studiot

Written whilst you were still editing. Thank you for post 29, it is most interesting and illuminating, so I hope you won't take my comments the wrong way. Not in any special order. I have been discussing this topic with a couple of pure math professors elsewhere, who very definitely use real and potential infinities, however see my SCIAM link. Your definition (1) of an infinite set is the one I usually adopt, except that I have seen it said that since 'infinite' can possibly be misinterpreted the use of either not-finite or transfinite is preferred. I have heard (and the SCIAM link attributes) your definition (2) attributed to Cantor, not Dedekind, though I understand Cantor was good at acknowledging the work of others, unlike some. As far as I can see, you have not proven that ZFC minus the axiom of infinity disbars the existence of an infinite set, merely that it does not provide one. I did wonder if your statment referred to the 2010 Cohen proof? http://www.scientificamerican.com/article/infinity-logic-law/

Can you outline or link to the proof please? Since you want me to define infinity, I take it you are prepared to define an infinite set?

OK I'll have another go. d. Now I have answered a question of yours please try one of mine. Take the collection of set axioms of your choice (pun intended for your pun collection) Remove the axiom of infinity. Now my question is Is the reduced collection of axioms a) Compatible with the existence of infinity b) Incompatible with the existence of infinity I see this as equivalent to the question Given that Mr Jines has never lived but is only a character in an excercise book. Is the perimeter of Mr Jines' garden a) 160 feet b) Indeterminate c) Some other value.

That is the problem. You appear to have reverted to quoting tracts of what I say, Declaring it false. But not actually addressing the content.

I rather suspect what you are trying to describe is what is known as a source or sink, which is a point in a flow pattern where charge or material enters or leaves the manifold (often 2 dimensional) in question. This means that conservation laws are not observed, amongst other things. For instance the outlet hole in your bath is a sink as the water exits the bath. I think, perhaps, you are speculating that there are points like this in our universe that are connected to other 'universes' How does that sound? Is projective geometry and cartography not a form of overlap of dimensions?

You originally stated you were constructing an alternator. You also stated that you don't need a capacitor to output DC from this generator. Subsequent discussion shows that you do not understand the basics of rectification or stabilisation. You also made various statements about the construction of the 'alternator' or whatever which demonstrate that you do not understand the electromagnetics of generators either. Yet when asked two key questions about stabilisation and electromagnetics your replies were flippant. The magnetic path inside a generator is quite tortuous and you need to understand both it and the right hand rule to understand why spinning a few magnets on axis inside a coil will not get you much electricity. You also need to understand that conventional electricty only flows from positive to something less positive. There is a very old fashioned and inefficient type of DC generator that is similar to what you are proposing, using what was known as a ring wound armature. https://www.google.co.uk/search?hl=en-GB&source=hp&biw=&bih=&q=ring+wound+armature.&gbv=2&oq=ring+wound+armature.&gs_l=heirloom-hp.3..0i22i30.1437.1437.0.2265.1.1.0.0.0.0.125.125.0j1.1.0....0...1ac.1.34.heirloom-hp..0.1.125.UuANibjDcKU

Maybe 4 or 5 people out of the four or five billion on our planet think that. I think it would be a good idea if you studied up on the big words you are using by listening to the professors of maths and science you have access to here, rather than Marvel comics. Singularities are common in everday life and in many branches of science and technology. As such they are extremely well studied mundane entities. There is, for instance, one in your bath as well as in complex analysis, fluid mechanics, electrical engineering, to name but a few. Have you studied graphs as plots of functions, for instance y = x2 and so forth?

So this is a speculation then? Not an application of Classical Physics and you have been wasting my time.

Thank you for that offer. I look forward to your contributions. http://www.scienceforums.net/topic/88336-differences-between-mathematics-and-physicsengineering/ I think we are still at cross purposes. The only meaning of "there exists an X such that" in mathematics is, as I have already indicated, that the stated properties of X are consistent with the definitions, axioms and deduced theorems we are currently employing. [aside] Don't forget it has been shown that there is no comprehensive list of definitions, axioms and theorems for the whole of mathematics at once. The progroms of Hilbert and Frege are unrealisble dreams.[/aside] It does not matter whether we have 'discovered' X or just invented it or whether X is an abstract construct in our minds or has physical manifestation, mathematically X 'exists'. I could invent pink elephants with green spots, for the purpose of counting spots on an animal. Mathematically, such an animal would exist. This is really no different from saying Mr Jines' garden is 50' by 30' in a problem in a maths book. There is no necessity for Mr Jines to physically exist or have a garden if he does. Therefore I assert that at least one infinite set exists, and therefore at least one infinite 'object', since object is a more general noun that includes set. I do not know of any inconsistency with the current definitions, axioms and theorems. If you can offer one or more, please post them. [aside] Sometimes we find that our rules conflict with experience. As such we need to re-examine our rules. Such was the case with the introductuion of i, which I hope you will grant mathematical existence to. [/aside]

Note Cryptolocker is not the only ransomware around. I have just received the following notification.

Yes they are called Lagrangian points. https://en.wikipedia.org/wiki/Lagrangian_point

But that is an AC machine. make you mind up do you want a dynamo or an alternator?

Look at the first picture in your post4 and plot the magentic field lines for 0o and 90o How many lines of magnetic force thread the loop at each position?

Yes a diode will prevent reverse current flowing. That is its function. Diodes used for protection like this are common. If the current draw is significant the ohmic heating effect in the diode can be significant as well. Generator is a generic term for dynamos (DC) and alternators (AC). Dynamos are significantly larger and heavier than alternators for the same current or power generation, because the alignment with the generating coil is only optimum for a short time. (This is actually almost the same effect as the question I asked you about ripple current and you declined to answer.)

Does it? And where would I find one?

That is what Bayes Theorem is all about.

Do you know what a singularity is and of any real world singularities?

Because magnetic monopoles have never been observed, even though they have been posited to exist. Modern permanent magnets certainly have much greater magnetic density than older materials. You haven't answered my question about current.

That is why cars have regulators and cutouts. They also have huge capacitors called automotive batteries. The ripple waveform is nothing like your picture. It is often a form of sawtooth. The current waveform is even more different and occurs as a series of short term pulses of very high current (do you understand why this must be so?) The 'bumps' may or may not be negligible, you would have to calculate that and you should be looking at the bumps in the current waveform more than the voltage. Polyphase generators are produced to reduce the height of the current pulse and the depth of the ripple sawtooth, becuase they reduce the time between current pulses. Google polyphase generators for lots of waveforms and specifications.

One should be careful about assigning a probability of 1 since its meaning may depend upon context. A) P(E) = 1 on an "a priori" basis implies that E has always occurred and must always occur. B) P(E) = 1 on an empirical basis means that means that E has always occurred (been observed to occur) but does not imply that E will occur in future - hence the common disclaimer in financial investment circles. C) P(E) = 1 on a subjective basis means that we may or may not have any data about past occurrences, but we think it will occur in the future, but this is not a guarantee like A.

I went for a holiday there once.

Cutworms and slugs having a party? Plant it rose end up about 4 inches (100mm) down and cover with soil. Traditionally this is done at Easter in the south of the UK. (I did mine about 2 weeks ago) My shoots have not yet started to show but I expect them soon. When the shoots grow to about 4 inches high cover with earth, leaving just the green tip showing. This is called earthing up. Keep doing this until your mound is about a foot of soil high. This is why potatos are known as a cleaning crop - you have to dig several times. Your potato looks like what are called maincrop rather than an early or new variety so harvest in July/August.

trumps mexican wave wall of course.

Whilst the ocurrence of a single midstream whirlpool is unlikely and the streamlines as drawn indicative more than anything else, I'm responding to the OP's idea that an immersed spinning body of fluid is subject to the same mechanics as any other spinning body, whilst noting the effect to be very small in the case offered. I also thought of tornados whilst I was reading it and then found he offered the same in his second post. I think it is a reasonable question, reasonably put.

Well done you. The process you are looking at is called chitting and relies on light to form the shoots. Potatoes don't grow roots in the light, they grow shoots. (Observation No 1) If the shoots are white there was not enough light. Most if not all the shoots are at one end, often more blunted / less pointy end. This is called the rose end.(Observation no 2). The roots will start to form in the dark, once planted. Obviously you plant the potato with the shoots pointing up. The potato contains enough food and mositure to start the growth going so roots are not needed initially. (conclusion no 1)