studiot

If the fluid is as viscous as you say, you can drop marbles or ball bearing into a graduated tube (plastic is safer) about 300 mm tall and time the fall between marks with a stopwatch or good wristwatch. You should be able to calibrate the tube (or its twin) with standard two stroke oil its viscoscity is tightly controlled. That shouldn't cost too much.

The method you refer to is known as the falling sphere method and is fully described in BS188. However for liquids as thin as water the sphere falls too quickly to time accurately so a falling piston fitting the graduated tube more closely is used as this drops more slowly.

Has anyone read Godel or studied fuzzy logic or the colouring problem with cellular automata lately?

I still don't like the use of the word 'condition'. In engineering there is a term 'condition factor' which is just one of many ponderables in the modern method of design known as 'Limit State Design'. You may not be aware of this, I would be happy to elaborate. I still haven't finished reading your article so there may be more to come. Here is one typo paragraph 5 current supercomputers have no enough memory : correction not

So we have the same idea. I hadn't fully read that far in your article, perhaps I will read more now. I think it is useful, important even, to identify the fact that a system may have one, several, many or even an infinite number of states available, but can only occupy one at a time. Obviously the separate elements of an aggregate can individually occupy different states as I have already noted.

music, was there something wrong with my last post?

Suggest a better alternative would be A scientific state is any single? uniquely identifiable? condition in which a scientific system can exist. This then allows you to usher in discussion about the probabilities of any given state and partition functions etc. Whilst I have no problem understanding what you mean, like John Cutherber I don't like the term scientific very much. I don't see that its use adds anything. I also realise that defining 'state' succinctly is a difficult task and that any resonable definition is likely to end up rambling on. I think replacing it with a near synonym like 'condition' is not good either. 'Condition' really means something slightly different. To me the state or list of states available to a system is composed of a list containing a value or the range of values attainable by parameters or properties of interest. These properties may be directly observable or deducable from observables. I hope this helps and I hope this thread does not degenerate like others recently. This is an open invitation to all to cooperate rather than confront.

Let us leave it that Physics is the most highly mathematical of all sciences (after maths itself of course).

Which means both Science and Physics in my book. In fact the full question was Only = exclusively. To which your reply was Since that post was a direct reply to my question aboveI took the emboldened part to mean yes.

I did say necessary. Of course measurement add much to the description but necessary? Let us go through them. rock Geologically rock is all the material that makes up the earth below the atmosphere, even water is a 'rock'. You have hard rocks and soft rocks, rocks tha flow and so on and so forth. leaf Well I'm not a biologist but I do believe there is something to do with ' an outgrowth of a stem of a plant which engages in transpiration and photsynthesis' concrete A mixture of aggregates that form a structural shape due to particle interlock, held together by a binding medium. support Well I don't need a single measurement to note that a table supports a book resting on it. foam A gas entrained in a liquid. I think that suggesting physics is only measurement is a bit like suggesting that Euclids geometry is only the five axioms or postulates. With Euclid there are 23 definitions and a further five 'common notions' So it is with other sciences. I have suggested several abstract 'common notions' such as sequencing and interlock which also play a part in science and even physics. I am sure ther are many more. Finally I return again to sequencing or ordering as it is directly relevent to Greg's question.

Go on then, what measurements, are necessary to distinguish the geological term 'rock', the biological term 'leaf', the materials science term concrete, the mechanical term 'support' and the chemistry term 'foam' By 'necessary' they have to be necessary and sufficient in the strict logical sense. In other words they have to be the only way to arrive at a conclusion that an object or idea is one of these.

I was so taken aback by the approach from a forum mentor that I thought I would not bother further. However the original statement did say 'science' not just physics so I included examples form several sciences. One of these was indeed physics, perhaps if I tell you that a support is very well defined in a branch of physics called mechanics? However I have thought of some more physics examples. What is the measurement necessary to define a crystal? I maintain that there is something non measureable that is particularly relevent to Greg's quesition. That something is order (not as in statmech) but order as in Let us suppose I have a fence comprised of posts set in at random intervals. Let me now walk along that fence painting the numbers 1, 2 , 3 etc on the posts as I pass them. To avoid being accused of counting them say I do not finish. Now let there also be a gateway in this fence and when I come to post 11 it is the first gatepost. What number do I paint on the second gatepost and where is the measurement?

It is more usual to prove that the locus of points where the tangents are perpendicular is the directrix to avoid solving a quadratic and is an equivalent question, (this was Dog's proof) but here goes one proof. Let the parabola be represented in standard form [math]{y^2} = 4ax[/math] Then the directrix is the line [math]x = - a[/math] and the tangent is the line [math]y = mx + \frac{a}{m}[/math] Let the point of intersection of any two such tangents be the point [math]{x_1}{y_1}[/math] Then the equation of any tangent through this point is [math]{y_1} = m{x_1} + \frac{a}{m}[/math] Rarranging we see that this is a quadratic in the slope, m [math]{x_1}{m^2} - {y_1}m + a = 0[/math] But we are told this lies on the directrix as well so satisfies [math]{x_1}=-a[/math] therefore substituting [math] - a{m^2} - {y_1}m + a = 0[/math] From the standard properties of quadratic equations [math]{\rm{product}}\,{\rm{of}}\,{\rm{roots = }}\frac{{{\rm{constant}}\,{\rm{term}}}}{{{\rm{coefficientof}}\,{{\rm{x}}^{\rm{2}}}}}[/math] So this quadratic has two solutions [math]{m_1}{m_2} = \frac{a}{{ - a}} = - 1[/math] Which is the condition for the two lines to be perpendicular

The topic asks about advantages and disadvantages of organic farming. I originally listed the ban on modern vetinary intervention by organic farming as a disadvantage. I will now add the judicious use of modern pesticides and fertilisers. Unfortunately we cannot trust the use to be judicious rather than indiscriminate.

Chasing the Molecule John Buckingham 2004 Sutton Publishing Good for your purposes because it integrates chemistry with society, but not comprhensive.

I don't. However neither do I see the point of verbal sparring with someone determined to avoid the issue. So I will confine myself to asking John Cuthber again for those recipes he tantalising dangled in front of us.

Unless the beef buying public can be guaranteed that there is zero BSE in the beef, why should they buy it? What politician would offer otherwise? Clearly there is none in clean replacement animals after total destruction of infected ones and disinfection of living space.

Oh, come on. By the definition of 'immune' there can be no occurrence of the infection within the herd. If there is an occurrence the herd is, by definition, not immune.

Its pretty obvious that the herd immunity must have lapsed or the disease would not have re-emerged. Did you mean innoculation not immunity?

Surely this is by definition?

I'm sorry but I can't agree with this view. What is the mathematical definition of 'rock'? What is the mathematical definition of a 'leaf'? What is the mathematical definition of 'concrete'? What is the mathematical definition of a 'support'? What is the mathematical definition of 'foam'? All these and many, many more have precise definitions in some branch of science or another. I think the issue is worth discussing.

Arete, If you 'vaccinate' the non infected part of a herd, how long before you can guarantee that none of the animals have any infective material? John Cuthbert This extract gave me that impression on first reading. I am sorry if I misunderstood it but that was my first impression so others may also have made that assumption. BTW do you have any good recipes you'd like to share?

Excuse me, are you suggesting that Science in general and Physics in particular can only define or describe things in terms of measurement? Surely this is a bit restrictive?

Yes so am I. However we don't go round eating sufferers from those conditions (I hope). Neither will a vaccine cure the disease once a suffer has contracted it. Please read the whole of my post next time. The last one concluded Which puts a different perspective on my statement from your partial quotation. John Cutherbert Why should there not be a vaccine for a disease because it is of non bacterial origin? Perhaps you think the smallpox vaccine does not work either? It is ironic that the original smallpox vaccine came from cows.

It's too late to vaccinate. (((perhaps this should be a new pop song for Eurovision?))) After the disease has taken hold. But yes I think we are too slow to vaccinate animals in the UK.