studiot

Yes, let's be clear as it is my turn to respond in our discussion on this. This discussion is sparate from the one with iNow, who said something different and I am answering separately. You did indeed say this and I quoted you in my original challenge. You have since amplified your proposition Yes I have never credited you with saying everything is quantised. But you do seem to be only considering one aspect of quantum theory and also implying that other aspects are insignificant. This latter is not the case. The commutation of observables only occurs directly in Heisenberg matrix theory, from which it arises quite naturally mathematically and leads to quantisation. But coherence and decoherence do not refer to these variables, but to wave functions which arise in Schrodinger wave theory as partial differential equations in the (quantum) wave function. The quantisation here again arises quite naturally in the choosing of integer multiples of solutions, but there is no commutation involved and further we obtain the familiar discreteness being talked about. You are correct in saying that the devil is in the detail, in the guise of the boundary conditions. A further point is that there are many (very) important quantities in Physics which are not quantised, for instance many dimensionless numbers, Avogadro's number, etc Finally not just for you but a general point, Physics is far from all of Science. So for instance the biological difference between a coal tit, a blue tit, a great tit and so on, and their classification, has nothing whatsoever to do with quantum theory.

I should start by understanding covalent bonds. Firstly there is not one shared electron in a covalent bond but two. Secondly these two electrons do not oscillate from one atom to the other. In truth, once bonded there are no 'atoms' in a covalently bonded molecule.

No idea what this is ?

Let us say that you have a simple equation f(x) = 3x -7 The equals sign here is an identity. This means it is true for any and all values of x. Or that f(x) and 3x + 7 are identical, and may be substituted for each other in any application. Now let us say that you have an equation 3x-7 = 0 There is only one value of x which satisfies this equation and any other value you assign to x does not. That is just an equality for x = 7/3 Does this help ?

No one has said you are not wanted. But I certainly find your attitude unattractive, and I expect others do as well. You asked a question and were answered with a simple technical example You were offered also some help with the workings of this website, that you have not bothered to acknowledge. So my advice is to ask your questions, contribuute where you can, and loose the attitude.

You have no evidence for what I have or have not read. So why not just pony up with your explanation ? By the way I seem to be having at least three different discussions with three different members in this thread. Here, I am responding to your connection of the phrase 'everything is' (as I have already explained) to the my separate discussion with Markus. That is still a matter of open debate in the scientific world. If you mean that everything is open for debate then I apologize for the misunderstanding. If you mean the everything is or is not quantised, which is the subject of my discussion with Markus, then please confirm this. I will reply to Markus separately as he seems to have missed some important points or incorrectly dismissed them as unimportant. I sincerely hope you do not mean that everything in Science or even everthing of importance in Science, is quantised, as that impression is easy to dispel by asking for the quantisation of Avogadro's number.

No it is not subject specific and my answer is not subject specific either. Self study is wonderful and the higher the level you go the more you have to study that way rahter than a course structured by others. However in my view the real difference between school and self study is that school (should) offers marked work or work guidance. That is the opportunity to get soemthing wrong and then to discuss with your teacher how and why you got it wrong and then to correct it. Or even just the simple yeah you did those well 10/10. With self study most people cannot do this for themselves. Coming to a forum such as this one is a great way to extend the base you are gaining from schoolwork by discussion with others here. If you are lucky you can also have great discussions with your classmates. It is often said that you can learn almost as much from your classmates as your teachers, I certainly did and was lucky that way. So get the best you can out of school and extend it outside.

First of all, the 5 posts rule only applies in the first 24 hours. This is good anti troll/anti spam measure. I see you have been a member longer than 24 hours and have made 7 posts, so you are past that. Secondly you posted, then deleted, some answer to my question to you. It would be nice if you would answer that one, especially as you are pushing Zap for some answer to your own.

Waiting a long time ? Only till my response. What 'love' do you thing a single celled organism experiences and where does that 'love' come from ? Perhaps your are right there is no purpose, but I like your idea of hedging one's bets when we simply don't know the answer. +1

Yes I get that you are trying to understand and not trying to force through a particular point of view. +1 So starting with a plane wave (do you know that all the slit experiments start with a plane wave, not any other sort ?) There are no slits and not screens or other 'detectors' So the plane wave just travels or progresses in the space. An 'observer' will see (detect) nothing at all ( as he has no means to detect the wave) Now introduce a screen detector. The observer will see a light on the screen, but no interference pattern. He will see this because the screen interacts with the plane wave (blocking it in this case) and illuminates. The screen therefore allows an observer to detect the wave. Now introduce a suitable slit or slits and the observer's view on the screen will change. Depending upon the size and configuration of the slits an interference pattern may observed on the screen. This is because the interaction of the slit array is not blocking but modifying the wave, changing it from planar to circular or spherical. Is the terminology becoming clear ?

I don't know enough cosmology to know what the equation is about, But it is important to realise that the equals sign ( = ) is used by many for two different meanings, viz equality and identity. Which do you mean ?

Good question. Detectors of what ? There are some subtle differences in the meanings and usage of the word detectors , interactors, and observers. There is no difference from the point of view of QM itself.

What do you know ? This morning I said to someone "when I have had breakfast" , as a short form for "I will do that, when I have had breakfast" which again is a colloquial abbreviation for the full future perfect, "when I will have had breakfast".

It should be noted that the screen upon which the pattern, interference or otherwise , impinges is also a detector. The results with and without that screen should be considered.

Indeed I was keeping them in reserve. But now you have outed them. +1

+1 for your previous post. It made me laugh. Yes, unlikely, but since dogs have sometimes been left money in a will, not impossible. But I do take you point about correctness. One thing we had drummed (dinned) into us at school was that to be correct English not only did the words have to follow 'the rule' but the collection of words also had to 'make sense' as well as blindly following the rules. As regards possession, ownershhip and possession are not necessarily the same thing. Again using my car example, many people 'possess' a company car. But they do not the own of that car. As as far as I am concerned, stative verbs are an artificial distinction, as are dynamic verbs. You could, just as easily argue, that something cannot be in a particular 'state' without a dynamic verb signifying its entry into that state. So there is some complementarity in the concepts.

Thank you, yes there are a lot of past tenses, perhaps I mixed some up. Remembering that the original source was a teaching programme for English as a foreign language, I would observe that people are more likely to talk about owning than possessing, which actually has a slightly specialised meaning. But of course these days the most likely verb is "I had a ....... something or another", which is pretty general. But as to any of these being a 'stative verb' personally I think that is ridiculous, judging by the Wiki definition of stative as fixed for all time This analysis is flawed as can easily bee seen by realising that both the verbs to know and to understand can be reversed, eg in mental deterioration conditions.

Answering this would take too much space in a discussion forum. My best suggestion is to get hold of this book. Kraus deals with all the necessary theory, and the practical detail including tables of measurements on a variety of materials, including metals. One thing to note is that the higher the frequency the more of the electromagnetic signal (current, voltage, power) trevels on the outer skin of the metal, rather than through the metal.

Is this homework, looks like you have copy pasted from a question sheet ?

Surely, if I have misunderstood, you can explain your point in more detail so I can understand ? The flysheet explains the scope of the book, which encapsulates the ongoing debate about the granularity (quantisation) or continuity of space and time and spacetime. Do you need more ?

According to some linguistics theories. But hey, not all of them. I agree that "I will have possessed 3 cakes." is unusual English as we don't usually talk about possessing cakes. However I suggest my examples of possessing cars is the only English construction to get those particular meanings across and that we often talk about the cars we have possessed or will possess or will have possessed in common parlance. I also agree that your English is pretty good. Edit I should add that I must disagree with some of the English examples Wiki gives of 'stative' verbs. My German is not good enough to comment on the German examples, although I wonder if the whole idea comes from German where noun gender and case play a differ part, from that in English and the idea makes perhaps more sense.

Perhaps I should have noted before that the Wiki article refers to other models/explanations of force - the article is fairly comprehensive. That is why I said 'force' and why I referred to 'interactions'. I suggest you get a good hold on the simple everday idea of force before looking at, for instance, the exchange particle model. Remember they are all models, none are perfect.

Except that you did not do this but made the bold claim that everything is quantised, in reply to my observation that quantisation of some quantities is still under debate. Here is my reason for claiming that debate for space and time. A recent technical book from Cambridge University Conversely I asked for yours claiming no debate for everything.

B says that, at some time in the future, I will have made 3 cakes and that I willstill have all three. A say that, at some time in the future, I will have made 3 cakes but that I might have disposed of (ate, gave away, threw away) one or more of them, Nothing wrong with either the original A / B statements or Country Boy's explanation. My apologies for the crap English turned out by the input editor here on my last post. Possibly the easiest way to understand the cakes, which we do not normally talk about possessing, is to pick up on Joigus' car example. A) Once I sell another car I will have possessed 3 cars. That is I have already possessed and sold 2 cars and I currently posses a third. Once I sell it I will no longer posses it so I will then have possessed 3 cars. B) Once I sell another car I will possess 3 cars. That is I currently possess 4 cars. So once I sell another car I will then posses one less or 3 cars.

Which force predominates depends upon the distance the interaction operates. That is often stated at bit more vaguely as the scale. When considered as 'forces' the scale or distance order ( not strength order) is weak < strong < electromagnetic < gravity. So the weak force predominates at the very shortest scales, smaller than nuclear particles, The strong force predominates at scales the size of the nucleus The electromagnetic force predominates at scales the size of a molecule (ie bigger than an atom) The gravitational force predominatres at the size of galaxies. This Wiki article has readable presentations of all this and more. Note the key word is interactions, not forces https://en.wikipedia.org/wiki/Fundamental_interaction At scales the size of the nucleus and smaller