studiot

None of this has any basis in fact. What is "Chromo dynamically emitted light" and do you think light from electrons has anything to do with QCD (It doesn't). What do you think quantum chromodynamics theory means? One type of nuclear radiation is called Bremstrallung - you should look this up. It is debatable whether an "atom without electrons" is an atom, but nuclear chemistry was well known when I studied it as part of my degree way back in the 1960s. So yes there is an established chemistry of nuclei.

To avoid red marks for something said in jest it is wise to add a smiley, lest your intention is misunderstood.

I'm sorry but you don't quite understand eddy currents - they are a bit more complicated. There are two sorts of eddy current (although the loss mechanism is the same in both) and I think you are mixing them up. Firstly there are eddy currents that are generated in transformer cores and motor components. These are generated when there is a circuit current flowing. These are not the type you are describing. The energy for these is taken from the electric power of the circuit. It appears as an electrical loss in the circuit. Secondly there are the type that are generated by the mechanically generated motion of a conductor in a magnetic field. This is the type you are describing. Since no circuit current is flowing, there is no current to 'oppose'. Energy is, however, lost to the system and appears as an additional mechanical resistance to the mechanical driver. In both cases the energy is lost to the resistive heating of the conductive material in which the eddy currents are circulating. Do you understand why the eddy currents must be circulatory and some of the conductor must be out of the field for them to occur in the second case?

I doubt anyone's list is exhaustive. Personally I think of structure as being more in the way of the formal axioms eg a space with one binary operation or two. So structure can be induced or inherited. Whereas I think of arrangements in terms of combs and perms or left handed v right handed or a star v convex region and so on. But arrangements just are. So the fruit is hanging on the 5th or the 15th branch of the tree or whatever. But that is no reason to expect every tree to have fruit on those branches. I think mathematics is about analysis and self consistency.

Do I look old? I don't feel old. I don't feel anything at all until noon and then it's time for my nap ajb, my apologies for the humerous diversions. I consulted my trusty shorter Oxford, volume 1 and it had this to say mathematics probably after French "mathematiques". Originally treated as plural, frequently with the. The sciences or disciplines of the quadrivium, collectively. Later these and optics, architecture navigation etc. Now treated as singular The abstract deductive science of space, number, quantity, and arrangement Colloquial abbreviation maths (N America, Math) I think that basically covers everything discussed so far, and shows why the OED is so reliable.

All you have proved is that you don’t know your subject properly. You seem to have mixed up U and E here. What is U? and What is E?, you have called them both potential energy in the above quote. Why not just use conventional notation then no one will get confused? At no time whatsoever does the particle move opposite to the restoring force, during the execution of SHM. This is fundamental to the definition of SHM. At no time whatsoever is energy “liberated”, during the execution of SHM. This is fundamental to the definition of SHM. Energy is conserved. The remainder of post#20 is just plain nonsense. *************************************************************************** I will have one more try to offer an explanation. If you do not respond to my comments, but simply repeat your eroneous claims ther is nothing more anyone can do. It is convention that energy input to a system is positive and energy extracted from a system is negative. This goes in other branches (eg thermodynamics) of science as well for the sake of consistency. So consider a system that is not yet executing SHM or indeed any motion. To exclude gravity, a mass is attached to a fixed point by a spring and sits on a frictionless table. At this point the system is at rest and has zero kinetic or potential energy (since gravity is excluded). The mass is given an initial pull away from the fixed point and released. As a result of the spring it then begins executing SHM. Work has been done on the system – energy has been input. This energy is the system energy that is subsequently exchanged back and fore between PE and KE. It is never “liberated” from this system. At the time of release the motion is zero so the KE is zero. The energy input to the system is all positive PE. Do you understand this so far? If you understand this part we can proceed to examine the definition of restoring force.

Why ever not, for the short time it would exist? It is nucleons that are made up of quarks, not electrons. I have already agreed and point out that this light is gamma radiation, not visible.

What on earth do you mean?

In posts 1 and 3 you made great play of the electronegativity of oxygen and linked it to 'large masses of electronegative material at the centre of the galaxy'. Now you tell me light is given off by fusion reactions. So what? This 'light' is hard gamma radiation, nothing like the light characteristic of electronic transitions in oxygen. QCD? I'm sorry I didn't mean to imply QCD. By quantum theory I mean theory appropriate to electronic transitions in oxygen. I repeat, if you stripped off all the electrons there would be no matter identifiable as 'oxygen'. As to your comments about charge, several times you refer to charge as measured in volts, kilovolts or millivolts. Please check your elementary physics book.

I am now wearing ear defenders, but really Leif, there is no need to shout. I don't see the connection between your over simplistic description of the electronegativity of oxygen and your description of plasma, which is also in error. You should not assign electron affinity as being simply due to coulomb forces. Quantum theory, using properties such as spin, angular momentum as well as coulomb attraction leads to the difference in electron affinities. As regards plasma, or other ionised states, only some of the electrons are parted from their nuclei. If all were parted as you suggested then they would not be in suitable states to provide the energy jumps to give off the observable light frequencies. So we would not observe spectral lines for oxygen. Can you tell me what is the half life of an oxygen nucleus without any electrons? Not very long I think. So please do not throw away conventional science and replace it by wishful thinking when considering phenomena beyond that which is well established. I would agree that dark matter is a form of wishful thinking that may or may not come to fruition.

Well I know that the fattest knight at King Arthur's round table was called Sir Cumference, becaue he ate too much pie.

However than can agree to disagree in a civilised manner, over a beer or glass of scotch, without all that claptrap and invective.

Did you read line 2 of post#10, from where I took the quote? In which direction is the (lateral) motion? In which direction is the field? Therefore in which direction is the eddy current? post#10 was dedicated to explaining strategies for eddy current reduction strategy 3 shows the geometric segmentation needs to be caried out in the direction of current. It is a three dimensional issue.

You have been talking about a permanent magnet so the magnetic fields are not varying. Eddy currents are generated in any conductor and flow at right angles to the field and to the motion. You can never fully eliminate them or the machine will not work. However, since the currents increase with the conductance of the conductor, reduction strategies are based on reducing the conductance. A more familiar way of saying this might be to increase the resistance. In order to increase the resistance we can do three things. 1) Decrease the cross sectional area. This is not usually an option for mechanical reasons to make the makine work, but it should be kept as compact as practicable. 2) Increase the resistivity of the material. We do this by using special steels eg with 5% silicon added. 3) Decrease the path length in the direction of (eddy) current flow. We can make this change to the design by using laminated construction. Does this help?

Of course, our UK islands and peoples being as disparate as they are cannot agree on math versus maths. The Scots, for instance, may be different. Witness the well known book by that equally well known Scottish Professor of Mathematics, Another Fine Math You've Got Me Into.... go well all.

Do you have any idea why it is called geothermal energy, not geogravitational energy? I will answer your question about the tides and also the change from liquid phase to vapour phase if you show you can discuss sensibly.

What of it? Work is done when a force move its point of application and in no other circumstances. So if the system does work (ie transfers energy out) then the point of application of that force moves. That is some objects move closer together, in the case you mentioned of hydroelectricity, water moves closer to the centre of the earth. The energy may be replenished in the system if another external agent raises the water again, which is what happens in solar driven evaporation.

So don't I get a +1 for highlighting the first spelling funny? ********************************************************************************************************************************************** Really I don't care one way or the other. Some have given me these things, I don't know where they come from.

Av = Lv, where L is a scalar. A(Av) = A(Lv) by above definition. Now for any matrix M and any vector w and any scalar S we can interchange the order of the matrix and the scalar so M(Sw) = S(Mw) Can you do it now?

Drag is the resistance to motion offered by a fluid to a solid object moving through that fluid. It may be regarded as the fluid equivalent of friction. There are other factors, but in simple terms the greater the speed the greater the drag. Now if an object is accelerated in a fluid obviously the speed increases so the drag increases. If the acceleration is constant as with gravity then eventually a speed will be reached where the drag is sufficiently strong to oppose any further increase in speed. This speed is called terminal velocity. Does this help?

You want A2 (v) yes? Well that is A( A(v) ) isn't it? Substitute for A(v) from your definition as instructed to get my expression in post #4. Since this is homework I am trying to prompt you to conclude the line using the fact the lambda is a scalar.

If Av = Lv What does A(Av) = A(Lv) = ?

Well you seem to be on the right track, but it is difficult to say for sure without knowing the question? An important thing with matrices is to make sure you are consistent with premultiplication or postmultiplication since for matrices AB is usually not the same as BA

I blame the Americans. When I was young I used to write "sums" on the front of my book in case I spelled "arithmetic" incorrectly. I never heard of "mathematics" until I started reading american books.