co.uk/Sagnac/RealSagnac.gif
>  http://www.androcles01.pwp.blueyonder.co.uk/Sagnac/RealSagnacFixed.gif

What in christ's name is that?

>|
>| This is a perfect example of how the use of rotating frames can be 
>misleading.
>| In fact, the rays travel different distances EVEN IN THE ROTATING FRAME.
>| AND their wavelengths are the same.
>
>In fact you are stupidly wrong and misleading only yourself, in fact,
>actually, and that's a fact. It is also a fact that anyone starting a
>sentence with "in fact" is in fact about to lie through their fucking
>teeth in an attempt to misleadingly convince themselves, in fact, actually.
>You are full of shit, Wilson.

I was being facetious when I said "you are more intelligent than the rest". 

>|
>| >| Alpha is the angle through which the STATIONARY EMISSION POINT of each
>| >'ray
>| >| element' moves (backwards) in the rotating frame.
>| >
>| >We know that, but the  STATIONARY EMISSION POINT is OUT IN SPACE
>| >for a TV signal sent from a tower in Sydney, and even then it is not
>| >stationary,
>| >the Sun moves too.
>|
>| We're only interested in rotation here not linear movement or position.
>| Rotation is absolute. Every rotating object has an associated nonrotating 
>frame
>| perpendicular to and at rest with its axis of rotation.
>|
>You are full of shit, Wilson.

Engineers obviously aren't aware that rotation is absolute.




Henri Wilson. ASTC,BSc,DSc(T)
www.users.bigpond.com/hewn/index.htm

....specialising in teaching physics to engineers and mathematicians....