studiot

A simple answer to the issue of antimatter is that yes it is in some sense the opposite of ordinary matter. That is because it was introduced to be exactly that. No more and No less. However that does not mean there is no room in the universe for some other entitity that is neither matter nor antimatter. All that is required is some evidence of this entity. So it is perfectly legitimate to postulate the existance of such an entity or entities and search for it (them). Scientists in the past have done exactly that, sometimes with success, sometimes not. Phlogiston, Philosophers Stone, Vital Force, Aether are examples of failure. Positrons, displacement current are examples of success

If you have access to X-ray equipment I'm sure you have access to proper computers so that you can post a serious and considered description of the problem. Until then you are wasting my time and yours.

Imatfaal, Thank you for explaining more details of the article, which, as I already stated, I was unable to obtain the full text. Yes I agree, (my post#13) that this was wandering off topic. However if you look back through this thread it is clear that I have been castigated (gently) by one moderator for not posting my thoughts And also by a different moderator for posting my thoughts. Ah well sigh!

I call it an attack because each time you reply you run away from or duck most of my previous post and pick on one point to well -- attack. This, coupled with the comment of the other moderator who obviously did not read my question as he or she made no effort to answer or discuss it, has driven away genuine discussion. Cap Refsmat has recently been deploring the low membership / activity here. Do you think this will help? In this case you are promoting a far to narrow view of the word measurement. The output of a measurement is clearly going to be set in appropriate units. Some units are numbers some are not. Of those that are numbers some are confined to the integers, some are not. Each and every occurrence of a given phenomenon is entitled to its own measurement, with its own accuracy. Precision is not necessarily applicable to an individual measurement, despite what you claim. It may be that as a result of a series or set of measurements (in the plural) further conclusions may be drawn. This does not alter the output of each individual measurement. But I'm sure you know all this so why the argument?

That's because they are too busy enjoying the emergent fruits of these chemical phenomena like ice cream and candy floss and whisky.

Thank you for this and your earlier comment, ajb. You did indeed read what I thought was my very clear question and provided your answer. I will have to investigate Heisenberg's original work because I had the impression that the principle arose in another manner. So if I find your history correct I will have learned something new.

This is just plain wrong. There is no other way to describe it. The count is an exact measurement. Period. It is, however true that you are very unlikely to achieve the same count in a repeat of the experiment. This is not due to the inability of the observer to measure correctly and with absolute accuracy. It is due to the inherently variable nature of the process involved. As to the ridiculous comment about how much copper (how many grams or whatever) was in my pocket? If asked in an examination how many pennies I had in my pocket and I replied I have 35 grams how many marks would I be awarded. Answer : an exact number - zero. Because I didn't answer the question asked. All this, is however, getting further off topic. If the BBC report claiming that the uncertainty principle had been disproved, which I investigated and posted the best information I could find, is true then it is at least as important as the recent claim of FTL neutrinos. Since I do not have much access to North American data I had hoped that there would be those here who do and have sufficient interest. However so far all that has happened is that I have been attacked by two moderators.

With respect, you are the one ducking the issue not I. Radioactivity measuring decices used to be called counters for good reason. Counts and counts per second or counts per area or volume have long been established as perfectly respectable units to measure in many areas of science, besides radioactivity. However there is the possibility of uncertainty in some forms of counting. For example yesterday I looked in the field and said to my friend, the statistician, "I see four horses" She replied "How many? I see two foals, a stallion and one pregnant mare" go well

Surely you can see that charge is the odd man out? It is the one physical quantity that we can only measure integral units. So far as we can tell (and that includes Plank units) there is no theoretical barrier to indefinite subdivision of the others and so can be measured in real valued units. We can also see this at the macroscopic scale, for instance the number of pennies in my pocket. I can achieve an exact measurement of this quantity, any time I like. Please bear in mind this was in response to an all embracing statement (not yours) that there are no exact measurements - a statement which I hold to be too strong to be accurate.

Can you explain exactly what you mean? I thought the value of the charge on one electron = the value of charge on one electron exactly, (if I measure charge in electron charges, not coulombs)

If I measure the charge on an electron in 'electron' or (proton) charge units surely I can measure with absolute certainty? Furthermore I have always understood the Uncertainty Principle to apply to ideal thought experiments as well as real ones.

Yes I make it that as well.

You are certainly getting the correct formulae from somewhere, but is it not explaining what is going on? Any two vectors that intersect (meet at a point) define a plane. If you draw a parallelogram in that plane with the two vectors forming two of the sides The cross product of these two vectors gives the area of that parallelogram. The third vector converts the parallelogram to a parallelepiped with volume equal to the perpendicular distance between the base area and the slant height (which is the length of the third vector). This, of course is the dot product of the third vector with the cross product of the other two.

http://prl.aps.org/abstract/PRL/v109/i10/e100404

Yes you got it. The three numbers are the (x,y,z) coordinates of the head of the arrow for each vector. You can draw each vector as a line from the origin to each point. The direction of the vector is the same as the sense from the origin (0,0,0) to that particular point. Geometrically they can be thought of as three edges of a parallelepiped that meet at a vertex placed at the origin. They are examples of what is known as the position vector. This describes a line from the origin to any point in space by a vector, thus allowing us to define any point in space by a vector and any set of points by a set of position vectors. Being able to describe any point in space in this way allows us to use vector algebra and calculus to calculate useful things like the volume of the parallelepiped. However I suggest you get a good hold of these basics before going on to this.

@stringjunky Do you mean to say you can't understand plain English? Or would you like to discuss your post #31?

Messing about with (the english) language for effect is one thing. But, for me at least, you have surpassed yourself thereby loosing the meaning in your last post.

I should take heart, the shadows over modern generations are much shorter than the one I grew up under. In the 1950s and early 1960s we grew up expecting to fight a major nuclear war. We thought that it was not a question of if, but when. It is to the credit of all sides that it never happened.

Gosh, how does anybody prove a notation? Sure not? Incidentally I don't think I have ever seen a maths proof that runs "assume X to be true and because......Y, Z are true or defined, X must be true" Normally this works for disproof ie "Assume X is true and show a contradiction ... Therefore X is false" Proof by Induction works on the basis of "demonstrating that X+1 must be true if X is true"

Museums often divide up their space into themes or categories. For example Science and Technology in the Service of Man Science and Technology through the ages Important figures in Science and Technology Frontiers of Science and Technology and so on I don't know where you are but are there any local or national heros in Science and Technology? Are there any local/national industries or observatories that deserve special mention eg an astronomy telescope? Interactive exhibits that measure personal perfomance eg a cycle powered generator that shows output as a function of effort are always popular with youngsters - There is alwys a queue for this sort of exhibit at the Science Museum in Scotland. Finally it is a good idea to allocate some space for changing exhibitions and some for fixed exhibitions.

too open minded your are an example to all, my congratulations to the youth of today. I say this because you are clearly demonstrating the ability to hold a respectful discussion with others. I feel that is making more progress than the offerings of many older posters are achieving.

Where is it? Where are the cracks in it? How big is it? Is it in the lab or part of an aircraft flying at MACH 2 or what? Ultrasonic testing equiment relies on an acoustic coupling medium to the specimen. At this temperature you will have to look for a new one, perhaps a high temperature industrial grease.

Actually this argument is another perfect example of some technical person or persons hijacking a perfectly well defined term from either the general languague or another technical discipline. Then later persons changed it again. The British Navy had a perfectly clear definition of the term evolution before 1790. An interesting question is: The original (species) 'definition' attributed all change to random events, without premeditation. We now have the possibility of a species interfering with the development of itself or others. We have recently discussed this idea here at SF.

Ultrasonic testing is the cheapest. What is your budget? What is the access to the specimen. How high is 'high temperature' ?

I believe Darwin introduced 'biological evolution' in 1838 with the publication of 'natural selection' Mendel did no publish the basis for Alleles until 1865. Today we perhaps have another more modified definiton So the definiton of 'evolution' is itself evolving!!! So why cannot this process continue and tomorrow too open minded be the scientist who introduces the newest definition?