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studiot last won the day on January 5

studiot had the most liked content!

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2108 Glorious Leader

About studiot

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    Somerset, England
  • Favorite Area of Science
    applications of physical sciences
  • Occupation
    Semi Retired Technical Consultant

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  1. But you are asking for a graph of a meaningless term.
  2. Well I hope you got something out of it for you did not ask a silly question at all. It was a perfectly reasonable question for someone starting to study these matters. You didn't say whether you read my first post, at least you didn't answer it. Do you still want answers to your questions ? The short answer to your headline question is Yes it is one dimensional in that it acts along a specific line. But there is a lot more to the subject which your other questions suggest you haven't yet understood.
  3. swansont was (correctly) quoting actual thermodynamic theory. unfortunately boilers such as condensing boilers can appear to havve efficiencies greater than 100% (according to advertisers and politicians) due to the way they measure it. The correct name for this term is COP (for Coefficient of Performance.)
  4. I don't know much about gauge conditions, but having 'one' EM field assumes homegenity does it not. Otherwise epsilon and mu become tensors in their own right. I hope this discussion has not frightened off the OP as the level is way above his presentation as I have already pointed out.
  5. So it is difficult to know how or even if to answer. So it good that your second post has improved my understanding over your first one. Have you considered looking at history and the development of Maths teaching in schools ? Much of what you describe already happens so is there to be studied. Also you should review your conception of 'first principles'. Maths has advanced to the point where many of the most basic principles are also the most difficult.
  6. When I used to service/repair instrumentation as part of my business I could put up with inadequate initial fault reports since I was being paid to fix things. Here at SF we are not paid. Another member here tried to be helpful (+1) as the user manual contains troubleshooting advice and does indeed list and offer advice on similar circumstances. So how about a proper fault report, starting with Hs this machine ever worked ? If so when and how did it go wrong ? What have you tried apart from battery replacement? Have you for instance tried any of the troubleshooting proceedures listed in the manual ?
  7. You don't seem very interested in answers to your question(s) , despite the effort you put into your opening post. Let us start again. I think your difficultly is mixing up an electric field and an electric force. This is very common at the beginning of study. Are you studying this ? Swanson mentioned vectors, do you understand what he meant ? Would you like an explanation of vectors and vector fields (of which electric forces and fields are an example ?
  8. studiot

    math test

    Yes it is copy and pastable, but sadly I now note that it did not produce my intended effect. Yes I copy.pasted from your post and it reproduced the listing of your code as you have shown it, But MathJax the Mangler later intervened and now my copy comes out showing the action (ie the fraction) not the code.
  9. studiot

    electric car

    If you really want to improve battery life, reduce the weight. So look at a car and ask yourself what can I remove to reduce the weight. Look around at vehicle occupancy. How many are full and how many have only one person ? So would a car to seat only one person need the same size battery as a car to seat four ? Alternatively which car would the same capacity battery take further? So you could own several cars say a big one and a little one ? Why is an electic bike or scooter battery smaller than an electric car battery ? Note that the wiring in a bike is shorter than the wiring in a car (why?) So resistive power losses in the wiring will be greater in a car unless the wiring is of greater gauge and so much heavier. Another thing to consider is that a fully charged battery will take you further than a partially exhausted one as their internal resistance rises with discharge. Good use of this fact used to be made in the days when we had daily home milk deliveries. Dairies used to maintain a fleet of electric powered milk 'floats' and charge them every night. In the morning the float started with a full milk payload and a full battery, but as the round proceeded the battery became discharged but the payload became less as the milk was delivered. This partly compensatd for the lowering of the batterie's efficientcy as it discharged. The floats could be seen to whiz out in the early morning, but crawl back slowly to the depot as their batteries discharged. This of course brings me to the last major variable affecting performance. Speed. Over a few mph, the slower you go the longer your battery will last. Air resistance due to speed is the most important factor in vehicle dynamics as it increases with a power somewhere between a quadratic and a cubic of the speed. You should also investgate driving style in relation to acceleration/braking.
  10. Well I can't agree with that statement. but I can (almost) agree with this one As always it is instructive to consider the behaviour of a simpler system than the universe. So I propose a football match between teams A and B. Now at kick-off there are no goals, and no football. Sometime into the match team A scores a goal. Later team A scores another goal. Later team B scores a goal. Now we could set up coordinate axes, including time, which extend beyond the game and pitch. But from the point of view of the match (which B won) there are 3 'events' of importance, since the object is to score more goals than the other side. So 'nothing' happened before kick off (ie there were no events) all time before kickoff is the same and effectively does not exist. 'Nothing' happened between kickoff and the first goal so nothing happened in measurable time before the first goal, but after kickoff. There were two further events before full time but again nothing happened between the third goal and full time, after which all time is the same. Hwever the entire match could be described in terms of those three goals and the (time) distance between them is fixed. Nothing else matters. Thus there is a simple system which has all the essential characteristics of a relativistic universe viz a fixed chain of events and a coordinate system which could extend empty to infinity.
  11. I am going to take you are your words here for your interest and say +1 for this part of your post. The thing is that the reference you alluded to is a biography (of a man). Biographies are not always the best places to study the history and philosophy of a subject. Obviously they provide the equivalent for the people. Fields and Relativity and the so called 'action at a distance question' all have a history, separate from, but connected to many people and their biographies. Here is a bibliography of the history and philosophy of these subjects (as well as the connnections to their author's bographies) you might find on interest. Brfore the list a further note is in order. Some of these authors are Mathematicians, setting the subjects in the context of pure mathematics and applying more general principles to the specific applications of Relativity and Fields. Others work are Physicists and Philosophers and work in the other direction using the physical observation and reasoning from it to develop the appropriate Mathematics to describe it and predict new phenomena. Yet others are the actual originators themselves. (I would beware of Whittaker - he was a Mathematician, but he was rather biased in his treatments of the work of others.) So The Physicists first. James Clerk Maxwell Matter and Motion, with appendices by Sir Joseph Larmour James Clerk Maxwell A Dynamical Theory of the Electromagnetic Field Einstein The Principle of Relativity This book is a collection of original papers by Einstein, Weyl, Minkowski and Lorentz with notes by Sommerfield Pedro G Ferreirra The Perfect Theory - A century of geniuses and the battle over General Relativity. Ferreira is currently Professor of Astrophysics at Oxford. Wilczek The Lightness of Being - Nobel Physicist brings in his modern version of the aether, via Feynman and others. Now the Mathematicians Erwin Schrodinger Space-Time Structure Shlomo Sternberg Dynamical Systems A mathematical companion to Relativity, setting it in modern mathematical terms. Finally the Philosopher in the chapter onRelativity. Sir Harold Jeffreys Scientific Inference. A good account of who new what, when they new it, and what that meant in the chaptern on relativity. William Berkson Fields of Force - the development of a World view from Faraday to Einstein.
  12. I see that a company near me is offering products that 'protect against harmful radiation' via Amazon amongst other outlets. These are called smart dots, pet dots and slep dots. https://www.bbc.co.uk/news/technology-55613452 They appear to be just stickers for the rich and gullible.
  13. studiot

    math test

    \[ \frac{a}{b} \] \[ \frac{a}{b} \] Yes it seems to be copy and pastable. I say that as I try to provide something that does not generate an error code here but can be copy/pasted rather than typed in.
  14. studiot

    math test

    \[CaC{O_3}\xrightarrow[{heat}]{}CaO + C{O_2}\] Displaying the command text in AMS Latex works if you omit the first backslash or put it between < > [CaC{O_3}\xrightarrow[{heat}]{}CaO + C{O_2}\] <\>[CaC{O_3}\xrightarrow[{heat}]{}CaO + C{O_2}\]
  15. Not all all sure about either the question or the answer. Iron particles are not soluble in water. They may be suspended which is a different thing. Since there is no solvation, there is no heat of solution to replace when you de-suspend them. In fact the particles move to a lower energy state because of the introduced magnetic field. But the jar containing the supension is definitely a closed system.
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