ABIAN's TROLLEY
Alexander Abian
A trolley glides on an unexposed film F. There are two very
small holes a' and b' at the bottom of the trolley and an
electric flash bulb M midway between a' and b'.
|--a'---M--- b'--| trolley glides -->
-------a---------------b-------------------------- stationary film F --
While trolley is in motion, M gives a flash and two dots
a and b appear on the exposed film.
After a while the trolley is stopped and brought back and a' and a
are aligned.
W0WHICH ONE IS YOUR ANSWER ?
(1) b' is aligned with b
(2) b' is to the left of b
(3) b' is to the right of b
Please respond at your earliest convenience. Thank you.
--
-------------------------------------------------------------------------
ABIAN TIME-MASS EQUIVALENCE FORMULA T = A m^2 in Abian units.
ALTER EARTH'S ORBIT AND TILT TO STOP GLOBAL DISASTERS AND EPIDEMICS.
JOLT THE MOON TO JOLT THE EARTH INTO A SANER ORBIT.ALTER THE SOLAR SYSTEM.
REORBIT VENUS INTO A NEAR EARTH-LIKE ORBIT TO CREATE A BORN AGAIN EARTH(1990)
THERE WAS A BIG SUCK AND DILUTION OF PRIMEVAL MASS INTO THE VOID OF SPACE
ryk...@my-deja.com
ab...@iastate.edu (Alexander Abian) wrote:
(1)
--
Rod Ryker...
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
Arctangent the Infallible
you big doofus.
BTW Dr. Abian's obituary was posted to
this group last summer, so maybe you
should give up now.
Look it up.
Arctangent the Infallible
Alexander Abian
att: UINCLE AL SCHWARTZ
Dear Uncle Al
You, as an avid reader of my postings and immediately commenting on them, I
would greatly appreciate it if you answer my recent posting (which
apparently you missed checking on it). Please post your answer:
ABIAN's TROLLEY
A trolley glides on an unexposed film F. There are two very
small holes a' and b' at the bottom of the trolley and an
electric flash bulb M midway between a' and b'.
|--a'---M--- b'--| trolley glides -->
-------a---------------b-------------------------- stationary film F--
While the trolley is in motion, M gives a flash and two dots
a and b appear on the exposed film.
After a while the trolley is stopped and brought back and a' and a
are aligned.
WHICH ONE IS YOUR ANSWER ?
(1) b' is aligned with b
(2) b' is to the left of b
(3) b' is to the right of b
I hope you answer as soon as possible. Many would like to read it.
I always, always enjoy your postings.
With love, Alexander Abian
deja
> |--a'---M--- b'--| trolley glides -->
>-------a---------------b-------------------------- stationary film F--
>While the trolley is in motion, M gives a flash and two dots
>a and b appear on the exposed film.
>After a while the trolley is stopped and brought back and a' and a
>are aligned.
> WHICH ONE IS YOUR ANSWER ?
>
>(1) b' is aligned with b
>(2) b' is to the left of b
>(3) b' is to the right of b
Interesting question...I'd think that the speed of the trolley (and the
film?) would have soimething to do with it, but I think that the answer is
(2).
Tom Roberts
> A trolley glides on an unexposed film F. There are two very
> small holes a' and b' at the bottom of the trolley and an
> electric flash bulb M midway between a' and b'.
>
>
> -------a---------------b-------------------------- stationary film F --
As described there will be no images on the film at all. To obtain images
you need to elevate M above the bottom of the trolley. Fix your description
and re-post it. Be sure to specify how high above the bottom of the trolley
M is, and how far below the bottom of the trolley the film is, and how thick
the bottom of the trolley is.
A suitable description would be: M is a distance L above the
bottom; the thickness of the bottom and the distance to the
film are negligible compared to L, so parallax can be ignored.
I could make guesses (as above), but I think it's better for you to specify
what you are really asking.
Tom Roberts tjro...@lucent.com
Alexander Abian
>
>> |--a'---M--- b'--| trolley glides -->
>>-------a---------------b-------------------------- stationary film F--
>>While the trolley is in motion, M gives a flash and two dots
>>a and b appear on the exposed film.
>>After a while the trolley is stopped and brought back and a' and a
>>are aligned.
>> WHICH ONE IS YOUR ANSWER ?
>>
>>(1) b' is aligned with b
>>(2) b' is to the left of b
>>(3) b' is to the right of b
>
>
>Interesting question...I'd think that the speed of the trolley (and the
>film?) would have something to do with it, but I think that the answer is
>(2).
Abian answers:
As to your questions: as mentioned in the figure THE FILM IS STATIONARY
and the Trolley glides from left to right, its speed has no bearing as
to the position of b' w.r.t b after the Trolley is stopped and a and
a' are aligned. As you have most probably notices the SIMULTANEITY
takes place in the Trolley.
Thanks for your answer and I am looking forward to see postings of
other experts in RELATIVITY THEORY. Would they commit themselves to
a definite answer ? If they need definite measurements (which is
just avoiding the issue), O.K. call your measurements, h, p, q, ...
and derive your formula in terms of h, p, q, .. and discuss
(1), (2), (3).
Wayne Throop
:: A trolley glides on an unexposed film F. There are two very
:: electric flash bulb M midway between a' and b'.
::
:: |--a'---M--- b'--| trolley glides -->
:: -------a---------------b-------------------------- stationary film F --
::
:: While trolley is in motion, M gives a flash and two dots
:: a and b appear on the exposed film.
::
:: After a while the trolley is stopped and brought back and a' and a
:: are aligned.
::
:: (1) b' is aligned with b
:: (2) b' is to the left of b
:: (3) b' is to the right of b
:: Please respond at your earliest convenience. Thank you.
See below for an objection, but if by "your answer", you mean what would
SR predict, then the answer is clearly that b' is to the left of b.
That is, the marks left on the track will be farther apart than the
distance between a' and b' with the trolley at rest. By a factor of
1/sqrt(1-v^2), instead of 1/(1-v^2) as would occur if the film were at
rest in a classical ether.
This illustrates the length contraction of the trolley compared to the
film, since the marks (which are not made at the same time) are *less*
stretched out than would be the case without length contraction. It
also illustrates the contraction of the film compared tot he trolley,
since more of the film was squeezed between the rest distance between a'
and b', by a factor of 1/sqrt(1-v^2).
As usual, the key to understanding this is the relativity of simultaneity.
Do you need to have simultaneity explained?
Note: Abian's trolley question has been answered many times.
What was the purpose of posting it Yet Another Time?
: Tom Roberts <tjro...@lucent.com>
: As described there will be no images on the film at all. To obtain
: images you need to elevate M above the bottom of the trolley.
Well, I answered as if the film, M, a', and b' were all
negligably separated in y, and that light was directed from M to
a' and b' was directed y-wards by a mirror or by diffusion or whatnot.
Indeed, in earlier versions of this, I think it was explicit that
there were mirrors at a' and b'
Wayne Throop thr...@sheol.org http://sheol.org/throopw
Alexander Abian
In article <37890486...@lucent.com>,
Tom Roberts <tjro...@lucent.com> wrote:
>Alexander Abian wrote:
>> A trolley glides on an unexposed film F. There are two very
>> small holes a' and b' at the bottom of the trolley and an
>> electric flash bulb M midway between a' and b'.
>>
>>
>> |--a'---M--- b'--| trolley glides -->
>> -------a---------------b-------------------------- stationary film F --
>
>As described there will be no images on the film at all. To obtain images
>you need to elevate M above the bottom of the trolley. Fix your description
>and re-post it. Be sure to specify how high above the bottom of the trolley
>M is, and how far below the bottom of the trolley the film is, and how thick
>the bottom of the trolley is.
>
> A suitable description would be: M is a distance L above the
> bottom; the thickness of the bottom and the distance to the
> film are negligible compared to L, so parallax can be ignored.
>
>I could make guesses (as above), but I think it's better for you to specify
>what you are really asking.
>
>
>Tom Roberts tjro...@lucent.com
Abian answers:
The picture above and my question are as clear as possible. Your answer
is just to avoid the issue and is an absolutely unnecessary hair-splitting.!
You want measurements. O.K. any measurement you want express them by
p, q, r, ... derive your formula in terms of p, q, r, ... and
accordingly discuss (1), (2) (3). Fair enough ?
In my picture the thickness of the bottom of the trolley is as small
as possible - This is unsatisfactory to you ? O.K. the thickness is
h, derive your formula in terms of h . The film is stationary,
and the trolley glides from left to right. Do you need its velocity ?
O.K. it is V , derive your formula in terms of V and discuss
(1), (2), (3).
I am almost sure that Einstein would not have asked your question and
neither a specialist in Relativity would have asked your questions.
But they would have answered one of (1), (2), (3)
With love, Alexander Abian
Alexander Abian
att: Wayne Throop
See below for an objection:
In article <9317...@sheol.org>, Wayne Throop <thr...@sheol.org> wrote:
>:: ab...@iastate.edu (Alexander Abian)
>:: A trolley glides on an unexposed film F. There are two very
>:: small holes a' and b' at the bottom of the trolley and an
>:: electric flash bulb M midway between a' and b'.
>::
>::
>:: |--a'---M--- b'--| trolley glides -->
>:: -------a---------------b-------------------------- stationary film F --
>::
>::
>:: While trolley is in motion, M gives a flash and two dots
>:: a and b appear on the exposed film.
>::
>:: After a while the trolley is stopped and brought back and a' and a
>:: are aligned.
>:: WHICH ONE IS YOUR ANSWER ?
>::
>:: (1) b' is aligned with b
>:: (2) b' is to the left of b
>:: (3) b' is to the right of b
>::
>:: Please respond at your earliest convenience. Thank you.
>
>
>Note: Abian's trolley question has been answered many times.
>What was the purpose of posting it Yet Another Time?
>
<snip>
Abian answers:
If it was answered many times, then WHAT WAS the purpose of posting your
answer Yet Another Time ? It was not answered satisfactorily for
those who do not believe in "ether" Also, some people requested the answer
derived mathematically primarily based on
(1) x^2 - (ct)^2 = (x')^2 - (ct')^2
and as less as possible usage of Lorentz Transformations. For instance
the way I have recently derived directly from (1) the following
t' = t sqrt (1 - (v/c)^2)
by setting t' = 0 and x = vt in (1) and using no Lorentz
Transformations directly. Please don't lecture me on the relationship
of (2) and the Lorentz Transformations.
If you have not noticed my abovementioned derivation, ask me and I
will gladly repost it.
Cyberia
Alexander Abian <ab...@iastate.edu> wrote in message
news:7mb7nf$1b$1...@news.iastate.edu...
>
> Abian answers:
>
> As to your questions: as mentioned in the figure THE FILM IS
STATIONARY
> and the Trolley glides from left to right, its speed has no
bearing as
> to the position of b' w.r.t b after the Trolley is stopped and
a and
> a' are aligned. As you have most probably notices the SIMULTANEITY
> takes place in the Trolley.
SIMULTANEITY ?
The trolley's speed has no bearing ? What if it approaches c, or even
a fraction of c ?
Would not motion at the velocity c cause the position of b to be
non-existent until the trolley slowed to less than c and the light
rays from M overtook the moving aperture b'? Moving at a significant
fraction of c would cause the spot b to be more distant from a than
the distance between the apertures a' and b'. How much so would depend
on the velocity, would it not ? If both of these statements are true,
than unless the trolley were totally motionless, there is always some
component of the motion of the trolley added to the distance between a
and b, and I think deja's answer was the correct one.
>
> Thanks for your answer and I am looking forward to see postings of
> other experts in RELATIVITY THEORY.
Sorry, you have not heard from one of those here. :-) Maybe one will
show up and tell you I am full of it.
>Would they commit themselves to
> a definite answer ? If they need definite measurements (which is
> just avoiding the issue), O.K. call your measurements, h, p, q,
...
> and derive your formula in terms of h, p, q, .. and discuss
> (1), (2), (3).
?
There were other unstated parameters in your question that would
affect the outcome, but you worded the question such that some of
those could be discounted. When you said "While the trolley is in
motion, M gives a flash and two dots appear on the exposed film" you
have indicated that the trolley is *not* travelling at c, or the spot
at b would not yet have appeared on the film (until the trolley
slows). You also indicate by the wording of this statement that the
angle of the light ray emitted from M does in fact reach the film as
opposed to being blocked by the outside wall of aperture a' or b'. (In
other words, the altitude of M matters with respect to the distance to
a' or b' and the thickness of the material through which the apertures
are bored.).
Of course, because of the angle of these light rays leaving M and
passing through apertures before reaching the film, the spots a and b
will not be the same size or shape as the apertures a' or b'. Assumin
the apertures are round, will not the spots a and b be elongated
outboard of these apertures ? Increasing the distance between the
apertures and the film will cause the centroids of the spots a and b
to diverge. You did not specify these parameters.
My estimation, though, based on what little information you did
provide, is that the spots a and b will be further apart than the
apertures a' and b' by some distance, however infinitesimally small,
due to the effect of the angles, even if the trolley was sitting
still.
So, Deja was right for two reasons.
--
SeeYa !
----------------------------------------------------------------------
------
Hello... Is this thing on ?
Wayne Throop
: If it was answered many times, then WHAT WAS the purpose of posting
: your answer Yet Another Time ?
You didn't want me to answer? Why did you post?
Why did you avoid answering the simply query: "why did you post"?
: It was not answered satisfactorily for those who do
: not believe in "ether"
Who didn't it satisfy, and why? For example, I answered with essentially
the same reply as this time, and I don't "believe in" the ether; my own
answer satisfies ME; so again: who wasn't satisfied, and why?
: If you have not noticed my abovementioned derivation, ask me and I
: will gladly repost it.
Of course I noticed it. I'm the one who pointed out that your claim
that t' = t sqrt (1 - (v/c)^2) is the lorentz transform is incorrect.
Bernard HP Gilroy, maximum proconsul
>
>> |--a'---M--- b'--| trolley glides -->
>>-------a---------------b-------------------------- stationary film F--
>>While the trolley is in motion, M gives a flash and two dots
>>a and b appear on the exposed film.
>>After a while the trolley is stopped and brought back and a' and a
>>are aligned.
>> WHICH ONE IS YOUR ANSWER ?
>>
>>(1) b' is aligned with b
>>(2) b' is to the left of b
>>(3) b' is to the right of b
>
>
>Interesting question...I'd think that the speed of the trolley (and the
>film?) would have soimething to do with it, but I think that the answer is
>(2).
Well, I'm not willing to stake an answer, but I would be willing to
bet that the speed can't have anything to do with it.
John Savard
I would have thought, at first glance, that the answer was
>(2) b' is to the left of b
but in fact the opposite answer is right: since the two dots are made
simultaneously *within the reference frame of the trolley*, it is the
viewpoint of the trolley that sees the film as Lorenz-contracted that
counts, so the answer is
>(3) b' is to the right of b
John Savard ( teneerf<- )
http://members.xoom.com/quadibloc/crypto.htm
John Savard
>As you have most probably notices the SIMULTANEITY
>takes place in the Trolley.
Which is why the answer is (3). But that is something only an "expert"
in relativity might notice.
ryk...@my-deja.com
jsa...@tenMAPSONeerf.edmonton.ab.ca (John Savard) wrote:
> ab...@iastate.edu (Alexander Abian) wrote, in part:
>
> >(2) b' is to the left of b
>
> but in fact the opposite answer is right: since the two dots are made
> simultaneously *within the reference frame of the trolley*, it is the
> viewpoint of the trolley that sees the film as Lorenz-contracted that
> counts, so the answer is
>
> >(3) b' is to the right of b
>
> http://members.xoom.com/quadibloc/crypto.htm
Rod: I disagree . Both holes are equally spaced wrt the
light source and the distance the light travels to the
film is also equal in distance wrt each other .
The holes and the marks on the film align .
The speed of light or near it isn't mentioned
I believe therefore length contraction isn't
a factor .
--
Rod Ryker...
It is reasoning and
faith that bind truth .
Bernard HP Gilroy, maximum proconsul
>I believe therefore length contraction isn't
>a factor .
Just because the speed of light isn't mentioned doesn't mean
you can treat it as infinite. The wording of the problem makes it
pretty obvious this is meant to be considered from the POV of
relativity.
ryk...@my-deja.com
Rod: Oh , he neglected to mention this fact .
So a trolley is traveling near c . Thanks .?