Hi

I have some questions about the michelson morley experiment that tried
to detect ether.

On this web page http://galileoandeinstein.physics.vi...michelson.html
it shows some of the mathematics involved in calculating the
difference in the length/time of the two paths of the light beam. The
article says that the apparatus was built to be rotated so that as it
is rotated, the interference pattern should change. The article says
that after 90 degree rotation, the two path lengths have "changed
places" so the interference pattern should change e.g. a 20 degree
phase difference would become a 70 degree phase difference I guess.
As far as I can tell, the article doesn't give the mathematics of how
the two path lengths vary when the apparatus is rotated by say, five
degrees and why the interference pattern would be expected to change.

Here are my questions.

1. Is it true that after a 90 degree rotation, the interference
pattern should change (assuming the ether theory is correct) - e.g.
would a 70 degree phase difference have a different interference
pattern to a 20 degree phase difference?

2. (this question has a yes or no answer) - is it possible to show
mathematically that as the apparatus is rotated, the interference
pattern and the phase difference should change (assuming the ether
theory is correct).

3. Was the "null result" of the experiment the fact that the
interference pattern didn't change when the apparatus was rotated?

4. Did the experiment at the time, depend on the path lengths of the
two paths being exactly equal and was any effort made to make them
equal or was this completely unnecessary?

5. I've heard that the error/noise/inaccuracy of the original
experiment was too great for its result to be meaningful. If the
experiment depended only on observing the change in interference
pattern, what kind of error could invalidate this result?

TIA
gamma

On Jun 20, 5:26 pm, gamma wrote:
Hi

I have some questions about the michelson morley experiment that tried
to detect ether.

On this web pagehttp://galileoandeinstein.physics.virginia.edu/lectures/michelson.html
it shows some of the mathematics involved in calculating the
difference in the length/time of the two paths of the light beam. The
article says that the apparatus was built to be rotated so that as it
is rotated, the interference pattern should change. The article says
that after 90 degree rotation, the two path lengths have "changed
places" so the interference pattern should change e.g. a 20 degree
phase difference would become a 70 degree phase difference I guess.
As far as I can tell, the article doesn't give the mathematics of how
the two path lengths vary when the apparatus is rotated by say, five
degrees and why the interference pattern would be expected to change.

Here are my questions.

1. Is it true that after a 90 degree rotation, the interference
pattern should change (assuming the ether theory is correct) - e.g.
would a 70 degree phase difference have a different interference
pattern to a 20 degree phase difference?


IF aether theory were correct (it isn't) the 90 degree rotation means
exchanging the roles of x and y, so the expectation was that the
fringes will move. The aether theory expected a certain fringe shift
for the first orientation and expected a doubling (a motion on the
other side of the null equal to the original shift) after the 90
degree rotation.


2. (this question has a yes or no answer) - is it possible to show
mathematically that as the apparatus is rotated, the interference
pattern and the phase difference should change (assuming the ether
theory is correct).


Yes, it is.

3. Was the "null result" of the experiment the fact that the
interference pattern didn't change when the apparatus was rotated?


Yes

4. Did the experiment at the time, depend on the path lengths of the
two paths being exactly equal and was any effort made to make them
equal or was this completely unnecessary?


Yes and Yes.

5. I've heard that the error/noise/inaccuracy of the original
experiment was too great for its result to be meaningful. If the
experiment depended only on observing the change in interference
pattern, what kind of error could invalidate this result?

TIA
gamma

For its time, the experiment was incredibly precise. Since Michelson
and Morley, the experiment has been redone many times, with incredible
prcision and very good control over noise sources. Today, the
interferometers are replaced by oscillator cavities.
http://en.wikipedia.org/wiki/Michels...led_experiment

"gamma" wrote in message
...
Hi

I have some questions about the michelson morley experiment that tried
to detect ether.

http://www.aip.org/history/gap/PDF/michelson.pdf


On this web page
http://galileoandeinstein.physics.vi...michelson.html


That's the tail wagging the dog.


it shows some of the mathematics involved in calculating the
difference in the length/time of the two paths of the light beam. The
article says that the apparatus was built to be rotated so that as it
is rotated, the interference pattern should change. The article says
that after 90 degree rotation, the two path lengths have "changed
places" so the interference pattern should change e.g. a 20 degree
phase difference would become a 70 degree phase difference I guess.
As far as I can tell, the article doesn't give the mathematics of how
the two path lengths vary when the apparatus is rotated by say, five
degrees and why the interference pattern would be expected to change.

Here are my questions.

1. Is it true that after a 90 degree rotation, the interference
pattern should change (assuming the ether theory is correct) - e.g.
would a 70 degree phase difference have a different interference
pattern to a 20 degree phase difference?

Pointless question. It doesn't change.


2. (this question has a yes or no answer) - is it possible to show
mathematically that as the apparatus is rotated, the interference
pattern and the phase difference should change (assuming the ether
theory is correct).

Pointless question. It doesn't change. The answer is no.


3. Was the "null result" of the experiment the fact that the
interference pattern didn't change when the apparatus was rotated?

Yes. That was a sensible question.

4. Did the experiment at the time, depend on the path lengths of the
two paths being exactly equal and was any effort made to make them
equal or was this completely unnecessary?

There was a screw attached to a mirror to adjust length.
http://www.androcles01.pwp.blueyonde...mx4dummies.htm
Turning the screw changes the fringe shift.




5. I've heard that the error/noise/inaccuracy of the original
experiment was too great for its result to be meaningful. If the
experiment depended only on observing the change in interference
pattern, what kind of error could invalidate this result?

TIA
gamma

The experiment can be done in your own home, lasers make it easy
and you can buy one for a pittance.

"Dono." wrote in message
...
On Jun 20, 5:26 pm, gamma wrote:
Hi

I have some questions about the michelson morley experiment that tried
to detect ether.

On this web
pagehttp://galileoandeinstein.physics.virginia.edu/lectures/michelson.html
it shows some of the mathematics involved in calculating the
difference in the length/time of the two paths of the light beam. The
article says that the apparatus was built to be rotated so that as it
is rotated, the interference pattern should change. The article says
that after 90 degree rotation, the two path lengths have "changed
places" so the interference pattern should change e.g. a 20 degree
phase difference would become a 70 degree phase difference I guess.
As far as I can tell, the article doesn't give the mathematics of how
the two path lengths vary when the apparatus is rotated by say, five
degrees and why the interference pattern would be expected to change.

Here are my questions.

1. Is it true that after a 90 degree rotation, the interference
pattern should change (assuming the ether theory is correct) - e.g.
would a 70 degree phase difference have a different interference
pattern to a 20 degree phase difference?


IF aether theory were correct (it isn't) the 90 degree rotation means
exchanging the roles of x and y, so the expectation was that the
fringes will move. The aether theory expected a certain fringe shift
for the first orientation and expected a doubling (a motion on the
other side of the null equal to the original shift) after the 90
degree rotation.


2. (this question has a yes or no answer) - is it possible to show
mathematically that as the apparatus is rotated, the interference
pattern and the phase difference should change (assuming the ether
theory is correct).


Yes, it is.

3. Was the "null result" of the experiment the fact that the
interference pattern didn't change when the apparatus was rotated?


Yes

4. Did the experiment at the time, depend on the path lengths of the
two paths being exactly equal and was any effort made to make them
equal or was this completely unnecessary?


Yes and Yes.

5. I've heard that the error/noise/inaccuracy of the original
experiment was too great for its result to be meaningful. If the
experiment depended only on observing the change in interference
pattern, what kind of error could invalidate this result?

TIA
gamma

For its time, the experiment was incredibly precise. Since Michelson
and Morley, the experiment has been redone many times, with incredible
prcision and very good control over noise sources. Today, the
interferometers are replaced by oscillator cavities.
http://en.wikipedia.org/wiki/Michelson%E2%80%93
Morley_experiment#The_most_famous_failed_experimen t

.................................................. .................................................. .....
.................................................. .................................................. .....

I dono how you can say all that with a straight face?

In the AT REST frame of the experiment NO interference
would ever be evident!

It is only the "idea" that the AT REST frame is "REALLY"
in motion that a difference could be talked about...and even then
a ballistic statement of the situation would dispense with that.

Spirit of Truth

"gamma" wrote in message
...
Hi

I have some questions about the michelson morley experiment that tried
to detect ether.

That is inaccurate: it tried to detect the absolute speed of the Earth to
test the stationary ether theory of that time. Here is the original paper:
http://www.aip.org/history/exhibits/.../michelson.pdf

Among others, the paper is based on a hypothesis that it fails to mention
but which turned out to be wrong: that L'=L (Galilean transformation).

On this web page
http://galileoandeinstein.physics.vi...michelson.html
it shows some of the mathematics involved in calculating the
difference in the length/time of the two paths of the light beam. The
article says that the apparatus was built to be rotated so that as it
is rotated, the interference pattern should change. The article says
that after 90 degree rotation, the two path lengths have "changed
places" so the interference pattern should change e.g. a 20 degree
phase difference would become a 70 degree phase difference I guess.
As far as I can tell, the article doesn't give the mathematics of how
the two path lengths vary when the apparatus is rotated by say, five
degrees and why the interference pattern would be expected to change.

Here are my questions.

1. Is it true that after a 90 degree rotation, the interference
pattern should change (assuming the ether theory is correct) - e.g.
would a 70 degree phase difference have a different interference
pattern to a 20 degree phase difference?

The theory assumed that L=L', in which case the interfernce pattern should
change indeed. It is explained in detail in the original paper.

2. (this question has a yes or no answer) - is it possible to show
mathematically that as the apparatus is rotated, the interference
pattern and the phase difference should change (assuming the ether
theory is correct).

Yes, as shown.

3. Was the "null result" of the experiment the fact that the
interference pattern didn't change when the apparatus was rotated?

A "null result" means that the predicted value has not been measured. In
this case, the minimally predicted fringe shift was not detected.

4. Did the experiment at the time, depend on the path lengths of the
two paths being exactly equal and was any effort made to make them
equal or was this completely unnecessary?

That was unnecessary; however the arms had to be made "approximately equal"
because white light was used. Later a similar test (as part of a different
test) was done with one short and one long arm by Kennedy and Thorndike with
the same result.

5. I've heard that the error/noise/inaccuracy of the original
experiment was too great for its result to be meaningful.

Yes, the original experiment was done in 1881. The one we talk about is the
more accurate one of 1887.

If the
experiment depended only on observing the change in interference
pattern, what kind of error could invalidate this result?

Many kinds of errors are possible, but only their interpretation of the
result has been seriously put in doubt. The experiment has been repeated and
is still being repeated in many ways, always disproving the classical theory
of that time.

Regards,
Harald

On Jun 21, 11:08*pm, "harry"
wrote:

3. Was the "null result" of the experiment the fact that the
interference pattern didn't change when the apparatus was rotated?

A "null result" means that the predicted value has not been measured. In
this case, the minimally predicted fringe shift was not detected.


What is a minimally predicted fringe shift? Do you mean the predicted
fringe shift was very small? If so, then did repetitions of the
experiment produce differing results i.e. different fringe shifts but
not the predicted fringe shift?

If the experiment did not produce varying fringe shifts, then doesn't
that mean that noise / error wasn't a factor?

gamma

"gamma" wrote in message
...
On Jun 21, 11:08 pm, "harry"
wrote:

3. Was the "null result" of the experiment the fact that the
interference pattern didn't change when the apparatus was rotated?

A "null result" means that the predicted value has not been measured. In
this case, the minimally predicted fringe shift was not detected.


What is a minimally predicted fringe shift? Do you mean the predicted
fringe shift was very small?

I assume he means the minimum amount of fringe shift for the result to be
significant, so we can determine statistically that it wasn't just "noise".
It didn't get over that threshold for one to be able to say the null result
did not occur.

On Jun 21, 1:29 am, "Spirit of Truth" wrote:

I dono how you can say all that with a straight face?

In the AT REST frame of the experiment NO interference
would ever be evident!


You are an imbecile.

"gamma" wrote in message
...
On Jun 21, 11:08 pm, "harry"
wrote:

3. Was the "null result" of the experiment the fact that the
interference pattern didn't change when the apparatus was rotated?

A "null result" means that the predicted value has not been measured. In
this case, the minimally predicted fringe shift was not detected.


: What is a minimally predicted fringe shift? Do you mean the predicted
: fringe shift was very small? If so, then did repetitions of the
: experiment produce differing results i.e. different fringe shifts but
: not the predicted fringe shift?

Are you unable to download the paper? As explained in the paper (p.341),
when only accounting for the earth's orbit around the sun, the fringe shift
should be 0.4. The measured shift was certainly less than 1/20 of a fringe.
See also the clarification about the combined motion of sun and earth.

: If the experiment did not produce varying fringe shifts, then doesn't
: that mean that noise / error wasn't a factor?

Quite so. As I explained:

5. I've heard that the error/noise/inaccuracy of the original
experiment was too great for its result to be meaningful.

Yes, the original experiment was done in 1881. The one we talk about is the
more accurate one of 1887.

Harald

"Spirit of Truth" wrote in message
...

"Dono." wrote in message
...
On Jun 21, 7:19 pm, "Spirit of Truth" wrote:
"Dono." wrote in message

...

On Jun 21, 4:54 pm, "Spirit of Truth" wrote:
In the AT REST frame of the experiment NO interference
would ever be evident!
You are STILL an imbecile.

You may let us know why the false interpretation of MMX
doesn't expose that SR itself is false.

Spirit of Truth



Because your really false interpretation of the alleged false
interpretation of MMX doesn't prove SR false :-)

Have you studied the MMX, or are you just guessing?

Spirit of Truth

Please remind me of this false interpretation (and who made it)