🚀 go-pugleaf

On Nov 5, 7:13 am, Tom Roberts <tjroberts...@sbcglobal.net> wrote in
sci.physics.relativity:
> Peri of Pera wrote:
> > 1. What is his real size and weight?
>
>         ["weight" => "mass", for the usual elementary reasons.]
>
> This depends on what you mean by "real". To me, my "real" mass is what I
> personally measure. That is, a measurement of my INTRINSIC mass. With
> that same meaning his mass is 60kg. Ditto for height, which is 180 cm.
> This is valid everywhere along his path.
>
>         Note, however, that in relativity mass is an invariant,
>         and an observer can measure the mass of a moving object
>         and obtain the same value. It is non-trivial to make such
>         a measurement, except in certain circumstances (e.g. in
>         elementary particle experiments specifically designed to
>         measure the mass of particles).
>
> > 2. What is his size and weight when v = 0? (The v of earth is not 0).
>
> This is relativity, and whenever you specify a velocity, you must also
> specify the frame relative to which it is measured. The v in the
> formulas is the relative speed between the object and the measuring
> apparatus; v=0 applies whenever the object is at rest in the same
> inertial frame as the measurement apparatus. For v=0 the answer is the
> same as above (i.e. my speed relative to myself is always 0).
>
> > 3. Who can measure Bertie during the trip as 18cm tall and weighing
> > 600kg and can do so by which method other than a calculation by the
> > Lorentz transforms?
>
> This would require assistants to the earth observer who are at rest in
> the observer's inertial frame, and are pre-positioned where Bertie will
> pass by, one for his head and one for his feet; they each have clocks
> synchronized with the earth observer. They both arrange to be
> pre-positioned such that they can both mark in their rest frame
> precisely where Bertie's head and feet are located at a time
> simultaneous in their (the earth observer's) frame. They then measure
> the distance between marks using a ruler at rest in their frame.
>
> If you think about it, this is the most sensible way to measure the
> length of a moving object.

No Roberts Roberts that is NOT the most sensible way. Your brothers
hypnotists in Einstein criminal cult have discovered a much more
sensible way. First they trap a long train inside a short tunnel:

http://www.youtube.com/watch?v=VSRIyDfo_mY&mode=related&search=

or a 80m long pole inside a 40m long barn:

http://www.math.ucr.edu/home/baez/physics/Relativity/SR/barn_pole.html
"These are the props. You own a barn, 40m long, with automatic doors
at either end, that can be opened and closed simultaneously by a
switch. You also have a pole, 80m long, which of course won't fit in
the barn....So, as the pole passes through the barn, there is an
instant when it is completely within the barn. At that instant, you
close both doors simultaneously, with your switch. Of course, you open
them again pretty quickly, but at least momentarily you had the
contracted pole shut up in your barn."

Then your brothers Roberts Roberts measure the length of the trapped
train or pole (in order to be able to make precise measurements, your
brothers do not always reopen the doors of the barn "pretty quickly").
The result of the measurement is: The length of the trapped train or
pole is exactly equal to the lenth of the trapping tunnel or barn. A
series of measurements would prove, eventually, that the length
contraction experienced by the moving object is exactly that predicted
by Divine Albert's Divine Theory. After publishing the result of the
experiment in Nature or Science, your brothers sing "Divine Einstein"
and go into convulsions:

http://www.bnl.gov/community/Tours/EinsteinPics/Einsteine.jpg
http://www.haverford.edu/physics-astro/songs/divine.htm
http://www.physicstoday.org/vol-58/iss-7/images/devine_einstein.mp3

Pentcho Valev