Re: The true crackpots
- From: "kenseto" <kenseto@xxxxxxxxxx>
- Date: Mon, 10 Oct 2005 14:08:05 GMT
"PD" <TheDraperFamily@xxxxxxxxx> wrote in message
news:1128951691.869114.180440@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
> mluttgens@xxxxxxxxxx wrote:
> > PD wrote:
> > > kenseto wrote:
> > > > "PD" <TheDraperFamily@xxxxxxxxx> wrote in message
> > > > news:1128718724.713401.183220@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> > > > >
> > > > > kenseto wrote:
> > > > > > "PD" <TheDraperFamily@xxxxxxxxx> wrote in message
> > > > > > news:1128626695.040370.318360@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> > > > > > >
> > > > > > > mluttgens@xxxxxxxxxx wrote:
> > > > > > > > I presume that you recognize that the Fermilab experiments
couldn't
> > > > > > > > prove "length contraction". Indeed,
> > > > > > > >
> > > > > > > > "In a tevatron, those collisions occur of course head-on.
> > > > > > > > Or, according to SR, physical bodies set in motion only
shorten in
> > > > the
> > > > > > > > direction of their motion, meaning that a proton colliding
head-on
> > > > > > > > with an anti-proton will not observe "length contraction" of
the
> > > > > > > > anti-proton."
> > > > > > > >
> > > > > > > > Now you are referring to HERA papers. Please give me a
*specific*
> > > > > > > > reference where such contraction has been demonstrated. I am
pretty
> > > > > > > > well convinced that there are none, unless in your
imagination, like
> > > > > > > > with Fermilab :-)
> > > > > > > >
> > > > > > > > Marcel Luttgens
> > > > > > >
> > > > > > > What I'm doing is comparing jet cross sections in two
environments:
> > > > one
> > > > > > > where the source is stationary in the lab (Tevatron) and one
where the
> > > > > > > source is moving in the lab (HERA). I don't think you're
getting that
> > > > > > > point.
> > > > > > >
> > > > > > > Let me see if I can find something that is a little more
direct for
> > > > > > > your tastes. Since this will be a bit older in the literature,
I'll
> > > > > > > have to search a little harder.
> > > > > > >
> > > > > > > At least you are willing to read in the library, which is
commendable
> > > > > > > and more than what folks like TomGee or Seto are either
willing or
> > > > able
> > > > > > > to do.
> > > > > >
> > > > > > ROTFLOL....You don't even understand what length contraction
means in
> > > > SR. In
> > > > > > SR the length contraction is not physical. It is an apparent
geometric
> > > > > > effect. It is the geometric projection of the moving rod onto
the
> > > > observer's
> > > > > > frame.
> > > > >
> > > > > That's right. Because length itself is a projection of the
interval
> > > > > between two spacetime events onto the observer's frame. It is
therefore
> > > > > natural that two different observers will see two different
lengths.
> > > > > But SR also says there is no deeper or hidden meaning to length.
> > > >
> > > > So you agree that in SR length contraction is not
physical.....right??
> > >
> > > In SR, length is not an intrinsic physical property. It is the result
> > > of a measurement procedure, which intrinsically produces results that
> > > depend on the motion of the observer.
> > >
> > > > >
> > > > > > From the moving rod point of view the space in the direction of
> > > > > > motion is contracted but the physical length of the rod remains
the
> > > > same.
> > > > > > BTW your bogus premise of physical rod contraction has the
following
> > > > > > problem:
> > > > > > 1. Two identical rods A and B and B accelerated away and becomes
initial
> > > > > > again.
> > > > > > 2. A sees B is physically contracted during B journey.
> > > > > > 3. B turns around and rejoins A. B's physical rod length returns
to the
> > > > same
> > > > > > length as A.
> > > > > > 4. That means that during the return trip B's physical length is
> > > > physically
> > > > > > expanded.
> > > > > > 5. That means that we will have both physical length contraction
and
> > > > > > expansion. Questions: How is B know when to physically contract
and when
> > > > to
> > > > > > physically expand??
> > > > > >
> > > > >
> > > > > You are assuming that length is a true physical property and not
the
> > > > > result of the projection of two spacetime events projected onto
the
> > > > > observer's frame.
> > > >
> > > > It was you who said that length contraction is physical and you said
that
> > > > many experiments have been performed to confirm this assertion.
> > >
> > > There have been many experiments that have verified that length, by
any
> > > reasonable definition of the same, depends on the motion of the
> > > observer. This does NOT mean that length contraction is a physical
> > > process, nor does it mean that length is an intrinsic physical
property
> > > of an object.
> > >
> > > >
> > > > >Assuming that is what would force the mental picture
> > > > > of something physically happening to the rod to change its length
or to
> > > > > produce a distorted illusion of something physical that is not
really
> > > > > changing. Since the assumption is wrong, the mental picture is
> > > > > misplaced.
> > > >
> > > > I didn't made that assumption. You did. You said that length
contraction is
> > > > measurable.
> > >
> > > Yes, indeed. Length is the result of a measurement. When you make this
> > > measurement, however, you are not measuring an intrinsic property of
> > > the object.
> > >
> > >
> > > > All the experiments you cited are based on that space in the
> > > > direction of motion is contracted. This is not the same as that a
moving rod
> > > > is contracted as you said.
> > >
> > > No, those experiments do NOT say which, or indeed if either, of space
> > > or the rod in space is contracted. Those experiments just verify that
> > > the measurements will produce what SR says the measurements will
> > > produce. SR is what says there is no deeper physical meaning to the
> > > length than what the experiment measures. No experiment is capable of
> > > verifying that, though the experiments are capable of verifying every
> > > *measurable* prediction of SR.
> > >
> > > > BTW space contraction is just a different way of describing that the
moving
> > > > frame has a higher state of absolute motion. Higher state of
absolute motion
> > > > produces a higher light path length for a physical rod. That, in
turn,
> > > > causes the rate of a moving clock to run slower than a stationary
stay at
> > > > home clock. That, in turn, means that a moving clock second has a
longer
> > > > duration (absolute time) than a stay at home clock second. That's
why a fast
> > > > moving moving upper atmosphere muon is able to reach the earth's
> > > > surface......the (2.2 us) lifetime of the fast moving muon (in the
fast
> > > > muon's frame) represents (gamma*2.2 us) lifetime on the earth clock.
> > > >
> > > > >
> > > > > SR says that length is not an intrinsic physical property of an
object.
> > > >
> > > > This is just a bogus assertion. You have no proof of that.
> > >
> > > I have no proof of what SR says? How about reading a few books on the
> > > subject?
> > >
> > > >
> > > > Ken Seto
> >
> > Length contraction has been variously explained as
> >
> > 1. true but not really true
> > 2. real
> > 3. not real
> > 4. apparent
> > 5. the result of the relativity of simultaneity
> > 6. determined by measurement
> > 7. a perspective effect
> > 8. mathematical.
>
> I don't care to try to fit my explanation into any of these categories,
> nor defend any of the categories above.
But your explanation includes all of the above!!!!!!!!!!
>The way I explained it is, to
> the best of my knowledge, an accurate representation of the truth. If
> you find that this clashes with other explanations you've heard, this
> (sadly) is not my problem nor anything I can help you with.
>
> >
> > (CF. http://perso.wanadoo.fr/mluttgens/sapere.htm#to )
> >
> > The one I prefer is "true but not really true". In fact,
> > it is a mathematical ephiphenomenon with no physical reality
> > whatsoever.
>
> As an example of what I said above, I don't even know what "true but
> not really true" means. I maintain there is indeed a physical reality
> to the measurement, and that the effect on the measurement due to the
> motion of the measurer is very real. However, the attribution of the
> measurement to some deeper physical attribute of an object is what is
> unwarranted, unneeded, and (as it turns out) wrong to boot.
>
> > If you want to convince yourself, just use time
> > dilation to explain the MMX.
>
> Just a brief comment on this. You are apparently under the impression
> that SR says that length contraction and time dilation happen
> independently or under different circumstances. This is not the case.
> In fact, what SR says is that the quantity
> I^2 = t^2 - l^2 (where t is the measured time difference between two
> events, and l is the measured spatial difference between two events)
> will remain constant independent of the motion of the observer. Thus,
> if in going from one observer to the other and length contraction is
> observed (that is, l^2 changes), then *necessarily* time dilation is
> also observed (that is, t^2 changes). A more in-depth explanation of
> this point is available in Spacetime Physics, by Taylor and Wheeler.
> Your claim that MMX is better explained as time dilation rather than as
> length contraction would cause physicists to scratch their heads,
> because they know that it is not a choice between one or the other, as
> *both* happen as indeed they must.
>
> PD
>
.
- Follow-Ups:
- Re: The true crackpots
- From: PD
- Re: The true crackpots
- References:
- Re: The true crackpots
- From: mluttgens
- Re: The true crackpots
- From: PD
- Re: The true crackpots
- From: mluttgens
- Re: The true crackpots
- From: PD
- Re: The true crackpots
- From: mluttgens
- Re: The true crackpots
- From: PD
- Re: The true crackpots
- From: mluttgens
- Re: The true crackpots
- From: PD
- Re: The true crackpots
- From: mluttgens
- Re: The true crackpots
- From: PD
- Re: The true crackpots
- From: kenseto
- Re: The true crackpots
- From: kenseto
- Re: The true crackpots
- From: PD
- Re: The true crackpots
- From: mluttgens
- Re: The true crackpots
- From: PD
- Re: The true crackpots
- Prev by Date: Re: The true crackpots
- Next by Date: Re: Electron at rest - magnetic field?
- Previous by thread: Re: The true crackpots
- Next by thread: Re: The true crackpots
- Index(es):
Relevant Pages
|