Re: The true crackpots


mluttg...@xxxxxxxxxx wrote:
> PD wrote:
>
> > mluttgens@xxxxxxxxxx wrote:
> > > PD wrote:
> > >
> > > >> I said elsewhere that length contraction is a mathematical
> > > >> epiphenomenon.
> > > >> Take for instance the relation z = axy. Mathematically, you can claim
> > > >> that z=ax*y or z=x*ay, but physically, you are wrong if a only applies
> > > >> to x or to y. This is here the case, because the factor sqrt(1-v^2/c^2)
> > > >> applies to time (we are pretty sure of this, cf. for instance the time
> > > >> "dilation" of cosmic muons), not to length.
> > >
> > > > That is incorrect. The factor of sqrt(1-v^2/c^2) applies to both length
> > > > and time. Moreover, the phenomenon of the increased survival of cosmic
> > > > muons is understood *equivalently* as a time dilation or as a length
> > > > contraction. It is not one or the other. It is both.
> > >
> > > You are wholly wrong. If the factor applied to both, you would need
> > > z = ax * ay.
> >
> > First of all, I don't know where z=axy is relevant here, where a is
> > sqrt(1-v^2/c^2), and where x is presumably space and y is presumably
> > time. What formula are you looking at and saying that a either applies
> > to space or to time but not both?
>
> Yes, you guessed correctly. For the formula, please see my other post.

Sorry, cannot find.

>
> >
> > Note the formula that I provided for the spacetime interval, which is
> > not of this form but is of the form z = x - y, where z is constant and
> > so if x is changed (by a factor a, for example), then y must also
> > change (by the same factor a).
> >
> > But in any event, let's take a more pedestrian case of an equation of
> > the form you provided. The work done by a force over a displacement is
> > given by the formula:
> > W = F*d*(cos a), where a is the angle between the vectors whose
> > magntitudes are F and d.
> > Now you might ask, to which does the factor (cos a) apply, to the F or
> > to the d? The answer is *either*. Both are equivalent. We can say that
> > the work is the product of the displacement d and the component of the
> > force along that displacement (F*(cos a)). Or we can say that the work
> > is the product of the force F and the component of the displacement
> > along that force (d*(cos a)). Both of those interpretations are
> > completely physically equivalent, and it is in fact sometimes
> > convenient in the *same problem* to treat it one way and then the other
> > way. There is no physical preference for one or the other.
> > It is simply not right to say that (cos a) belongs more to F or to d.
>
> I agree, but this is not the case for the MMX, whose null result can
> only been explained by time slowing, which, unlike length contraction,
> is a proven phenomenon.

I gave you evidence that length contraction is a proven phenomenon. You
asked for a digest.


>
> > >
> > > You cannot claim on the one hand that
> > > "the phenomenon of the increased survival of cosmic
> > > muons is understood *equivalently* as a time dilation or as a length
> > > contraction", and on the other hand, that "it is both". The increased
> > > survival
> > > of the muons is of course not due to length contraction!
> >
> > On the contrary! As measured in the frame of reference where the muon
> > is slow moving (or stationary), the muon lifetime is 2.2 usec and it
> > would be a problem for this observer to account for the fact that the
> > muons make it all the way to the ground, were it not for the fact that
> > the this observer measures the distance from the top of the atmosphere
> > to the ground to be considerably shorter than the earth-bound observer
> > measures it to be. Thus, this observer accounts for the survival of the
> > muon because of length contraction, not time dilation.
>
> This is a fantastic interpretation made by SRists. Space doesn't
> contract because a muon is moving.

No one says space contracts. You'll note elsewhere in this thread what
"length contraction" means, and it doesn't mean that space or the
object in space is physically contracting.

I note, however, that you have no problem thinking that time dilates
just because the muon is moving. Yet you have a problem with length
contracting...

>
> > Moreover, since there is no reason to think that the observer that is
> > flying along with the earth has a better position to be measuring the
> > physics of what's going on than the observer that is flying along with
> > the muons, there is no reason to think that what's going on is
> > physically more time dilation than length contraction. Both are right,
> > because they are coupled phenomena.
> >
>
> One is right, the SRist is wrong.

Neither of them is SRists. Both of them are *observers* making
measurements. The SRist is the one who explains why it is that those
observers have made the measurements they have.

PD

.

Relevant Pages

  • Re: The true crackpots
    ... >>> I said elsewhere that length contraction is a mathematical ... > muons is understood *equivalently* as a time dilation or as a length ... the this observer measures the distance from the top of the atmosphere ... physics of what's going on than the observer that is flying along with ...
    (sci.physics.relativity)
  • Re: What is the " ACTUAL " length ?
    ... But each observer have different standards for time and length ... the same applies to all physics .. ... Wrong those experiments are not a measure of leng5th contraction. ...
    (sci.physics.relativity)
  • Re: The true crackpots
    ... >>> depend on the motion of the observer. ... This does NOT mean that length contraction is a physical ... Length is the result of a measurement. ... > this point is available in Spacetime Physics, ...
    (sci.physics.relativity)
  • A Challenge to Orthodox Relativity
    ... it's length contracts along the axis of motion. ... Since the contraction was invoked to explain the ... Einstein: Relativity Demystified by ... Another reference is "Observation of Length by a Single Observer," by ...
    (sci.physics.relativity)
  • Re: STR contraction
    ... > In Weisskopf's Fig. 1 he shows that ABCD is NOT length contracted. ... It clearly isn't showing the relativistic contraction that ... the observer wuold measure on teh LHS .. ... relativity did not apply. ...
    (sci.physics.relativity)