studiot

Like so many classification schemes, phenomenological v noumenoligical is very limited and incomplete. Yes I agree the idea is good and can serve a useful purpose, but I still consider that the plain old English concrete v abstract nouns covers more situations, which do not require the causal connection of ph v nou. For instance I have just used a couple of abstact nouns (classification) schemes and ideas. Is there a causal relationship between the idea and its realisation ?

Thanks for the reply and links. I thought you might be interested. I was wondering what sort of printable material would withstand rocket launch and propulsion techniques. PS I did my first bit of plastic welding repair recently, to a broken laundry stand boss. Was not so successful with my second repair attempt to a broken freezer handle.

Yup MigL has said it simply Nothing wakes up one morning and decide I am gong to 'evolve'. There is a whole formal theory of rock structure evolution. I don't agree. The Romans had piped fresh water and centrally heated buildings. 2,000 years later do we have better?

@Sensei get your 3D printer out and see what you can do. This rocket nearly made it. https://www.bbc.co.uk/news/science-environment-64893578

So what do you mean by evolution ? Do you mean change? That is a perfectly acceptable usage. Rocks 'evolve'.

Not too sure about any of this. The tread is entitled Human Evolution. Isn't this a strange idea ? After all if we evolved would we still be human ? I suppose it depends what you mean by 'evolution' ?

Actually the OP described a function since it used a letter for a variable, not a specific number. It is important to distinguish between a function and the value of that function at a specific point. A square root of a number is another number, a square root of a function is another function. So a square root of 4 is 2 and another square root is -2, all of which are numbers. Folks also often make this mistake with the differential calculus, where the derived function (the derivative) has, possibly different, values at every point where the original function is differentiable.

I agree wholeheartedly that deadly sins numbers 2 (greed) and gluttony (6) are between them the biggest obstacle to be overcome. +1 As regards the second part of you statement I think the size of the world population makes little if any difference to this stark fact. Have you come across the doctrines of Schumaker (Small is Beautiful) and Allaby (Limits to Growth) ? https://en.wikipedia.org/wiki/Small_Is_Beautiful http://www.herinst.org/envcontext/limits/writings/ecologist.html They are very attractive to well balanced, well motivated human beings. The only real drawbacks to these doctrines is that thay have no answer to threats from so called 'Military-Industrial' societies.

Your mechanical base variables can't be for instance time, velocity and acceleration. There would be one 'missing' variable in your set of 3. In fluid mechanics force, length and time are often used instead of mass, length and time.

I really don't see why either of these wild assed guesses (the other being that nonsence about gravity and heat) have not been move to speculations where they undoubtedly belong. They are most certainly not in accord with Physics theory, modern or classical. What do you mean by an electrical circuit ? Do you mean a complete loop or the more colloquial use of the word circuit as an assembly of electrical components ? Whilst it is conceivable that there could be an electron beam connection between the Earth and the Moon - like a giant cathode ray tube - I think that to well beyond our present technology. There is no natural process to achieve the same effect available, although we do receive natural charged particles from the Sun.

I know you can write more than repeating you first very short question. This one sided communication is becoming very tiresome.

No idea what you mean by this ?

For a single variable, yes. But you can't pick any old set of variables to fill your quota.

Even then it may still be fiction, depending upon how it is derived. Good points +1

A very complicated question. They allow dual Which makes things even more complicated. For one thing the Dutch still have a form of (military) conscription. For another they have an annual wealth tax. But they do not have inheritance tax.

I agree that there are a great many individuals in the world that feel powerles by themselves and actualy resentful of the fact that the literally can't make a different whatever they do. I certainly feel like that. This is especially sad since the totality of such folk is probably actually what is often referred to as "the silent majority". Our society actively promotes greed on a massive scale and this, combined with beaurocratic obstructionism and downright fraudlent secretism and (mis)use of public resources for private gain. 1% or 4% ? Well I suspect the scandalous cover up of Drax has much to do with it. is Drax bio friendly or very very bio unfriendly ? I sympathise with the planning refusal, especially as 6000 solar cells for the whole of your company's requirements, would not be so vey many. We have larger solar farms in the south west already. But there is currently an argument from objectors to a new one, because standard application practice has become to simply show the panel array and not mention the complex of ugly battery housing containers that are necessary to make the project viable. Yet this is nothing compared to the way the state supports new 90% of the oil drilling finances in the North Sea, whilst offering exactly zero support for solar and wind alternatives, unless they service a tax deductable drilling platform. I was shocked to learn this - source a recent BBC Countryfile investigation.

It doesn't usually rain organic solvents. To add to what exchemist said and what you may be thinking about. Plastics do not take part in many acid - base or redox reactions in normal environmental conditions. This is unlike many other materials, from wood to metals to soils etc. This is why the are considered less reactive but as has been pointed out in the right environment they are every bit as reactive.

In case you think this is purely academic showing off, here is a practical use of the cotangent, much used in cartography and surveying. https://en.wikipedia.org/wiki/Tienstra_formula

Here is a section of questions from an old trig textbook, involving the use of the secant, cosecant and cotangent. If you look in tables of standard integrals you will find these fromulae employed to solve the integrals, as swansont says.

I suggest you have a large shovel of salty skepticism when you read about Pearson and his work. Both the man and his work were coloured by extremely his extremely polarised views of the sunjects he applied his mathsmetics to. He was an able mathematician and a leading developer of statistics in the abtract world, although he was rather overtaken by Fisher (who has a pseudonym - Student) But I think him less than expert in the subjects he dabbled his purist maths in. Particularly what we now call anthropology and biology. I doubt any real influence on Einstein, whose mind and social inclinations were from an entirely different stable. Interesting he was, like Eddington, a of Quaker stock, although I think not a Quaker himself. I say be careful of what you read because for instance here is some rubbish, dated 2021 from Michigan Technical University, advertising their Masters in Statistics. The "top ten statisticians of all time", in which they include Pearson. https://onlinedegrees.mtu.edu/news/top-10-famous-statisticians I ) They claim Florence Nightingale as an American ! 2) They omit Thomas Bayes completely. Some better links are to the BBC DVD about the relation between Eddington and Einstein https://en.wikipedia.org/wiki/Einstein_and_Eddington and a more accurate historical link about the relation between Pearson and other statisticians and world events. https://errorstatistics.com/2018/11/30/where-are-fisher-neyman-pearson-in-1919-opening-of-excursion-3/

Rejoice for thou art living in the modern age. In your last question about concentration I told you that different disciplines use different measures of concentration. It was even more confused in oder times as chemists used equivalents and normalities, - you can still come across these measures. So beware of using the term 'equivalents' or is equivalent to. How can 100 grams be equal to 100 mL ? grams are not millilitres. In fact what you mean is that 100 grams occupies 100 mL or 100mL weighs 100 grams, neither of which is true except at zero concentration. So please, for you furute sake, try to be more precise with your wording. But, I said rejoice because solutions of sodium chloride have a density that is very close to that of water. In fact you can get density tables and calculatiors on the internet these days to find the exact weight of 100mL of solution or the exact volume of 100g of a given % solution. https://www.handymath.com/cgi-bin/nacltble.cgi?submit=Entry

Here is a scary sketch to show why it doesn't work that way. I have shown a tree and a human in appropriate scale. Around the green treetop I have drawn a circle showing all the light reflecting off in all directions. I have also shown a really tiny sector showing just how little of that light hits the eye of the human. The rest misses completely. As Eise said it is a question of optics as to how the human can see a clear image not a blurry mixed up one, so long as he has normal eyesight. Does this help ?

I don't know what they paint bridge steelwork with in America, but the UK standard uses a 7 coat MIO recipe. MIO = micaceous iron oxide. The obviously thick paint contains tiny flakes of mica which diffuse the incoming lightfrom penetrating as far as the base steel. Sadly the coulour pigments used are almost exclusively battleship grey or puke green. British Rail has experimented with some brighter colours. I have experimented with some modern alternatives and every time I drive up the motorway I look to see how they are going. I can see no visible degradation 25 years on.

My Ebay lists 60 pages of them.

Well congratulations, I really hope so. +1 If I might offer a final piece of advice. Next time try to focus on what yoy need to know for one aspect of analysis at a time. I know everyhting joins up in the end but that is only when you have covered everything. Trust you helpers to help narrow this down with you instead of rambling about all over the whole subject of analysis or functions of a real variable or whatever you wish to call the subject.