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Everything posted by studiot

  1. As MigL (+1) has noted, direct proportionality between two variables is the starting point for this. But a variable (force, F in this case) can be proportional to more than one variable at the ame time. In with your example, Force, F, is directly proportional to the mass of a body all other influences be held constant. It is also proportional to acceleratio, again all other influences be held constant. When this happens, the dependent variable (F) is given by the product of the two influencing variables as in F = ma. (Sometimes there will be three or more variables then we have a triple product. This happens in fluid mechanics and electronic signal theory) This is very good and very important mathematically because the variables are 'separated', which means we can deal with them separately or independently. Separation of variables is the method of solution for some of the most important equations in Physics. Going back to two variables, one directly proportional to the other I would add to MigL's description that a graph or plot of one variable against the other is a straight line graph through the origin. Straight lines not through the origin, are not representative of direct proportionality.
  2. Hi Moon, I hope the recovery is going well. I wonder if your question is a bit short and general ? Why metal alloys ? Do you mean all metal since a carbon -iron alloy is not? Then again predict the properties is a very big ask. All of them ? and how accurately ? The short answer is yes. The longer answer is we can predict some of the properties some of the time and sometimes very accurately indeed. For instance the alloying process to make the earliest transistors with metallic germanium literally counted atoms of alloying element to achive the desired electrical properties. There are not that many possible crystal structures or arrangements and alloying means combining two elements into one structure so their respective crystal structures must be compatible, other wise a mixture is produced instead. Physical properties such as melting point can be estimated quite well, though some systems are more complicated than others. The Iron - Carbon system is particularly complicated by itself. Start to add further alloying elements such as manganese, chromium, nickel, vanadium, ... and it gets real complicated. We know from experience, rather than theory, what constituents produce desirable properties such as corrosion resistance (stainless steel). So give us some more detail to work with please.
  3. Thank you for the clarification. When speaking to wooden planks like myself it helps to say exactly what you mean. 😉
  4. Bayko dates from the 1930s. Like Meccano it had the characteristic of being dissassemblable. Another type of constructional toy, not yet mentioned would be the type where the result of construction was permanent. such as the 'Airfix' kits, mostly model aircraft. These followed on from earlier hobbies such as 'matchstick modelling' carried over from the previous century into the early part of the 20th. If you visit western Europe there are lots of toy museums scattered around, with some really fascinating toys and games. The one in Perth (Scotland) and the one downstream of Duisburg and Dusseldorf particularly spring to mind.
  5. The answer to what ? I didn't ask a question, nor did you.
  6. Thanks beecee, nice one. +1 Do you know if the 'waterfall' is the result of a step in the bed or is just in the water, looks like a bit like hydraulic jump to me. In fact it seems to be more like the effect you get pouring a bucket of water into a bath of water. https://parks.dpaw.wa.gov.au/park/lalang-garram-horizontal-falls
  7. Looks very similar to the description by Alan Turing in his essay "Can a Machine think ?"
  8. Perhaps the organic parts come from decayed fossils from this process http://preparation.paleo.amnh.org/56/pyrite-disease https://www.zoicpalaeotech.co.uk/pages/pyritefossils
  9. A good place to start looking for information is this book - 700 + pages of wisdom. Chapter 2 is dedicated to your tidal question.
  10. If you are not going to take the discussion seriously, you will need to find another to continue the discussion with.
  11. Please elaborate on what you mean by these statements, since they are not mathematical ones I recognise. Note mathematical statements need not be symbolic, English is perfectly good. Please pay particular attention to what you mean by 'derivation' and 'set'. I seen no point worrying about the rest of the material in your post until the basics are cleared up.
  12. I've not seen that method of mass accounting before, well done for spotting the issue and presenting it. +1 However perhaps you should explain the meaning of your square brackets, some may have difficulty working it out for themselves.
  13. Of course they are, that is how the water body moves up and down to support the vertical movement of the water/air interface. Of course they are not the only source of water movement.
  14. Let me repeat a previous post. OK so to continue with the Mathematics, though Euler also had much to do with applied maths. Princeton University has been home to some of the greatest geniuses in History. They also have a small publishing house which publishes specialist topic books, most of which become standards in their field (see another use of the word field ?). I am recommending one about Euler and his constant, gamma to you as you should find much of interest in it. Most of the book is lightly mathematical to be more generally accessible but read the introduction here and see what you think. Gamma - Exploring Euler's Constant Julian Havil - Princeton University Press 2003 & 2021
  15. You chose to quote the vertical deflection, yet the horizontal deflection can be from a few to hundreds of kilometres. People always forget tidal streams.
  16. I suppose they both depend where you live. We have 30 metre sea tides where I live.
  17. It should be possible to make a reasonable estimate of the loss of rotational kinetic energy, which as Moon says, must be degraded to heat. It has been possible to detect 'earth tides' in the crust, but the deflections are tiny compared to the deflections of the water covering (oceans) and energy depends upon the square of the deflection amplitude. So deflection of the liquids in the outer core will also be greater than those in the more solid crust and mantle and of course the inner core. The outer core will generate much friction as it rubs between the undermantle and the inner core. We now have believable models of the (rate of) heat transfer between the various layer of the Earth that can be applied.
  18. Out of interest I looked up the word solipsism in the Oxford English Dictionary. Physics, and not only modern Physics but also classical Physics uses the term isolation or isolated extensively. So in that sense it must support solipsism. But this whole thing is a philosophical/semantic argument as you have not fully defined your use of the term solipsism and its limits.
  19. Swansont is far far more qualified than I am to pronounce on the relationship between physics and solipsism. He is a working professional Physicist, whilst I am a retired applied mathematician. Perhaps that is why he is less sympathetic towards philosophy than I am. And I regard this as a philosophical question, not a physics one. Perhaps this question should be moved to philosophy.
  20. Interesting topic and photos. +1 Thanks for the article. +1
  21. Seems to me that you have combined two mutually exclusive ideas to produce a self contradictory question. If solipsism is true there there can be no Physics, modern or otherwise. Further I wonder why you are asking other 'selves' ? Surely the doctrine that nothing exists or can exist other than one's self automatically denies the existence of other 'selves' and other doctrines ?
  22. Looking forward to the next installment ! +1 I would observe that density is important because there is an unaccounted for force acting here - gravity. We should not losse sight of that in the discussion about central forces. But you are correct that using pressure would be more appropriate since this is a fluids calculation. I hesitate to use the term pseudo-force, since a force is a vector and there is something called a pseudovector which is a horse of a different colour alltogether, which is definitely not non-real. Centrifugal force could be called virtual or imaginary, since it is introduced by the analyst to aid calculation (and perhaps visualisation). Virtual may be too general. Imaginary might be confused with complex numbers. The point is that it does not exist.
  23. Thanks but I don't have the petrol to spare these days. Surely someone in the industry might know this. Seth and Exchemist were both in petrochem industries.
  24. 1) Neither are forces. 2) The evidence for each is quite separate and independent of the evidence for the other, as are the effects they describe. 3) Read Frank Wilczek, it will help a lot.
  25. I watched your video, should it have sound ? I didn't hear any. Your weak magnetic field seems to lack any technical definition/description and I couldn't see items (for instance charges A and B ) that were referenced in the accompanying text. In general it seems to require the introduction of entities and dimensions we have no access to and rather than unifying dark matter and dark energy (which are entirely different phenomena) it introduces yet more 'magic media' currently beyond our ken. There are only a few frames and ideas. I'm sure you could summarise them here for discussion. A suggestion for you. Read Frank Wilczek's just published book Fundamentals : ten keys to reality. As an educated engineer you should find it easy reading and Frank does have the knack of bringing most, if not all, your disparate topics together very simply and cogently.
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