Science > Physics > Basic questions about the Michelson-Morley experiment
| Topic: |
Science > Physics |
| User: |
"rambler" |
| Date: |
26 Nov 2004 05:28:19 PM |
| Object: |
Basic questions about the Michelson-Morley experiment |
I am trying to understand the notion of light and aether before
special relativity.
It was assumed that the propagation speed of light depended on the
speed of the inertial reference frame. This is the same as for other
waves such as sound: the propagation speed of a sound wave depends on
the inertial reference frame in which the observer is located.
On the other hand it was assumed that a medium was necessary for light
to propagate. This medium was called aether. This is again the same as
in case of sound, which needs of matter to propagate.
Now, the medium in which sound propagates is located in, or may be
comoving with any reference frame. Also, it exists no preferred
reference frame in which this medium is located. Regarding aether:
Consider the Michelson-Morley experiment from the point of view of an
observer in the reference frame of aether (as a preferred reference
frame with coordinates x, y). From the point of view of the
laboratory (coordinates x', y'), the light beam is splitted and one
beam sent in the direction of the y'-axis and the other beam is sent
in the direction of the x'-axis. Both beams are reflected and
actually meet again at the beam-splitter.
But, why does the light beam travelling on the y'-axis return exactly
to the beam-splitter? If I consider sound, e.g. a longitudinal wave
propagating on air which is NOT comoving with the laboratory, I would
say it moves on the y-axis without any x-axis component of speed (or
it moves back on the x'-axis), and, therefore, it would not meet or
reach the other beam at the beam-splitter (which is at rest on the
x'-axis).
Thus, I understand this as a reason which may lead to assume that the
medium "aether" must be comoving with or is dragged by the motion of
reference frame of earth with respect to the preferred reference
frame aether. Is this correct? (This is my first question)
Lets go ahead from the point of view of the observer located on the
preferred reference frame (x, y). For this observer, the beam on the
x'-axis should show a doppler shift. The same should be valid for the
beam on the y'-axis, since from the point of view of the preferred
reference frame it has a component of speed on the x-axis. But the
references I read about special relativity explaining the MM
experiment do not consider the doppler shift. This seams confusing,
because to know whether the aether assumption predicts a phase shift
between both beams the doppler effect should be taken into account.
(Second question).
*-----------------------*
Posted at:
www.GroupSrv.com
*-----------------------*
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| User: "greywolf42" |
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| Title: Re: Basic questions about the Michelson-Morley experiment |
28 Nov 2004 01:44:17 PM |
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"rambler" <johann_dome@yahoo-dot-com.no-spam.invalid> wrote in message
news:41a7bc13$1_2@Usenet.com...
I am trying to understand the notion of light and aether before
special relativity.
It was assumed that the propagation speed of light depended on the
speed of the inertial reference frame.
A false history. "Reference frames" (inertial or otherwise) were invented
by the Relativists (Eddington) in 1920. Reference frames work in an
absolute space, not in any aether.
This is the same as for other
waves such as sound: the propagation speed of a sound wave depends on
the inertial reference frame in which the observer is located.
???? The propagation of the speed of sound at any point depends only the
local conditions of the atmosphere (or other sound medium). It may vary
with time, space, windspeed, temperature, etc.
On the other hand it was assumed that a medium was necessary for light
to propagate. This medium was called aether. This is again the same as
in case of sound, which needs of matter to propagate.
The luminiferous aether was not assumed to be matter. Every other wave
known to science has a medium. That is what a wave *IS*.
Now, the medium in which sound propagates is located in, or may be
comoving with any reference frame.
Since a coordinate system is a mathematical fiction, this is trivial.
Also, it exists no preferred
reference frame in which this medium is located.
This is true of any fluid.
Regarding aether:
Consider the Michelson-Morley experiment from the point of view of an
observer in the reference frame of aether (as a preferred reference
frame with coordinates x, y). From the point of view of the
laboratory (coordinates x', y'), the light beam is splitted and one
beam sent in the direction of the y'-axis and the other beam is sent
in the direction of the x'-axis. Both beams are reflected and
actually meet again at the beam-splitter.
This is the description of an absolute space, not an aether theory.
But, why does the light beam travelling on the y'-axis return exactly
to the beam-splitter? If I consider sound, e.g. a longitudinal wave
propagating on air which is NOT comoving with the laboratory, I would
say it moves on the y-axis without any x-axis component of speed (or
it moves back on the x'-axis), and, therefore, it would not meet or
reach the other beam at the beam-splitter (which is at rest on the
x'-axis).
Thus, I understand this as a reason which may lead to assume that the
medium "aether" must be comoving with or is dragged by the motion of
reference frame of earth with respect to the preferred reference
frame aether. Is this correct? (This is my first question)
Your primary problem is that you are using modern, purely Relativist notions
of "reference frames" as dopplegangers for absolute space. Hence, you are
confused.
Lets go ahead from the point of view of the observer located on the
preferred reference frame (x, y).
There are no "preferred" frames of any kind in an aether theory. Just like
there are no preferred frames in sound theory.
For this observer, the beam on the
x'-axis should show a doppler shift. The same should be valid for the
beam on the y'-axis, since from the point of view of the preferred
reference frame it has a component of speed on the x-axis. But the
references I read about special relativity explaining the MM
experiment do not consider the doppler shift. This seams confusing,
because to know whether the aether assumption predicts a phase shift
between both beams the doppler effect should be taken into account.
(Second question).
You have not included a single "aether assumption" anywhere in your post.
--
greywolf42
ubi dubium ibi libertas
{remove planet for e-mail}
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| User: "OG" |
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| Title: Re: Basic questions about the Michelson-Morley experiment |
26 Nov 2004 07:23:13 PM |
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"rambler" <johann_dome@yahoo-dot-com.no-spam.invalid> wrote in message
news:41a7bc13$1_2@Usenet.com...
I am trying to understand the notion of light and aether before
special relativity.
It was assumed that the propagation speed of light depended on the
speed of the inertial reference frame. This is the same as for other
waves such as sound: the propagation speed of a sound wave depends on
the inertial reference frame in which the observer is located.
On the other hand it was assumed that a medium was necessary for light
to propagate. This medium was called aether. This is again the same as
in case of sound, which needs of matter to propagate.
Now, the medium in which sound propagates is located in, or may be
comoving with any reference frame. Also, it exists no preferred
reference frame in which this medium is located. Regarding aether:
Consider the Michelson-Morley experiment from the point of view of an
observer in the reference frame of aether (as a preferred reference
frame with coordinates x, y). From the point of view of the
laboratory (coordinates x', y'), the light beam is splitted and one
beam sent in the direction of the y'-axis and the other beam is sent
in the direction of the x'-axis. Both beams are reflected and
actually meet again at the beam-splitter.
But, why does the light beam travelling on the y'-axis return exactly
to the beam-splitter?
The reason that the split beam on the y' axis returns to the beam
splitter is because the beam splitter has its own velocity v relative to
the x axis. On reflection, the beam orthogonal to the x axis now
includes a -v velocity wrt the x axis. This ensures that y' is
orthogonal to x' (which is parallel to the x axis), and the return of
the beam to the splitter.
propagating on air which is NOT comoving with the laboratory, I would
say it moves on the y-axis without any x-axis component of speed (or
it moves back on the x'-axis), and, therefore, it would not meet or
reach the other beam at the beam-splitter (which is at rest on the
x'-axis).
but the movement of the splitter dx/dt *does* give an x-axis component.
Thus, I understand this as a reason which may lead to assume that the
medium "aether" must be comoving with or is dragged by the motion of
reference frame of earth with respect to the preferred reference
frame aether. Is this correct? (This is my first question)
No, it's not a good assumption. The movement of the beam splitter
accounts for the fact that the beam meets up again at the splitter after
reflection. There is no inherent reason for frame dragging.
Lets go ahead from the point of view of the observer located on the
preferred reference frame (x, y). For this observer, the beam on the
x'-axis should show a doppler shift. The same should be valid for the
beam on the y'-axis, since from the point of view of the preferred
reference frame it has a component of speed on the x-axis. But the
references I read about special relativity explaining the MM
experiment do not consider the doppler shift. This seams confusing,
because to know whether the aether assumption predicts a phase shift
between both beams the doppler effect should be taken into account.
(Second question).
The doppler shift is real, but irrelevant to the MM experiment.
The null result of the MM experiment represents an absence of phase
shift as the split beams are rotated through 90 degrees.
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| User: "mountain man" |
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| Title: Re: Basic questions about the Michelson-Morley experiment |
26 Nov 2004 10:24:37 PM |
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"rambler" <johann_dome@yahoo-dot-com.no-spam.invalid> wrote in message
news:41a7bc13$1_2@Usenet.com...
I am trying to understand the notion of light and aether before
special relativity.
It was assumed that the propagation speed of light depended on the
speed of the inertial reference frame. This is the same as for other
waves such as sound: the propagation speed of a sound wave depends on
the inertial reference frame in which the observer is located.
On the other hand it was assumed that a medium was necessary for light
to propagate. This medium was called aether. This is again the same as
in case of sound, which needs of matter to propagate.
Now, the medium in which sound propagates is located in, or may be
comoving with any reference frame. Also, it exists no preferred
reference frame in which this medium is located. Regarding aether:
Consider the Michelson-Morley experiment from the point of view of an
observer in the reference frame of aether (as a preferred reference
frame with coordinates x, y). From the point of view of the
laboratory (coordinates x', y'), the light beam is splitted and one
beam sent in the direction of the y'-axis and the other beam is sent
in the direction of the x'-axis. Both beams are reflected and
actually meet again at the beam-splitter.
But, why does the light beam travelling on the y'-axis return exactly
to the beam-splitter? If I consider sound, e.g. a longitudinal wave
propagating on air which is NOT comoving with the laboratory, I would
say it moves on the y-axis without any x-axis component of speed (or
it moves back on the x'-axis), and, therefore, it would not meet or
reach the other beam at the beam-splitter (which is at rest on the
x'-axis).
Thus, I understand this as a reason which may lead to assume that the
medium "aether" must be comoving with or is dragged by the motion of
reference frame of earth with respect to the preferred reference
frame aether. Is this correct? (This is my first question)
Lets go ahead from the point of view of the observer located on the
preferred reference frame (x, y). For this observer, the beam on the
x'-axis should show a doppler shift. The same should be valid for the
beam on the y'-axis, since from the point of view of the preferred
reference frame it has a component of speed on the x-axis. But the
references I read about special relativity explaining the MM
experiment do not consider the doppler shift. This seams confusing,
because to know whether the aether assumption predicts a phase shift
between both beams the doppler effect should be taken into account.
(Second question).
Additionally, the refractive index of the medium needs
to be taken into account --- and was not. See Cahill's
treatment of the results of experiments based on gas
mode michaelson interferometers here:
www.mountainman.com.au/process_physics
Cahill's claim is that these experiments are showing
evidence of absolute motion: See register:
http://www.mountainman.com.au/process_physics/absolute_motion_register.htm
Pete Brown
Falls Creek
Oz
www.mountainman.com.au
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| User: "rambler" |
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| Title: re:Basic questions about the Michelson-Morley experiment |
28 Nov 2004 03:31:00 AM |
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I thank you all for the replies. I am not interested in questioning
special relativity, but just understanding the reasons which lead to
this theory. I was wondering if someone could help me to understand
which are the errors in chapter 2.d. in this paper:
http://arxiv.org/abs/physics/0401092 in which the author claims (from
a pre-SR point of view) that the MM experiment is blind to speed due
to doppler effect (the number of periods is the same in both arms,
regardless of the time difference).
*-----------------------*
Posted at:
www.GroupSrv.com
*-----------------------*
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| User: "Martin Hogbin" |
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| Title: Re: re:Basic questions about the Michelson-Morley experiment |
28 Nov 2004 05:44:29 AM |
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"rambler" <johann_dome@yahoo-dot-com.no-spam.invalid> wrote in message news:41a99ad4_2@Usenet.com...
I thank you all for the replies. I am not interested in questioning
special relativity, but just understanding the reasons which lead to
this theory. I was wondering if someone could help me to understand
which are the errors in chapter 2.d. in this paper:
http://arxiv.org/abs/physics/0401092 in which the author claims (from
a pre-SR point of view) that the MM experiment is blind to speed due
to doppler effect (the number of periods is the same in both arms,
regardless of the time difference).
If you wish to study the MMX from a pre-SR point of view,
you must make clear exactly what model you propose to use.
The only viable model at the time was a 'rigid' aether, relative
to which EM radiation travelled at a fixed speed.
Martin Hogbin
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| User: "greywolf42" |
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| Title: Re: re:Basic questions about the Michelson-Morley experiment |
29 Nov 2004 12:25:45 AM |
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"Martin Hogbin" <goatNOSPAM1@hogbin.org> wrote in message
news:cocdmt$571$1@hercules.btinternet.com...
"rambler" <johann_dome@yahoo-dot-com.no-spam.invalid> wrote in message
news:41a99ad4_2@Usenet.com...
I thank you all for the replies. I am not interested in questioning
special relativity, but just understanding the reasons which lead to
this theory. I was wondering if someone could help me to understand
which are the errors in chapter 2.d. in this paper:
http://arxiv.org/abs/physics/0401092 in which the author claims (from
a pre-SR point of view) that the MM experiment is blind to speed due
to doppler effect (the number of periods is the same in both arms,
regardless of the time difference).
If you wish to study the MMX from a pre-SR point of view,
you must make clear exactly what model you propose to use.
The only viable model at the time was a 'rigid' aether, relative
to which EM radiation travelled at a fixed speed.
A pathetic, slimy lie by Martin. ALL aether theories were viable "prior
to" the MMX.
Maxwell's zero-viscosity (superfluid) aether [the one used by Maxwell to
derive "Maxwell's equations," calculate the speed of light (unlike any
"modern" theory), and predict superconductivity 100 year before it's
prediction in the lab] was completely viable prior to 1887. In fact, it
remains viable to this day.
--
greywolf42
ubi dubium ibi libertas
{remove planet for e-mail}
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| User: "Uncle Al" |
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| Title: Re: Basic questions about the Michelson-Morley experiment |
27 Nov 2004 11:58:53 AM |
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rambler wrote:
I am trying to understand the notion of light and aether before
special relativity.
It was assumed that the propagation speed of light depended on the
speed of the inertial reference frame. This is the same as for other
waves such as sound: the propagation speed of a sound wave depends on
the inertial reference frame in which the observer is located.
On the other hand it was assumed that a medium was necessary for light
to propagate. This medium was called aether. This is again the same as
in case of sound, which needs of matter to propagate.
Now, the medium in which sound propagates is located in, or may be
comoving with any reference frame. Also, it exists no preferred
reference frame in which this medium is located. Regarding aether:
[snip]
Physics Today 57(7) 40 (2004)
No aether
http://fsweb.berry.edu/academic/mans/clane/
http://physicsweb.org/articles/world/17/3/7
No Lorentz violation
No Michelson-Morley (10^(-8) sensitivity in 1887) deviations to at
least 1.7x10^(-15),
Phys. Rev. Lett. 88(1) 010401 (2002)
Phys. Rev. Lett. 90 060403 (2003)
Phys. Rev. Lett. 42(9) 549 (1979)
Phys. Bull. 21 255 (1970)
Europhysics Lett. 56(2) 170 (2001)
Gen. Rel. Grav. 34(9) 1371 (2002)
All your stated arguments are quashed by contemporary empirical data.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
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| User: "mountain man" |
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| Title: Re: Basic questions about the Michelson-Morley experiment |
29 Nov 2004 06:35:25 PM |
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"Uncle Al" <UncleAl0@hate.spam.net> wrote:
No Michelson-Morley (10^(-8) sensitivity in 1887) deviations to at
least 1.7x10^(-15),
These published results are for vacuum based M-interferometers.
Gas mode M-interferometer experiments all show deviations.
The literature and you fail to make a distinction but should.
Pete Brown
Falls Creek
Oz
www.mountainman.com.au/process_physics
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| User: "Sam Wormley" |
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| Title: Re: Basic questions about the Michelson-Morley experiment |
26 Nov 2004 05:38:28 PM |
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rambler wrote:
I am trying to understand the notion of light and aether before
special relativity.
Reasonable Description
http://scienceworld.wolfram.com/physics/Michelson-MorleyExperiment.html
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| User: "RP" |
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| Title: Re: Basic questions about the Michelson-Morley experiment |
26 Nov 2004 07:29:33 PM |
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rambler wrote:
I am trying to understand the notion of light and aether before
special relativity.
It was assumed that the propagation speed of light depended on the
speed of the inertial reference frame. This is the same as for other
waves such as sound: the propagation speed of a sound wave depends on
the inertial reference frame in which the observer is located.
On the other hand it was assumed that a medium was necessary for light
to propagate. This medium was called aether. This is again the same as
in case of sound, which needs of matter to propagate.
Now, the medium in which sound propagates is located in, or may be
comoving with any reference frame. Also, it exists no preferred
reference frame in which this medium is located. Regarding aether:
Consider the Michelson-Morley experiment from the point of view of an
observer in the reference frame of aether (as a preferred reference
frame with coordinates x, y). From the point of view of the
laboratory (coordinates x', y'), the light beam is splitted and one
beam sent in the direction of the y'-axis and the other beam is sent
in the direction of the x'-axis. Both beams are reflected and
actually meet again at the beam-splitter.
But, why does the light beam travelling on the y'-axis return exactly
to the beam-splitter? If I consider sound, e.g. a longitudinal wave
propagating on air which is NOT comoving with the laboratory, I would
say it moves on the y-axis without any x-axis component of speed (or
it moves back on the x'-axis), and, therefore, it would not meet or
reach the other beam at the beam-splitter (which is at rest on the
x'-axis).
Thus, I understand this as a reason which may lead to assume that the
medium "aether" must be comoving with or is dragged by the motion of
reference frame of earth with respect to the preferred reference
frame aether. Is this correct? (This is my first question)
Lets go ahead from the point of view of the observer located on the
preferred reference frame (x, y). For this observer, the beam on the
x'-axis should show a doppler shift. The same should be valid for the
beam on the y'-axis, since from the point of view of the preferred
reference frame it has a component of speed on the x-axis. But the
references I read about special relativity explaining the MM
experiment do not consider the doppler shift. This seams confusing,
because to know whether the aether assumption predicts a phase shift
between both beams the doppler effect should be taken into account.
(Second question).
Doppler shift doesn't occur between the fixed elements of the
interferometer. Any doppler shift between the initial source and the
interferometer simply doesn't matter, it won't cause fringe shifts, it
will only cause changes in fringe spacing. The purpose of the experiment
is not however to measure ones speed wrt the source, which is all that
this anomaly will allow. Though the effect is useful: It is possible to
detect ones speed wrt the source by the use of the Michelson
interferometer, because of the doppler shift.
Google: Doppler Michelson "velocity determination"
http://www.google.com/search?hl=en&lr=&as_qdr=all&q=Doppler+Michelson+%22velocity+determination%22&btnG=Search
Richard Perry
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