studiot

I can see where you are coming from now, although as swansont said the wording could have been ameliorated. What definition of balance are you using? What definition of differential are you using?

I've no idea whether these long lists of rubbish new posts I see each time I log on and click on "view New Posts" are generated by human fingers or autobots. My point was that I can simply ignore them, but someone has to remove them and moderators must be wasting significant amounts of time doing this. Sambridge certainly a telltale sign is a list of 5 or more posts by the same "new member" often with the same title.

You owe me an apology. I, rather gently, pointed out that you mislead me earlier by directing me to look for something you must have known was not there in Little's paper. As the only reader of this thread, until recently, prepared to listen and evaluate your statements, rather than dismiss and ridicule them I find this strange payback. Unlike your highly selective responses to my comments on your statements, some of which were actually supportive of your ideas I try to answer each and every query or comment returned to me. So the answer to your question above as to why I posted equations on disturbances in a field. They are the equations that 1) Classical wave theory 2) Quantum wave mechanics offer to describe a neutron beam, that you have made so much of. Now I am not very interested in neutron beam theory but those are the equations and each offer a very different physical picture from the other. Of course, only one matches our observations of reality. Unfortunately you have made quite a number of fallacious statements about the results of quantum mechanics, relativity, classical wave mechanics, field theory, which form a poor basis to compare with your new proposed theory. You have also contradicted yourself several times in these posts. In particular you sometimes claim that TEW predicts the same numerical results and has the same equations as Schrodinger, but then also claim that TEW does not posess any equations.

Yes that's right. Once you have dH and dU you can use dH = mCpdT dU = mCvdT dH/dU = Cp/Cv to find Cp from Cv You were not justified using gamma for this ratio that is for reversible adiabatic expansion, which this is not. Do you know why not? Remember that you are working per kg so the R you are calculating will be the characteristic gas constant for this particular gas, not the universal gas constant. The value of Cv given is certainly not for air, which has Cv around 0.7. Perhaps it is an air/hydrogen mix or a heavy hydrocarbon at around 3. https://www.google.co.uk/#sclient=psy-ab&site=&source=hp&q=characteristic+gas+constant&oq=characteristic+gas+constant&gs_l=hp.12..0l5j0i22i30j0i22i10i30j0i22i30l3.1593.9187.1.27500.27.18.0.9.9.3.1031.6140.0j9j1j1j2j4j0j1.18.0...0.0...1c.1.16.hp.HP1GTVG4_2g&psj=1&bav=on.2,or.&bvm=bv.47534661,d.d2k&fp=82c5307a998d7faf&biw=1024&bih=559

I have been editing my post# 5 whilst you came online so have another look. Meanwhile The defintion of enthalpy is H = U + PV or at any state 1 H1 = U1 + P1V1 Can you see how to get dU = (U2 - U1) from this?

Is this a condition of work done? Work is only done when the volume changes. This is true in this case. Since the volume expands work is done by the gas on the surroundings. As a result of doing work the gas suffers a loss of internal energy. This loss of internal energy shows up as the enthalpy change given. Many problems with several parts are set so that you use the first thing you calculate to calculate the second answer required and so on. Hint 1 You are first asked for dU Do you know ( can you state) the relationship between enthalpy and internal energy? Hint 2 You are given dH and are asked to calculate Cp Do you know (can you state) a relationship between dH and Cp .You will also need to look at Danitons post. Hint 3 You are asked to calculate Cp and given Cv and then asked to calculate R Do you know (can you state) a relationship between Cv , Cp and R Hint 4 beware of the units Cv is given in

Having just seen the contaminated 'new posts' list, I would just like to extend a warm thanks to our moderators for using their valuable time to clear all the chaff.

Ask yourself what changes to the gas state variables from the initial state to the final one. The enthalpy changes so what happens to the energy ? Is any work done? Is there any change to the temperature ? How does this affect the change to internal energy

True but we often specify the reference frame by reference to an object. For examples the reference frame with respect to the person on the spaceship/train/vehicle. the frame with respect to the observer waving from the platform the frame with respect to the person in the jet flying by etc. Further there is one frame in which any object can be considered at rest we say that it is at rest with respect to itself.

An object that has spatial extent will appear to have a different shape depending upon the observer's reference system. So any 'part' of an object may 'exist' in one frame but not another, depending upon how you chop it up.

Ask here allaboutcircuits.com

Good catch, John Cuthber, but how does that help the OP?

Why do so many machines these days no longer perform the function they were designed to? Or more precisely why do they try to tell you that you don't want to do what you have just asked them to do? In particular I posted a letter c in brackets in this thread. http://www.scienceforums.net/topic/75428-i-need-help-in-physics-please/ The computer controller told me I didn't want this and substituted a copyright symbol. I even wasted time editing the text back but the central controller was adament. I cannot have ( c) only ©. I can however have (a), (b), (d) etc. Tron please help!

This is a tricky one, especially if English is not your first language. It was not the first language of the question writer either, since none of the answer sentences are in correct English. However we do not do all the work so can you tell me a little about each. a) do the molecules themselves expand? b) Is there any difference between answer (a) and answer (b) ? c) Tell me, in your own words, what happens when the balloon of air heats up. d) Is there any difference between answer © and answer (d) ?

Hmm, let's look at what you have said in the cold light of reason. Field equations describe, surprise surprise, the field, the whole field and nothing but the field. That is they describe the undisturbed field, not the disturbance. In order for a disturbance to exist in the field there must be at least one agent, external to the field but interacting with it. A wave is a disturbance. We call this a source. There may be other agents also interacting with the field. We call these variously sinks, observers, targets and many other things. The disturbance itself is governed by its own set of equations which describe it. I did not ask for field equations, I asked for equations describing the disturbance. This must be possible if the disturbance exists. Now imagine my disappointment. When I asked for this information you told me to read a certain paper. I read that paper and reported that it did not contain any such equations. So I posted some. Note these were not field equations, they were disturbance equations. You replied that no the paper does not contain equations because there are none. So why did you direct me to read the paper? Unlike some, I have treated you seriously and not pretended that mathematics is the only way to deal with technical matters. But nor should it be absent from the discussion. Here is a simple example. Consider the mixing of concrete, without any mathematics at all. Take some aggregate, sand, cement and water and mix them together. This will form concrete. Or will it? Only if you are lucky enough to arrive at reasonable proportions. So to try again Mix 4 parts by weight of aggregate with 2 parts by weight of sand and one part by weight of cement. Add water and continue mixing, until the required consistency is achieved. This will get you a respectable concrete. Note that the instructions are part mathematical – for the dry ingredients And part procedural for the water. This part cannot be mathematical. But both types of analysis are required to get good concrete, you cannot exactly quantify the required water.

Yes, of course. Please expand on both themes and any other you wish to present.

Ophiolite, no rudeness was intended so please do not take offence. "Where are you going with this?" Well I am an applied mathematician, not a biologist and I was 'told off' in another thread for my interpretation of the word in a 'biological sense'. So I am attempting to explore what is meant by the term, testing for logical inconsistencies as part of the process. Hopefully I will then be able to distinguish between what is and what is not evolution in the biological sense, without committing any logical errors. The last line was not an attack on anything you may have said, or not said. It was an observation that IMHO the participants in this thread have managed to exchange views and information without a slanging match, in a proper discussing manner. Incidentally I am suprised you can be so personally critical of soneone whose opening reply to your goodself was "Thank you for your thoughts" Why do you think I would have said this if my objective was a personal attack?

Forgive me for worrying at this issue, but at the outset my comment was that the 'wave' in quantum mechanics was not a true wave in the strict sense. By this I mean: There are many solutions to the wave equation, which we call wave functions. For a single particle, in one dimension [math]\Psi (z,t) = C{e^{i(kz - \omega t)}}[/math] Now this is a complex function and in classical mechanics we discard the imaginary part, leaving us with only the real part [math]\Psi (z,t) = {\mathop{\rm Re}\nolimits} [C{e^{i(kz - \omega t)}}] = A\cos (kz - \omega t + \varphi )[/math] Where k, C and A are constants; t is time; z is distance; omega and phi have their usual angular significance. For a string of identical coupled oscillators the classical choice of the real part only leads to the familiar cosine wave form of oscillation. However consider a beam of particles. We do not want a cosine variation of our parameter. We want each particle to appear the same. This is achieved by taking the entire complex wavefunction in quantum mechanics. Now I have looked through Dr Little's paper and cannot find such an equation describing his TEW. Perhaps you could point it out as I may have missed it?

I am not familiar with this experiment, but the principal of boundary lubrication is that the weight forces (Py) are taken by the pressure in the fluid and the friction forces (Px) due to the relative movement are taken by the viscoscity of the fluid. If this is the case the the partial will come from this. The b constants will originate from the geometry - separation, contact area etc which appear in theoretical analysis when applying Newton's laws, but do not appear explicitly in your analysis. However there appear to be springs M and D connected to the funnel. A more detailed description of the experiment would help.

What have yo done so far? You already know the equations from your previous thread on this subject. Can you not rearrange them to to solve this one?

Eugene, I have not asked you for maths, others have done this. If you choose to respond mathematically, that is fine. If you choose to respond with a chain of reasoning, that is also fine. But I cannot accept a 'because I say so' type of explanation. Waves are very precisely defined in their properties and also what they do not do. Mathematics is very convenient for this, but you can also do this descriptively. I asked you descriptively about some proposed properties of Little's 'wave' that I cannot reconcile with my understanding of basic requirements for wave motion. You cannot cherry pick some properties and ignore others. As an example you would be erroneous to say that because clay is a soil it behaves as a granular material like sand. They are both soils with some common properties. But there are also differences. The modern quantum theory can provide many accurate outputs. But this is only the same as same as a modern engineer saying that his steam tables are accurate to n decimal places because some gentlemen in the 1920s made many measurements to synchronise them with reality. We still use the gas laws for understanding gas behaviour. The kinetic theory and the gas laws form logical basis for deducing much about the behaviour of gasses. So am seeking a gas law explanation of TEW, that is as consistent with and develops further the theory of waves as the kinetic theory is for the gas laws. As to the reciprocal theorem, you introduced it, not I. However I would observe that the principle of reversibility of light, which is in fact a simple application of the reciprocal theorem, depends upon a linear system. It does not hold for a non linear one. The initial switching on or off is always non linear. The principle assumes a steady stae (=linear) condition. So, specifically I recap on my original question: Why does a Little wave need to be a travelling wave, not a standing wave? And if it travelled from effect backwards towards the source what happens during the initial switch on?

Eugene, since you introduced reciprocity, you may find it interesting to know that it was originally introduced by Maxwell and I understand it in that form. A stimulus applied at point A of a linear system produces the same response at point B of that system as an identical stimulus applied at point B produces at point A. Unfortunately the world is decidely non linear and I have spent my working life dealing with this uncomfortable truth.

I agree that it is rather a big step from your line 1 to line 2, where you have introduced a number of undefined variables. I can observe that the derived function of the sine is the cosine and vice versa to a +/- sign. So are u and v auxiliary functions or what and where did gamma and its (?time) derivative come from? Line 1 looks as though you are working with the solution to a differential equation is this the case?

Perhaps if you were to rephrase your question to make sense is could be answered. What do you actually mean please?

Round trip distances are not required for this calculation. It is not even necessary to have a return cable. Part of continental North America and Australia are still fed via the single wire system, using the earth itself as the 'return'. But you are right and as several have already said, more specific calculations could be offered against the supply of more specific cable data, including configuration. So if moses would like to provide more detail about what he had in mind?