studiot

Instead of being such a smartass why not find out the ideal or best way to do something, which may not be practicable and/or economic in some cases ? That was what was mean by my use of that small word 'should'. I gave you approprate acknowledgement for stating that sufficient ventilation may be the correct solution to the OP's problem, after all we do not know if the masonry actually is damp or not. So why can you not return the compliment ?

Perhaps if you paid as much attention to what I said as I did to what you presented you would not make such inappropriate answers. I did try to help you rather than just dismissing your stuff out of hand as others did. Clearly there is no point continuing.

Where did the OP state this room to be a cellar, I must have missed it. ? If you built a retaining wall, where would you put the waterproofing ?

This far from a foolish question and highlights a very important principle in mechanics. "A single body cannot move itself without interaction with an external force or other body" So to look at why you man in the waggon cannot push himself and the waggon, but the man ouside the waggon can. Simply put the man in the waggon has nothing to push against but the man outside pushes against the ground. There is a further twist to this you might like to think about. The man pushing the waggon can push a heavier weight (mass) than his own. Why is this ?

When discussing coordinates sytems and metrics is is important to realise that they are independent concepts. A space can have a metric but no coordinate system and vice versa. References to topological spaces have been made. Topological spaces do not require coordinate systems and some topological spaces do not require a metric. What is required for GR is continuity for the equations to make sense and the tensors to exist at all. Mathematics now separates continuity into several allied concepts ( coincidentally all beginning with C) and I did promise Joigus a thread on the subject. I suppose this is now becoming urgent.

I am aware of this since the neutrostatic field mainly rely on the bohr radius, this hypothesis (not theory) does not follow the equivalent principle when the bohr radius is significanly over or below the 5e-11meter distance. Therefore in plasma or in neutron state (I imagine neutrons have its electron very close to its proton), it couldn't hold up. A Neutron has no electron. So it is a particle with mass but no charge. So why does it respond to your proposed gravitational neutrostatic force ? The sphere is not a plum pudding model of an atom. It is a visualization of charge distribution on a conductive sphere. I understand that, so what is this ? I was actually referring to this diagram In both cases you have mixed up (arranged) the charges in an impossible way. Here is a clip of your dipole. A problem with this is that you have shown forces acting as though the positive and negative have equal masses. An electron and a proton have equal charge but very unequal masses. The mass of a proton is nearly 2000 times that of an electron. The mass of say a Uranium ion and an electron are tens of thousands of times different. If you mean by placing a conductor in the middle of the dipole, then the space permittivity will increase and reduce the neutrostatic field. Similarly if we can just simply reduce the bohr radius of the atom it would have the same effect. A neutron might fit the description. And for this, I will acknowledge that it is an obstacle with mainstream science. Yes I mean placing a conductive shield between the positive and negative poles of a dipole. But size has nothing to do with this. You could use the original device of Cavendish to do this. Charge one sphere positively and the other negatively and fit the shield between them. You would still find the same gravitational attraction as measured on the torsion balance. These are meant to be constructive criticisms of your proposal, not "I know more Physics than you so shut up little boy" type answers. You do not need advanced maths or physics to test your ideas and see that they are wrong because they contravene measurable reality.

I was reading through Mordred's long standing thread on space and I came across some posts from Mike in the early part. Members may wish to know that Mike passed away earlier this month after a long standing degenerative illness (not covid). Mike was an interesting character, an artist with a degree in Physics and the founder of a successful manufacturing business before retirement to Cornwall. His artistic (dreamy) side gave him an unusual and sometimes frustrating perspective on Physics, especially later in life when we knew him. But he was a genuine character and sometimes offered suprising insights as well.

Have you considered the possibility that your plumber may have had a point, even if his solution was less than ideal ? You mention that he thought your wall was damp. Was this ever measured ? You say that your wet room was being refurbished. If your previous wall covering (I note there is no plaster) was not perfectly waterproof, perhaps moisture was getting through from the inside and building up. If this was the case then the new wall finishes certainly need to be waterproof but the brickwork also need to be dried out first. Tanking (that is the correct building term) with bituminous or other waterproof membrane materials is the correct treatment. However the tanking should be applied on the same side of the wall as the source of the water as this will then mean that the pressure will hold the tanking harder to the wall. If it is applied on the other (wrong) side the pressure of the water coming through the brickwork will tend to blow the tanking off the wall. So if water is coming from the inside the tanking should be applied on the inside and if the water is coming from the outside then it should be applied to the outside. If you are facing internal tanking then there are special plasters/renders designed to adhere onto the tanking. You would need these in any case to tile or otherwise finish the walls. The bituminous tanking will loose 90% of its smell in about 1 week to 10 days. After this the appropriate render can be applied which will prevent the rest. Or you could simply remove the tanking (mechanically would probably work best) and do something else.

Can have a long life yes, if properly manufactured and installed. They said this about early transistors but then came the 'tin whisker' effect due to migration of metal from the leads into the semiconductor material and disabling the transistor. https://nepp.nasa.gov/whisker/anecdote/af114-transistor/index.html I said maunfactured and installed because this effect can also effect inappropriately chosen circuit board materials, solder, leads and other components as John has noted. We do not yet know if another unforseen effect will rear up and bite us in the ass in years to come. I have never seen a long life compact flourescent that achieved more than half the promoted service life bulb for instance.

I am going to say +1 for your efforts. Not only has this been one of the few speculations posted in accordance with the rules here (including the way you posted the video) but also it is a respectable train of thought that should not be lightly dismissed. However there are some points your hypothesis (not theory) has failed to address. 1)Neutrons have no charge whatsoever, yet are subject to gravitational effects. This is a serious obstacle. 2) Whilst I take you point about the generation of your field, you have taken situations that are electrostatic and combined them in a way that is forbidden by Earnshaw's theorem. Earnshaws theorem basically states the two or more charges in an isolated universe cannot ever be in equilibrium and therefore cannot ever be stationary or static. It is just not possible to have two charges and nothing else (ie no other forces) in the way you describe. Something else has to hold them in position if they are still. 3) The charge distribution you introduce on your sphere containing both positive and negative charges at about 3.5 minutes is incorrect. Thomson's 'plum pudding' model has long been (experimentally) discredited. 4) What would happen if I placed a long strip of continuous conductor between the positive and negative charges in your early diagrams ? The conductive material would fully shield each charge from the electric field of the other, yet there would still be a measurable gravitational effect between them.

To emphasise this, the degree of 'protection' depends upon the nature and quality of the grounding. Inadequate or wrongly placed grounding can lead to damage in its own right.

Hello Col and welcome. +1 for a good start, I look forward to further worthwhile contributions. I've been a member since 2012 and in that time I have seen many threads started discussing the question, "What is space ?" So it is indeed apressing question. So pressing that in fact we now need to separate what is meant by a physical space and what is meant by a mathematical space. Defining a mathematical space is easy. You need a set containing at least three (perhaps four) sets of objects. 1) A set of mathematical objects you wish to work with. 2) A set of coefficients you wish to apply 3) A set of axiomatic relations between these objects 4) Perhaps if you want to be complete then a set of results (theorems lemmas etc) you can deduce from these. Hi Markus, I think you have this the wrong way round. Mathenmatical structures are models of physical reality, rather than physical reality being a model of mathematics.

Anyone wish to own up ? https://www.bbc.co.uk/news/business-55738540

This claim is not meaningless it is just plain wrong and arises from a basic misunderstanding of celestial navigation with a sextant, where the term 'arc of the sun or arc of other celestial body arises' It is not the altitude (which is the arc measured in degrees) but the plane from which is it is reckoned that changes with altitude and with altitude and other factors which have to be corrected for. This plane is called the true horizon and is not directly available to the observer so various 'observable horizons' are employed - marine navigators use the water horizon, aerial navigators use an 'artificial horizon' (yes aircraft still carry sextants for emergency navigation when the more modern electronic systems are broken). Clearly these calculations are correct since navigators do arrive at their destinations using them. The calculations and sight corrections can be quite complicated, here is a simple explanation. https://knowledgeofsea.com/correction-to-sextant-altitudes/

Generally an excellent explanation, +1, but your examples need updating somewhat. Both these examples were used in 1930's electrical equipment but have long since been abandoned as wasteful of power and potentially dangerous as they result in the excessive generation of heat. https://electronics.stackexchange.com/questions/252352/setting-heat-on-electric-stove Electronerd, are you sure you meant a bridge rectifier ? There are many sorts of bridges, but a simple bridge rectifier is not directly comparable to a rheostat. A bridge is a particular sort of circuit configuration containing four circuit components arranged in a 'diamond pattern. Some bridges are used for power control. This application would be comparable to using a rheostat for this purpose, but much more efficient. Such a bridge would be called a 'controlled bridge rectifier' and contain at least one, probably two or four silicon controlled rectifiers (SCR) or TRIACs If you have been reading about bridges for power control are you sure you don't mean this sort of bridge rectifier ?

Several countries have tried using Bluetooth to measure soical distancing distances. None (to my knowledge) have found a successful method. So what are the problems they are facing ?

Yes, yes and yes. +1

OK so I will try to discuss communication of Mathematics, rather than principle of Mathematics. I can't see where you have mentioned any basic Maths, computer code is hardly basic if it is indeed Maths at all. However I beg to disagree with your outright rejection of History. Perhaps your experience of History at school was of the sort "History is a list of dates of battles, deaths and treaties to be learned by heart and regurgitated for the examiner". History actually offers many lessons for those that care to peer into them. Not the least being concerning computer code. Coding languages have a very short lifetime; I have seen them come and go and stopped bothering to learn the new fashion decades ago now so I have little idea of the meaning of your example. The last serious program I wrote was PFortran TRIP (Trigonometric Intersection Program). British schools went through a phase of demanding that every child learn 'programming'. This mean resources were wasted on teaching first, different versions of BASIC, then PASCAL, then some early scripting. None of which are current today. History also tells us that the basic mathematical operation of counting is at least as old as writing, probably much older. Now schools used to teach using the old fashioned balance scales. Good schools would actually get the pupils to set up pretend shops acting as customers and shoperkeeps. They would weigh out amounts of materials, say potatoes or sand and also practice with pretend money. This allowed a method of counting by the custemr presenting say a half crown coin and the shopkeeper saying That's one and fivepence and then making up the one and fivepence to half a crown with coins to provide the change. Instant communication of arithmetic and fractions. For those who were a dunce at school arithmetic there was the joke, you say you can't do maths but you can still instantly recognise that you need a treble eighteen, double top and single nineteen to finish in a darts match when you are on 113! Would these be the sorts of examples you are looking for ?

Well thought out and presented answer +1

Is it? I wasn't aware of this. A detailed explanation of what I mean would be off topic in this thread so I will start another one for that purpose. I will let you know when I have posted it.

Swedish scientists use slowmo videography in a wind tunnel to confirm 1970s hypothesis of the aerodynamics of butterfly flight. https://www.bbc.co.uk/news/science-environment-55719955

To add to this. Mathematical continuity is defined in terms of the inverse functions, not the functions themselves. This has implications for any calculus you choose to adopt.

Ok. As a little tip - conventionally, writing (t,x,y,z) will imply Cartesian coordinates to most readers; if you want to indicate a general coordinate basis, it is better to use the notation x0,x1,x2,x3 , as it is less ambiguous. @Anamitra Palit I would like to add to this my comment to the OP. "(t,x,y,z) could represent coordinates of four dimensional space in a general manner" No they couldn't. t has the wrong physical dimensions to make this a physical space of four dimensions. You can only make an abstract 'space' (in the mathematical sense) with mixed dimensions on the coordinate axes. It is important to always keep this distinction in mind.

Reviewing your opening post I see that I did not give enough prominence to your actual question in my answer. Which is just how much of our NHS resources are being diverted by C-19 because of how long those patients who need hospital spend there All this week the BBC news cameras are following events in the Royal London Hospital, where they also went at the start of the pandemic. The RLH is a small 500 bed distict hospital in the middle of the East End of London. In normal times they have 40 odd intensive care beds, counted into the 500. Yesterday (Monday) it was reported that of the 500 beds over 490 were occupied by a 'high dependency' covid patient. Some of these will still be there months later. So what about the other 450 odd displaced would be patients ? This phenomenon also affects your interpretation of figures. The figures I was quoting were the daily new infections set against the daily deathis within 28 days of testing positive for C-19. This gives a good estimate of your chance of dying from C-19 if you caught it today. It would be false accounting to count in the number or % in the population with C-19 at any one time since the condition lasts a long time and you do not catch it every day. Here are some figures on that just released by the Office for National Statistics. https://www.bbc.co.uk/news/health-55718213

I wasn't and the OP stated You misunderstand although you posted a fair description of the partial working of a condensing boiler, it is a pity you have to always contradict me. The situation is much more complicated, for instance there may be no 'return' flow to a boiler running in DHW mode. But certainly if the inlet water is 100oC or greater then the output water would scald you. In fact it would scald you at a much lower temperature. The point is that the inlet water temperature is not fixed. But the output temperature will be set (there are often adjustable controls in a boiler for this) for both DHW and CH mode for efficiency purposes.