studiot

Well in some ways just the same, electrons are still transfered, but the explanation is slightly different. Tribo-electric effects are contact potential effects. The QM explanation is the equalisation and therefore minimisation of the Fermi Energies in both bodies leading to a transfer of electrons, which obviously remain transferred when the bodies are physically separated.

The book I recommended offers answers to many to the questions you have grappled with here. You can rely on the provenance of these, the author is head of Physics and Astronomy at University College London and also works at CERN. He also has a good way with expressing matters in plain English.

Thank you for wasting my time and goodnight.

Actually the dimensions of the hubble constant are LT-1L-1 = T-1 or the reciprocal of time or a frequency.

I didn't use the word space. But the balloon skin is the analogy or model for space in this case. And yes the galaxies experience interactive forces just as the molecules of the skin does, but that is outside the analogy.

1) Nothing to do with me. 2) It is perhaps unfortunate that we don't have good words for this or that the words we have possess more than one meaning. So selecting the wrong (inappropriate) meaning for a word can result in a self contradictory meaningless statement. We have the 'balloon analogy". Like all analogies it is not an exact match so it has some properties in common with what we are modelling and some that are different. This is OK just so long as we stick to the matching properties. One property that does match is the process of inflating the balloon. (It is regretable that one small section of scientists chose to hijak the word inflation to mean something entirely different) But anyway imagaine the balloon partly inflated and we paint grid lines onto the surface with dots at each intersection. Now let us inflate the balloon further. We can easily observe several important facts that match what we see in the heavens. 1) The lines and dots are still attached to the same piece of balloon skin. They have not moved. 2) The balloon skin is still a continuous whole, it's just bigger. 3) New skin has appeared everywhere. 4) The lines and dots are now further apart as measured with our original tape measure. Is there anything that troubles you about this?

Space doesn't 'go' anywhere. That is a false premise. What would it move through?

Koti is correct, although he could perhaps have expressed it better. If this is the beginning of a conspiracy theory I am leaving the thread.

The milestones don't change, it's the numbers on them that change. And since they are artificial constructs we can allow new ones to 'appear' without pushing the old ones.

Well he didn't actually say that. Space is a more wooly and general concept. Spacetime is an artificial framework we use to measure with, just like the milestone or kilometer marking posts along the motorway. The Universe is expanding, not our framework. What is happening is that new pieces of 'space' are appearing/being isnerted between the existing ones. These new pieces are identical to their older counterparts. So the galaxies, milestones and kilometer posts stay the same, but just get further and further apart.

Thank you for this better description. My comments are as follows. This is not suprising and quite consistent with the other statements. Firstly the door presumably opens inwards and has some sort of threshold and framing stops which would prevent it moving outwards. So why does it move inwards and why the bottom not the top? Well the top part of the door will be at least partly shaded by any porch or overhang etc. So the bottom half will receive more sunshine. Obviously the outside is heated much more by the sunshine compared to the inside so will try to expand. This will cause the outside to lengthen, compared to the inside and the door will then curl under, rather like a bimetal strip in a thermostat. I can't be persuaded that paint and or veneer finishes have significant effect on piece of 40mm thick particle board, it must be that which is bending. Can you erect a temporary shade for the lower part to test if the door doesn't then curl under? We are expecting another week of warm weather. You could even remove some or all of the grey paint and show that it still happens with this door. Proof positive that it is the door not the paint. There is an known effect where if you only paint one side of a lightweight door, the skin tension of the paint can cause the door to bow, but that would be in the opposite direction. Perhaps the manufacturer is pinning his hopes on that? It certainly does sound (On the face of it ) as though that door is not suitable for that location. As regards temperature, my front door faces due south and on a 20oC day the door itself can reach over 30oC on the outside.

Hello Jeff, I really sympathise with your predicament as I am living with a very expensive defective front door supposedly engineered to replace the original oak one after 65 years of service. Sensei is both right and wrong. You have mentioned a warping of 6mm which suggests you are in a metric country, ie not North America. But he is right insofar as you have not supplied sufficient information. Firstly what do you mean by 6mm warping? How is the door fixed? Did the frame come as part of the door-set? Who installed it? You say it is well sheltered. Does that mean that part of the door is in shadow and part fully exposed? You say it has a lightweight core with oak veneer, which means it probably has low thermal capacity, especially in the core, but more details are needed. Who decided that a composite door was suitable for this location and why? Why are you painting an oak door, veneered or not? What is the detailed construction of the door? Without these details it is impossible to make a rational assessment of the causes. Assuming the framing is sound and unmoving, I would start by looking for differential heating in the sun's rays, regardless of wavelength and work from there.

Demokritis read here. https://www.scienceforums.net/topic/115096-non-mathematical-reasoning-and-physics/?tab=comments#comment-1057686

So I ask again, Did you have a point to make or question to ask?

It is the result of a mathematical model that does not take inhomogenity in to acount. Many such models exist in Physics, such as the water /air interface, the shape of the gravity field on Earth and so on. These are smooth at the level of the mdoel but bumpy at a molecular or sub molecular scale. So too would the S Radius be at scale of whatever passes for primary lumps of matter in the black hole.

This thread is IMHO a prime example of one that would benefit from this book. I posted a description here. https://www.scienceforums.net/topic/115096-non-mathematical-reasoning-and-physics/?tab=comments#comment-1057686

Any interface is only as rough or smooth as the initiating structure.

I have been reading this library book, apart from the 4 pages removed by some previous reader. A Map of the Invisible by Professor Jon Butterworth, University of London. This little book should be read by all those coming here to propose new grand theories of anything. Jon takes the reader through all the important aspects of modern Physics - Quantum theory, Special Relativity, General Relativity, Standard Model and beyond. But he does it in such a way as to bring out the important Physics of the material. The insights offered are stunningly crystal clear, as are the chains of reasoning behind the mathematics. Yes, Mathematics is mentioned including some pretty advanced stuff such as the Dirac relativistic wave equation, Einstein's Field equations and group theory. But these are all approached through Physics reasoning. The 'why it all fits together and works' stuff. Jon is also prepared to illustrate what we didn't know in the past, what we don't know now but may know in the future. The points and reasoning brought out include many oft forgot matters such as the different types of mass, the different types of force and so on. His setting is a bit trite, but otherwise a masterpiece. https://www.amazon.co.uk/Map-Invisible-Journeys-Particle-Physics/dp/1785150936

Any subject can be difficult until you get that eureka moment when things click together. Tell us about your difficulty (in your own words). Remember that you can only post a few times in the first 24 hours because of trolls.

Like it, must remember that one it's much earthier than comapring properties at points in Hilbert Space. +1

I glad you are at least half listening. I warned you about specialist technical terminology. Here is an example https://en.wikipedia.org/wiki/Ricci_flow Note carefully they make a point of saying that the flow may be in time or in something quite different (but static). You need to start by differentiating clearly between the following concepts. Static Quasi static Dynamic Note that Nature ( as so often) thwarts our desire to create a binary (one or the other, A or B) choice. Before the days of computers and finite element numerical methods much calculation was done by the method of 'conformal mapping' as applied to electrostatics, magnetostatics, fluid flow quasi statics, elastostatics, thermostatics, aerostatics and so on. Solutions to Laplace's or Poisson's equations abounded. Most of the work was done in complex analysis format and many famous names were associated with this work. The point is, as I said, the equations and techniques are similar. All involve comparing the value of some quantity at some point A with that of other points, B, C, D etc. As a result a table or map of how the quantity changes from A to B to C to D can be made up. This quantity may be a dynamic quantity such as fluid velocity or volumetric flow rate. Or it can be a totally static quantity such as the magnetic field lines of a permanent magnet. I stress that the equations are simialr, not identical. The mathematical analysis of most situations boils down to identifying the controlling driving forces and contraints and writing equations for them. The driving forces are often called the equations of constitution The constraints are often called the equations of compatibility For each of the situations (applications listed above) there is a unique set of these.

This makes a lot of sense. +1 I'm pretty sure the UK MinTransport has some sort of thoughts/proposals about this and , but sorry I haven't a reference at the moment but I seem to remember it involved a simple system linking and locking 'trains' of heavy goods vehicles to top the all to frequent event of one lorry running into the back of another in a motorway procession.

Mistermac It is worth noting that the word 'event' is one of those terms which has been given special meaning in relativity. The trouble is event implies 'something happens', but this is not the case with the special meaning. An event in spacetime is simple a point in spacetime, whether there is anything there or not. A a point it takes up no space and lasts for no time, it is just a (set of) coordinate(s). To me. at any rate, an event implies change, as does a flow. Now if there is something that has a value at a bunch of points located together in spacetime, for example a gravitational field, then we can compare the mathematics of the change of the value of this from one event point to another. We find that mathematics describing this can be very similar to that of fluid flow in ordinary mechanics. That is where the idea of 'flow of space / spacetime ' arises. I doesn't mean that property physically moves from one point to another (although it can do for some flows); it means that a scanner (the moving finger of Omar Khyam if you like) reading out a sequential list of values registers a change. Does this help?

Worry not. (and concentrate on your coursework). Many first degree was a Batchelor in Applied Mathematics (though it was a very long time ago). Although I obtained subsequent qualifications, it had let me into a widely varied career in structural engineering, the offshore oil industry, aircraft engines, electronic and computer engineering, gas distribution to name a few. But your degree must be more than "a review of invented methods". Any mathematician must have a good overview of the structure behind mathematics and how it all links together. This is all known stuff, nothing new here. But an applied mathematician also needs to know quite a bit of the Science of what (s)he is applying the mathematics to. These days even Masters courses are basically 'taught'; you don't really develop anything new, that comes at or after Doctorate. So practice one all the examples you can. Finally there is plenty of help here at ScienceForums for when you get stuck.

When you describe your course in your next post, please include the place / country and subject level in the system as some countries use the qualification words differently. This applies to both 'degree' and 'diplomas' or diploms as some have it.