exchemist

Sure. Or if there is an electrical coil, it may be that means vibration makes it move or something. (I think we had one of those a while back.) That's why I'm all the more keen to get this momentum aspect brought to a head. At this time of year it seems to be traditional for someone to pop up with a perpetual motion machine, a free energy device or some other thing that is claimed to break the laws of physics. I tend to regard straightening these out as a sort of Christmas puzzle.

Well, I can understand someone who thinks he has invented something not wanting to share all the details. I think we can get further by focusing on momentum. I've come across people before who have proposed impossible things because they have a blind spot about some aspect of basic physics, whether it be the 2nd Law of TD or, in one memorable case, someone who simply did not believe in the conservation of angular momentum. Anyway, I am keen to see @Aquatek's response to my last post. Perhaps this will smoke out his attitude to momentum in his device.

Yes, I think our poster has been looking at it from the viewpoint of energy rather than momentum. This may have led him to overlook some aspects.

Aha I see. So you have a working fluid, in effect, that is recycled, being accelerated by the thruster and then decelerated, 3/4 by the KE converter and 1/4 by the right hand wall of the box. So that deals with my query about the box blowing up. Fair enough. A word about Inelastic collisions: these do not conserve kinetic energy, because they convert some of it to heat. However they do conserve momentum. This is why your idea that the KE converter experiences no force from the exhaust it intercepts can't be correct. I am not sure your 3 questions are very relevant to this issue, but maybe you will explain why you think they are if I answer. So here goes: 1) total momentum of the ball + box system before the collision is m1v1 +m2v2 = 1x10 + 1x0 = 10kgm/sec, in the direction of motion of the ball (momentum is a vector). This is conserved during the collision, whether elastic or not. If the ball sticks to the box, then after the collision we have one mass of 2kg, still with a momentum of 10kgm/sec. So v = 5m/sec, still in the direction of motion of the ball. (Note, in passing, that the kinetic energy of the system has decreased from 50J to 25J, so 25J have been converted to heat). 2) if the ball is 3kg and the box still 1kg then total momentum before is 3x 3.333 +1x0 ~10kgm/sec, in the direction of the ball. After the collision we have a single 4kg mass. So v =10/4 = 2.5m/sec, again in the direction of motion of the ball. 3) Initial momentum is zero so this is conserved after the throw, i.e. 100xv1 +100xv2=0. Therefore v2 = -v1. So if v1 = 10m/sec for the ball then you recoil at v2= -10m/sec, in other words at 10m/sec in the direction opposite to that of the motion of the ball. What light does that shed on the problem of your thruster setup?

Correction: F=ma

Thanks for the responses. From your answer to the first question I have the feeling the K E converter must be converting the exhaust stream via a phase change of some kind, to avoid the thing blowing up. But no matter, the important thing is you are saying there is nothing leaving the box, so we can rule out anything leaving it possessing residual momentum. Regarding the second question, you say this KE converter stands directly in the exhaust stream, reduces its momentum to a quarter of what it was, and yet does not experience any force from the gas it intercepts. That, I am afraid, is just not credible. Even if, as I now suspect, the converter carries out some kind of phase change (condenses gas to liquid, converts a stream of electrons to electric current, or even absorbs 3/4 of a beam of "exhaust" light) the momentum of the intercepted exhaust will exert a force on it: F = d(mv)/dt.

Yes, in a way I suppose they are, though I had never thought about it like that.

It is certainly a poster previously banned, on numerous occasions, from several other forums I belong to. However I don't know if he has history here.

No, kinetic energy would not be lost due to the phase change. The phase change would release Latent Heat, that's all, though the volume reduction would allow a sealed system to run a bit longer before blowing up or splitting from the accumulated water inside. I do not see why you can't confirm: (1) whether or not the exhaust intercepted by the KE converter leaves the box, and (2) whether, if you put the KE converter on castors, you would expect it to move or not. Neither of those things involves disclosing anything material regarding your invention. If you can answer these questions then I think we will be making progress in analysing the system correctly. Because as it stands, it looks nuts. I agree with @swansont that the key to the analysis is momentum rather than energy, which is why I am asking these two questions.

I think something is wrong with this diagram, or rather the accompanying labels. There is no way for the KE converter to avoid exerting a force on the enclosure, if it reduces the force on the back wall to 25% of the value at the jet nozzle. The force is equal to the the rate of change in momentum. If the KE converter reduces the force to 25% , it must absorb 75% of the momentum. This must generate a rightward force on the enclosure that is the missing 75%. You can't avoid that because of conservation of momentum, so far as I can see. If the KE converter imparts no force on the enclosure then you are telling us you could mount it on castors and it would not move, in spite of being directly in the path of the exhaust stream. That can't be right. Or is that really what you claim? You don't tell us how this KE converter works, but my guess is it diverts some of the exhaust out of the enclosure in some way. If you have measured a net thrust from the assembly, my guess would be that the diverted exhaust stream has retained a bit of rightward momentum and it is that which is producing the net thrust leftward thrust. If, on the other hand, there is truly no gas escaping from the enclosure at all, then the thing will blow up after a short while, due to build up of exhaust pressure in the enclosure. Unless I suppose the exhaust is steam and you condense it in the converter, in which case you can buy yourself some time before it fills up with water, before it blows up or stops functioning. Which is it?

Yes, my understanding is one needs to distinguish between phase velocity, which is what changes with refractive index, and front velocity, which as I recall remains at c. But this is from a while ago now so I may be mis-remembering.

I think I read recently that fire engines can't be electric, due to the power demand of the pumps. It may be that emergency vehicles should use whatever system is developed for lorries, for which batteries seem to too heavy. Hydrogen, perhaps, or some kind of renewable biofuel. But diesel fuel will around for a few decades yet, so exempting emergency vehicles so they can continue to use it would be quite rational.

You can produce thrust (i.e. a force) without exhaust if the force is generated via a field of some kind, rather than kinetically. But as you give no details of the operating principle it is impossible to comment any further on the science. If you want to commercialise this invention without patenting it, then the best thing to do may be not to discuss it publicly until you are ready to offer it commercially. On the other hand that may carry some risk (only you can judge how much) that someone else meanwhile patents the same thing independently and stops you commercialising it. Some inventors make a "defensive disclosure" to prevent that possibility. (Once the invention is in the public domain, nobody can patent it.)

OK, you seem to be in need of medical help, so I won't bother you further.

That quote seems to come from the simple Wiki. I must say it feels wrong to me. I don't see how one can ever speak of a "field of energy". Energy is not a physical entity, but a property of an entity. Whereas, to my understanding, fields are physical entities. If the Higgs field confers rest mass, then I guess by the same token it confers rest energy. But let's wait for someone to turn up who understands the Higgs field. I don't pretend to. Perhaps we can both be enlightened.

I think you just tease out the biggest crystal you can find - and then spend ages cursing and swearing as you try to tie it with a loop of cotton thread. Perhaps if you make a little slipknot you can tighten it around the crystal and trap it firmly enough to be able to suspend it. (I use slipknots at this time of year to tie the string round the paper and foil coverings over the Christmas puddings, before I steam them.🙂)

Were and when did the pope say calculus should not be used to study the human soul? Which pope? I have not come across this. If there is any truth in it, it would be interesting to know, from the viewpoint of the history of religion and science. Can you quote a source?

You could try hot filtration. You might need a fairly high temperature to bring down the viscosity of the molten wax sufficiently. There are industrial filtration systems that could do this sort of thing, in principle at least. For example, earth treatment of certain grades of lubricating oil is a well-established procedure.

I'm not sure what you mean by containers in this context. These plastic pellets are used to make all manner of plastic articles, from ropes to dustbins to car dashboards. But yes, we do have to find biodegradable replacements for as many of these items as possible. And we will need to if we greatly reduce our refining of crude oil, as we wont be producing the naphtha etc to make the monomers.

That's rather interesting though, isn't it? Tidal interactions dissipate kinetic energy as heat. In some cases, e.g. ocean tides on Earth, that dissipation is due to friction. Though I suppose that tidal distortion of solid bodies is mainly not due to friction.

Friction is a distraction here. The basic point is @Ken Fabian's one, that any attempt to extract energy from the system will cause it to slow down and eventually stop. The energy you are trying to harness from the spinning flywheel is kinetic energy. If you remove kinetic energy from something, it slows down. The flywheel contains a finite amount of kinetic energy and that is the maximum energy you can obtain from it.

SCIRP appears on Beal's List of possibly predatory journals: https://predatoryjournals.com/publishers/ More about its questionable nature here: https://en.wikipedia.org/wiki/Scientific_Research_Publishing And you are a spammer.

No. Not recreational. Biologically necessary. These were semi-substantial alien beings in this sci fi novel, in which there were 3 sexes. All 3 were needed in the procreational act. The 3 sexes were designated male, female and parent, as it was the parent sex that did most of the caring for the offspring. I've forgotten a lot of it, but I do remember the quote from Schiller at the opening, which gave the book its title: " Mit der Dummheit kämpfen Gotter selbst vergebens." "Against stupidity the gods themselves struggle in vain."

Yes: it's all nonsense. I don't know where you got this from, but it's full of arbitrary statements requiring explanation, from beginning to end. To take a few at random: - What does a "faster" rotation rate mean? Faster than what? - Why would centrifugal force suspend dust that is floating at the same height as the water surface and not the water as well? - Why would there be more D2O in the past than today? Deuterium is stable. - Why would higher density of water, whether in conjunction with centrifugal force or not, affect in any way the "stability" of Pangaea? - Why would the rotation slow? And then it gets worse. Hopeless rubbish, really.

Not really. The XXY and XYY can be seen to arise from defective splitting of the pairs of chromosomes when sex cells are formed. The extra copies perform no function in gene mixing, which remains a process involving the merging of two sets, one from each of two parents. So there is no way they define additional sexes from a functional point of view. A third sex would imply some process like the 3 sexes in Asimov's "The Gods Themselves", in which it took a merging of Odeen, Dua and Tritt (Russian for one, two and three) in order to procreate.