studiot

Good evening, John. Once again Talos is avoiding the question, as predicted - ain't scientific theory predictions wonderful? That's a very posh explanation of weight. How about simply pointing out that Archimedes (whom Talos has already invoked several times) was the first to distinguish between real and apparent weight?

Yes we are all agreed on that. He also tried to avoid the question every time someone asked a searching question about his statements. I particularly noted his attempts to avoid answering swansont's question about the closed room.

Odd, but I could have sworn that you introduced the balloon powered generator, although Talos introduced the balloon.

Perhaps, but I would say the length of the string was more significant than the size of the balloon.

I agree Science is about discovery, but surely you cannot discover something that is incorrect? I would add that Science is about a whole lot more than mere discovery, important though that is. Words or phrases like application, codification, connection to other discoveries, recording, postulation, prediction come to mind.

Although there is energy stored in the balloon, this is not the energy to fly. This energy is not stored in the balloon. Will a balloon rise in a vacuum? Agreed, which is why you should specify your baseline. This applies to any object with mass, including helium balloons, not just rocks. Yes indeed and the work against air friction has the same source of energy as the work of electricity generation during the ascent. This source of energy springs from an agent external to the balloon. No it's quite clear by both the equations you quoted and since the source of energy is not the gravitational PE, by whatever measure, the gravitational energy is unaffected by work done.

I also said, a while back, that Talos and John are talking about different things in the GPD (Great Potential Energy Debate) Both views are presented here. http://hyperphysics.phy-astr.gsu.edu/hbase/gpot.html#gpt and again here http://hyperphysics.phy-astr.gsu.edu/hbase/mechanics/gravpe.html#c1 So, because of a difference of origin both Talos and John are correct and gravitational Potential Energy can be regarded as positive or negative to suit. However both must agree that it takes external work to lift an object, even a helium balloon, from the surface to height, h, whether you count that work positive or negative. The important fact is that (from the equations) that work is the same whether the balloon is contrived to generate electricity or not in the course of its ascent to h Further h is quite independent of the quantity of electricity generated.

And John has consistently maintained this throughout the thread. The difference is he has offered a reason for his view. You simply reiterate yours without support as yet again in the quote above. Moreover you have never once offered a view as to where the energy of the generator comes from, if not from the gravitational potential energy of the balloon, although you promised to do so and have been repeatedly asked for this. Way back, I even agreed with you, but I have been waiting for you to show that you understand the mechanics of your statement and are not just blindly quoting others. I am still waiting.

But some observations are more exact than others. Take the observation "the colour of X is.........." Now orange is, by definition, the colour of that particular fruit. That, to me, is an example of the strongest available truth. But what is the colour of my bedroom wall? Well the paint manufacturer called it April Yellow, but another manufacturer calls it Spring Sunshine and yet another just used the British Standard colour number, called cream. In theory I will get the same ccolour, whichever product I choose.

Canadians +1

If there's a leak in my bath plug does it follow that I can't fill my bath?

All this presupposes there is only one grand truth that is universally applicable. Perhaps there are, in fact many smaller truths, each only applicable in their own domain. Or perhaps there are no truths at all.

This is this most reasonable post you have made. Since you have an alternative explanation, the way is clear for you to state it. I do agree, however, that any electrical energy generated does not arise from the gravitational potential energy of the balloon.

Good question, but I'm afraid an answer is rather more complicated. Any theory of heat generation from friction must explain the following facts. The force of static friction does not generate heat, only dynamic friction results in heat generation. An object of mass, m, that is moving at velocity, v, has the same kinetic energy regardless of whether it is rubbing against something or not. If I fix something down to the workbench so that it does not move and rub something past it, both the moving and fixed objects experience a rise in temperature. The standard coefficient of dynamic friction, and therefore the standard dynamic frictional force is usually independent of the relative velocity. Obviously the heat energy ultimately comes from whatever supplies the source of motion, but the mechanism is another thing entirely.

Well two issues that could concern humanity come to mind. Firstly the BBC state that it has implications for climate science. What are they? Secondly they state that the current pattern is the way it is because water flows down hill. I thought there was also a large thermal component to this which causes the worry that climate change will change the pattern of currents. But if the water is basically flowing into dips in gravity then will it not be more stable than previously thought?

Thanks, some discussion would also be appreciated.

http://www.bbc.co.uk/news/science-environment-30191584 It would be nice if anyone had a link to the (sea)horse's mouth on this.

Looking at the times of your last visit here, and looking back at your previous posts I find this is typical, You clearly don't wish to hold a discussion, which is the purpose of a discussion forum. You simply wish to preach prepared sermons rather than offer discussion, proof and reasoned argument. And when they are rumbled you resort to insult.

You either cannot or will not answer John's question about the electricity generator. To answer John's question you need to understand that he is talking about a different potential energy from the potential energy you keep mentioning. John is talking about total potential energy, which includes gravitational potential energy, but is not limited to that. A tethered helium ballon has at least one additional source of total potential energy besides gravitational. You are talking about gravitational potential energy alone. Given the above information can you prepare a cogent argument as to all the relevant energy interchanges that occur when we release the tether and the balloon rises?

Yes indeed and thrice now you have failed to answer since this is now the third time. Which is highly appropriate since ploy # 3 from the manual of tactics for trolls reads. "When faced with a question you cannot answer, do not try to answer just change the subject" Of course my post#112 was such a question. I have never disputed that there is descending air associated with heavier-than-air flight and indeed the combined posts by ccweb and myself explained the need for this fully along with the mechanism. What I do dispute is your interpretation of the laws of physics, cavalierly discarding some and cherry picking others to suit your self. Worse you even misapply them. You have linked to some nice photographs, without any proof or explanation that they show descending air, and still without answering the question "Where did it come from?" A further related question might be; "where is the centre of gravity of this descending air in relation to the plane?"

OK I said I'd post some more. I have tried to show things in diagrams and I am assuming normal distributions. Bignose will no doubt wish to generalise this if he comments again. If we go through my diagram, hopefully it will become clear. Most texts show a diagram like sketch A, but do not make it clear that there are two distributions in play, not one. And few show you the sequence sketch B through sketch F I cannot stress this enough. My sketch A refers to the distribution of all possible sample distributions. (of the size of sample we are taking) All the others refer to the population distribution. Unlike in your previous thread we either have the population mean and standard deviation or we are assuming it as H0 So in my example the population mean is postulated as being 8.0. So in this case the mean of all possible sample distributions should be the mean of the population, and we will take this as our null hypothesis and examine the errors that may arise if this is not true. This allows us to set the cut off points which are also called critical values. In my example they are 7.9 and 8.1 These cutoff points are where the acceptance criteria / decision rules I mentioned arise. If we take a sample and the mean of the values falls between 7.9 and 8.1 we accept the H0 Since H0 and H1 are mutually exclusive accepting H0 means rejecting H1 So we don't test for H1 That is our acceptance criterion is [math]7.9 \le {\mu _{sample}} \le 8.1[/math] Outside this acceptance range we reject H0 and the area of the tails gives us the probability of a TYPE I error This reappears in sketch D. OK so now we ask what happens if the population mean is not 8, because there is something wrong that requires action. In sketches B, C, D, E and F I have successively moves the population curve along the axis to show it in various positions in relation to the critical values I have projected down from above by the dashed lines. Note these have not moved from the original sample basis in sketch A So in sketch B if [math]{\mu _{pop}} = 7.7[/math] then the right hand tail only enters the acceptance region. That is there is a small probability that a sample drawn from this population could have a mean within the acceptance region. This only occurs for a small % of cases but if our sample mean lies between 7.9 and 8.1 we will (wrongly) accept it. This is a TYPE II error The area that this tail intrudes into the acceptance region yields the % or probability of this. This is the reason you were asking why a one tailed value was calculated in one of your examples In sketch C I have moved the population curve mean along the first critical point at 7.9 Now there is a considerable probability that a sample mean drawn from this population could fall within the acceptance region. The right hand tail may even extend beyond the upper critical value. In sketch D the curve has moved back to a mean of 8 and we are back to TYPE I error possibilities. Sketches E and F are simple mirror images of C and B as the lower tail moves past the acceptance region.

Electrons do not 'hang' around on their own in an electrolyte. An electrolyte is a solution, gel or paste, containing ions and a solvent or a bulking material such as a gel. Overall the electrolyte is neither positive nor negative it is neutral. Atoms or molecules become ions by either gaining or loosing one or more electrons from other atoms or molecules. Electrons themselves are far too reactive to hang around in the electrolyte on their own. They are always attached to some molecule or ion. Since electrons carry a negative charge, molecules that loose electrons become positive ions and those that gain electrons negative ions. When molecules form ions some reasily form positive ones, some readily form negative ones. Protons are positive ions formed from hydrogen atoms. So it is natural to find them in an electrolyte, unlike electrons. Electrons, however, can travel in a conductor and that is the purpose of the external circuit (wires). Because the positive ions congregate on ones side of the cell and the negative ones on the the other side there is a net movement of electrons within the cell towards the negative side, carried by the ions. The negative region doesn't carry on getting more and more negative, however, because the electrons return via the external circuit, balancing things up. Does this help?

I'm just shutting down for the night, so look again when I have has a chance to post something.

Are you really saying you do not consider any other physical laws apply?

Remember that the general solution will not in general be eigenfunctions, these arise when you apply the boundary conditions. The quantum equivalent of my stretched string is the 'particle in a box'.