Please kindly point out how the question is "wrong?" Analog FDM is precisely what we're discussing, not TDM.

@Jennifer Solomon

you state " Analog FDM is precisely what we're discussing "

can we get back to that then

we had some discussion a while back,

For istance we agreed

"
Can we agree that by using the word frequency , we are talking about a time variable signal ?
after all, frequency is "cycles per second"

So any instantaneous point in time can not tell you anything about a frequency .

So if we agree the above,
lets define a signal as varying in amplitude over time.,

theory one.
Any signal, can be made up by adding a number of single frequencies, which are phase / amplitude modulated.
This can be shown with sine waves or walsh codes et all ( there are many ways )

theory two
Any signal we wish to send over a cable is band limited,

theory three, Take a sine wave for simplicity, but it works for square waves et all,
Any frequency at frequency A, does not interfere with a separate and different frequency at frequency b.
"


and we got to a point where I asked you two questions,
can you answer them please, and we can move on,

For your convenience here are the questions,

what sine wave equation would I have to use to make a triangle wave ,
again a simple triangle wave, based around zero with fixed amplitude.

Question 2
assuming equation V = A sin (wt)

if we wanted to add a phase shift to that sine wave so it did not start at zero at time t=0,
what would the equation be

 

For the record, to address any question concerning any “apparent” misgivings about the math of wave mechanics inadvertently conferred from my general direction, it is not at all the math itself; it is about getting at precisely what that math is correlating to in physical space. I am not seeing an intuitive description of how the infinite data are amalgamated yet discrete, componental yet monolithic.

understanding the maths,
will guide you always,
its evident from some of the statements that you are either miss understanding or have missed some oo the maths,
as ever, PM us and I can help you with the maths off line, or we can keep going on the forum

 

understanding the maths,
will guide you always,
its evident from some of the statements that you are either miss understanding or have missed some oo the maths,
as ever, PM us and I can help you with the maths off line, or we can keep going on the forum

We're currently discussing the physics of superposition from the point of VIEW of FDM, not the math behind it. You're simply not understanding the specific scope we're discussing.

As bogosort pointed out, the math doesn't elucidate the physics in this case.

Feel free to just spectate the discussion for now.

 

What in the name of Claude Shannon and George Boole occupying the same space!? I did not actively "avoid" the question. You are not reading my replies close enough to see that question has no meaning when my intention was to update it as a topic-broadening courtesy for those watching the thread. But just for the holy record, your honor! No separate human who can fog a mirror specifically encouraged me to change the first post months after it started! I did, because the topic changed and the first post sets the tone of the discourse and I wanted it to encapsulate the change in discourse. Things change! The Berlin Wall is now available in souvenir shops! Do you want to go visit it? Can you now kindly bandpass filter yourself from this sub-topic at your earliest inconvenience? Much appreciated!

So can we just quickly clarify
did you or did you not get permision from the mods as you imply in previous posts to change an original post.

 

So can we just quickly clarify
did you or did you not get permision from the mods as you imply in previous posts to change an original post.

I will assume you must have some beef with a moderator, that's why you're pushing this.

But because this should be 100% public information:

The mods changed the subject and category per our discussion, to accurately reflect where the thread had evolved to. The first post was edited per me for the same aim, and no permission is required to do so.

This sub-topic should be 100% complete now.

 

Please kindly point out how the question is "wrong?" Analog FDM is precisely what we're discussing, not TDM.

That's why I said *IF* you were discussing as in telecom. FDM/FDMA is usually use for broadcast, like TV or FM-Radio. It MUXes lower frequencies basically divided by guard-bands) onto a higher-frequency and then demuxes them back using a band-pass filter for each frequency to be recovered. Not complicated.

 

Jennifer,

Please stay focused, what is it you are wanting to know? If you want answers please force yourself to stay on topic and ignore any comments that trying to divert you. The stroke makes me very ADD, so I do understand how hard it can be. I don't usually say this but this is a subject I consider myself an expert of. And as long as the subject is on topic I can be of help. So use me.

 

Agreed.


Not quite. A composite signal is separable when its components each have distinct bandwidths. So Pepsi as a signal is separable, as is Sprite. But Spepsi is the case of mixing component bandwidths. Therefore, Spepsi is like signal A1 (or A2).

In other words, the demux can reliably separate/distill Pepsi and it can reliably separate/distill Sprite, but it cannot reliable separate/distill Spepsi. Therefore, signal A is not Spepsi.


Sort of. Even without the prior knowledge of A1 and A2, an analysis of signal A will reveal the existence of A1 and A2 -- they would stand out like sore thumbs on a spectrum analyzer, basically screaming "there is information here!" in two distinct places.


Yeah, a wave needs a medium, but the medium isn't the wave. The medium constrains the range of the waveform's various parameters, but otherwise the wave is independent of the medium.


"Where" is not a precisely answered question about waves. Look at an ocean wave; can you tell me "where" exactly it is? No.

As for the how, this boils down to the physical properties of waves. You're fine with accepting that bricks combine additively, right? We stack some bricks and don't freak out. Why is it so difficult to accept that waves combine algebraically (addition and subtraction)? Drop a small rock in a pool and concentric rings of waves will be generated. Lovely. Now drop two small rocks and the result will be far more interesting as the waves combine algebraically, reinforcing each other in some places and cancelling each other out in other places.

Note that we can transmit as much information with bricks as we can with waves. The only differences between the two, as information transmitters, are that 1) waves are more easily generated than bricks, and 2) waves have more parameters that we can reliably play with and so are more efficient carriers for our particular abilities of discernment. It's just a convenience thing. If we had enough bricks and a suitable encoding system, we could broadcast the London Philharmonic's 1969 performance of Beethoven's 9th symphony by launching bricks at a receiver. The receiver would transduce brick strikes into a time-varying voltage that drives a pair of speakers, generating all the details of the original performance. We could even do an FFT analysis on the brick stream and see all of the music's frequencies encoded in the bricks.


The only metadata in the waves is the encoding used. If the receiver has pre-knowledge of the encoding, they can simply decode the output; otherwise, the encoding has to be guessed (but that's not very difficult to do, which is why we need cryptography to double-encode for privacy). That's the only metadata. The waveform itself, in all its complexity, is just a physical response to a driving force. And if there is distinct information encoded in the wave, e.g., an NFL broadcast and a music performance, their separability is achieved before creating the wave. We must shift the two performances apart in frequency or time before we broadcast the wave, otherwise they will not be separable.


No, the wave is assuredly a finite form of energy transfer. Finite energy = finite information.


Information, as originally defined by information theory and now used by physicists, is degrees of freedom. A coin flip has two degrees of freedom -- heads or tails -- and so flipping a coin can transmit 1 bit of information.

Right, from everywhere I'm reading, information is scientifically defined as exclusively a kind of quantitative, "effectual" definition: "degrees of freedom" and "that which reduces uncertainty." Personally to me it's as currently satisfying as calling ℝ "real," or like defining a car as "that which gets you somewhere." Not enough "is-ness" for me. ;--) It doesn't address the dog™ in space as something different than the concept of the dog, how it differs from the information about the dog-in-mind, how consciousness knows that it knows about the dog, etc. but that's been fully hashed in the other thread and may or may not cause Andrewmm to magically close the thread despite having no moderator powers.

Now, I think I can better crystallize the superposition issue here:

Every single wave requires a discrete physical medium to oscillate as an information-carrier in space in order to carry the discrete information.

Pepsi is a wave. Sprite is a wave. Algebraically combine them and you get Spepsi. Spepsi is now a unique wave unto itself. Zero problems with mathematically combining waves to yield brand new waves with a new waveshape and signature. Constructive addition, subtraction, cancellation, etc. Whatever. Check.

Send Spepsi down a wire? Through the air? Convert it into a mechanical, acoustic wave? No problem.

Spepsi has its own medium to transmit the information within it in every case, whether acoustic or EM.

The problem is, every wave needs a medium to induce an undulation in, because every unique point is a voltage and data point. If we want to say Spepsi, Pepsi, and Sprite all exist at the same time, in the same exact locale, each need their own "medium space." Spepsi is A voltage at x point, but Pepsi is B voltage ALSO at x point, and Sprite is C voltage at x point. They MUST be different voltages to maintain unique identities.

Actual question: What is the mechanistic explanation for 100 waves occupying the same space in what is apparently one medium, all uniquely addressable with separate, conserved information?

In addition, when you turn on the spectrum analyzer for Spepsi, and you see the fully intact Pepsi and Sprite when you do so, it's as disturbing as this scene from the Thing 2011:

It's cartoon-bad CGI, but every wave is its own tentacle.

That's why I said *IF* you were discussing as in telecom. FDM/FDMA is usually use for broadcast, like TV or FM-Radio. It MUXes lower frequencies basically divided by guard-bands) onto a higher-frequency and then demuxes them back using a band-pass filter for each frequency to be recovered. Not complicated.

I'm not sure if AAC's forum here is not carrying all the information I'm conveying. The current issue being discussed is the actual physics superposition manifestation of the modulation mathematics. I will clarify this further in the next post.

 

Jennifer,

Please stay focused, what is it you are wanting to know? If you want answers please force yourself to stay on topic and ignore any comments that trying to divert you. The stroke makes me very ADD, so I do understand how hard it can be. I don't usually say this but this is a subject I consider myself an expert of. And as long as the subject is on topic I can be of help. So use me.

Please see the thread above for clarification—thanks.

 

That's why I said *IF* you were discussing as in telecom. FDM/FDMA is usually use for broadcast, like TV or FM-Radio. It MUXes lower frequencies basically divided by guard-bands) onto a higher-frequency and then demuxes them back using a band-pass filter for each frequency to be recovered. Not complicated.

Please see post 128 above, after the first paragraph to see what the issue is.

 

While frequencies can interact, it is not given that they will interact. I do not know your level of technical expertise so I will assume some basic knowledge of AC/DC theory.If I mention a spectrum Analyzer do you know what that is? I need to know what your basic education in electronics level is.

Filters for example, select and reject frequencies, and are a very deep subject unto themselves.

FYI, erasing a post does not stop a moderator from viewing it, being a nosy wench I always look.

Frequencies are not physical entities and have no problem existing on the same wire at the same time.

I'm still trying to figure what concepts you are trying (and failing) to understand?

Electronics is a science, not a philosophy.

 

While frequencies can interact, it is not given that they will interact. I do not know your level of technical expertise so I will assume some basic knowledge of AC/DC theory.If I mention a spectrum Analyzer do you know what that is? I need to know what your basic education in electronics level is.

Filters for example, select and reject frequencies, and are a very deep subject unto themselves.

FYI, erasing a post does not stop a moderator from viewing it, being a nosy wench I always look.

Frequencies are not physical entities and have no problem existing on the same wire at the same time.

I'm still trying to figure what concepts you are trying (and failing) to understand?

Electronics is a science, not a philosophy.

This is a physics question at present, not an electronics or philosophical one. :--) I have foundational electronics knowledge, yes, but I don’t believe that’s really material here.

Post 182 above clearly elucidates the question.

I’m investigating the specific physics of superposition. “Frequencies have no problem traveling down a wire” is actually oxymoronic when you examine the physics that require the same medium for all of them, and the intra-modulation information conservation wrought by them.

 

I will assume you must have some beef with a moderator, that's why you're pushing this.

But because this should be 100% public information:

The mods changed the subject and category per our discussion, to accurately reflect where the thread had evolved to. The first post was edited per me for the same aim, and no permission is required to do so.

This sub-topic should be 100% complete now.

Thank you @Jennifer Solomon

I have no actual knowledge as to who the mods are,
and I do not hold anything against anyone

As per your statement,
Im also 100% for an open forum
every one has the right to enter, providing they are polite and not miss guiding

I am shocked that Mods allow, if not actively encourage a forum start post to be changed after lots of people have replied, and possibly a period of weeks after it started,

I must apologise,
I have seen your other posts,
at the start of this forum, you said this post was not related to the others, which moved more into the meta physical, and you wanted this post to concentrate on the physics and the maths,

Not having realise that you had dropped the maths from the start of the post, ( I did not go back pages to check )
I kept on, trying to keep on the maths,

I must apologise for this

Topics such as Meta physical , philological, "god" and "mystical" effects are not my area,

I hope you find an answer, soon.

 

This is a physics question at present, not an electronics or philosophical one. :--) I have foundational electronics knowledge, yes, but I don’t believe that’s really material here.

Post 182 above clearly elucidates the question.

I’m investigating the specific physics of superposition. “Frequencies have no problem traveling down a wire” is actually oxymoronic when you examine the physics that require the same medium for all of them, and the intra-modulation information conservation wrought by them.

All can say is

that if you followed the maths, they prove that there is absolutely no oxymoron in the system,

 

Right, from everywhere I'm reading, information is scientifically defined as exclusively a kind of quantitative, "effectual" definition: i.e., "degrees of freedom" and "that which reduces uncertainty." Personally to me it's as intellectually satisfying as calling ℝ "real," or like defining a car as "that which gets you somewhere." Not enough "is-ness" for me. ;--) It doesn't address the dog™ in space as something different than the concept of the dog, how it differs from the information about the dog-in-mind, how consciousness knows that it knows about the dog, etc. but that's been fully hashed in the ToE thread and may or may not cause Andrewmm to magically close this thread despite having no moderator powers.

Now, I think I can better crystallize the superposition issue here. To anyone reading, the issue is with the actual physics at present, not the math that describes them.

Every single wave requires a discrete physical medium to oscillate as an information-carrier in space in order to carry its discrete information.

Pepsi is a wave. Sprite is a wave. Algebraically combine them and you get Spepsi. Spepsi is now a unique wave unto itself. Zero problems with mathematically combining waves to yield brand new waves with a new waveshape and signature. Constructive addition, subtraction, cancellation, etc. Whatever. Check.

Send Spepsi down a wire? Through the air? Convert it into a mechanical, acoustic wave? No problem. Check.

Spepsi requires a discrete physical medium to transmit the information within it in every case, whether acoustic or EM.

The specific physics problem is, every wave needs its own medium to induce a localized vibration in, because every unique point is a voltage and data point. If we want to say Spepsi, Pepsi, and Sprite all exist at the same time, in the same exact locale, each need their own "medium space." Spepsi is P voltage at x point, but Pepsi is Q voltage ALSO at x point, and Sprite is R voltage at x point. They MUST be different voltages to maintain unique identities.

Actual question: What is the mechanistic explanation for 100 waves occupying the same space in what is apparently one medium, all uniquely addressable with separate, conserved information?

In addition, when you turn on the spectrum analyzer for Spepsi, and you see the fully intact Pepsi and Sprite when you do so, it's literally disturbing. It's as if Spepsi is a mother wave carrying her 2 children around, and they know to not leave her side with ZERO apparent meta-data that connects them to each other. There's 3 things there: the amalgamated wave Spepsi which contains all the fourier data for itself, which includes Sprite and Pepsi, but then Sprite and Pepsi ALSO contain their OWN 100% conserved, discrete fourier data concurrently that if combined YIELD Spepsi, but still stand alone in their own right concurrently.

" Every single wave requires a discrete physical medium to oscillate "

this a wrong statement,
multiple signals can and do exist simultaneously and separately in / on a medium.

Two examples,

Radio, the medium is "air" / "space"
multiple channels co exist , that's how analog radio allows you to select different programs / channels.

Polarized light , say in a fibre,
the right left hand signal is totaly independent of and co exists with the right hand polarised signal.

 

Since frequencies are independent nonphysical entities (They do not occupy a space). You (JS) seem to want to think of them as physical which is false, they are not. Therefore the have no problem sharing a medium. as Andrew states. I do not have the patience or bandwidth to teach physics in a single thread. Typing is hard for me since I only have one working hand. Please stop treating electronics and basic physics as a philosophy, it is a distraction.

 

The specific physics problem is, every wave needs its own medium to induce a localized vibration in, because every unique point is a voltage and data point. If we want to say Spepsi, Pepsi, and Sprite all exist at the same time, in the same exact locale, each need their own "medium space." Spepsi is P voltage at x point, but Pepsi is Q voltage ALSO at x point, and Sprite is R voltage at x point. They MUST be different voltages to maintain unique identities.

This is a misconception. Let's try to build the proper intuition by imagining an acoustic sine wave propagating through the air. The wave fills 3D space with a single, constant frequency. We can place a microphone at some point and sample the 3D waveform at that point, recording the voltage changes as time passes. Graphing these voltages we'd see the familiar shape of a pure sine: the information that we care about in the 3D wave -- amplitude, frequency, and phase -- has all been captured in a 1D representation of voltage amplitudes over time.

Now we add another acoustic sine wave at a different frequency from the first. The two waves combine in the air and a more complex 3D waveform travels through space. Our microphone, in the same spot as before, captures the pressure changes at that point and converts it into a time-varying voltage. Graphing these voltages, we no longer see the familiar sine shape; the 1D sequence of voltages has changed. This is the crucial part. Just as the single sine wave produced a very specific 1D sequence of voltage amplitudes, the combined waveform produced a different 1D sequence that changed in a very specific way.

Please think about that carefully. The difference between the pure sine and the two sine combination is the difference between their respective pressure changes at each point in space. The microphone captures these changes, so whatever changed in the acoustic waves is reflected in the sequences of voltages. In other words, if a single sine wave would cause the next voltage amplitude to be 0.745 V, but instead we record 0.302 V, then we've just recorded the "presence" of another component within the parent waveform. The change in a single, zero-dimensional number gives us information.

Now, because waves combine linearly, there is one and only one way to make the waveform shape that the two sine combination produced. This is equally true of its corresponding 1D graph of amplitudes. But the shape of the graph is literally built from the values of the amplitudes, which -- as we just saw -- encode information in how the amplitudes change. We have all of the amplitude changes recorded, so we can reconstruct the shape of the wave in a graph, or we can take the Fourier transform and graph its shape in the frequency domain. And if we do that, we'll see a signal with 2 peaks, one at each frequency in the original sine waves.

Your misconception was this: "Spepsi is P voltage at x point, but Pepsi is Q voltage ALSO at x point, and Sprite is R voltage at x point. They MUST be different voltages to maintain unique identities." Do you now see how this is false? Pick some point (x, y, z) where the microphone is. At some time t, a pure sine would produce the voltage 0.5. At the same point and time, a wave that was a combination of two sines would produce the voltage 0.4. At the same point and time, a wave that was a combination of three sines would produce a voltage -0.1. And so on.

One single voltage amplitude is enough to show us that the waveform shapes are different. But a history of all voltage amplitudes is enough to encode everything we need to know about the various waveforms. This is why we don't need each waveform component to have "its own voltage".

Actual question: What is the mechanistic explanation for 100 waves occupying the same space in what is apparently one medium, all uniquely addressable with separate, conserved information?

There is no such mechanism, unless we first take steps to prepare the waveform correctly. That is, if we have a large enough bandwidth that we can subdivide it into partitions, and we shift the component waves in frequency to occupy distinct bandwidth partitions, then and only then is the information of the components is conserved in the parent wave.

It's easiest to see this with sine waves. If we have two sine waves at the same frequency but different amplitudes, and we sum them together into a parent wave, we have lost information. There is no way to tell what the amplitudes of the original sine waves were. If instead we have two sine waves separated by 10 kHz, then each sine has its own, well-separated frequency partition, and so we can use filters to recover the original information from the parent wave.

In addition, when you turn on the spectrum analyzer for Spepsi, and you see the fully intact Pepsi and Sprite when you do so, it's literally disturbing. It's as if Spepsi is a mother wave carrying her 2 children around, and they know to not leave her side with ZERO apparent meta-data that connects them to each other. There's 3 things there: the amalgamated wave Spepsi which contains all the fourier data for itself, which includes Sprite and Pepsi, but then Sprite and Pepsi ALSO contain their OWN 100% conserved, discrete fourier data concurrently that if combined YIELD Spepsi, but still stand alone in their own right concurrently.

Incorrect. Remember, Pepsi is separable and Sprite is separable (sugar and water are like sine waves at different frequencies), but Spepsi is not separable. Once we've mixed the Pepsi with the Sprite, we've destroyed the bandwidth partitions -- the sugar from Pepsi mixed with the sugar from Sprite, and we can't reliably separate sine waves of the same frequency.

 

Since frequencies are independent nonphysical entities (They do not occupy a space). You (JS) seem to want to think of them as physical which is false, they are not. Therefore the have no problem sharing a medium. as Andrew states. I do not have the patience or bandwidth to teach physics in a single thread. Typing is hard for me since I only have one working hand. Please stop treating electronics and basic physics as a philosophy, it is a distraction.

Thanks for the reply, but “waves” were considered that way before the modern quantum era. Today, modern physics journals disagree. For example, the European Physics Journal makes a clear statement waves are physical, and seeks to elucidate this very notion:

https://www.epj.org/images/stories/news/2013/epj_d_01-11-13.pdf

“...The regrettable textbook practice of invoking analogies between Schrödinger’s probability-
amplitude waves and sound waves, water-surface waves, or electromagnetic waves provokes and feeds that desire...The fundamental difference is then ignored: Sound waves, water waves, electromagnetic waves are physical objects with mechanical properties, they carry energy, momentum, angular momentum from here to there, whereas the Schrödinger waves are mathematical symbol...”

That’s just one academic example of experts that study waves all day long.

Clearly, just from a basic observation perspective, if “frequencies”—which are one property of describing a physical wave (and a semantic conflation of functional property and object actuality) —aren’t “physical things,“ they couldn’t exist as referential, independent, measurable, knowable elements carrying actual knowable information as seen by the wave processor and collator that is the human brain, nor be correlatable one to another. Waves have discernible properties and exist in our physical world. Treating them as philosophical “woo woo” is where science stops.

So especially from a modern scientific and technological perspective, waves are certainly physical entities, or we would not be able to measure them, refer to them in outer space, visualize them on an oscilloscope, work with them in software, modulate or manipulate “them“ (“them“ even implies “object”).

In particular, the nature of superposition and its relationship to multiplexing, is what I’m discussing here, which is patently not philosophy. It is endemic to graduate-level Physics syllabi the world over.

Newton, for the record, believed forces were physical things, and the “Newton” is a measure of “how much” of one we need.

I am a former Google Researcher, and I have qualifications to semantically discuss these things. Mathematicians and physicists such as Bogosort in here are also well qualified to discuss these things and how they relate to the wave multiplexing of nature and synthetic devices. Philosophy is merely abstract talk of scientific things yet uncrystallized. ;--)

Incidentally, one might dismiss George Boole’s seminal “Laws of Thought” as philosophy, but it wasn’t. It was hard mathematical, analytical science that undergirds every circuit discussed here. This is an extension of Boole’s line of work.

 

NOTE:
ALL the TS's posts, in this Thread, have been Reverted back to their original text and format.

Moderation.

 

"Spepsi is P voltage at x point, but Pepsi is Q voltage ALSO at x point, and Sprite is R voltage at x point. They MUST be different voltages to maintain unique identities." Do you now see how this is false? Pick some point (x, y, z) where the microphone is. At some time t, a pure sine would produce the voltage 0.5. At the same point and time, a wave that was a combination of two sines would produce the voltage 0.4. At the same point and time, a wave that was a combination of three sines would produce a voltage -0.1. And so on.

Absolutely, from a mechanical wave perspective. Mechanical waves are the equivalent to a Pro Tools or Cubase DAW native file with all the separate tracks flattened into a WAV where are the track metadata are gone. Or taking a screenshot of a Photoshop file with myriad grouped layers flattened.

This is why we need to discuss EM waves in my estimation. They contain the conserved independent parts, which is the meat and potatoes of this analysis.

Spepsi, pepsi, and sprite, as EM waves, co-exist as correlated discrete info carriers in the same space, with implied discrete group correlations connecting them. It’s important to note, Spepsi is the “flattened” amalgamated voltages of Pepsi and Sprite. But! Pepsi and Sprite maintain their independent voltage levels or conserved group metadata in the same place at the same time. As a result, their voltages are being represented in some concurrent, colocational medium, consistent with the definition of a wave.

Fourier Analysis gives us the sine waves, but NOT the group data. It is is the preserved, colocated group data that I’m after here.