Re: GR ?


"sue jahn" <susysewnshow@xxxxxxxxxxxx> wrote in message
news:42e4c515$0$18648$14726298@xxxxxxxxxxxxxxxxxx
|
| "Significant Zero" <paulpsremove@xxxxxxxxxx> wrote in message
news:1122284814.28734.0@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
| >
| > "Tom Roberts" <tjroberts@xxxxxxxxxx> wrote in message
| > news:tuZEe.512$vq2.330@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
| > | Significant Zero wrote:
| > | > "Tom Roberts" <tjroberts@xxxxxxxxxx> wrote in message
| > | > news:SpBEe.3241$fx4.3153@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
| > | > | A rotation is a rotation -- in Euclidean space or in
| > | > | spacetime. Rotations affect projections of objects onto axes,
| > | > | but THEY DO NOT AFFECT THE OBJECTS THEMSELVES. A relative
| > | > | velocity is merely a rotation in the x-t plane. <shrug>
| > | >
| > | > That seems fairly clear to mean that in your view time dilation and
| > length
| > | > contraction are products of remote observation, measurement and
| > perspective
| > | > and have no basis in physical reality in the same way that Picassos
| > pictures
| > | > have no basis in physical reality other than from an interpretation
of a
| > | > reality in his head.
| > |
| > | Where do you get such outlandish notions? Certainly not from what I
wrote.
| >
| > You appear from my pov to have jumped the rails Tom as you have been
writing
| > that observation cannot effect the conditions of the objects under
| > observation
|
| The Coulomb force between a photoelectron in a rail passenger's
| retina and a lightning stroke is insufficient for this to occur. However
| the Coulomb force between a free particle and HEP apparatus is
| sufficient for observation to affect the conditions.

Yes I agree that locally the observer can effect the observed but its
difficult to see how looking at a star can effect it to any noticeable
degree. BTW I was just trying to sort out the apparent, from my pov,
incoherence that Tom posts. I do try and understand him but he seems to keep
shifting his position to fit the situation which is fine for a game of
stone,paper,string but seems to just make him look silly in the realm of
scientific enquiry.

|
| As you have pointed out earlier,
| mounting a linac on a railcar moving at 1/2 c can produce
| electrons moving at 1.498... times the speed of light wrt the
| "embankment".

Yes this point never seems to be addressed by the advocates, perhaps they
will one day{:-)

|
| Sue...
|
|
| and the only sensible conclusion I can make from that is, if the
| > ladder wont fit the door way then it wont fit from whichever way you
observe
| > it. So to get the ladder through the doorway you have to go and turn the
| > ladder to an orientation that allows it to fit the through the doorway
or
| > postulate that ladders in motion are shorter in physical reality. You
have
| > stated a number of times that the apparent shortening of ladders in
motion
| > is due to observer position\rotation, see the first paragraph in *this*
| > post.
| >
| > |
| > | Yes, time dilation and length contraction are observational effects of
| > | rotations in spacetime, just as whether or not a ladder is wider than
a
| > | doorway is an observational effect of rotations in space. But these
have
| > | real, physical effects: pion beams in accelerators are many times
longer
| > | than c*\tau (the distance pions could travel at speed c if there were
no
| > | time dilation), and ladders do or don't fit through doorways.
| >
| > But then you contradict yourself by claiming that they do have real
physical
| > effects.
| > Perhaps you have been rather confusingly trying to take both positions
i.e
| > that observation effects *apparently* dilate and shorten and physical
| > effects *actually* dilate and shorten without clarifying which effect
your
| > referring to. ?
| >
| > |
| > |
| > | > This doesn't seem good grounds for presenting something
| > | > as a useful scientific interpretation.
| > |
| > | SR itself, and what I wrote most definitely ARE "good grounds". But
your
| > | fantasies (above, comparing to Picasso) are not. <shrug>
| >
| > It seems from my pov that you are the one with fantasies and paradoxes
| > embedded in your thinking perhaps due to learning instead of trying to
| > understand.
| >
| > |
| > |
| > | > The ladder and doorway are fine by me untill a better example is
| > presented
| > | > as presumably as they are physical reality, or examples of, you
should
| > be able
| > | > to deal with them presented in a SR\GR context and be able to state
a
| > result
| > | > so I have put your example in a SR\GR context to just confirme my
| > | > understanding of your position.
| > | > Ladder L to L 10ft long moving down page ar near c.
| > | > Doorway D to D 3ft moving across page at near c
| > | >
| > | > L
| > | >
| > | >
| > | >
| > | > L
| > | > \/
| > | >
| > | > D
| > | > >
| > | > D
| > | >
| > | > Will length contraction allow the ladder to pass through the door
way
| > | > without them contacting each other if the relative intersecting
| > positions of
| > | > the ladder and door were appropriate?
| > |
| > | This situation is not amenable to analysis using just length
| > | contraction. You need to use the entire Lorentz transform. This is
| > | essentially the same as the "pole and barn paradox"; both are resolved
| > | by realizing that simultaneity is DIFFERENT in the two relevant
inertial
| > | frames. Look in any elementary textbook on SR for "pole and barn".
| >
| > This just seems a failure to address and answer the issue both by you
and
| > the text books.
| > Is the ladder ever short enough to go through the doorway under any
inertial
| > conditions that don't change the orientation, no or yes. No
prevaricating
| > into complicity as I will take this or a failure to answer or as a don't
| > know..
| >
| > |
| > |
| > | > A rough drawing of physical facts
| > | >
| > | > D
| > | > L L
| > | > D
| > | >
| > | > Time 5pm my garage {:-)
| > | > Ladder fits.
| > | >
| > | > L
| > | > D
| > | >
| > | > D
| > | > L
| > | >
| > | > Time 5:10pm my garage {:-)
| > | > Ladder dont fit
| > | >
| > | > Now do me as clear a one for time dilation and length contraction
| > please.
| > |
| > |
| > | The problem is that this page is Euclidean and those effects are
| > | Minkowskian.
| >
| > I could have described above in a more detailed 4D form of space time
but I
| > didn't think it was worth it you probably would not have understood my
| > notation as your reply indicates and an inability to improvise your
| > thinking to the medium available.
| >
| > |
| > |
| > | > | You keep insisting that this is a "difference" in the clock's tick
| > | > | rates. But in fact you have no basis for that particular
prejudice --
| > | > | all the actual MEASUREMENTS show is a difference in MEASUREMENTS.
And
| > | > | that could be due to EITHER a change in clocks' tick rates or in
the
| > | > | signals used for the measurements.
| > | >
| > | > !00% agree but which view are *you* taking and believe to be the
facts ?
| > | > My view is still relatively immature and needs to be banged against
| > others
| > | > views to knock the wood worm out so please state *your* view.{:-)
| > |
| > | My interpretation is that NEITHER of those is an effective
description.
| > | Instead, this is a manifestation of spacetime curvature. As I said:
| >
| > What in your view is spacetime curvature in a few words that we can all
| > understand ?
| >
| >
| > | > | In GR this is modeled NOT as a "change in tick rates", and not in
a
| > | > | change of the local speed of the light signals used in the
| > measurement,
| > | > | but rather as a curvature of spacetime.
| > | >
| > | > You now seem to be claiming that "curvature of space-time" is a real
| > | > physical reality that produces an effect on real physical reality or
| > even is
| > | > the real physical reality.
| > |
| > | What is "physical reality"??? Certainly I don't know, and unless you
| > | have a direct channel to God, you don't either.
| >
| > I've asked via my direct channel {:-) and the reply was " a poke in the
eye
| > with a sharp stick" which I understood 100% {:-) do you ? I was also
able to
| > work out what a 1% poke in the eye with a sharp stick was, were you ?
| >
| > | What we humans can know
| > | is the results of experiments,
| >
| > And the pokes in the eye they give.
| >
| > | and we can make models to explain many
| >
| > Or fantasies.
| >
| > | such results. GR is the most successful model known to date for an
| > | enormous number of such measurements in this domain.
| >
| > Well be consistent and clear in your interpretation if you wish others
to
| > understand *your* interpretation of this model.
| >
| > |
| > |
| > | > I understand "curvature of space-time" as a real
| > | > physical reality to mean a relative change in space and time from
one
| > place
| > | > to another which you have denied, if this is not accurate please
correct
| > it.
| > |
| > | See above -- you DON'T know what "physical reality" actually is. And
| > | never will....
| >
| > See above you appear to me to be an ignorant confused pompous
fantasist.{:-)
| > but may be doing there best.
| >
| > |
| > |
| > | > I far as I am aware I don't have a personal prejudice,
| > |
| > | Right. That's your problem, or at least a major part of it....
| >
| > Thanks I will think up some inappropriate critic of your mental state
when I
| > feel its suitably amusing {:-)
| >
| > |
| > |
| > | > the muon and clock
| > | > data seemed to support the actual physical reality of time and
length
| > | > variance
| > |
| > | See above. In seeking "physical reality" you are setting yourself up
to
| > | fail....
| >
| > See above there are degrees of "physical reality" and confidence of, as
| > anybody with any common sense is aware of.
| >
| > |
| > |
| > | > so I was just working from the data as presented.
| > |
| > | No! That's your problem -- you imposed your personal prejudice about
| > | what the data "mean" and how they relate to "physical reality", rather
| > | than merely accepting the measurements and asking: how can we MODEL
| > | these measurements?
| >
| > But if you believe that the railway lines in the distance physically
measure
| > 1 cm then you may be modelling a fantasy of reality that exists only in
your
| > head so some common sense as to the appropriate nature of your
measurements
| > is needed.
| >
| > |
| > |
| > | > If you are
| > | > categorically stating that time and distance are invariant except
| > | > *apparently* when measurements are not corrected for observational
| > | > distortions then I need to look and rethink my position.
| > |
| > | I'm saying nothing of the sort. But you do have a lot of rethinking to
| > | do....
| >
| > You never seem to stick to one position from one sentence to the next.
| >
| > |
| > |
| > | > | In fact, the MEASUREMENTS are exceedingly accurately predicted by
GR,
| > | > | and in GR the intrinsic rate of clocks does NOT depend on either
| > gravity
| > | > | or any velocity. All your statements clearly show that in order to
| > | > | understand this you need to STUDY.
| > | >
| > | > This seems a clear statement that the twins scenario is a none
factual
| > red
| > | > herring.
| > |
| > | I don't know what you mean here. Certainly real experiments
implementing
| > | the twin scenario have been performed, and the predictions of SR/GR
have
| > | been confirmed: the traveling (non-inertial) twin is QUITE CLEARLY
| > | younger when the twins reunite.
| >
| > Stick to a position for at least two words as you are posting
contradictory
| > nonsense.
| >
| >
| > |
| > | See the FAQ for a reference to Bailey et al, who performed
| > | a twin scenario using muons traveling ~0.9995 c, using a
| > | storage ring.
| > |
| > | Note please that I have repeatedly stated that length contraction and
| > | time dilation are the results of perspective (geometrical projection),
| > | and they are frame dependent. But the twin scenario involves elapsed
| > | proper time over different paths, and that is NOT perspective and is
NOT
| > | frame dependent.
| >
| > But it is a result of time dilation which you intermittently deny is a
real
| > effect and is all due to observation.
| >
| >
| > |
| > |
| > | > Your definition of moving is CLEARLY different to mine and the
| > dictionary
| > | > <shrug> {:-)
| > | > Try reading it
| > |
| > | My dictionary says "move" means "to change place or position...". That
| > | is consistent with what I said, and is obviously inapplicable to time
| > | itself.
| > |
| > |
| > | > T = kinetic energy of system. Whats the kinetic energy of a field
and
| > how do
| > | > I calculate it ?
| > |
| > | That depends on the type of field. But you want the LAGRANGIAN, not
the
| > | energy (fields do not have "kinetic energy").
| >
| > Yes so how can the LAGRANGIAN apply to fields as LAGRANGIAN use T =
kinetic
| > energy of system, if you remember.
| >
| > | For the E&M 4-potential
| > | A_u and charged 4-current J^u the Lagrangian is:
| > | k1 F^uv F_uv + k1 J^u A_u
| > | F_uv = (d/dx^u A_v) - (d/dx^v A_u)
| > | Where k1 and k2 are constants I forget, and I may have an overall sign
| > | error (I forget).
| >
| > Probably best thing you can do {:-)
| >
| > |
| > |
| > | > | > | Why do you think that it is impossible to cover the surface
| > | > | > | of a sphere with a single coordinate system? That is
| > | > | > | directly related to the impossibility I discuss here.
| > | > | > Latitude and longitude seem a fairly good system.
| > | > | But not good enough -- they do not COVER the sphere S^2.
Specifically:
| > | > | there are coordinate singularities at the north and south poles. I
| > | > | repeat: you need to STUDY.
| > | >
| > | > I see that as a bit of a red herring as my ref. on spherical
geometry
| > seems
| > | > happy to use latitude and longitude or simlair systems for dealing
with
| > | > spheres <shrug> {:-)
| > |
| > | Your ref. is not good enough. Those coordinates do not work at the
| > | poles. <shrug>
| > |
| > | This is an immediate corollary of a famous theorem known
| > | as the "hairy ball" theorem -- it is not possible to cover
| > | a sphere with hair without at least two cowlicks (the
| > | actual theorem is expressed in terms of vector fields, not
| > | hair). The poles are the "cowlicks" of latitude and
| > | longitude.
| >
| > The cowlicks are normally called north and south or + and - in similar
| > systems and the latitude and longitude type system can be extended as
| > required by radius and other variables so I have no idea why you seem
unable
| > to cope with it.
| > --
| > Significant Zero E-field = Electric field, M-field =Magnetic field,
two
| > unbound field effects
| > http://home.freeuk.com/paulps/
| > Maybe updates. (1-(1/(1/3))^2)/(1 + (1/(1/3))^2) = - 0.08 = FTL ? -p<+p
or
| > (m*-v)<(m*+v) or (m*-c^2)<(m*+c^2) =g?
| >
| >
| >
|
|


.

Relevant Pages

  • Re: Are SR effects real or not? Simplified case.
    ... But whether or not this L-F contraction is "real" or not depends ONLY on the meanings of words. ... Here's an analogy between a ladder and a doorway, ... and in some orientations it will not. ...
    (sci.physics.relativity)
  • Re: Are SR effects real or not? Simplified case.
    ... But whether or not this L-F contraction is "real" or not depends ONLY on ... Here's an analogy between a ladder and a doorway, ... Moving rulers get shorter -- they ...
    (sci.physics.relativity)
  • Re: Are SR effects real or not? Simplified case.
    ... But whether or not this L-F contraction is "real" or not depends ONLY on ... Here's an analogy between a ladder and a doorway, ... Tom Roberts ...
    (sci.physics.relativity)
  • Re: GR ?
    ... Nice example but neither the doorway or the ladder change in physical ... relationship between moving clock and stationary clocks, ... Both geometrical projection and rotation are such models ... all the actual MEASUREMENTS show is a difference in MEASUREMENTS. ...
    (sci.physics.relativity)
  • Re: Length contraction is not an intrinsic property of an object
    ... in one orientation a tall ladder can be ... cannot -- what matters is the PROJECTION of the ladder's length onto the ... width of the doorway. ...
    (sci.physics.relativity)
Loading