studiot

First gravity v epicycles. Gravity is big, fundamental and long range. Epicycles were a small correction to a big fundamental theory to explain small perturbations. the main geocentric theory of the celestial sphere otherwise worked quite well. So they are quite different. Perhaps the caloric theory would be a better example? Perhaps, though that is debatable. However can Science not determine that which is definitely untrue / unreal? Did not new and better data allow us to move on from the geocentric theory to more modern and better theories, heliocentrism being the subsequent step, but not the last or latest. I think we are all saying (Simon included) that Science moves on in the light of better data. Please remember that, as swansont has hinted, what you understand 'bending' to mean and what GR means are also quite different. I attribute that to the popular analogy of the 2D surface of a 3D sphere. The analogy is poor to put it mildly

So what? So the theory of fluids regards hydraulic fluid as incompressible when you are designing a braking system, but compressible when you are measuring the displacemment of the piston to micrometres. So if you are designing an antenna to pick up radio Denver then your EM wave theory is more than adequate, but if you want to discuss Bremstralung then perhaps QED is the better option. It's horses for courses mate.

Gosh was it so long ago? Here is some tech data from a textbook in 1983. Note that the matrix is two bytes or 16 bits high and 7 bits wide. Whtever, the characters you can use are determined by the fine dot matrix of the 'character generator' chip in the electronics. The example shows upper and lower case P I am not up with the latest chips but the principle remains.

Here you go The bible http://www.amazon.co.uk/Underwater-Acoustic-Positioning-Systems-Milne/dp/0419121005/ref=sr_1_1?s=books&ie=UTF8&qid=1455642872&sr=1-1&keywords=underwater+positioning+systems and a useful e-paperback http://www.amazon.co.uk/Acoustic-Network-Underwater-Positioning-System-ebook/dp/B007QF5IZO/ref=sr_1_2?s=books&ie=UTF8&qid=1455642872&sr=1-2&keywords=underwater+positioning+systems

Lets do shells first. Here is a table of ionisation energies in kJ/mol. (after Stranks et al) This is a table of the energy to successively remove electrons from atoms. Look first at Sodium at the right hand end of the table. Sodium has eleven electrons. The first electron is comparatively easy to remove. The second electron takes about 8 times as much energy to remove. The increase for the next seven electrons `is relatively modest. There is again a big jump to remove the last two electrons, but a small difference between them. This pattern is repeated in the other atoms listed, as far as they have electrons. Now if we assume that how tightly bound an electron is (as measured by the energy to remove it) depends upon its distance from the nucleus we can see three distinct groupings of electrons, diminishing with distance. We call these shells and give them a number, n (1,2,3) or a letter (K,L,M) Because we number outwards from the nucleus the K shell = shell 1 corresponds to the closest and highest energy and therefore last two ionisation energies in the table. There are two electrons in this shell, eight in the next and one in the last. If this is helpful we can go on to the connection to orbitals.

I have to say I'm puzzled by these posts. The first one makes no sense. The second add nothing by way of explanation or the reason for either in this thread. As regards the scientific method, its purpose is simple. We can create many theoretical constructs, the scientific method is there to enable us to establish which one in fact holds sway. That is it is there to sort the sheep from the goats.

Simon, I apologise that my link in answer to your post#10 question concerned general relativity, I got sidetracked. Perhaps that is why you have not replied to my post #11. Please note that the book referred has much useful background you might still like to conside for your pastiche. Meanwhile back to the nitty gritty. I think that you are following a common misconception. That is you are trying to separate space and time. You cannot do this they are inextricably linked for moving objects. By inextricably linked I mean that affecting one affects the other. In Mathematical Physics we describe this link by stating an 'equation of motion' Since there are different types of motion, there are several different corresponding equations of motion, appropriate to the circumstances. This is true even in pre relativistic mechanics and also true that Maxwell's equations lead to the so called wave equation which is an equation connecting , yes you guessed it space and time. Of course Einstinian mechanics are also equations of motion. Please feel free to indicate if you wish to develop this theme further. In answer to your direction question in your post# 14 The first and most famous experiment was by Frisch and Smith American Journal of Physics 31 No 5 p 342 1963 A second equally important but less famous was by Greenberg Physical Review Letters Vol23 No 21 p 1267 1969.

Try this http://www.amazon.co.uk/The-Perfect-Theory-Geniuses-Relativity/dp/1408703106

Well I think the OP was a perfectly reasonable question from a younger member seeking guidance so +1 Rajnish. I also think you guys have been rather hard on rajnish so I have reviewed his other threads and find much the same . Rajnish, it is well recognised that when we are you we tend to seek extremes and 'cut and dried' answers. So we demand true or false - right or wrong (morally) - the biggest or smallest -and so on. It is usually after we mature that we realise 'There are no absolutes' (Note the deliberate paradox) and that the answer to most questions is "It depends upon circumstances" .The answers in your question about metallic or non metallic hydrogen is a good example. Here things are just the same. You need to think about what you mean by "the laws of physics". They are not just empty staments in isolation. They are no good whatsoever without somethign to apply them to. So they always come equipped with some statement about this. You can be sure that a law derived from careful repeated scientific experiment will be true for the circumstances for which it was produced. Step outside those circumstances and it may or may not still be true. Many laws are idealisations or approximations but we cannot always (if ever) separate out only the quantities that are acting in a particualr law. A good example is heat flow. We calculate Fourier's Law in one dimension on the assumption that there is no sideways flow because the heat conductor is perfectly insulated.

I never really thought about that, thank you. +1

It is a pity that your main on topic response was the above. Such a response is proof positive you have little or no idea what you are talking about. Posts largely devoted to discussing linux are surely off topic in a thread specifically about Windows 10.

What are you not convinced about? If you are not convinced, why did you quote these articles? I agree the Wiki article contains some glaring inconsistencies. Edit I have just seen this You asked this in another thread So here is a simple proof that there is only one null (empty) set. By definition two sets are equal if both sets have exactly the same elements. (Note in the context of sets this equality is an identity which means that they are the same) But all the elements of all null sets must be the same So all null sets are the same Or there is only one null set. Does this help?

What would happen if you interchanged the words set and category? One of my beefs with the system is that different, well respected, authorities use different words for 'category'. Russell developed a system of 'types' Graves, Simmons and Phillips use Classes Hobson and Kestleman use aggregate. Some (eg Borowski and Borwein) have categories as particular restrictions of classes, more general than sets, but less so than classes It is small wonder that outsiders of this clique are confused. The rest of your post simple demonstrates my point that there is a heirachy of different types of collected objects for different purposes, because some purposes are incompatiable with each other. For instance if we want to include the set of all sets or even a set which can include other sets we have to abandon a very important property of some sets. Namely that every member of the set is the same type of object and that defined operations on a set will apply to every member and always be guaranteed to be the only way to produce another member of the set and to always produce one. this is particularly desirable in numbers and arithmetic. Another oft required property is that each instance of a member is counted only once. But that cannot be resolve Russell's sock paradox. Sorcerer, I am trying to offer you a practical man's balanced view to make sense of all the confusion. I don't think you can start with some glorious fundamental set or collection and refine it to suit all purposes because of the incompatabilities. You need to start with what you want your collection to do for you.

In that case your subsequent remaks are not founded on any justification. To quote your later comment I'm sorry I didn't phrase it in such a way that you could understand it. ZFC theory is a restriction of a more general theory for a specific purpose (which I loosely associated with numbers). You say that ZFC does not define sets and said (or implied) last time that ZFC also does not define numbers. So why is the first OK but the second verboten? Finally in my study of Euclid, Definition 1 concerned a point, definition 2 concerned a line. Euclid puts the definitions where they belong, preceding the axioms which tell us what we can and can't do with the material of the definitions.

So you too have sidestepped the thorny issue of "What is a set ?". You use the word collection, I have seen the words aggregate, type, class, amongst others to park the problem one stage up-the-line. The problem is that no-one has yet come up with a definition of sets that is fit for all purposes we desire to use the concept for. So we have a 'bunch' of 'thingies' and restrict these to particular cases with particular properties, that serve our purpose of the moment, not caring that some excluded thingies break our rules. In fact we are so enamoured of this ruse that we construct a whole heirarchy of bunches and sub-bunches, each with a new name and more restricted properties. But hey, it is a good ruse and serves us well. How do you get on with Russell's shoes and socks paradox?

Whatever definition is offered for a set it will not satisfy everyone for every purpose. Various devices have been used to get around this difficulty. These devices usually amount to a restriction on what the theory under discussion applies to. For instance we can avoid the issue in the quote by simply saying at the outset that we are dealing with sets of numbers.

It is you that does not understand resonance. The soundbox in a violin is a resonant structure and the pulling into synchronisation of multiple oscillators is a resonance phenomenon. You example is an example of forced not resonant oscillation.

I note the initials AI could stand for a poster in this thread or somthing else in computer circles. I also note that AI claims to work for M$. In response to the hijack of my thread to advertise W10, please comment on this editorial in the current trade press.

The trouble with those pesky scienceforum members. They don't know when they have been terminated. They just keep getting up on going on. The world ended yesterdaaaaaaaaaaaaay.

The first thing to know is that there are two types of CRT and to find out which you will be using. Both types generate a beam of electrons emitted by the cathode and accelerated and through the anode. On passing through they impact on the phosphor of the screen whence light is emitted. To prevent build up the screen has an earthing layer. This electron beam constitutes an electric current. It is this electric current that needs to 'thread' any conducting pickup loop to generate current, and yes, if it does so it will generate current in accordance with Faradays's's laws. So much for the similarity of the types of CRT. Now for the differences. The electron beam is not arandom broad brush spray, it is focused into a tight beam that strikes as small a spot on the screen as possible. This strike spot is moved about on the screen to create the wanted image. The difference lies in the way the beam is focused and moved about (deflected). Two methods are available, magnetic and electrostatic. Magnetic methods are used in CRTs designed for television and computer screens. Such screens are designed to display what is known as a raster. In a raster the beam is scanned in regular lines abckwards and forwards across the screen, covering the screen in a series of lines. Electrostatic methods are used in CRTs designed for oscilloscopes, radar and echo sounders and similar instruments. The beam here is used as an electronic pen and 'writes' (traces out) a continuous line on the screen of the desired image, going where is will (needs to) in order to achieve this. Two comments about safety need also to be made. CRT's employ the use of (very) high voltages which can result in serious accidents if not properly treated CRT action generates x rays which can be a hazard if allowed to spread into the surroundings. Does this help?

One last time. No it doesn't. Read it properly.

Well I'm sorry if I drew the wrong conclusion there. I did find who said what to whom a mystery and I hope my comments were suitably discreet.

Let us get this out of the way first shall we? Here is the text of the last PM in my sent box sent, dated 27 January 2016. It had nothing to do this thread or you. Enough said? As to my statements in post#31 here I stated you made a false statement. Here it is This was made in response to my showing the GCSE classification into four layers where they classify the top layer as 'mainly charged particles' Yet you are adament that this layer has the same composition as the others. Note that the scientific and educational authorities include all the parts of the atmosphere I included and you consistentlywished to exclude. I think they are right and you are wrong, hence my contention of the false statement. Although my quote above was dislexic in the placement of the word large (which should have been largely) it does not alter the fact that I drew attention to a known variation of composition of some lesser components of the atmosphere with height. I have also consistently agreed that the main two components do not vary with height within this zone, which is the zone you wish to claim as 'the atmosphere' Hence my contention about you ignoring facts. Edit this section added later and meant as a separate post. Thank you Sensei for clearing up the PM mystery +1 I think perherhaps it may be a language issue but saying John made a false statement doesn't necessarily mean calling him a liar in English. That would be a much stronger statement which would be totally unwarranted. I think he just got carried away, as we say. I also didn't yet take the opportunity to thank you for trying to cool things early with your delightful videos, though I did give +1 at the time.

I really think this has nothing to do with you, Strange. But if you find the truth uncomfortable, fire away.

And why are you selectively ignoring or making false statements about valid statements that are made? That is not only bad science it is bad for science.