studiot

Giving the best hairstyle to a tennis ball. (The Hairy ball theorem - Brouwer https://en.wikipedia.org/wiki/Hairy_ball_theorem )

I don't usually refer to Brittanica, but clay minerals have a special chemistry due to their structure. https://www.britannica.com/science/clay-mineral/Chemical-and-physical-properties

Most discussions of this nature tend to founder on what is meant by 'exist', so I suggest you start by discussing this. For instance you claim "all that exists.........." If that is so, what do they exist in? What lies between the bits of matter and/or energy and separates them?

For something of this complexity some explanation would be helpful. Especially description of the variables. It's not clear what is known and what you are trying to get to. You start with equation 1 and then state that one of the vectors (A) is a scalar times another vector s' in the second un-numbered equation. The third equation is almost a substitution of this second equation into teh first, but is suddenly equated to vector B. Where did this come from? Then again you state "I've found this result", but not where or how.

Indeed it may be. It is the electric field that antenna respond to.

This is a science website so why are you using from a general language dictionary to look up a science specific word?

An alleged conversation at the Royal Astonomical Society conference November 6th 1919. Silberstein "Professor Eddington, you must be one of the three persons in the world who understand General Relativity" Whilst waiting for a reply as Eddington thinks, Silberstein "Don't be modest, Eddington" Finally Eddington "On the contrary, I'm trying to think who the third person is."

Yes. A question for you to think about. You describe the scope display as increasing when you move the probe towards the room walls or the capacitor plates. Did you try placing the probe statically at decreasing distances and recording the scope readings at various distances after the display had settled? That is did the movement make any difference? Do you know anything about the effect of capacitance on scope inputs?

I'm not complaining about the BBC science programmes in general, some are absolutely brilliant and I have linked to them here myself. The Earth Science ones are especially good as was the one on Electricity a couple of years back. But my comments on the JAK style are twofold. 1) Asking questions the audience (or anyone else) can't answer and then handwaving when things get difficult. 2) Presenting explanations as though they were cut and dried Physics, not the subjects of considerable modern debate. Here is an interesting two pages from a Roger Penrose book covering much of the same ground. RP has the guts to admit when we just don't know and offers an evently balanced presentation of different speculations by world class scientists. #The Large, the Small and the Human Mind

Hello marco is this homework? The pdf doesn't work Just write it out by hand and post a scan or photograph.

I have to say that I am not a fan of \prof Al-Khalili's presentations. I find them shallow and glossed over in the difficult bits. Sometimes they are at best just misleading as with the TV 'science'' programme referred to above. In particular the probability explanation provided for the slits just does not work mathematically, it is too much of a simplification that is IMHO misleading. Probabilities are defined as positive real numbers. You have to work with complex numbers to achieve wave cancellation, despite the pretty diagram animation AK shows. Unless, of course, you are prepared to introduce negative probabilities and work with them.

With all that huff and puff do you understand what superposition asserts? It is simply a mathematical shorthand for saying that when two (or more) causes, drivers or activities are present, their effects add up and in particular certain properties combine in a linear fashion according to the normal rules of arithmetic. This has been used widely from engineering stress analysis to electrical circuit theory to chemical bonding to classical and quantum wave mechanics and many more. It is one of the most field tested proceedures in applied mathematics.

Something to remember when discussing mass and other parameters. It is called renormalisation. http://www.volkerschatz.com/science/renorm.html In regards to mass it involves replacing the mass one would measure for a free isolated particle by what is called the 'effective mass' in formulae such as QM or Newton's second law. The effective mass is based on the free mass but modified by the environment. The environment inclues the self interaction by the particle particularly in quantum field theory. The QFT version is difficult. The original proposal by Green in 1830 in regards to replacing mo in Newton's second law by me = (mo + 0.5M) in hydrodynamics. M is the mass of the water displaced by the particle and Newton's second law works properly using me.

I think Strange was referring to the structure which may well not be preserved by the mapping. I think this whole thread has arisen because I failed to make this distinction when I first talked about the one-to-one correspondence. Cantor provides a simple example within one of his proofs. You can put the even (or odd) positive integers into one-to-one correspondence with all the positive integers. The structure of continually increasing magnitude is preserved, but the odd/even characteristic is not.

I note that the treatment for many of these unusual conditions includes "Reassurance".

I think we should separate this into two questions. 1) Should you tell them? Yes, they will find out sooner or later anyway and could sue you if you hide it. Early diagnosis may help treatement if needed. 2) How do you tell them? This is where the rest of their circumstances should be taken into account in the telling.

Since you have posted this question in classical Physics, where bodies are allowed to be 'at rest' I think it should be pointed out that a body at rest has no momentum, but may have mass. Its mass may be modelled as' light' that is insignificant in application.

Thank you Strange, I have learned a new word today. +1

Where exactly did I suggest it was?

Amazing what some folks have on their kitchen tables. +1 I want one.

No it was a joke and quite funny I thought.

I have to observe that TIS is correct here. I meant to add exactly this to my post but it somehow got lost. The verb "to be happy" is a reflexive verb, so the subject and object are the same. So both are clear if someone says "I am happy". On the other hand, the verb to lie is transitive as it requires an object (the subject of the lie). So the question "about what ?" is valid, unless the subject has already been stated, as I said above. The paradox is a somewhat artificial construct in that people don't normally lie about everything.

There is also no paradox if you think harder about the physics of the situation since grains of millet are indifferent to sounds as they have no ears. pun intended

I think this is a tad unfair as TIS has the germ of the resolution, but has just not stated it clearly. However in view of the reception I got in the last thread about these ancient paradoxes, I am disinclined to help further.

+1 for understanding the point. and "I am lying" doesn't refer to anything. The conventional way to phrase this is to first classify everyone as either liars or truthers in everything they say. Then to offer the statement I am a liar.