studiot

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 ?

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 ?

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.

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.

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.

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.

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.

\[ \frac{a}{b} \] \[ \frac{a}{b} \] 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.

\[CaC{O_3}\xrightarrow[{heat}]{}CaO + C{O_2}\] 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}\]

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.

Thank you, I like it. There is a twist in that it is instructive to compare the economics of such a scheme in India and say, Arizona. How much would you have to pay an American to clean the panels compared to an Indian ?

I too would like further explanation of this statement. At the moment I am not at all sure what you mean. Note the English appears very very old fashioned (by at least a century) to me. This is not a criticism but an offer to help recast your words into modern English so that nobody misunderstands them.

What indeed ? Perhaps if you explained the context in which you are asking this and what your thoughts are on the subject, since this is homework, then someone might help further.

Thank you for your reply. I am really wondering if big business should be allowe to overturn the long held maxim "There are no unsafe roads only unsafe drivers" The idea that no matter how difficult the conditions and configuration of a particular section of road, there is a safe precedure set down in the driving regulations for negotiating it. The responsibility lies fairly and squarely with the driver (and other road users of course) to follow that procedure. Automated vehicles take away (some of) the drivers ability to follow that maxim.

Should car manufacturers blame road design and construction or themselves if their technology fails to account for all road types ? https://www.bbc.co.uk/news/uk-england-somerset-55571080

swansont said much of what I was going to say, but I think the question was a good one and deserves encouragement so +1. Firstly no nuclear reaction produces or generates electricity. So by themselves nuclear reactors (ie plant and equipment where controlled nuclear reactions take place) need further plant and machinery to generate the electricity. Nuclear reactions generate heat (and fission products of course) - lots of it. So much of it that much is wasted. However this released heat is used to heat coolants by a series of heat exchangers to drive turbines that drive the generators. But the reactor is designed to run 'up slowly'. In theory it may be run down very quickly for emergency purposes by moderators. The issue then becomes how to use the spare heat to meet a sudden increase in demand. One way is to have standby generators that can be brought online very quickly. These would be needed in any case for maintenance purposes. Another way would be to divert more steam to driving turbines, but that would mean they were working at less than full capacity before. Another way would be electricity or heat storage, neither being very practical in marine environments, though a buffer of either could help overcome a short term increase in demand. Electricity storage would be better for this. In any event the whole power plant comprises more than just the nuclear reactor.

I can assure you from practical experience that this method doesn't work. An indirect heat exhanger is necessary.

Yes the Glycemic index of coconut flour is around 50. But the GI is not directly related to the % of carbohydrates of any description. It is a time thing. Here are some useful links explaing it. https://www.diabetes.org.uk/guide-to-diabetes/enjoy-food/carbohydrates-and-diabetes/glycaemic-index-and-diabetes https://www.nhs.uk/common-health-questions/food-and-diet/what-is-the-glycaemic-index-gi/

+1 I'm only suprised no one has already started a thread on this subject.

Something rather is happening with the notifications. Just logged on and looked at a string of notifications. At the top is on from 'Charles', claiming to be 10 hours ago but was actually from November 2020. I am pretty sure I have also seen the other listed notifications as well. I have seen this several times recently.

Can I request that DanMP's discussion be split off as totally off topic and not to do with quantum mechanics. This is not a complaint as his issue is possibly also interesting and certainly deserves a thread of its own and there now seems to be two separate discussions going on at once and becoming intertwined.

Thank you for this. OK so it is 'false colour imaging' So it is not a true photographic picture of what is there but a generated 'image', rather as Xray diffraction picture 'can measure' a lattice spacing. Very clever work nonetheless. I still maintain that this was not made clear at the outset.

I can't find anywhere in the procedures in the article that anything was burned. I know that the English is not good and there appears to be a mistake in the Abstract list of % since polysaccarides referred to in a later list is missing, but both lists state explicitly that the ash is present in the flour ie before burning of any sort.

An electric jet ??? Whatever next. Just reading the intro calls into question the credibility of the source. No offence meant CL, you sometimes post some very interesting finds.

Enough is Enough ! I have tried to be helpful but you seem to be wandering all over the shop without properly understanding anything. I am particularly worried about continued references to spectroscopy in relation to 'imaging'. Your idea of imaging seems quite different from mine. Imaging to me refers to creating some sort of pictures of the spatial disposition of the objects being imaged. Raman spectroscopy is conducted on the randomly scattered light at near right angles to the beam and looses all of this spatial information. You have not responded to my offering onphotogrammetry, which is what I thought you wanted. If this is not the case please make clear what you are seeking before I can post again.