Can this relationship be derived between Schrodinger equation and Doppler shift?

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Offline Colin2B

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If there were 2 light beams what you are saying would be correct. 
It works for one beam and 2 mirrors, you really arn't getting this are you. Sit down and think it through.

Now Colin - a thought experiment.  If we simply shine a static line of light onto the second mirror, ie: a line of light that is not being created by wobbling a dot of light, and then wobble the second mirror, will the second mirror turn this static line of light into a circle?  Or any other Lissajous figures?
Why should it?
The whole point of this is that what you see on the screen is the resultant of 2 sinewaves projected onto the screen by the 2 mirrors. If you only have one mirror and one tuning fork (i.e. one sinewave) you don't get the patterns.

I don't know if this helps but here is an example of doing the trig using graph paper, which is what I meant by drawing it out. http://www.intmath.com/trigonometric-graphs/7-lissajous-figures.php
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Offline timey

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Colin - I've always had a nice time with you online, so tucking my sensitive soul back into top pocket, I'm going to ignore the rather hurtful tone of your recent posts.

My contention with your post was that you said that a Lissajous figure is the result of 2 laser dots combining on a screen.  Its not 2 dots, its 1 dot vibrated into a line, that is then vibrated into a pattern.

Thank you for the link.  Please excuse me if I am wrong, but the maths portrayed are describing the dimensions of the Lissajous pattern itself.

I am interested in the maths of the physics of the wave periods creating the pattern.

It is because both mirrors are vibrating back and forth that a Lissajous pattern is caused in the beam of light reflected from one vibrating mirror to another vibrating mirror...  In that both mirrors are moving back and forth, albeit the movement of each is at right angles to the other, the distance between both of the mirrors is altered by this movement and constantly changing from long short, or short long - or the distance between the mirrors stays the same but the position of this distance in space is changing from one side to the other and back. (In phase, out of phase)

Are you with me so far?

All of what I describe above are wave periods in themselves.

Can we agree on this?

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Offline alancalverd

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Quote
you said that a Lissajous figure is the result of 2 laser dots combining on a screen.

No he didn't! Everyone here has said in all sorts of ways that a Lissajous figure is simply the locus of a point that moves cyclically in two dimensions. The most common is the sum of two sine waves in the x and y directions. That's all there is to it.
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Offline timey

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Yes he did...

So the spot on the screen traces, albeit magnified, the motion of the end of the tuning fork.
With 2 tuning forks the motion on the screen will be a combination of one moving the spot up and down, and the other moving it side to side such that at any point in time it's xy position (coordinates) will be specified by the value derived from the formulae Alan posted.

...and the reality is that the first mirror in line vibrates the spot into a line, and the second mirror vibrates the line into Lissajous figures.   Therefore the relationship of changing distance between the 2 vibrating mirrors has got to be the defining factor.

Now if you are telling me that the formula you provided describes not only the dimensions of the Lissajous figure itself, but also the wave periods of the changes in distance between the mirrors caused by the vibrations, and the wave period that would be apparent if you attached the laser in line to the top of a vibrating tuning fork for a measure of the distance of the back and forth, then I will agree to agree that that is all there is to Lissajous figures.

So what are you telling me?

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Online jeffreyH

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Yes he did...

So the spot on the screen traces, albeit magnified, the motion of the end of the tuning fork.
With 2 tuning forks the motion on the screen will be a combination of one moving the spot up and down, and the other moving it side to side such that at any point in time it's xy position (coordinates) will be specified by the value derived from the formulae Alan posted.

...and the reality is that the first mirror in line vibrates the spot into a line, and the second mirror vibrates the line into Lissajous figures.   Therefore the relationship of changing distance between the 2 vibrating mirrors has got to be the defining factor.

Now if you are telling me that the formula you provided describes not only the dimensions of the Lissajous figure itself, but also the wave periods of the changes in distance between the mirrors caused by the vibrations, and the wave period that would be apparent if you attached the laser in line to the top of a vibrating tuning fork for a measure of the distance of the back and forth, then I will agree to agree that that is all there is to Lissajous figures.

So what are you telling me?

If a trained physicist with decades of experience is telling you something it might be at least polite to pay attention.

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Offline timey

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I've asked a question of said experienced physicist concerning the maths that were posted by that experienced physicist.  A natural response from a non mathematician, and hardly impolite.

The purpose of your post being what?   That you know the answer but just wish to
continue in your position of superiority and make belittling remarks?

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Offline Colin2B

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Please excuse my 'tone', but it is born of frustration. I've tried to explain this from a number of different angles and I've often had the feeling that you really haven't read, or at least not understood, what I have written. The impression you can give is that I really don't understand what I am talking about. So tucking my sensitive .....

Ok, example of misreading:
My contention with your post was that you said that a Lissajous figure is the result of 2 laser dots combining on a screen.  Its not 2 dots, its 1 dot vibrated into a line, that is then vibrated into a pattern.
Look again at the quote in your reply to Alan:
So the spot on the screen traces, albeit magnified, the motion of the end of the tuning fork.
With 2 tuning forks the motion on the screen will be a combination of one moving the spot up and down, and the other moving it side to side such that at any point in time it's xy position (coordinates) will be specified by the value derived from the formulae Alan posted.
I've emboldened the key words that show I was speaking of one spot. I've also made it clear in other posts that it is one spot.

Thank you for the link.  Please excuse me if I am wrong, but the maths portrayed are describing the dimensions of the Lissajous pattern itself.
It is the locus of the spot over time.
I'm not sure what you mean by dimensions because the figure will be larger or smaller depending on how far away the screen is. The maths shows the locus which traces out the shape. So if by dimensions you mean shape, then yes.

I am interested in the maths of the physics of the wave periods creating the pattern.
That is what the maths shown does.
a and b in the formula represent the frequency of the 2 tuning forks. As Alan explained, the relative frequency and phase of a and b determine the pattern.

It is because both mirrors are vibrating back and forth that a Lissajous pattern is caused in the beam of light reflected from one vibrating mirror to another vibrating mirror...  In that both mirrors are moving back and forth, albeit the movement of each is at right angles to the other, the distance between both of the mirrors is altered by this movement and constantly changing from long short, or short long - or the distance between the mirrors stays the same but the position of this distance in space is changing from one side to the other and back. (In phase, out of phase)

Are you with me so far?
Ok up to the word albeit. Why did you write "albeit the movement of each is at right angles to the other"? The movement has to be at right angles otherwise you would just get a single line.
It's not the changing distance between the mirrors as I explained in an earlier post.
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Online jeffreyH

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It is not a case of me knowing the answer. We all know the answer and have been trying to impart it to you. You have chosen to be obstinate and self defeating. Instead why not pick up a book on arithmetic or algebra and start reading. You might have a pleasant surprise. Once you start becoming confident with the mathematics then you won't have these problems. To do otherwise is laziness.

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Offline timey

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You know Jeff - I've been talking to people on this thread for a year and a half.  I can remember that Colin plays guitar, is interested in outside sound recording, and has either an outsized or undersized woodpile on one side of his garage (unless he's dealt with it since last year)...
You were very ill in hospital last year, you lungs, you have worked as a water flow engineer (or something very similar), you have an intelligent wife, your dad is bigger than Theboxes dad, and your daughter displayed usual behaviour as a child...
What I remember about details of Alan would fill a couple of pages.

Is it so hard for you to remember that I conduct all my internet activity on a small phone screen (that is cracked and constantly freezing up) because my laptop is broken, that my horse and carriage business is far and beyond on the skids, I have no money and both my family and the animals are driven by a powerful need to eat, and time is the payment required to achieve that.  Alternatively animal welfare will take the horses that are too old to sell or re-home, and put them to death.

I am not too lazy to learn maths, I just don't have a natural affinity with the notation and find it hard to visualise the physics of an equation unless it is broken down into words and put into context.

I think it is perfectly acceptable to ask for help, and for clarification of that help when necessary, and that skill sharing is a pleasant ideal.  I have certainly always helped others to understand anything they thought that I might be able to help them with.

I also think it a display of dubious character to ridicule those who one feels are inferior to ones own self, as you clearly feel that I am to you.  But please know, I am not inferior to you, I am different to you, and although I do have a high opinion of my own abilities, I don't have any less high opinion of anyone else's.  I feel that we all have something to offer, and at the other end of the scale, no person can know everything.  Therefore it is just as well people are different from each other, and think about things from different perspectives, because it would be a bloody well boring world if we didn't.

I'm not here to have a my cock is bigger than your cock competition.  I understand and fully admit where and when my understanding is lacking, and know that I sometimes miss use terminology.  But on the basis that you guys are pretty clever, right?
...I merely wish to talk in depth about physics, and the physical experiments of physics, and preferably I'd like to have FUN when I'm doing it. 

Is that too much to ask?

Now what I am asking is if the formula that Alan provided describes the changes in the distance between the vibrating surfaces the light is being reflected off, or if it would be a different formula that describes this...

I'm quite sure that no-one has tried to impart this to me as of yet.

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Offline timey

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Please excuse my 'tone', but it is born of frustration. I've tried to explain this from a number of different angles and I've often had the feeling that you really haven't read, or at least not understood, what I have written. The impression you can give is that I really don't understand what I am talking about. So tucking my sensitive .....

Ok, example of misreading:
My contention with your post was that you said that a Lissajous figure is the result of 2 laser dots combining on a screen.  Its not 2 dots, its 1 dot vibrated into a line, that is then vibrated into a pattern.
Look again at the quote in your reply to Alan:
So the spot on the screen traces, albeit magnified, the motion of the end of the tuning fork.
With 2 tuning forks the motion on the screen will be a combination of one moving the spot up and down, and the other moving it side to side such that at any point in time it's xy position (coordinates) will be specified by the value derived from the formulae Alan posted.
I've emboldened the key words that show I was speaking of one spot. I've also made it clear in other posts that it is one spot.

Thank you for the link.  Please excuse me if I am wrong, but the maths portrayed are describing the dimensions of the Lissajous pattern itself.
It is the locus of the spot over time.
I'm not sure what you mean by dimensions because the figure will be larger or smaller depending on how far away the screen is. The maths shows the locus which traces out the shape. So if by dimensions you mean shape, then yes.

I am interested in the maths of the physics of the wave periods creating the pattern.
That is what the maths shown does.
a and b in the formula represent the frequency of the 2 tuning forks. As Alan explained, the relative frequency and phase of a and b determine the pattern.

It is because both mirrors are vibrating back and forth that a Lissajous pattern is caused in the beam of light reflected from one vibrating mirror to another vibrating mirror...  In that both mirrors are moving back and forth, albeit the movement of each is at right angles to the other, the distance between both of the mirrors is altered by this movement and constantly changing from long short, or short long - or the distance between the mirrors stays the same but the position of this distance in space is changing from one side to the other and back. (In phase, out of phase)

Are you with me so far?
Ok up to the word albeit. Why did you write "albeit the movement of each is at right angles to the other"? The movement has to be at right angles otherwise you would just get a single line.
It's not the changing distance between the mirrors as I explained in an earlier post.

Ah Colin - just saw your post, and I take on board your underlining of emphasis as pointed out, and can say I was mistaken in my interpretation...

It may look as though I am not reading through because I do not answer each point in multi quotes.  It takes hours to create them on this phone screen, so much as I'd like to, I don't have time.  I just pick the most relevant bits.

So if a) is one frequency, or sine wave, and b) is the other, ie: tuning fork 1 and tuning fork 2, can we now look at the phase that you refer to?  What in the physical experiment represents phase?

(edit: we can come back to the angle the beam of light hits the mirrors at after)
« Last Edit: 18/10/2016 04:00:55 by timey »

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Offline alancalverd

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The distance between the tuning forks is irrelevant. What matters is the angular deflection of the beam in the x and y directions. The separation has to be small enough (or the mirrors large enough) that the beam reflected off the first mirror is always intercepted by the second mirror, but that's it.
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Offline timey

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I realise Alan that the length of distance that the tuning forks are 'set up' apart is irrelevant, apart from the image created by the back and forth of the first mirror fitting onto the second mirror...
It is the miniscule changes in this set up distance caused by the back and forth motions of the mirrors that I'm referring to.

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Offline alancalverd

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That will induce a minuscule asymmetry of the Lissajous figure. So?   
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Offline timey

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So - do the maths you provided describing the geometry of a Lissajous figure also describe this asymmetry, or would describing this asymmetry of the Lissajous figure require a different set of maths?

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Offline alancalverd

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I think you would just add a small constant to one of the sine waves, but now I'm having difficutly even imagining the optical path!
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Online jeffreyH

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I think you would just add a small constant to one of the sine waves, but now I'm having difficutly even imagining the optical path!

Maybe you need to revise a little trigonometry. And no don't mention equilateral triangles.

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Offline timey

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I think you would just add a small constant to one of the sine waves, but now I'm having difficutly even imagining the optical path!

Yes...(chuckle)...  It's beyond mind boggling trying to imagine the the optical light path creating the circle, let alone more complex patterns...

The changes in the 'set up' distance between the mirrors is phase dependent...

Hit both tuning forks at same time from the left side, and we have the 'set up' distance rocking back and forth in space right to left...
Hit both tuning forks at the same time from the right side, and we have the 'set up' distance rocking back and forth in space left to right...
Hit both tuning forks at the same time, 1 to the left, 1 to the right, from the internal orientation, and the 'set up' distance changes, rocking from longer, shorter...
Hit both the tuning forks at same time, 1 to right, 1 to left, from outside orientation, and the 'set up' distance changes, rocking from shorter, longer...

...the changes in distance between the mirrors are then vastly complicated by the orientation of the movement of the mirrors being at right angles.  This in effect adds another dimension of long short, short long, and rocking of distance in space from right to left, or left to right.

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Offline Colin2B

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So if a) is one frequency, or sine wave, and b) is the other, ie: tuning fork 1 and tuning fork 2, can we now look at the phase that you refer to?  What in the physical experiment represents phase?
It is the relative phase of the 2 sinewaves.
In the double pendulum you can start them together or with any phase relationship you want.
With the tuning forks starting them with a specific phase relationship will be tricky as the common way of starting is by tapping it and, as you will never get the timing exact, the phase will be random.
However, it's not too critical, it is unlikely you will hit exactly inphase or at pi so if f1=f2 you are unlikely to get straight lines, neither are you likely to get a perfect circle, an ellipse is the most likely.

I notice you are asking Alan if the maths he described covers the change of distance between the forks. The thing to consider is that the maths describes perfect lissajous curves (produced mathematically) and any mechanical system will introduce some imperfections.
For eg I had a think about the double pendulum and reckon there are at least 3 imperfections:
- the sand comes out at a constant rate but pendulums have their max speed at the bottom of swing and minimum at the ends, so the thickness of sand will change making the line slightly wider in places.
- the sand also has inertia so at the ends of the swing I think it will overshoot slightly distorting the curves.
- the pendulum doesn't trace a path parallel to the surface, so some distortion will result.
Also, if the system uses a pen rather than sound there will be friction that affects the curves. I'm sure you can think of others.

The tuning fork/mirror system doesn't introduce much distortion, Alan is typically understating when he says minuscule as it is far less than that. I won't spoil your fun by telling you what I think it is, but to aid your calculations, the amplitude of the tuning fork can be taken as 1mm and you don't have to do all the combinations for the 2 forks, just the bounding conditions will give you the range of the effect.
When you've concluded that it is irrelevant to discussion on lissajous curves let me know.

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the feebleminded have inherited the earth.

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Offline timey

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The phase between the sine waves is physically represented in the changes of position of the set up distance in the surrounding space, or changes in the distance of the set up distance between the mirrors...

Yes these changes in distance are minuscule, but they are the distances that the light beam travels and these miniscule differences are what is amplified by the distance between the second mirror and the display screen.  If not for this amplification, what we would observe would be too miniscule to properly discern.

You are correct, this discussion is not concerning Lissajous figures, it is concerning the distribution of resonant vibrations.  It's what's happening between the mirrors that interests me, not what is occurring on the screen.

Evan made a post earlier this thread explaining how a singular mirror on an axis can be driven to creating Lissajous figures.  The phasing between the sine waves occurs on 1 mirror moving in 3 dimensions.
« Last Edit: 19/10/2016 01:23:18 by timey »

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Offline alancalverd

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OK let's have another go at the tuning forks. Assume the first one produces a perfect sinusoidal oscillation in the x direction. This is amplified by the distance from the center of oscillation to the final screen. The second mirror would do the same in the y direction but also alters the x amplification because it is altering the length of the optical path from the x mirror.

Of course it isn't the linear displacement that causes the beam to move, it's the angular movement, and this is a fraction of a degree for a tuning fork, so you would probably need a meter or so of optical path to get a visible display. If the amplitude of the fork vibration is 1 mm then the variation in x amplification will be +/-1/2000, almost certainly undetectable and anyway of absolutely no physical significance.

     
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Offline timey

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OK - stating any amplification of effects as being due to a) the distance between the first mirror in line to the laser beam source and the second mirror, and b) the distance between the second mirror in line to the laser beam source and the screen...

We can now look at the scenario where there is just a singular mirror set up on an axis being driven by 2 sine waves, and the amplification of effect is due only to the distance between this singular mirror and the screen - where clearly these very small movements of the phasing between the sine waves in the mirror are of physical significance, because if they were not occurring, a Lissajous figure would not be reflected onto the screen...

The axis provides the mirror with 3 dimensions to move in... So - the 2 dimensional image on the screen is the result of motion occurring in 3 dimensions.

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Offline alancalverd

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And the third dimension is irrelevant except for a possible tiny asymmetry of the curve. Not that anyone would use an optical  Lissajous to make a precise sine/sine curve anyway. It's OK for arty photographs and stadium laser shows, though it's probably easier nowadays to wiggle the laser or LED directly, but it's a bit old-hat in either case and a lot more complicated to set up than a Spirograph.

The appearance of the figure does not depend on small movements of phasing. A stationary figure will have a fixed phase difference which can vary from 0 (to give a straight line) to 90 degrees (a circle). If the phase difference is a multiple of 90 degrees + a constant, ie  phase locked sine waves of different frequencies, you will get stationary multiple closed loops with a tilt. All that the z-induced phase error will do is induce a bit of jitter into your nice image.
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Offline timey

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My interest doesn't stem from an arty point of view, nor musical...

What I am interested in is the wave period, ie: amplitude of vibration, of 1 sine wave being changed by the wave period, ie: amplitude of vibration, of the other sine wave, and that a 3rd wave period of vibration emerges as a result of this change.  It is the maths of these 3 dimensions of motions that interest me.  (Yes I can appreciate that jittering, or a Lissajous figure that is displaying movement is due to various degrees of 'out of phase'.

The Lissajous figure is a 2 dimensional representation of motion in 3 dimensions over time...  Are there maths that describe these motions?

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Offline Colin2B

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The Lissajous figure is a 2 dimensional representation of motion in 3 dimensions over time...  Are there maths that describe these motions?
No, because as we've said before the lissajous figures are not a 2d representation of 3D.

What I am interested in is the wave period, ie: amplitude of vibration, of 1 sine wave being changed by the wave period, ie: amplitude of vibration, of the other sine wave, and that a 3rd wave period of vibration emerges as a result of this change.  It is the maths of these 3 dimensions of motions that interest me.
Just a point of terminology, wave period is not the amplitude of vibration.
What you describe doesn't happen in this tuning fork set up and doesn't need 3 dimensions. Have a look at Fourier transforms to understand mixing of waves.
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Offline alancalverd

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Amplitude is the height of a maximum, or half the total span.

You can alter amplitude by adding waves of the same frequency. The Lissajous figure does not do this. The x and y amplitudes are the amplitudes of the original waves.

Period is the time or distance between two successive maxima.

You can alter periods by multiplying waves of different frequencies. The Lisassajous figure does not do this although the rate of repetition of a cyclic figure does depend on the frequency difference. The x and y frequencies are the frequencies of the original waves.
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Offline timey

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Alan - Yes, as you say "The x and y amplitudes are the amplitudes of the original waves."...

These amplitudes of those original waves are causing changes in the distance between the mirrors attached to the tuning forks creating those original waves, and this amplitude of those original waves changes in each of the mirrors at every position in time of the back and forth motions that are occurring at right angles to each other.

It is this part of the process that I wish to discuss and understand the maths of.  In that a pattern is created that is a continuous line, the motions between the mirrors are repetitive...  And in that the motions are repetitive, they constitute a wave form, and a wave form has a period.

Are you with me so far, 'cos if you are I'd like to expand the discussion into translating distances into time periods.  If not, say where your problem is and we will address the problem/s first.

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Colin - the mechanics that cause a Lissajous figure are occurring in 3 dimensions, it is these mechanics in 3 dimensions that are of interest to me.  That something that is moving in 3 dimensions creates a pattern suggests to me that there are 3 dimensions involved, but if you insist that a Lissajous figure itself is 2 dimensional, then so be it... Actually whether it is or not is incidental to the discussion itself which is about the 3 dimensional mechanics causing the patterns, ok?

As to your statement that says that the mechanics creating the patterns are not occurring in 3 dimensions, either I'm just not understanding what you mean, or you need to think it through more thouroughly.  The mirror is attached to a tuning fork, the fork has a frequency it resonates at when hit, and when hit it rocks back and forth. This action tips the mirror from side to side, or up and down.  These motions 'are' 3 dimensional, and it is these motions that cause the pattern, over time.

...and, I will most certainly have a look at the maths, but to be clear, are you saying that it is the Fourier transformations that are describing the 3 dimensional motions of distance change occurring between the mirrors?
« Last Edit: 19/10/2016 19:51:28 by timey »

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Offline alancalverd

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By pythagoras, the distance between two points oscillating at right angles to each other is the rest separation plus the square root of the sum of the squares of their positions which at time t are x = a sin ft and y = b sin f't.

You can't "translate distances into time periods" unless there is a known velocity, in whcih case the question is as trivial as navigating by dead reckoning. d = vt.

So you want to know the speed of each mirror at time t. Easy. a cos ft and b cos f't. The calculation of square roots is left as an exercise to the reader, but the answer must be cyclic because there's nowhere else to  go!

 

« Last Edit: 19/10/2016 22:08:16 by alancalverd »
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Offline timey

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In this case translating distances into times wouldn't present a problem, as the light travelling these distances is doing so at constant velocity...

...but the concept of knowing the speed that the mirror is travelling at works well enough, (speed, distance, time formula) and is convenient to the discussion in that it leads to the concept of Doppler shift...

The distance the light is travelling from the first mirror to the second mirror is constantly in flux.  On the forward motion the light is travelling from a surface being pushed forward towards the receiving surface.  On the outward motion the light is travelling from a receding surface.
« Last Edit: 19/10/2016 23:55:40 by timey »

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Offline alancalverd

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If you are just interested in the Doppler shift from a moving mirror, why not say so?  deltaf = 2v x f/c where v is the instantaneous velocity of the mirror.
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Offline Colin2B

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As to your statement that says that the mechanics creating the patterns are not occurring in 3 dimensions, either I'm just not understanding what you mean, or you need to think it through more thouroughly. 
I can assure you I have thought it through very thoroughly. I have even worked out the best orientation of the fork/mirrors which minimises distortion and tested some ideas with mirrors and laser.

The mirror is attached to a tuning fork, the fork has a frequency it resonates at when hit, and when hit it rocks back and forth. This action tips the mirror from side to side, or up and down.  These motions 'are' 3 dimensional, and it is these motions that cause the pattern, over time.
You need to separate out the motion which creates the lissajous and the motion which doesn't. I have taken to calling them lateral and longitudinal in order to keep them clear in my mind.
If the mirror is attached to the side of the fork it does, as you say, rock - like a lever pivoted at the bottom of the arm. This creates 2 movements. First, a change of angle of incidence between the beam and the mirror, this creates a changing angle of reflection or deflection causing the beam to sweep up and down - I call this the lateral movement. This sweeping, vertical movement is passed to the second mirror which vibrating at right angles to the first adds a horizontal movement. It is the combination of these 2 dimensional movements - up/down, side to side - which creates the lissajous figures. No third dimension is required - think about the double pendulum, 2 dimensions of movement.
In addition, as you say, the rocking of the arm causes a movement along the path of the beam (longitudinal) shortening  and lengthening the distance between the forks. This causes, as Alan rightly said,  a very small timing jitter in the beam, it also causes a very small alternating Doppler Shift in the beam.
The jitter causes a very slight variation in the dwell time as the beam traces out the lissajous (remember how the sand can pile up less when the pendulum speeds up) and if it were possible to measure it there would be a very slight variation of brightness over the curve. The Doppler, again if you could measure it, would cause slight variation to the colour of the beam at various sectors of the curve. However, both of these effects are so small that it is impossible to see them.
There is also a a very, very slight distortion of the curves due to the angle of incidence of the mirror relative to the beam not twisting in the same plane but following a slight curve, I haven't plotted this out but I think it slightly distorts the extremes of the loops, but again it is below measurable level.
As I said before, every mechanical system introduces some distortion, but this system produces very little.
It's worth noting that on the net there are diagrams showing some setups with the mirror attached to the end of a tine facing upwards with the beam shining down onto it, in this case the forward back motion is virtually eliminated and yet lissajous curves are still produced.
As you can see I have thought it through, but why do I expect you won't be convinced?

...and, I will most certainly have a look at the maths, but to be clear, are you saying that it is the Fourier transformations that are describing the 3 dimensional motions of distance change occurring between the mirrors?
No, you were asking about 2 waves being combined to create a third. If you want to look at 3 dimensional motion between the mirrors forget Fourier it won't help you.

Note- I see Alan has responded while I was typing. He understands.
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Offline timey

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If you are just interested in the Doppler shift from a moving mirror, why not say so?  deltaf = 2v x f/c where v is the instantaneous velocity of the mirror.

What interests me is that the 'speed' of a Doppler shift can be translated into a period of time via the speed distance time  formula where light is the travelling phenomenon, but enough of this for the moment...
So long as we can agree that Doppler shifts are occurring in the passage of the lights optical path?

Edit: To clarify, I am not referring to a frequency change in the light...  A Mossbauer effect of receiving a gamma ray conducted horizontally in a uniform gravity field will not respond differently if the gamma ray emitter is attached to a vibrating speaker cone.  The photon will still be received.
« Last Edit: 20/10/2016 00:39:48 by timey »

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Offline Colin2B

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So long as we can agree that Doppler shifts are occurring in the passage of the lights optical path?
Alan agreed this back in #41 and pointed out that it doesn't affect the lissajous patterns.
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Offline alancalverd

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What interests me is that the 'speed' of a Doppler shift can be translated into a period of time via the speed distance time  formula where light is the travelling phenomenon, but enough of this for the moment...
This sentence is meaningless.

Quote
So long as we can agree that Doppler shifts are occurring in the passage of the lights optical path?
obviously

Quote
Edit: To clarify, I am not referring to a frequency change in the light...
but that is exactly what a Doppler shift is! 

Quote
A Mossbauer effect of receiving a gamma ray conducted horizontally in a uniform gravity field will not respond differently if the gamma ray emitter is attached to a vibrating speaker cone.  The photon will still be received.
only at those times where v(cone) = 0 i.e. at the max and min displacement,  when there's no Doppler shift. That's the whole point of the experiment.
[/quote]
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Offline timey

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No, it is not meaningless Alan...  The speed that the mirror moves forward with is inherent with a distance.  The mirror only moves so far forward... Subtract the distance that it moves forward from the original distance, divide this distance by speed of light and you have a time value.  The light didn't travel that distance, therefore the time it takes to complete the shorter distance is lesser.  Subtract time value from the original time.
A backward motion will do the opposite and add time to the distance.

Yes - the frequency of light changes in a gravitational gradient and this effect is thought to be due to Doppler shift, because distance between source and receiver is expanding or contracting.  The frequency of the Doppler shift denotes the speed at which the expansion or contraction is occurring...

But we can see in the mechanics of the movement between the mirrors that the light does not travel the distance that is behind the moving forward mirror, nor the distance behind the moving back mirror, and neither of these forward or backward speeds can add or subtract from the velocity of the light.

Adding a vibration to the gamma ray emitter of the Mossbauer simply means the light has a little less time (forward motion), or a little more time (backward motion), in which to travel to the destination.

The Pound Rebka is a vertical experiment...  Have you got any experimental data on a Mossbauer conducted on the 'horizontal' that states frequency change in the gamma ray via this vibration.  I have never come across any myself...
Provide me evidence of this and I'll be packing up my 'New Theory' on new theories as a waste of time!

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Offline alancalverd

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Come on, lass, this is going backwards into the mists of incomprehension that you left at least a year ago!

No, it is not meaningless Alan...  The speed that the mirror moves forward with is inherent with a distance.
Please don't talk bollocks! The speed of the mirror is a cos ft. What on earth does "inherent with a distance" mean? 
Quote
The mirror only moves so far forward... Subtract the distance that it moves forward from the original distance, divide this distance by speed of light and you have a time value.  The light didn't travel that distance, therefore the time it takes to complete the shorter distance is lesser.  Subtract time value from the original time.
A backward motion will do the opposite and add time to the distance.
No! A thousand times no! It adds distance to the  distance, and time to the time. If you start arbitrarily mixing dimensions you will mislead yourself and look very silly.

Quote
Yes - the frequency of light changes in a gravitational gradient and this effect is thought to be due to Doppler shift, because distance between source and receiver is expanding or contracting.  The frequency of the Doppler shift denotes the speed at which the expansion or contraction is occurring...
utter bollocks.

Quote
But we can see in the mechanics of the movement between the mirrors that the light does not travel the distance that is behind the moving forward mirror, nor the distance behind the moving back mirror, and neither of these forward or backward speeds can add or subtract from the velocity of the light.
as far as we know, c is constant

Quote
Adding a vibration to the gamma ray emitter of the Mossbauer simply means the light has a little less time (forward motion), or a little more time (backward motion), in which to travel to the destination.
No. The photon has no idea of its destination. Moving  the emitter adds energy, and since c is constant, this must appear as a change in frequency.

Quote
The Pound Rebka is a vertical experiment...  Have you got any experimental data on a Mossbauer conducted on the 'horizontal' that states frequency change in the gamma ray via this vibration.  I have never come across any myself...
Provide me evidence of this and I'll be packing up my 'New Theory' on new theories as a waste of time!
PR alone results in equal and opposite values to the gravitational shift between up and down, so horizontal = no shift.   

Sorry, I can't go on responding to this drivel. I thought you had read and understood the Pound-Rebka experiment. You certainly claimed to have done so. Why have you suddenly started writing utter nonsense about it, and now Mossbauer too? 

Maybe you'd prefer to delete the entire post, and I will do likewise with this one, to save embarrassment?
« Last Edit: 20/10/2016 17:41:15 by alancalverd »
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Offline timey

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Alan - you can leave the post as is... You might not comprehend the notion that if the speed of light is involved, that a distance and a time are the same thing, are interchangeable, and more to the point can be confused with each other, but someone might...

You are correct in that you thought I had read and understood the Pound Rebka.  I have, 'extensively' and do understand that the Doppler shift is thought to add or subtract energy for a 'longer' or 'shorter' wavelength.

What of it?  Am I not allowed to call 'anything' into question?  Am I just to accept what is spoon fed to me parrot style without engaging brain?

If you have experimental data that describes the use of a speaker in a horizontal Mossbauer experiment that confirms the frequency change on the horizontal, then fair enough!  As I said, my curiosity then over and done with.

Do you?  'Cos as said last post, I haven't been able to find any...

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Offline Colin2B

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You are correct in that you thought I had read and understood the Pound Rebka.  I have, 'extensively' and do understand that the Doppler shift is thought to add or subtract energy for a 'longer' or 'shorter' wavelength.
You may think that, but it is not what you said. Alan is questioning:
the frequency of light changes in a gravitational gradient and this effect is thought to be due to Doppler shift, because distance between source and receiver is expanding or contracting.
which is not true.
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Offline alancalverd

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If you have experimental data that describes the use of a speaker in a horizontal Mossbauer experiment that confirms the frequency change on the horizontal, then fair enough!  As I said, my curiosity then over and done with.

Do you?  'Cos as said last post, I haven't been able to find any...

Obviously not, because there is no frequency shift in the horizontal plane. http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/mossb.html describes a classic demonstration that any movement reduces the absorption.
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Offline timey

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You are correct in that you thought I had read and understood the Pound Rebka.  I have, 'extensively' and do understand that the Doppler shift is thought to add or subtract energy for a 'longer' or 'shorter' wavelength.
You may think that, but it is not what you said. Alan is questioning:
the frequency of light changes in a gravitational gradient and this effect is thought to be due to Doppler shift, because distance between source and receiver is expanding or contracting.
which is not true.

Before I answer your post, just want to say from one sensitive soul to another, that on my reading through of your posts that it is difficult for me to multi mlquote...so I dont, I took on board your description of a light source moving closer to the screen, and further back from the screen in relation to Doppler shift, and found your analogy of longditudal and lattititudal waves rather inspired.  Thank you.

Alan is not questioning anything.  He is saying bollocks, drivel, and that we sorted this out last year.  No we didn't... Although I can appreciate that Alan does not read every post I make, nobody posted the data I have asked for last year either.

The frequency of light does change in a gravitational gradient.  It is thought that the Doppler shift created by the velocity of the light source (star) moving away from point of observation (earth), ie: a distance expanding - or moving towards point of observation, ie: a distance contracting, changes the wave length of the light.

Where have I gone wrong?

Edit: just saw Alan's post, looking at that now.

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Offline timey

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Alan - I just cannot get that link to load, but I gather from the short description you gave that introducing motion to the gamma ray emitter results in less absorption.

This will be the case in both the vertical experiment, where this effect would be factored in, and a horizontal replication of the vertical experiment.
In the horizontal experiment, whereas no motion is introduced to the gamma ray emitter, a rate or percentage of absorption is observed.
Replicating this horizontal experimental on the vertical, where again no motion is introduced to the gamma ray emitter, results in this rate of absorption being zero (?). It is only when the motion is introduced to the gamma ray emitter and the frequency of this motion is cancelled out, that the gamma ray is received by the Mossbauer.
To complete the experiment definitively, (in my mind anyway) one would need to replicate the vertical experiment, where motion is introduced to the gamma ray emitter on the horizontal... where by the remit of the vertical experiment, introducing the motion to the gamma ray emitter should shift the frequency of the gamma ray and the Mossbauer will not be able to receive...
If the Mossbauer does not receive, this confirms the premises of the understanding of Doppler shift in relation to distance.
If the Mossbauer still receives the gamma ray, one must then re-examine the current understanding of introducing a Doppler shift to the gamma ray on the vertical, and the fact that the Mossbauer only then receives it.

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Offline Colin2B

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Thank you.
Glad it helped

The frequency of light does change in a gravitational gradient.  It is thought that the Doppler shift created by the velocity of the light source (star) moving away from point of observation (earth), ie: a distance expanding - or moving towards point of observation, ie: a distance contracting, changes the wave length of the light.

Where have I gone wrong?
Both of your statements are true.
Doppler is created by a moving star relative to detector.
Frequency does change in a gravitational gradient, but it changes even when source and detector are stationary relative to each other, so no Doppler in that case.

I'll let you and Alan discuss the subject as there is obviously some history I'm not aware of.
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Offline timey

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Yes me too :)

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As to history Colin, I remember reading way back Alan saying somewhere that he only comes in 2 modes: Intellectual thug...and (scratches head), hmmm...I can't for the life of me remember the other mode...(chuckle) ...

But for anyone who might not realise, do not think that my getting gloves off and going a few rounds with Alan means that I do not respect him.  It's quite the opposite actually.

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Offline alancalverd

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Timey: RTFM. I'm out.
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Offline timey

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Only trouble is that the manual comes with a post script that clearly states that it is incomplete and cannot provide a full picture of the universe. Hence a bunch of frustrated physicists who are still mulling over the same unsolved problems that incite the same conversations repetitiously day in day out.

For anyone who can appreciate a conversation that deviates from the norm... that attempts to approach a problem stated in the manual by taking logical steps to unpick the physical mechanics of experiment and understand that there are symmetries that must be adhered to...
ie: That if shaking a gamma ray emitter on the vertical causes a frequency shift in the gamma ray, that shaking it in the horizontal will do the same... And because the gravitational shift will not re-shift the frequency of that shaken gamma ray on the horizontal, because the gravity field is uniform(ish) on the horizontal, that the Mossbauer on the horizontal will not be able to receive it!  The gamma ray will not have the correct energy level to be received!

Am I wrong about this symmetry?
« Last Edit: 21/10/2016 11:47:20 by timey »

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Offline timey

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The link Alan provided loaded for me today, so let's examine said manual.

http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/mossb.html#c1

Quote:
"The Mossbauer effect involves the emission and absorption of gamma rays from the excited states of a nucleus. When an excited nucleus emits a gamma ray, it must recoil in order to conserve momentum since the gamma ray photon has momentum. But this takes energy, and the gamma photon has less energy by about 1 eV for a 100 keV photon. The sharpness of an energy state in a potential target nucleus has a natural line width on the order of 10-5 eV, so that the shift in the photon energy prevents the target nucleus from absorbing the gamma photon.

Mossbauer discovered that by placing emitting and absorbing nuclei in a crystal, you could use the crystal lattice for recoil, lessening the recoil energy loss to the point that these extremely sharp emission and absorption lines would overlap so that absorption was observed. An important result was that you now had an extremely sensitive detector for energy shifts - a motion of either source or absorber with velocities on the order of millimeters per second was enough to detune the absorption."
Unquote

So - examining this stage by stage:

Quote:
" When an excited nucleus emits a gamma ray, it must recoil in order to conserve momentum since the gamma ray photon has momentum."
Unquote

...And the gamma ray photon is not absorbed by the target nucleus...

By adding the crystal lattice this recoil motion is reduced - so we are seeing a backward motion of recoil being eliminated by the addition of the crystal lattice.  Now we have overlapping line widths, and the gamma ray can be absorbed by the target nucleus.

In adding motion to the gamma ray emitter, it makes logical sense that adding a backward motion would ensure that the gamma ray will not be absorbed.  Or that adding a backward motion to the target nucleus would elicit the same physical effect...

So effectively the motion added to the gamma ray emitter could be viewed as adding in the same effect that the crystal lattice took out, and the result is that we see the absorption reduced.

In the vertical experiment, when whatever it is in the gravity field cancelled out the added effect of adding in motion, absorption is observed.  It is only when this added motion is matched to whatever it is in the gravity field that is cancelling out this added motion, that absorption will be observed.

The motion added has an associated distance. ie: the distance the speaker cone moves back and forth, (or mirror, where Lissajous is concerned)...  This distance, in respect to the speed of light 'can' be translated into a period of time.  Therefore in the vertical experiment it could be viewed that in adding a backward movement, that this is in effect adding time to the journey of the gamma ray, and that what is being matched by the gravity field is a time related matter, and not distance related.  The mechanics of the motions between the mirrors of the Lissajous are suggestive that this may be the case.

A perspective that would require you to consider that a gravity field itself, ie: the space surrounding a body of mass is inherent with a gravitational time dilation factor of its own, separate from GR time dilation, and that this factor of time dilation causes time to get increasingly slower (for the empty space only) with distance from mass.
« Last Edit: 21/10/2016 14:37:56 by timey »

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Online jeffreyH

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What a load of old cobblers. If you made sense it would be worth replying to your posts.

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Offline timey

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Sure - stick with your vastly overcomplicated quantum computations and your search for dark energy.  And be as unpleasant as you like while you do it... Its hardly original behaviour.

I can fully understand why it is that so many of the people who 'have' made controversial and game changing contribution to physics and science have had such a miserable time of it in their lives.

The history books are full of exactly this kind of blatant unwillingness even to make a consideration of alternatives, a type of almost religiously slanted dogma that has historically driven many intelligently oriented minds to starvation, illness, and even suicide.

So do I take it that there is nobody here who can take a conversation beyond textbook parroting.  No-one who can look at the physics of experiment asymmetrically, and no person who can observe or observe anyone else observe anything other than what is written in the text book without lapsing into rudeness, and hateful prejudice?

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Offline timey

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If Einstein had not been looking for a steady state universe he would not have added a cosmological constant, which he then retracted in light of Hubble's redshift 'velocities'.  He would have been forced to consider a contracting universe...

Now line me up and shoot me down for it as is your wont, but that is what I am considering, and it is indeed a highly logical approach!

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Online jeffreyH

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I am getting very tired of watching you insult the people that are trying to help you. You may find it amusing in your own passive aggressive way. I don't.

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Offline timey

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I am getting very tired of watching you insult the people that are trying to help you. You may find it amusing in your own passive aggressive way. I don't.

And I am getting very tired of you commenting on anything apart from the topic of the thread...

I have insulted nobody.  I am stating facts.  Nobody here wishes to discuss anything in terms that are not already written in a text book.  This is understandable, because if something is not written in a text book, then you guys have not been taught what we are talking about.

It is a fact that this seems to present a problem for all of you to some degree and manifests itself in different ways dependant upon the character of the person I'm talking to...  You seem to relish any opportunity to give anyone else reading the impression that you are of the intelligence to be able to discern between sense and nonsense, and really do seem to enjoy being belittling...otherwise why would you do it?

Alan and Colin, I feel, can see that I am in possession of a degree of intelligence, but become frustrated at their lack of understanding (due partly to my having difficulty explaining myself) of the concepts I'm trying to impart.

Now 'if' you do actually wish to comment on the topic of the thread, be my guest...