Re: HOCUS POCUS


"PD" <TheDraperFamily@xxxxxxxxx> wrote in message
news:1158419074.087269.165580@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
|
| Mike wrote:
| > PD wrote:
| > > Mike wrote:
| > > > PD wrote:
| > > > > Mike wrote:
| > > > > > Randy Poe wrote:
| > > > > > > mluttgens@xxxxxxxxxx wrote:
| > > > > > > > PD wrote:
| > > > > > > > > mluttgens@xxxxxxxxxx wrote:
| > > > > > > > > > HOCUS POCUS
| > > > > > > > > >
| > > > > > > > > > Two electrons E1 and E2 are ejected along a straight
line with
| > > > > > > > > > opposite velocities v1 and v2 from a device stationary
in S,
| > > > > > > > > > at t=0 according to S clock.
| > > > > > > > > >
| > > > > > > > > > Assuming that v1 = -0.6 c and v2 = 0.8 c, what is the
relative
| > > > > > > > > > velocity between E1 and E2 ?
| > > > > > > > > >
| > > > > > > > > > After a time interval t measured on his clock, S will
conclude
| > > > > > > > > > that the distance separating E1 from E2 is (0.6 + 0.8)
ct = 1.4 ct,
| > > > > > > > > > hence that E2 is moving away from E1 at V = 1.4 c, or
that E1 is
| > > > > > > > > > moving away from E2 at V = 1.4 c, meaning that the
relative velocity
| > > > > > > > > > between E1 and E2 exceeds c.
| > > > > > > > >
| > > > > > > > > Yes, and there is nothing wrong with that.
| > > > > > > > >
| > > > > > > > > >
| > > > > > > > > > Ein Zwei Ein Stein HOCUS POCUS
| > > > > > > > > > E1 = S',
| > > > > > > > > > V = (.8 c-(-0.6c))/(1+0.8*0.6) = 1.40/1.48 c = ~.9459 c
| > > > > > > > > > E2 moves at 1.4/1.48 c relative to S'
| > > > > > > > > > E2 moves at 1.4/1.48 c relative to E1
| > > > > > > > > > ABRACADABRA
| > > > > > > > > > 420000 = ~283784
| > > > > > > > > >
| > > > > > > > > > By assimilating E1 to a frame S' moving away at -0.6 c
from a frame S,
| > > > > > > > > > Srists claim that the electron E2, which had a velocity
V = 1.4 c
| > > > > > > > > > wrt E1 measured in S, has only a velocity V' = ~0.9459 c
measured in
| > > > > > > > > > S'.
| > > > > > > > >
| > > > > > > > > Yes.
| > > > > > > > >
| > > > > > > > > >
| > > > > > > > > > But the electrons don't bother about which name they are
given, nor
| > > > > > > > > > does their relative velocity V depend on their velocity
wrt the device
| > > > > > > > > > by which they have been emitted. Such device -the frame
S according
| > > > > > > > > > to SRists- should be ignored after their emission, it
belongs to
| > > > > > > > > > history.
| > > > > > > > >
| > > > > > > > > Not at all. You seem to think that relative velocity
between two
| > > > > > > > > objects should be a frame-independent quantity. It's not.
I don't know
| > > > > > > > > why you think it should be.
| > > > > > > > >
| > > > > > > >
| > > > > > > > I am skeptical about the physical validity of a formula (the
| > > > > > > > relativistic addition of velocities), which gives an
infinity of
| > > > > > > > solutions for a same velocity V between to objects, for
instance
| > > > > > > > 1.4 c, measured in one frame (S in my example).
| > > > > > >
| > > > > > > Because you have divine knowledge that separation rate
| > > > > > > is independent of reference frame?
| > > > > > >
| > > > > > > Well, the rest of us without divine knowledge are stuck
| > > > > > > with describing what we see in experiment, which
| > > > > > > is that the Lorentz transform is valid.
| > > > > >
| > > > > > You cannot devise an experiment to validate the velocity
addition
| > > > > > formula since that would require measuring the OWSL. The
velocity
| > > > > > addition formula is a deduction from the postulate of c
invariance in
| > > > > > inertial FoR. So talk about valid deduction, it is ok, b ut do
not
| > > > > > bullshut people that this is experimentally verified.
| > > > >
| > > > > That's simply not true. Relativistic kinematics is confirmed all
the
| > > > > time in particle experiments, where those high speeds and also
| > > > > observations from two different reference frames are common.
| > > >
| > > > Yes, nobody disputes relativistic kinematics. The problem is that SR
is
| > > > a particular variation of relativistic kinematics that assumes c
| > > > invariance in all inertial FoR.
| > > >
| > > > Since c invariance in all inertial FoR cannot be proven, neither
| > > > logically (no universally quantified propositions can be proven) nor
| > > > experimentally (since it requires measuring OWSL in a SR way) you
then
| > > > sound too stupid to me spewing the same crap about particle
experiments
| > > > verifying velocity addition in SR.
| > >
| > > Well, what I sound like to you is not of particular importance to me.
| >
| > Obviously, because you continue bullshuting me.
| >
| > > There are three facts that remain
| > > - The correct formula for combining velocities (independent of what
| > > assumptions are made to *derive* that formula) has been completely
| > > verified in particle experiments. Call it an empirically confirmed
| > > formula, if you like, and forget about deriving it from any
| > > assumptions. It's nevertheless a confirmed relation.
| >
| > Since there is no way to establish an observer that would measure
| > anything from any fast moving particle in an accelerator, the only
| > measurement possible is from a frame at rest wrt to the accelerator.
| > There is no way to measure the relative speed betweeen two particles
| > directly, but only infer it.
|
| Proton-proton collisions and electron-electron collisions (for example)
| are routinely done in both collider and fixed-target environments. The
| physics of these collisions is simple enough (at least for some
| measurable distributions) that comparison of the nature of the
| collisions in both environments is tantamount to measuring the same
| process in two very different frames of reference. The relative speed
| of the colliding particles is measured in both cases as a normal part
| of beamline monitoring operations. The fact that the distributions are
| identical if and only if the relative speeds in the two reference
| frames are related exactly by the relativistic prescription, is
| compelling evidence that the relativistic prescription is correct.
|
| >
| > Because the above is true and makes sense, everything else you have
| > said sounds again too stupid to me.
| >
| > I will re-phrase the questions has anyone ever measured directly the
| > relative speed between to moving particles at speeds close to c so that
| > the velocity addition formula can be validated?
|
| Yes.

How fast does this spinning magnet transfer energy to the
compass needle?
http://www.androcles01.pwp.blueyonder.co.uk/spin.gif




|
| >
| > The answer is NO. All measurements can take place from the frame at
| > rest in the frame of the laboratory and relative speed only calculated
| > using the velocity addition formula.
|
| No, that's not correct.
|
| >
| > Mike
| >
| >
| >
| >
| >
| >
| >
| > > - TWLS invariance has certainly been measured, and TWLS and OWLS
| > > isotropy has certainly been measured. This is mathematically
equivalent
| > > to a direct OWLS invariance measurement and so the latter measurement
| > > is not required except to make people like you feel better about the
| > > whole thing.
| > > - The invariance of c in *different reference frames* has certainly
| > > been measured, using direct time-of-flight measurement of single
| > > photons in a number of measurements. A pion decay experiment is the
| > > most cited one, but it is also routinely measured at the Advanced
Light
| > > Source and Advanced Photon Source facilities.
| > >
| > > PD
| > >
| > > >
| > > > Mike
| > > >
| > > >
| > > >
| > > >
| > > >
| > > > >
| > > > > PD
| > > > >
| > > > > >
| > > > > > Mike
| > > > > >
| > > > > >
| > > > > > >
| > > > > > > There's nothing I can do about the fact that your
| > > > > > > divine knowledge contradicts experiment, that there
| > > > > > > is some unknowable "reality" different from my
| > > > > > > observable universe and accessible only to you.
| > > > > > >
| > > > > > > So I'll stick with the equations that describe life
| > > > > > > in my universe.
| > > > > > >
| > > > > > > > Let's consider a planet inhabited by advanced ET's, situated
at
| > > > > > > > x billions light-years from the Earth. Their physicists,
from the
| > > > > > > > redshift of the Earth galaxy A and the Hubble constant,
calculate that
| > > > > > > > the Earth is moving away from them at -0.7 c. Opposite the
Earth,
| > > > > > > > they observe another galaxy B, whose velocity relative to
them is
| > > > > > > > +0.7c.
| > > > > > > > They conclude, in accordance with the cosmic expansion, that
such
| > > > > > > > galaxy has a velocity 1.4 c relative to the Earth.
| > > > > > >
| > > > > > > No, they conclude that those two points are separating
| > > > > > > IN THEIR REFERENCE FRAME at 1.4 c.
| > > > > > >
| > > > > > > > As they have mastered FTL communication, they transmit those
data to
| > > > > > > > the Earth SRists, who calculate that B is in fact moving
away from
| > > > > > > > them at 0.7c + 0.7c / 1 + 0.7*0.7 =~ 0.94 c, forgetting that
it is
| > > > > > > > impossible to observe a galaxy moving away at 1.4 c.
| > > > > > >
| > > > > > > On Earth, galaxy B is OBSERVED to be moving
| > > > > > > away at 0.94c. Earth scientists easily calculate that
| > > > > > > the two points are separating at 1.4c from the point
| > > > > > > of view of Planet X. They also can see galaxy C
| > > > > > > receding at 0.7c (i.e., separating from Planet X
| > > > > > > at 1.4c IN THE EARTH FRAME). They can easily
| > > > > > > calculate that IN PLANET X FRAME, the observers on
| > > > > > > Planet X would see Galaxy C receding at 0.94 c.
| > > > > > > Planet X sends a message confirming that the
| > > > > > > redshift of Galaxy C is consistent with a relative
| > > > > > > velocity of 0.94c.
| > > > > > >
| > > > > > > - Randy
|


.

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