When Rail Roads in England got going it was said after 45 MPH or so the $hidd would hit the fan, wouldn’t go faster, then it was the sound barrier, next it the Light Barrier. I think they will work around the Relativity Theory or maybe just prove it isn’t a barrier.
After 140 years in school you can be CE on this ship: …I think they’ll need to push a asteroid or something in front of it to protect from debris though. : https://www.youtube.com/watch?v=xNL-8ucNF5E
“It is important for the scientist always to remember that the ‘Laws of Physics’ were written by men as the result of their experiences to date. All laws are therefore valid only until better laws are needed to replace them, or, what is more common, to be built on top of them, for many of the laws have withstood the test of time and are not likely to lead us vastly astray, until a new phenomenon demands the ‘mixture as before’ with a little addition to embrace the new information. …the laws of physics can only ever be partial truths… and we, in our time, would be foolish indeed to pretend that these are the only facets and therefore the truth.”
From Chapter 3 of Electric Energy: its generation, transmission and use, by E.R. Laithwaite and L.L. Freris, 1980
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Now it would be very remarkable if any system existing in the real world could be exactly represented by any simple model. However, cunningly chosen parsimonious models often do provide remarkably useful approximations. For example, the law PV = RT relating pressure P, volume V and temperature T of an “ideal” gas via a constant R is not exactly true for any real gas, but it frequently provides a useful approximation and furthermore its structure is informative since it springs from a physical view of the behavior of gas molecules.
For such a model there is no need to ask the question “Is the model true?”. If “truth” is to be the “whole truth” the answer must be “No”. The only question of interest is “Is the model illuminating and useful?”. - George Box
Is that the textbook you’re using?
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I wish this was our text. Its fantastic. An instructor leant it to me. They don’t write them like that any more. Old texts are gold texts.
We learned that one as pV=mRT, where m is the mass of the gas. Or sometimes pV=nRT, where n is the moles.
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Looking atWikipedia i think R can either be an ideal gas then PV=nRT or in George Box case he is using R= a specific gas which would be the ideal gas R times n (n*R).
Alternatively, the law may be written in terms of the specific volume v, the reciprocal of density, as
P v = R specific T . {\displaystyle Pv=R_{\text{specific}}T.} {\displaystyle Pv=R_{\text{specific}}T.}
It is common, especially in engineering applications, to represent the specific gas constant by the symbol R. In such cases, the universal gas constant is usually given a different symbol such as R ¯ {\displaystyle {\bar {R}}} {\displaystyle {\bar {R}}} to distinguish it. In any case, the context and/or units of the gas constant should make it clear as to whether the universal or specific gas constant is being referred to
I’ve been looking for info about the local power grid, that book looks interesting .
That quote brings to mind The Structure of Scientific Revolutions by Thomas S. Kuhn. which is very good. I got through by reading just a little bit at time. Sometimes just one paragraph.
Depending on your question, this might be the right book. It isn’t marine specific, and has a fair treatment of power lines and demand forecasting.
I will enquire with my heroic librarian. Sounds like my kind of thing. Have you read The Age of Wonder by Richard Holmes? Its a really great bit of story telling. I brought it to work with me one time, and had guys hovering around wanting to read it when I was done. Really a beauty of a book.
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“Truth emerges more readily from error than from confusion.”
― Thomas S. Kuhn, The Structure of Scientific Revolutions
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kennn cpt: in places DC pwr grid is making a come back… maybe the easiest to see are remote mining operations in canada and scandanavia where DC lines are replacing AC.
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Keep an eye on your elephants.
yea, tesla came up with the 3 phase rotating field and went to Westinghouse with it wanting a commission on 3 ph. motors he would (and did) produce but the old man told him he simply could not afford that and gave him some $ for the idea… or maybe for his patent? but anyway, Tesla walked out with a consolation prize but think if he’d of gotten even a small commission, it would of been a psychological boost as well as good funding and who knows what he would of eventually come up with for as it was he died pretty poor, maybe in debt in a small apartment in new York or somewhere back east. I think he may well of been in debt after spending a bunch of money in Colorado at his experiment station(s) there.
I used the George Box quote (and his other one, “All models are wrong but some are useful”) in my teaching. The other one I use is from Alan Turing, in the last paper he wrote:
“This model will be a simplification and an idealisation, and therefore a falsification. It is to be hoped that the features retained for discussion are those of greatest importance in the present state of knowledge.”
Many people overlook the genius manifest in the phrase “it is to be hoped.” No model rests on any firmer base than guesswork. A model is like a map, and maps are not the terrain. Models provide a framework for discourse, nothing more, and we must always be cautious of how they frame the discourse without our being aware.
Models can never be validated, they can only be falsified. No matter how many cases have been run and shown to correspond to experimental evidence, the very next one could blow it out of the water. And of course, as Imre Lakatos so cogently argues (in “Proofs and Refutations”) it is the falsification that teaches us the most.
Cheers,
Earl
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Electric Energy: its generation, transmission and use, by E.R. Laithwaite and L.L. Freris,
This is from Laithwaite’s Wikipedia page:
Eric Roberts Laithwaite (14 June 1921 – 27 November 1997) was an English electrical engineer, known as the “Father of Maglev” for his development of the linear induction motor and maglev rail system.
He derived an equation for “goodness” which parametrically describes the efficiency of a motor in general terms,
In 1974, Laithwaite was invited by the Royal Institution to give a talk on a subject of his own choosing. He decided to lecture about gyroscopes, a subject in which he had only recently become interested.
In his lecture before the Royal Institution he claimed that gyroscopes weigh less when spinning
Laithwaite later acknowledged that gyroscopes behave fully in accord with Newtonian mechanics,
Although Laithwaite is best known for his ideas concerning gyroscopes, he also held an idea concerning moths. It was that they communicate via ultra short wave electromagnetic phenomena (Inventor in the Garden of Eden, E R Laithwaite 1994 page 199). He persisted in this belief even after the pheromone which they actually use had been isolated
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In the same text in the same chapter the authors are talking about the hydraulic analogy for electricity and where it breaks down (high frequency AC and the skin effect). They say,
“Let therefore our teaching be a succession of analogues and let the teacher make it know to his audience that any given analogue may not be as profitable for a particular member of his audience as it has been for him. In that way, we shall set the next generation on a firmer footing than perhaps the one which we were given.” They go on to quote Gilbert Walton: “The force of analogy is this, that it refers what is doubtful to something like it which is not in question.”
You might get something out of this book. I was loaned it after I started pestering my instructor with questions about the geometry of fields. I am wondering: how can 2 three dimensional fields be at right angles to one another? I understand a right angle on a Euclidean plane, I understand it on a sphere-surface, I understand it on a conoid-surface… but wth. The books are just casually like: they’re right angles, that’s all. You know. Nothing to see here.
I’m pawing through my copy of The Electric Life of Michael Faraday, by Alan Hirshfeld looking for a quote of his. I can’t find the one I’m looking for… but I could also recommend this book: not because it answers the question about magnets, but because it has a lot of ideas, insights, and even a few avenues that probably need to be chased up experimentally (and its a chocolate cake of a book). I didn’t find the quote I was looking for, but I did find this quote from Faraday:
“It is better to be aware or, even suspect, that we are wrong, than to be unconsciously or easily led to accept an error as right.”
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I did not know that. Our trains here in the city use linear induction motor effect. There’s a few pages in this book devoted to the topic of goodness, too.
Cheers, Dr. Laithwaite!
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RE: gyroscope weighing less when spinning: There are numerous ‘sightings’, on U-Tube mostly, arguing this.
I mostly dismissed it but one can see should this work that the maneuverability of such a craft might be phenomenal. I think it is worthy of serious investigation but fear the speeds required for practical application may be beyond current technology. G forces, speed of rotation etc. , of course maybe just a 3 phase rotation at near the cosmic speed limit would suffice? i wonder how many g’s that might be on something 30 ft. across?
How in terms of shape / arrangement?
If one field was a big donut (A) and another donut (B) are orientated with A horizontal and B vertical (their axes perpendicular) then the fields would be perpendicular to each other where they intersect. I don’t think you need to consider that they are perpendicular at all points, obviously they could be parallel at some points (and depending on direction repelling or attracting).
It may make more sense if you consider the fields are made up of lines of flux. For rotating apparatus it’s where these lines meet and their direction that produce the mechanical forces in a motor or the changing flux through the window to generate voltage in a generator. Trying to imagine a complete field(s) at all points within an apparatus could be mind bending.
The toroidal fusion reactor uses stationary external coils in both longitudinal and latitudinal directions to create the magnetic field (shaped like a donut no less) in which the plasma is injected and in which it runs around. This would seem to be a case where many multiple magnetic fields are intersecting at various angles including perpendicular to form a new 3D field to contain the reaction.
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This seems promising. Some of the material my instructor lent to me is about toroidal fusion (Enter the Dynomak, IEEE Spectrum December 2014).
I’m not trying to imagine all the fields in a motor or a generator. I’m only trying to get my head around magnetic and electric fields around a wire… or maybe two parallel wires. How do you imagine toroids A and B in relation to the wire? I was trying to imagine them as sine waves (wavoids?), which doesn’t seem to be getting me anywhere.
I’ve not thought a lot about it but I’d imagine some ratio of weight to thrust equation would be involved. also: perhaps any weight spinning at such incomprehensible speeds would not have to be counterbalanced? maybe it goes so fast vibration doesn’t even have time to happen? FTL? It’s neat to think about and it quickly gets deep in technicalities but we know there is stuff that moves FTL some of which will be needed the further we venture from earth for communications etc. I just think it unproductive to believe in barriers, we can not even start the research for FTL without first believing it is possible. (FTL) faster than light.
PS; KP, I would have to think hard to keep up with you, sorry, but it’s beyond me right now!!