studiot

OK, thanks for the replies. Here is my process example for idscussion. I have a 4 x 4 square board as in the diagram. On one square I have placed a coin but you cannot see it (you can see the one in the diagram for the purposes of explanation) In order to 'win' the coin you ask questions that may only be answered yes or no, represented by 1 (yes) and 0 (no) When you think you have determined the position of the coin you represent the answers to your questions by a string of ones and zeros. Using the example Is it in the first column? - No Is it in the second column? - Yes Is it in the first row? - No Is it in the second row? - Yes represented as information by the string 0101 What happens to the information entropy at each stage of the Q&A ?

The thread is inspired by a claim in a recent thread that information entropy, as defined by Shannon, is the same as the thermodynamic definition of entropy which obeys the Second Law and therefore cannot decrease. Is this correct ?

I agree there is sometimes no bulk flow of matter. But how much momentum flows in the case of a standing wave ? This is not as I understand the mechanism

By all means demonstrate that this is the case but consider this So let us consider computer memory chip, A RAM chip. So I agree it takes a specific amount of energy input to 'write' to one cell of the Ram chip. But there are several ways to effect erasure, each with their own energy cost. Note I have started a new thread, specifically to examine any correspondence between Shannon entropy and Thermodynamic entropy.

The disturbing force has nothing to do with gravity.

Thank you. +1 Yes was beginning to wonder if anyone else knew how the original effect was generated. But, @Ken Fabian the distrubing force is not of the same type as the restoring force in the original effect. In fact disturbing force is generated by elastic flexing of the wall of the glass. This results in a direct ( and local) contact force on water. The waves are generated by the rotating finger on the glass, in contrast to the equilibrium tide in the Earth's oceans I referred to. Again the rotation of the Moon around the Earth provides the required periodicity. You are correct in saying that the restoring forces is gravity in both cases. Incidentally probably the best definition of an elastic system is "A system in which the displacement is directly proportional to the applied disturbing force." This would include both the volumetric compression of gases and the distortion of solids and the displacement of liquids.

There are lots of physical processes that are characterised by the expression A = Blogp(C) Where A and C are variables and B is a constant (which may incorporate a negative sign) and p is a given base for the logarithm. Why are folks so determined to dream up a physical link beteen two such processes, one in thermodynamics and one in Information theory ? Should we be adding say a link to chemical pH ?

It is worth, as I suggested, considering the mechanism of disturbing and the restoring forces of the original example. I agree How do you think this applies to the disturbing and restoring forces in the glass of water ? Another similar wave, but with differences, is the wave that is called 'the equilibrium tide' for the Earth-Moon system.

Good question as you are considering the fundamentals of the question "what is a wave" ? I has been posited here that in order to have a wave a 'restoring force' is required. Surely this force is only required if mass is involved. If you are going to stick to the original example, mass is involved so it is worth investigating disturbing and restoring forces. So thank you for starting off a worthwhile discussion, but please try to offer more focus at the outset.

I think you need more black coffee. Was he not only following your lead? Since you don't want to discuss the basics with me I will leave you with this 1950s University Physics textbook extract, which directly addresses what seem to be you basic misunderstandings. In particular it provides a simple mathematical derivation of the 1/r relationship from the 1/r2 Law. Please be aware this applies in any number of dimensions for Newtonian gravity. Also note the explanation about infinity and the negativity of PE and the difference between PE and potential. As regards the reasons for our universe being a 3 + 1 universe: Vector statics is complete in a 3 spatial universe and vector dynamics complete in a 3 +1 universe, but not a 2 spatial universe or a 2 + 1 universe. As I have been trying to lead you towards. In the early days of Einstinian Relativity, there was much discussion about the possibility of other universes with A spatial and B time dimensions and the consequences if these were assumed. Eddington provides a good mathematical reasoning to discount these for our own in his book 'The Mathematical Theory of Relativity'.

Perhaps you have no takers, because, like myself, others are confused as to where you are coming from or going to with this question. Please clarify.

Somewhere between a quarter and three quarters of the world's population suffer this. Is that good/bad? Thank you for your reply. I made that comment not realising that you might have meant something totally different from what I understood your statement to mean. That is why I subsequently asked you to clarify it. I still don't know what you meant. Only a few agree is quite clear, but what they agree to is not. Do you mean that they are prevented in some manner from speaking whatever they want or do you mean that they should not speak whatever they want (common colloquial use of can't) ?

You have made some very valid points in this thread, but I believe Vashta is talking about our Universe. Further the rules of SF require our Universe as this was posted in classical Physics. I agree, but would go further and suggest that GR is inappropriate in this thread, except as a passing mention. +1 Incidentally Markus said solve Laplace, not deduce it. I have plenty of expositions of Newtonian gravity involving Laplace, I just want to help Vashta find the appropriate format. Of course solving Laplace will not get us the potential. It will get us the potential function, which is different. It is confusing to those just studying this subject that the word 'potential' is used in several different ways. I actually must now apologise and correct an incorrect statement I made earlier about the units. I said that potential energy and potential (difference) have the same units. This is not quite correct. PE has units of energy, potential by itself or PD has units energy per unit mass.

You have placed your thread in the Mathematics section, which is totally independent of Physical Science, as are the respective disciplines definition and use of the concept of zero. Please clarify what answers/discussion you are seeking. You are correct in stating (in the title) that in Mathematics Zero (by itself) is a number. I note that your 'absolute zero', 'virtual zero', polar opposite, etc hint at mathematical set theory which leads to a mathematical notion of zero, but using unusual terminology.

Why don't you just clarify your originally ambiguous statement ? Who are the few and what do they agree with ?

Actually none of this is a solution to Newton's Law of Gravity. Newton did not use potential theory - It had not been invented in his day. In modern notation Newton's Law of gravity is [math]F = G\frac{{Mm}}{{{r^2}}}[/math] This is a straighforward algebraic expression and a solution means that you have a value for all the variables, except one so you substitute them into the expression to obtain the unknown quantity. So instead of arguing at cross purposes, Vashta how about posting your maths working to obtain whatever you have obtained ? Then we can help you tighten up your maths. As regards the curl, do you understand the concept of a vector that represents a turning moment ? I am convinced that this is the key to your difficulty reconciling 2D and 3D. Actually

You mean I can't blow my own trumpet ? But Zap, I love Daleks.

No, I was keeping in mind this is a discussion about Classical Physics. Working in terms of densities - something per metre, something per square metre, something per cubic metre is a very common technique. Of course if you go to two or three dimensions your integrals become area or volume integrals, which is why I keep recommending using the one dimensional case for starters. How about answering my questions, they are designed to help ?

Yes indeed but surely it is pretty damn obvious that the only way we can establish/measure how long the protection from a vaccine or course of vaccines will remain effective is to keep monitoring until the vaccination becomes ineffective.

I'm not sure what your idea of field dilution is or entails. However I have some suggestions. If you want to work in terms of what I suspect 'dilution' to mean, I suggest you work in terms of energy density not energy. This will also work more easily in any number of dimensions. This would be energy per unit length, area or volume as appropriate. I attempted to address to your idea of 'leakage' by pointing to the vector curl, but you have not responded to this. Perhaps I have misunderstood your explanation of this issue ?

The universes in this case cannot tend to a state of lesser energy. The total mechanical energy of an isolated system is constant.

If that were the case then the gravitational field would contain an infinite amount of energy. The point that I already made is that whilst the length of the bounding curve is infinite, the area under it remains finite. https://en.wikipedia.org/wiki/Improper_integral

I very carefully didn't say gravity was acting in this case, because some of what was offered was correct. In fact gravity is (also) responsible for the ordinary surface waves in water that we see in the ocean. However two members seemed to be suggesting rather strongly, that fluids cannot be elastic or support elastic waves. How would you describe a sound wave in a fluid, if not as an elastic wave ?

Somewhere between a quarter and three quarters of the world's population suffer this.

It's called the area-moment method for the bending of cantilevers (which is what your type of torque wrench is) https://www.engineersedge.com/material_science/areamoment_method_13659.htm +1