studiot

Quantum theory doesn't in general involve forces and reference to a 'fabric' is popsci. I am suprised that you jumped to such conclusions when I suggested to find out about some basics. I'm sorry but there is a lot of learning and work required between those basics and something as advanced as quantum theory. And as yet, you don't seem to have the basics. Energy does not exist by itself. There is no such thing as pure energy. Energy is, in fact, a property of things which do exist. One of its properties is that it may be transferred from one thing to another. Quantum physics arose from the description given by Einstein to the discovery that energy can only be transferred in certain definite quantities. This was only a description and referred to only one sort of transfer originally. It did not answer the questions of how or why this is so. Einstein called these definite quantities quanta. As joigus points out, it has later transpired that the restriction also applies to some other properties of things such as angular momentum. Quantum Physics is the study of such phenomena and its implications. Does this help ?

I suggest yoy look more closely into the nature of vibrations, oscillations, waves and other forms of motion. We have many names beacause they are all different in the way they work. Vibrations require what is called a 'restoring force', in addition to the original 'disturbing force'. If no such force is present then free motion occurs which may be random and if impeded ( eg by collisions) may generate a variety of phenomena, one of which we call pressure, another we call heat, another we call pair production and so on.

The fact remains that you have made a good many claims, some of principle, some numeric and some totally irrlevant to the issue. But I have not seen a single piece of mathematics or calculation to support them.

Elizabeth David ? I believe they originally had a ham joint with the bone in. Of course you can't get them in England today. One very useful tip concerns the roast. Traditionally cleaning the roasting dish is a chore, But we take the dish as is the following day, and use it to start off some lentils and vegetables, then some stock and finally a left over worst bits of the meat. This either becomes a curry or plainer dish or even pea soup base. The good bit is at the end because all the water added cleans the roasting dish almost as well as our retriever (when we had one) so washing it up is a treat. Thanks and +1 to both for your input.

What are your (favourite) recipes for cooking ham ? My family had used the following for generations and most folks we feed the result to seem to think offers significant improvement of the standard method. Use smoked or plain ham to preference. First prepare you ham by making small slits in opposite sides or ends with a very sharp knife. Then insert a sliver of fresh garlic clove into each slit, as deeply as practicable. Follow this up by inserting one or two cloves into each slit, tailend inwards. These are removed after cooking. Place the treated ham in a pot deep enough to cover with cold water and place on stove. Add a rounded desert spoon of soft brown sugar to the water. Bring to the boil and simmer for 1 hour per kg. Do not over cook. Once cooked the ham can be removed to stand. The ham water can be used to add extra flavour to vegetables such as cabbages, carrots and so on. Most folks are pleasnatly suprised when they come across this last bit.

I am sorry line 2 of my second quote above should have read ...I am convinced that philosophers have had a harmful effect..... ...I am convinced that have had a harmful effect... My apologies for that important omission, and the spelling mistake in the first quote, my typing degenerates as the day wears on.

Yes it is exactly zero. By the way How did we move from a discussion about time to a discussion about distance ?

As irrelevant as what ? Or did you really mean soemething else ? Here is a quote from a famous Philosopher Pray tell me what it means Here is a piece from a famous scientist

I think it is very important that you separate numbers , units, symbols and the objects which they refer to. That is you think separately about them, each in their own right. Let us take an example of this: Making bread. Bread has ingredients. The ingredients are flour, yeast and water. There are 3 ingedients. Here the objects referred to are ingredients. The number 3 is called a quantifier or a coeffiecient. There are no units involved or if you prefer the unit i 'number or count of' But there are several types of number and 3, each with their own special features. So we could have said: There are 3 ingredients 1st ingredient,, 2nd ingredient, 3rd ingredient. Or we could have said even more First ingredient flour Second ingredient yeast Third ingredient water. Which tells us even more. First second and third are numbers, just a different kind of number. ~They are cvalled ordinal numbers, as they show order. We could also write a 1 on the jug of water, a 2 on the tub of yeast and a 3 on the bag of flour. Then the instructions might read Mix the contents of 2 with the contents of 3, than add the contents of 1. We are now using the numbers 1, 2 and 3 as symbols (you mentioned symbols) We can make the description even more use full if we add units so Mix 2 of yeast with 400 of flour and then add 250 of water is not very helpful. But Mix 2 teaspoons of yeast with 400 grammes of flour and then add 250 mililitres of water is very helpful. Much more helpful than Mix 2 teaspoons of 2 with 400 grammes of 3 and then add 250 mililitres of 1. Although both are strictly correct and Mathematicians and computer engineers like the last as it is shorter. I have another example to explore but let us see what you make of this one first.

A ROM is a form of truth table.

How w ell do those learning English do with acronyms ? +1 An SMPS is a Switched Mode Power Supply. Switched mode power supplies often also incorporate a voltage change and use an inductor and or transformer for this. Inductive switching generates large reverse voltage spikes known as backswing which can damage semiconductors when they are reverse connected. (see Sensei's graph) Zener diodes are used as protection to limit (called clamping) the size of the backswing voltage to a safe level. A second use is to clamp the voltage created on the storageor reservoir capacitor, which stores the switched pulses, to the desired level.

Not in the least bit suprised. +1 for a proper attempt at evaluation. Chemically basalt is nothing like portland cement concrete, although both are silicates. As a material basalt is more susciptible to chemical weathering attack, enhanced by subsequent detrimental attack on its own structure (HAC, ASR, Ettringite, Carbonation) and on any embedded ferrous reinforcement. This is in direct contrast to Roman lime based concrete, which continues to gain strength and hardness forever on a diminishing curve, from the atmouspheric carbon dioxide.

Since you seem to just want to copy others, rather than answer my questions I will leave you to it.

Did I see that knee jerking before you read and investigated my article ? The ground up basalt is produced anyway. It used to be discarded as slag waste. It can be spread along with fertiliser don't forget that this is reduced, they mentioned a fig of 25% saving of fertiliser. However I do agree with your point about carbon credit trading. I regard it a scandal. So are you saying that new improved technology should not be employed even if it brings environmental benefits ? To all I never said this to be a universal panacea. In the advertising words of one supermarket, "Every Little Helps"

Why not ? you are just dressing up incredulity as something more; I still don't see a problem. I haven't checked your numbers but it is an observed fact that clocks lower in a gravity well run more slowly so Bob will record less elapsed time for the same interval.

Earlier this year I watched the BBC Earth series, presented by Chris Packham. One new theory was presented of many years of almost continuous rain on the early basalt eruption surfaces, leading to chemical weathering of the basalt removing significant quantities of acid greenhouse gases, particularly carbon dioxide, from the atmoushphere and chemically 'fixing' it into the ground. Last Sunday the BBC Countryfile programme had an article about trail replication of this process by spreading the waste products of the aggregate industry (ground up basalt) onto farmland. The greatly increased active surface of such basalt powder not only reacts quite quickly (ie at human timescales) not only fixing the carbon but also releasing new nutrients to the soil, thereby reducing fertiliser demand. It is too early to tell just how good this since trials have been going on for little more than a year but apparantly early results are 'encouraging'. ****************************************************************************************************************************************************************** Then I see that someone has done something about waste plastic from laboratories, formerly just burned (5.5 million tonnes in the annually), to make recycling possible. Well done Helen. Nice to see up and coming graduates succeeding like this.

That was going to be my next question. +1 But the issue here is How do Bob and Alice know when to start their clocks ticking ? Obviously they must have lived 14 thousand million years in order to make the measurement, plus a little bit to build their clocks and synchronise them.

So why is that a problem ? Bob is at the bottom of a gravity well, compared to Alice, so expects his clock to run more slowly. But you haven't demonstrated that your figures are correct for the time of flight and height difference.

Thanks, Joigus. +1 I think you may well be right, although I try to avoid these more exotic non mainstream symbols. You have done better than the author who had the opportunity to this is what he meant, but chose not to for some reason. If nabla squared is meant then in my opinion that is what should be said. The square is often called the box operator but it suffers from the disadvantage that I have seen it confused (used for in lecturres) with the Hodge star operator and also is presented by some parsers as a general symbol when they come across something not in their vocablulary. Word is bad in this respect. Also remaining is the mathematical demonstration that the second order differential equation obeys the Lorenz transformation, using the speed of sound as an invariant. The simple fact is that to an inertial observer moving differently from the air, the speed of sound appears different.

Or set the problem out correctly, filling in the missing lines telling us where your figures come from and showing us how exactly the two photons can have followed exactly the same path (world line ?)

Guiding would be better than telling. You still haven't answered my questions. Since you are doing this in preparation for a real exam it is no good just looking up formulae on the net (especially as I suspect it is wrong but I can't see the rest of what you found). You need to understand what you are doing. And that is exactly what both Seth and I are trying to help you with. So let us go back to first principles and answer my simple questions. Do you have to derive your equations or have you been given them in lectures ? Using your knowledge of Physics is the internal ressure greater than or less than the external ? Why did I suggest you will have a circular blob ? You new picture is wrong because the vertical meniscus is not a complete semicircle. Why do you think this is the case ?

How's that ? We all have trouble with the TEX of one sort or another. I have a ridiculously expensive commercial generator called Mathtype. Alternatively you can use free sites Codecogs or Sciweavers to have a TEX editor and copy paste from it. Another possibility (though limited by the inability to produce almost any sort of fraction) is to combine this SF super and subscript and use windows charmap to pick out special characters such as greek letters. You can actually achieve quite a lot this way.

I was going to examine your 'mathematics'. I can't make head not tail of this equation unless you have nabla the wrong way up ? If you have written Δp then the equation is nonsense. You seem to have corrected this few posts further on but a recognisable wave equation is stated and is indeed the equation you seem to have copied from Wikipedia. Unfortunately you seem not to have read the text where Wikipedia clearly states that this is the equation of a standing wave. My example involves a travelling wave and Wiki refers you to a simpler first order differential equation, which it call a one way wave equation in its own style. Note Wiki clearly states these 'preferred frames' to be hypothetical for the purposes of exploring what if there were such a frame. It makes no guarantees that there is one and indeed states there is not such a frame in an inertial set of frames (as we all know).

Love it to bits.

Is that incompatible with what I said ? Glad to hear it. We need We need philosophers to ruminate, but it is better if they chew on what we know rather than guessing, of if and when they do guess then they cary out testing of their guesses.