Re: Actual data for Sagnac?


"The Ghost In The Machine" <ewill@xxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:10vmk5-2ck.ln1@xxxxxxxxxxxxxxxxxxxxxxxxxx
| In sci.physics.relativity, Androcles
| <Headmaster@xxxxxxxxxxxxxxxx>
| wrote
| on Fri, 11 Jul 2008 12:48:13 +0100
| <4VHdk.196144$P83.32341@xxxxxxxxxxxxx>:
| >
| > "The Ghost In The Machine" <ewill@xxxxxxxxxxxxxxxxxxxxxxx> wrote in
message
| > news:0spjk5-f3t.ln1@xxxxxxxxxxxxxxxxxxxxxxxxxx
| > | This is probably a dumb question, but where is there
| > | some actual experimental data for Sagnac, not merely a
| > | treatise of how SR explains it (as opposed to, say,
| > | H. Wilson)?
| >
| > Finding actual data for anything is quite difficult on the www, few
people
| > are interested in it.
|
| True enough.
|
| > For example, What is the burn time of gasoline in a Ford 8 cylinder
| > engine at standard air pressure and temperature?
| > Not of much interest except to an automotive engineer and he'll
| > get it from the oil companies so that he can design his engine for
| > a suitable RPM range.
| >
| > However, you can rest assured that Ford engines do work, they burn
| > coal dust in oxygen to make CO2.
|
| And here I was taught they were burning injected fuel.

Yeah... coal dust is fuel. Hydrocarbon and oxygen in, CO2 and H2O out.
You were taught right, that black treacle stuff is a hydrocarbon, just like
coal dust.


| > You are correct, it is a dumb question.
| > If you really want to get data from a couple of lights on a carousel,
| > go and measure it.
| >
| > The funniest SR explanation is this one:
| >
| > http://www.mathpages.com/rr/s2-07/2-07.htm
| >
| > wherein it says:
| > "As a result, the counter-rotating pulse arrives at the "end" point
slightly
| > earlier than the co-rotating pulse" (at the same time).
| >
| > Albert would be delighted to see his third postulate denied.
| > 'we establish by definition that the "time" required by
| > light to travel from A to B equals the "time" it requires
| > to travel from B to A' because I SAY SO and you have to
| > agree because I'm the great genius, STOOOPID, don't you
| > dare question it. -- Rabbi Albert Einstein
| >
| > A smart chap like you might be able to figure out
| > that (x+vt)/(c+v) = (x-vt)/(c-v) ... since even I can.
|
| (x+vt)*(c-v) = cx+cvt-vx-v^2t
| (x-vt)*(c+v) = cx-cvt+vx-v^2t
|
| Doesn't look quite equal to me...

Well, see, you used a minus sign and velocities don't have one...
especially c. Just to make sure that never happens v and c are
always squared and divided, like this: v^2/c^2. Never added.

Now you can use a minus sign thusly, 1-v^2/c^2, and take the
square root. It is illegal in physics to write "-c", only mathematicians
are allowed to do that.
The other thing you did wrong was to compute cx instead of xc.

In any event you are not allowed to use (x+vt)/(c+v) at all, it has to
be (x+vt) / (the composition of [c,v] ).
By the time you are done confusing yourself you should be able to
get any result you want.

I just love it that the two pulses arrive one before the other but
arrive simultaneously and take the same time to get there by
definition, which is the SR solution to Sagnac. Even funnier
than Laurel, Einstein and Hardy.
http://www.youtube.com/watch?v=i7prVx4BnrA

(Einstein is the one with the moustache and state trooper hat...)


.

Relevant Pages

  • Re: Actual data for Sagnac?
    ... engine at standard air pressure and temperature? ... it is a dumb question. ... light to travel from A to B equals the "time" it requires ...
    (sci.physics.relativity)
  • Re: Actual data for Sagnac?
    ... engine at standard air pressure and temperature? ... it is a dumb question. ... light to travel from A to B equals the "time" it requires ... -- Rabbi Albert Einstein ...
    (sci.physics.relativity)
  • Chinook helicopter question
    ... Perhaps a dumb question, but if an engine failed on a Chinook would ... meaning does the pilot keep both engines at the same power setting? ...
    (rec.aviation.piloting)