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Re: Ballistic Theory and the Sagnac Experiment

Subject: Re: Ballistic Theory and the Sagnac Experiment
From: ""
Date: 30 Mar 2006 14:20:27 -0800
Newsgroups: sci.astro, sci.physics.relativity, sci.physics
George Dishman wrote:
> jgreenfield@xxxxxxxxxxx wrote:
> > George Dishman wrote:
> > > "jgreenfield@xxxxxxxxxxx" <jgreen@xxxxxxxxxxx> wrote in message
> > > news:1143605716.799659.97390@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> > > >
> > > > Jeff Root wrote:
> > > >> George Dishman wrote:
> > > >>
> > > >> > (3) AND (4) ARE QUESTIONS, NOT REASONS.
> > > >>
> > > >> Actually they're scenarios, which were described in order
> > > >> to pose and answer the questions.
> > >
> > > That's more accurate but Jim didn't seem to be
> > > listening so I needed a more direct opposite.
> > > The scenarios were used as "thought experiments"
> > > with the intent of making Jim question his
> > > explanation so "questions" isn't too far off.
> > >
> > > > Agree. George is running interference
> > >
> > > No, I was just trying to get you to pause and
> > > rethink. Jeff seems to have accomplished that.
> > >
> > > >> Of course, a scenario doesn't cause Doppler shift, any
> > > >> more than a question does.
> > > >>
> > > >> The question is:
> > > >> What causes the Doppler shift in scenario (3)?
> > > >
> > > > Make that question (a)
> > > > Answer: Change in position at instant of firing
> > >
> > > Excellent, we can all agree on that. Since the
> > > change of position is the only difference between
> > > (1) and (3) we can say the change of position must
> > > be the cause of the Doppler shift in this case, but
> > > we cannot yet say it is the _only_ cause of Doppler
> > > shifts, there might be other effects that also have
> > > the same effect.
> > >
> > > > Question (b)
> > > > What causes the Doppler shift in scenario (4)?
> > >
> > > There are two _possible_ cause comparing (1) and
> > > (4), first the position has changed, which we know
> > > will cause a Doppler change, but also the bullet
> > > speed has changed and that might also have an effect.
> > > We need a way to test that.
> > >
> > > To find out if a change of bullet speed produces a
> > > Doppler shift, we would like a scenario in which it
> > > is the only possible cause and in particular change
> > > of position has been eliminated. We have that by
> > > comparing (1) with (2). In (2) the rifleman is
> > > moving forward when he fires so the bullet speed is
> > > increased but he runs back between shots so the
> > > firing position is constant. From Jeff's animation,
> > > the target hit rate is identical to the firing rate
> > > in (2) so there is _no_ Doppler shift in that case.
> > > We can therefore conclude that a change of bullet
> > > speed does _not_ cause a Doppler shift.
> >
> > Why do you now find it necessary to retrieve from the rubbish bin, the
> > (2) red herring which you agreed had NO bearing?
>
> Again if you had read my post I carefully explained
> why we needed to look at (2) before commenting on it.

_YOU_ need to look at red herrings-- _I_ do NOT
>
>
> > _IF_  (2) scenario was considered, it is obvious that the kE imparted
> > to the bullet
> > by way of the gun's motion (as separate from the charge) is cancelled
> > by hte reversal of the gun's direction (as it returns to the firing
> > position)
>
> Don't be stupid Jim, the speed of the bullet isn't
> changed by what the gun does after it fires.

Idiot! Which way are the other bullets in the magazine travelling
half a rev after the first is fired????????????
What speed would that be?
Does "negative" ring a bell?
>
> > So (2) is OUT, and (3) as well   (original scenario was an aircraft
> > mounted gun-
> > which does NOT stop to fire    :-)
>
> The original was to compare that with a gun on a
> carousel, Henry and I were comparing 2) and (4)
> and had been for about a month. You introduced
> the start-stop scenarios of (1) and (3) which is why
> Henry had to list all four and suggest we all agree
> what to talk about.

I asked that (3) be considered (?) in order for it to be REJECTED!
Hint: It is customary for intelligent people to REJECT a scenario as
being
correct, when evidence UNAMBIGUOUSLY is against it, and in favour of
one where the evidence is in support.
>
> > > > Answer: Increased bullet velocity
> > > > .........(for an extra 1/2 mark, the position change is incidental)
> > >
> > > Sorry Jim, the correct answer is that the Doppler
> > > shift is again caused by the change of position
> > > between shots. The rifleman's motion at the time
> > > of firing does also produce the change of impact
> > > energy which is therefore the "incidental" aspect.
> >
> > Blythely ignoring conservation of energy. The increase KE
> > MUST be due to increased velocity.
> > WHAT ELSE COULD IT BE????????????
>
> I'm not going to waste any more time on this Jim,
> you obviously have some serious reading impairment.
> I just said the folowing:
>
>   "The rifleman's motion at the time of firing does
>    also produce the change of impact energy ..."

...and (3) doesn't!!!!!!!!!!!!!!!!!!!!!
THEREFORE IT IS (4)
What part of "evidence" don't you understand?
>
> I suggest you buy a book on basic physics that covers
> Doppler and find out for yourself, your not going to learn
> anything here with that attitude.

I suggest you get a machine gun, and a mobile mount.
You haven't a clue

You are still welcome to discuss HOW energy differs, and why.
I doubt that you will though--------long since in your "too hard"
basket.


Jim G
c'=c+v


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