studiot

Thank you for introducing the point I referred to in my first post in this thread, that somehow led to a jibe about poisonous potatoes. Moontanman thank you for that quote about andean potatoes, I have learned something. Not at all I have temendous respect for the cultures (there were many) of the population native to the americas but I think that is off topic and have therefore been trying to keep my discussion down on that topic. However I would be happy to discuss it on a more friendly basis in another thread. For instance the fact that the central / south structures were, I understand, built without metal tools - a considerably greater achievement that that of the ancient egyptians and babylonians. Further I understand their pyramids were not basically large solid structures with small voids but basically full buildings in the more modern sense. Perhaps we could also discuss the area of Patagonia where they speak Welsh? Or the destruction of the Hugenots by Cardinal Richlieu at La Rochelle in France?

Some, but it's a new and developing technique. And yes they are currently still excessively exopensive (even the El Cheapo poor quality ones) Last year for instance many manufacturers had to withdraw/recall products because they had not correctly assessed the heat generation by LED equipment and this lead to real building fires. I was suprised that my super fittings generate significant local interference to AM and FM radios. It's too late here for details but I can post them if you are interested.

Moontanman I agree, although some earlier 'civilisations' also used BW further east. However it does not do to tar a perfectly respectable (if colourful) technical term with emotive baggage. Some peoples native to the americas were primarily hunter-gatherers and did no real farming. Others were farmers and 'Slash and Burn' was exactly what they did - after all they had plenty of spare land. In those circumstances it is a very efficient and viable farming (and living) technique. But any farmer must have crops to farm so it stand to reason that they must have developed them, so how can you say All I'm asking for is evidence that they did any sort of selective breeding of the type Swansoft mentioned rather than just growing what they had found in nature. In particular I'm asking for evidence that the tubers of potatoes were ever poisonous (except when green). The point is that with their type of agriculture they moved on every few years so how did they have the settled periods to do the development? How much development, for instance, did the chinese ( a settled people) put into rice in an even longer time period?

I don't know if that was a reply to my post but if so it is a pity you didn't read it properly. I was not talking about light bulbs. I have been testing a 14 watt LED light fitting in my recently extended utility room. It is the brightest domestic light I have ever seen, considerably brighter than the 100 tungsten bulb and halogen fitting I used to have in there. Furhter the the new type of fitting distributes the light more evenly. The manufacturers have not bothered with the fictitious equivalent ratings that accompanies CFL lamps. The recessed LED lights I have seen suffer greatly from an inappropriate mounting.

Moontanman Well then help me with my research. What crop selection and development in respect of potatoes did the population native to the americas practise prior to 1450 AD ? I am not sure what you mean by native american, as in how it applies to the modern day but if you can trace ancestors back to the people that were native to the americas when the europeans arrived you should be proud of that fact not so touchy. I didn't use the word savages - you did. I was giving considerable credit to the population native to the americas around 1450 -1500 for cultivating crops (I think tomatoes and tobacco were also included) that europeans had never seen. I did not expect you too since my comment was not asked of you. So far as I can make out you had not asked a question to the point where I made my remark so how could it have been? I specifically stated I answered someones question, but you had not asked one? Which is all a pity since you have also expressed confusion about the subject of the modern day development of crop varieties. I think that some more questionable purposes, than I outlined in post#11, are being served by modern techniques . I further think that these darker purposes are contaminating the motives of the post#11 in the eyes of many (including my own), thereby casting a shadow over pefectly sound scientific and technological developments.

Many thanks. +1

Maybe I was asleep in history lessons, but I understood that Sir Walter Raleigh brought potatoes from the Americas to Europe because the native indians cultivated and ate them there. If they ate them they were not poisonous, and I doubt that the native indians of the americas went in for any form of crop development. I understand they were a slash and burn culture. In any event I do believe that the tubers have always been edible, but the above ground parts of the plant less wholesome. Now that I have answered your question how about answering mine?

Thank you for that information, Paul. Any pictures available please?

Amazing how the rational thought is suspended by normally thinking people when this subject comes up. Why would it not be OK if the only reason was to improve crop quality, yield and disease/pest resistance? Yet that is the implication of your over sarcastic remark, which is not even accurate.

Well I too have been doing some checks on LED lights and have come to the opposite conclusion. I don't think the problem is to do with the LEDs, I think it is to do with customers and manufacturers not understanding the differnce in fitting design mandated by differences in light source characteristics.

Make mine a double, I've already tipped you!

It would be ok if that were the only reason.

Why?

The big difference between the theories is granularity. Relativity, in any form, relies on the mathematics of continuous systems and continuous functions. On the other hand QM is inherently about discrete or granular systems and requires discrete or granular maths. This difference has been discussed and worried over at great lenght by many famous people, but never satisfactorily resolved.

Yes I understand that. I just have this difficulty with statements of the form 'everything (in the universe) is made of XXXTheory' followed by statements of the form 'XXXtheory does not cover YYY' I have spent 60 years with the notion that the 'universe' to include quite literally everything. It has been my experience that much misunderstanding has been propagated when someone restricts that definition to less than everything. I much prefer a universe that includes matter, empty space and anything else, warts and all.

Juanrga, Thank you for your answers, they provide useful information. I think you misunderstood my last point. I was not considering the particles (or their localisation or otherwise) I was trying to concentrate on the 'spacetime' between them.

If that is all there is then what is 'spacetime' made of? Does spacetime have an existance independent of these particles? Say there are 4 particles A, B , C, D. If I compare the chunk of spacetime between A, B to the chunk of spacetime between C,D I am applying numbers to it. So how can I apply number to (measure ) nothing?

Do you want to quibble about the numbers or discuss the beef? I think my meaning is clear.

Not in the posted computer program I referred to it wasn't. Edit I apologise you were correct. Looking at posts#84 and #85 I see that this was for a different solution from the one I was looking at, which was your arctan solution. However my original point is still valid. some early computers used truncating not rounding and you always had to be aware which was which in those days. I have long since discarded all my Commodore paperwork so I can't look it up now.

What does this have to do with my comment?

16 elementary particles and 4(?) elementary forces to bind them all.. It's like something out of Lord of the Rings. One problem I have with this description is the question What do the particles exist in? Clearly if 'everything' is to be made of 16 or 60 elementary particles these particles must be 1) Distinguishable 2) Aggregates of such particles must be capable of assembly from these particles and disassembly into them and all the time the individual particles must be clearly distinct and identifiable, at least in a thought experiment. 3) There must be something for them to exist in. 4) This something must be distinct from the particles and must exhibit a clear boundary round each particle. Comments and discussion are invited.

It is strange that we have been debating/ discussing wave v particle v w_p_duality for 170 posts in this thread and we do not yet have an agreed definition of either. The proper way to discuss is to agree such things at the outset so that the argument of each side has something to measure against.

Actually, to be fair, the computer holds the value to quite a few more places than 3. The fault is in the user programming which does not include rounding. I can't remember if the C64 used truncation or rounding when asked to report to a specific no of figs.

But according to The Man, that is the wrong answer! That is it is not pi.

I haven't looked at this thread for some time, but I see you did have a go at the Wallis formula I posted. However you did express some uncertainty in the algebra. With a computer, the easiest way to eliminate the square root is to square the equation. It is perfectly acceptable to square the infinite products term by term and the extra multiplications are no problem to the computer. The idea of breaking the multiplications into a sequence of fractions multiplied together is also good. On squaring the expression becomes [math]\frac{\pi }{2} = \frac{{2*2*4*4*6*6*8*8...........\left( {2m - 2} \right)\left( {2m - 2} \right)2m}}{{3*3*5*5*7*7*9*9.........\left( {2m - 1} \right)\left( {2m - 1} \right)}}[/math]