Re: Rigid rod problem


Kim B wrote:
> On Sat, 27 Aug 2005 03:09:20 GMT, dseppala@xxxxxxxxxxxxx wrote:
>
> >Let's look at things with respect to the problem I posted, please post
> >your answer to the following questions.
> >1. If I place all points along the length of a steel rod 1 meter in
> >diameter and 10 meters in length onto a conveyer belt moving 3 meters
> >/ second, will the rod break?
> >2. If the rod is 100 meters in length when I do this, will it break?
> >3. If the rod is 1000 meters in length when I do this, will it break?
> >4. If the rod breaks, what length does it have to be before it
> >breaks, and at what point of the rod will the break occur?
> >5. If the rod is only 1 cm in diameter, does it break at a different
> >point or at a different length?
> >Thanks,
> >David
> >
>
> David, you are creating unnecessary complicated experiments, with the
> most frequent flaw being an instantaneous speed change. It is of no
> use that the speed change is small (in the "normal" range), as this
> just make the error small. A small error can NOT be ignored when the
> the length is huge. Huge length/small speed, small length/huge speed,
> the problems don't go away.
>
> My advice to you is to understand the simple problems first, e.g. the
> acceleration problem. You obviously haven't got to that point yet.
> Acceleration is certainly not intuitive and has a few surprises
> builtin, e.g. an event horizon and varying clock and acceleration
> rates along the rod.
>
> I'm thus not going to comment further on your complex problems, partly
> due to your "reputation" among some of the "older" posters in the
> group.
>
> Kim


I was working on a problem like that for a while... I never did quite
finish, though. I think I came to the conclusion that there wasn't an
event horizon. I kept going back and forth on the question at the
time.

http://www.spoonfedrelativity.com/files/myGravity7.swf
http://www.spoonfedrelativity.com/files/myGravity-contractionvelocity.swf

Actually, I think Dirk Van De Moortel gave me the mathematics I needed
to finish it...

http://groups.google.com/group/sci.physics.relativity/msg/7c14cd2810305e5d?hl=en&;


.... but it was going to involve an almost complete rewrite. Performing
all the calculations of position and time of events in advance instead
of in real-time.

Anyway, I think it seemed resolved to me that t'(t) and x'(t) were
pretty well behaved functions, and no wierd event horizon effects
showed up under constant acceleration. Then I got sucked into the
bewilderment of Tensor Geometry, and never got around to working on it
anymore.

When you worked this, Kim, did you apply a 9.5 m/s^2 acceleration in
velocity or rapidity?

.

Relevant Pages

  • Re: Rigid rod problem
    ... >Kim B wrote: ... If the rod is 100 meters in length when I do this, ... >> Acceleration is certainly not intuitive and has a few surprises ... e.g. an event horizon and varying clock and acceleration ...
    (sci.physics.relativity)
  • Re: How can this work in relativity?
    ... > that as long as you do your calculations in a single frame, ... >>> uniform acceleration by applying the appropriate compensating ... >From the moving FoR that includes the rod, ...
    (sci.physics.relativity)
  • Re: SR Length Contraction - how do physicists explain this
    ... >> reference frame. ... >> accelerated rod stops accelerating, the rod is 5 meters longer than an ... >> change length during the acceleration. ... It takes more energy to accelerate something and stretch it ...
    (sci.physics.relativity)
  • Re: How can this work in relativity?
    ... >> that as long as you do your calculations in a single frame, ... the same at all points of the rod. ... >> Uniform acceleration means that the ...
    (sci.physics.relativity)
  • Re: TomToms stupidity (re: was always TomToms stupidity)
    ... >> acceleration is immaterial, and Daryll was right to neglect it. ... >> relative to the stationary frame. ... and this "pulling" will stretch the rod. ...
    (sci.physics.relativity)
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