studiot

What about It ? Hve you done no work on it wither from a physics or statistical or even medical point of view ? You first post seems to me to be more like a blog, summarising other people's blogs. 5,500 deaths ? Let us put that in context of the 8 billion or so people on the planet, that's almost 1 in 2 million. How does this compare with other causes of death ? https://ourworldindata.org/causes-of-death That's just slightly less than the bottom line of the longest list I could quickly find 'Natural Disasters'.

And I am weak in my French, although my time at the lycee Francois Villion in Paris helped me immensely with my schoolboy French. But I think both of us are intelligent, after all you have mastered at least French and English, n'est ce pas ? I do not think the world (universe) tells us anything as that would imply it was deliberately trying to communicate with us. Certainly it interacts with us an we interact with it. In doing so the interaction influences us and quantum theory is still debating how much we influence it. We learn not to put out hand into the fire. The passage from Dicke I posted has more to say on this. But in your statement you have done something very scientific. A very important theoretical scientific techique is to theoretically separate the 'subject of interest' into two parts and draw a line or boundary between them. Then to examine and study whatever passes across that boundary. You have drawn the boundary between us and the rest of the universe. Well done. You have mentioned non linearity twice in the last post and before that so let us look more deeply into the subject of linearity and non linearity. Not only do I agree with you, but I like the sentiment with which you posted something intended to be helpful. +1 But there is much more to linearity and linear Maths and linear Science than this so let us see how we get there. Essentialy linear means ' arranged in a (sensibly straight) line' Luc do you understand what I mean when I say 'sensibly straight' ? For example in particle physics the particles in a linear accelerator travel in a straight line whereas those in a cyclotron travel in a circle or spiral (ie a curved line). If I take the numbers 1, 2, 3, 4, 5, 6, 7, 8 , 9, 10, 11, 12, they are arranged in a straight line or linear order. But if I look at a clock face those same numbers are arranged around a circle so something is different. I have stuff to do now, but I will expand on this in my next post, where we will find the simplest of (schoolboy maths is non linear) Did I mention that we define 'linear' and declare that everything else is non linear. This is much much simpler than the other way round.

Other feature ? Other than what ? Here is some important ones. Firstly the photoelectric effect Classically there should be no threshold frequency to this effect. Yet observationally it is very sharply defined, as required by QM basic tenet that energy can only be accepted in certain quanta. So if the incoming photon does not have enough energy for the electron to transition to participate in a current, there is no current. In the Bohr atom and subsequent models, QM overcomes the classical problem of why an electron accelerating in the electrostatic field of the nucleus does not radiate its energy and fall into the nucleus. QM explains why the nucleus holds together (shell theory) Qm explains radioactive elements and radioactivity. QM explains observed spectra. QM explains band theory, metallic and semiconductor bonding and results in the non linear Konig Penny equation. These are all huge gains in our knowledge of how our world works. There are many other more specialist details but I note a discussion between @Luc Turpin and @Genady about 'our world' The core of the two major modern theories in Physics, relativity and QM were done and dusted and ironed out during the first half of the 20th century. This allowed many applications and also refinements and technology improvements to be made during the second half. Here is a very clear explanation of 'our world' from just after this half way point from two Princeton Professors, Dicke and Witke This clarity about Our world and physics (models) should also be of interest to @mar_mar In their book there is consider help transitioning from a classical mechanics to a quantum mechanics viewpoint. Also included is a whole chapter on the 'correspondence principle', using an interesting view of going backwards from QM to classical as a limit of very simple cases.

Why small? That is not always so.

Yes you are right. +1 Thanks for all the extra detail. But please remember tha many of these equations are 'linearised' (approximated linearly) in order to be able to solve them. Even special relativity employs a linearised quadratic for this. It's an inequality.

Good question, especially if you actually know what linear means ? Vector spaces are the backbone of linear mathematics. I already mentioned a while back that with the Schrodinger equation (which is linear) we are working in the vector space of square integrable functions of class C∞ However the relativistic version of Schrodinger is non linear ( Dirac equation, Klein Gordon equation etc) https://en.wikipedia.org/wiki/Nonlinear_Dirac_equation This bears out Seth's comment that combining linear operators may result in a non linear equation. +1 It should also be remembered that of the famous Four Laws (of Thermodynamcs) , only the First Law is linear and even has q and w as incomplete differentials. Back to Luc, Heisenberg's Uncertainty Principle is not even an equation - It is an inequality like the Second Law of Thermodynamics. Pauli Matrices are linear.

I have posted core information several times, but you seem to have little to ask or discuss about it. Lasr time spin and entanglement were new. Both are key quantum features. I have also drawn on the classical world, where possible, as it is easier and also easier to not be suprised by parallel features there.

Indeed +1. Luc, there are always those who try to 'push the envelope'. This is good and part of the Ccientific Method. But the successful ones which eventually add something to body of knowledge generally know the core of the subject they are hoping to expand. And I thought that it was the core of Quantum Mechanics you are hoping the get to grips with not the fringes. There is a whole Wikipedia article on the subject of Bell's Tests with quite a list of isolated esoteric experiments that generally have not been independently repeated. It is this repeatability that is important so the as near as every time we go to the cupboard the same thing happens, rather than the odd instance where the mouse has got into the cookie jar. Take entanglement. There are questions, but this happens every day all over the universe in an entirely predictable way. We rely on it, our existence relies on it. This is the entanglement of two electrons in a molecular orbital forming a bond. This exploration of conceivable, but fringe, effects has been going on for a long time in many disciplines. In classical mechanics, it is known that a spinning top has two stable positions - upright and upside down. And that it is theoretically possible for the spinning top to spontaneously flip between these states. Such flipping has been invoked to explain geological process from Noah's flood to plate techtonics on Earth, but we have never found evidence that this is what actually happened. However such flipping has been observed as a frequent and regular occurence in the sub atomic world of bonding orbitals so is not 'pie in the sky'

Becasue it's by Deepak Chopras's mates ? I'm sorry Luc, that blog reminds me of the early days of the science of Geology. Lots of discoveries were made by people whose motivation was to prove the glory of God.

Because we have had 6 pages of listening to failed attempts to reconcile a series of self contradictory statements. In particular "Gravity is still a force." do you mean a newtonian force following all the Newtonian rules ? or Do you mean a special Relativity 4 force following the rules of special relaticity? or Do you mean something following some other as yet undefined rules ? Since these choices are not compatible you need to pick one and stick to it, not pick n mix

If you knew the meaning of the basic terms you are bandying about, you would know exactly what my simple question is asking. You want to introduce imaginary hobgoblin 'forces' when you don't actually know what a force is.

If folks want to have a ding dong about judicial deterrence, prisons, sentences and so on can we have a proper thread for it please, rather than dragging this thread about free will further and further off topic ?

The answer to a person's difficulties in understaning existing names for natural processes is not by introducing fresh imaginary extra processes with fancy names but by putting in the effort to properly understand the ones we already work with. Once that has been done and there is still a phenomenon that cannot be explained is the time to introduce new ones. Now one thing about forces, and I don't see any evidence that you understand what is meant by a force, is that all known forces except one, can be shielded against. How would your proposals work in the case of shielding or not ?

But, just like the number pi we can do calculations involving the wave function. 😀

There has been lots of, probably confusing, argument about quantum interpretation, calculation and 'measurement' . A fundamental question that need to be addressed before any of this can be done concerns the wave function. Consider a photon or electron just poddling along. It has a wave function Ψa , Now let the particle interact with the rest of the universe. What is the wave function now ? Let's call it Ψb Is Ψb the same as Ψa or is it a new wave function ? If the wave function for the part of the universe that it interacts with is Ψc , can Ψb be constructed from some combination of Ψa and Ψc ? In other words when there is an interaction does a new wave function appear which now includes the 'observer' in the quantum system ? Please note this extremely important comment from swansont. You only get one dot. Moreover this one dot 'contains' all the quantum of energy of the one photon or electron. This is not wave behaviour. (The italics were mine, the bold was swansont.) We will see why this is important when we fully examine the mechanism of the double slit from both classical and quantum points of view. But I keep saying, and I hope you can now begin to see, that the double slit experiment is difficult and complicated for an good intructory explanation of QM. Here is an excellent short extract from a Cambridge University text, Optical Physics by Lipson and Lipson whcih introduces QM via the PhotoElectric Effect, which is much simpler and more understandable.

You are the musician, not I. But I have always understood that in English, and internationally, we borrow from the Italian, not the German. And I see that there is a whole range of terms for playing vigorously, available, but none that I can see related to my version of coerce. the middle one meaning emphasise would by marcato https://en.wikipedia.org/wiki/List_of_Italian_musical_terms_used_in_English The OED is not very helpful but seems to go along with my notion that coerce is reserved for some animate entity imposing its will on another as opposed to an inanimate entity the actions of an animate one.

Put simply The Correspondence Principle basically says that whenever a physical theory is displaced by new theory, the new theory must 'correspond' to the old theory. That is it must match the old theory in those realms of physics that have been tested (by experiment). Variations/ corollaries of this are RTFM (read the frigging manual) and the so called Domain of Application that every lecturer says at the outset of a series of elctures and everyone promptly forgets about. So what does this mean for the double slit ? Well what has been tested ie what actually happens? That is what do we actually observe and what does it depend on ? What was the old theory and where does meet and where does it fail the observations ? And what is the new theory - obviously in this case the quantum theory - and how does it meet both the conditions the old theory satisfies and those it fails ? Well I contend that too many modern explanations actually degrade the old theory in order to make it look bad. And of course you have to ask which old theory ? A wave theory ? Well there were several levels of wave theory and elementary texts match the simple wave theory of Huygens and Fresnel against quantum statistics. In fact there are several levels of wave theory, each more exact but more difficult The first theories due to Grimaldi and Marcus we not of wave interference but wave diffraction. Grimaldi actually coined the word diffraction. Undergraduate level Physics today makes a distinction between diffraction and interference. More advanced work does not. Instead the fully rigorous vector wave theory is based on Maxwell's equations and the boundary conditions associated with the obstacle (in this case the double slit). The boundary conditions are used to calculate a field scattered by the obstacle. The origins of this scattered field lie in currents induced in the obstacle by the incident field. The scattered field is vectorially combined with (allowed to interfere with) the incident field to produce the resultant diffracted field. This is a very difficult approach, the simplest solutions being the Kirchoff -Sommerfield Integrals. The normal undergraduate approximation theory is a scalar theory where the Huygens-Fresnel wavelets interfere to produce a new wavefront. Even this is difficult and produces the Huygens-Fresnel Integral. An alternative modern treatment involves solving the Helmholtz Equation to find the Gaussian Wave . This can be carried into laser territory. The problem is that all these methods introduce their own difficulties, for example the backward wave in the Huygens method, which is simply ignored as it is not observed. Bit it was necessary to move on from Grimaldis original (though a nobelworthy effort in 1665) to the nearly accurate version introuced by Young in 1801 The intensities and widths of Grimaldis laight and dark zones dod not correspond to observation, in particular the central one was too big.

Its not the actual words I care about but the enormous and significant differences in the meaning I outlined. So can you suggest alternative words for my terms coerce, force, and constrain. If these alternative can be shown to represent the different ideas better than I will happily adopt them.

I give no quarter to vthose who take a word they did not invent, create a special meaning for it, and then fail to make their special usage plain when they trot it out infront of others. To coercion implies a clash of at least two separate and distinct wills, possibly accompanied by threats before the event, but not necessarily involing itself in the event. Forcing implies a direct intervention in the event and its course, perhaps changing the circumstances (boundary conditions) and thereby changing the event. This can be and is given mathematical status.

Acceleration misconceptions. https://spark.iop.org/many-students-think-objects-acceleration-always-direction-which-object-moving

Yes I think so, sort of. Every action must be the result of free will, determinism, something else, or some combination thereof. Take the modern automatic half barrier level crossing. There is coercion in play. The law says that drivers must stop and wait for the barrier to lift. It is coercion because of the will of Parliament, combined with a threat. However it is not full forcing and we have recorded notable accidents over the years where a driver has chosen to act to the contrary and try to drive around the barriers. In the old fashioned legal philiosophy, yes although compulsion (coercion) still applied it was considered better to "Make it impossible for the driver to do anything else" So a man would come out and physically close off the entire road by shutting very solid heavy gates so no one could drive through until they were reopened. This is not probabilistic but where totally impartial circumstance forces or dictates or determines the course of action. What is your opinion ?

There is yet another aspect to this. Coercion has been mentions several times in these thread. A while back I said I preferred the much more general term forcing, of which coercion is a small subset with some additional characteristics. I'm glad to see you back up your input with examples. The case of the railway evel crossing forms an admirable example of the difference between forced and non coercive (or not coercive) activity. I also prefer non coercive to uncoercive, as an expression.

@Luc Turpin I think this is the time to bring in the correspondence principle and see how it bears (not koalas 😀) on Young's slits. Have you heard of the correspondence principle ?

I notice you carefully avoided the mathematics I picked out for you in @joigus' post.

For the same reason that early mediavel cathedrals fell down, until they discovered side thrust and put ties or buttresses into the architecture. The bottom member of a standard roof truss for a double pitched roof is just the same.