studiot

Before I go ? Where are you going ? I have no idea where you obtained the formula you posted, but it is just plain nonsense. The equation is dimensionally unbalanced so totally non scientific. go well

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I know I shouldn't, but +1 to Eise. We should all learn to be able to laugh at our ownselves.

I'm glad to see that you are reading posts carefully. +1 I can tell this is a statistics textbook or part of the book because 'population' is special statistics term, like 'null hypothesis.' Now strictly the population refers to the entire set of objects possessing the characteristic or property being observed or measured. It is usually not practicable or sometimes even possible to measure this characteristic for every object in the population, only for some of them. So the observations form a perhaps incomplete dataset called the 'sample'. So there are three variables in play; the population, the characteristic and the sample. An example may make this clearer. Consider a sack of potatoes, or perhaps a pile of aggregate (stones) for making concrete. The sack or the pile would be the population. We might be interested in the average size of the pebbles or the potatoes. That would be the characteristic or property. We could, of course, measure the size of every pebble or every potato but that would be impractical so we take a sample and only measure the sizes in that sample. (Note sometimes we can and do use the entire population say marks for students in a class so in that case the sample is the same as the population) Coming back to your null hypothesis, what we want is reassurance that our sample correctly represents the population so our null hypothesis should be The average size in the entire population is the same as the average of the measure sizes in the sample. We can (should) add to the the 'confidence level' or probability that this is a corrct statement. An alternative null hypothesis is The sample data could have come from the population as unbiased data. This is version is important to check our sampling technique. For example with the pile of stones the larger ones tend to roll down to the bottom at the sides so if we just take a shovel of these we will get an overestimate of the pebble size. So back to your book's statement. "Null hypothesis: Population characteristic = observed characteristic." You can only use the NH in this form if you know the population characteristic as with the average class mark. In which case it is no longer a hypotheses but an identity. Does this help. By the way forming a good null hypothesis can make all the difference to the quality of a statistical analysis.

Does all this have any meaning or is it just gibberish and should I report it as such, as well as breaking the rules here ? I should not need a ytube video to make sense of it.

I'm sorry to need to post this but it seems we are enjoined to give time wasters what is, in my opinion. excessive rope. I put a deal of thought and effort into trying to offer help, at an appropriate level to one such who was a self confessd novice at science. After several tap dancing replies to my moderately lengthy explanations, I was beginning to smell a rat when this person decided to no only question what was being said, but also expound his own gospel of the laws of physics something he had already said he knew little or nothing about, all the while carefully ignoring simply prepared explanations, just for him. What other behaviour would this suggest, other than trolling? I further note that since I and other regular members left the thread in question, he has opened a series of increasingly far fetched new threads.

Upvote Thanks, glad I haven't wasted any more time. Upvote

Exactly. +1

Thanks for the information, how did you get on understanding that energy is not a substance - there is no such thing as pure energy?

Very much so. +1 It's a bit stuffy, but adopting Genady's suggestion. Premises 1) P is a valid statement. 2) We are forming the conjunction of P and itself. (This is a valid statement) Conclusion The statement is invalid For the reason you stated Not because the premises are contradictory, as you originally stated. You are correct, but haven't followed through explicitly using your method for the benefit of the OP.

That's not how I read it, though I will grant you that the opening post is not strictly correctly formulated, as the stated null hypothesis is not actually a null hypothesis at all.

MathML works (actually can be made to work) very well for me here. Not perfectly as there are some things not available in mathjax. But I am perfectly happy to explain how I work it. [math]\sqrt[{15}]{{5983249}}[/math] math]\sqrt[{15}]{{5983249}}[/math MathML does look very similar to LaTex, especially the simple stuff. But the TEX for arrays, tables and more difficult stuff does not. Incidentally there is newer form of MathMl, I'm now having to use on a maths forum I visit called inline mathml. But it isn't recognised here [imath]\sqrt[{15}]{{5983249}}[/imath]

How do you make this out ? (I agree that the conclusion of the proposition is invalid)

It's entirely your choice but I suggest you reflect on your method of discussion. You can see from Dima's tally of negative points that he has had difficulties here. I have had better success communicating since I found out he has to do everything both ways through a translator. Communication thus requires a deal of patience on both sides. But the end result of your spat with Mordred is that Dima seems to have abandoned his own thread. As to this thread, I have been here 10 years now and this is the first time anyone has ever called my efforts to help with post maths as trivial. In my opinion the IT industry could easily have offered the facility to directly type maths in, but chose not to do so for reasons known only to itself. So we are left with unwieldy workarounds for the situation, including learning yet another computer language or languages.

I am saying that whilst the term hypothesis is a general scientific and philosophical term meaning a proposal that may be (is hoped to be) valid, the term 'null hypothesis' is a specifically statistical term that means something more and has to be set in a way that can be numerically compared. There is for instance a form of descriptive statistics that cannot have a null hypothesis. How does that square with the opening post examples ?

I was coming to that but it will entail you knowing exactly what 'energy' is. Being a science novice is just fine; one of the main reasons for this site to exist is for novices to ask questions. So this is not a criticism, but I suspect you think of energy as a sort of thing or substance of some sort. That is not the case. Energy is a property of things and substances. Scientists often say loosely that 'energy is transferred' whilst they actually (or should) know that 'energy transfer' is really an accounting device. 7 take away 3 leaves 4. You question about loss into is similar. I hope you can see that the 3 above does not evaporate into space. As a physical example let us consider boiling a kettle on a gas hob. The burning of the gas raises the temperature of the gas particles, which means they move faster. When they strike the bottom of the kettle they slow down - we say energy is transferred to the kettle, but what we mean is that the impact of gas molecules makes the kettle walls vibrate faster than before we heated them. In turn the kettle walls transfer some of this additional motion to the water inside which means the water molecules now move faster, eventually fast enough to boil. Working out all the maths of this chain of events takes several pages. Far easier to just say X amount of 'energy' is transferred from the gas to the water. So when you are asking about electrical energy dissipated to space what exactly are you thinking about and why do you think the conductance of space (if any) plays a part ? The better you can explain your question the better will be the final answer. Incidentally we do say that all bodies give off and receive electromagnetic radiation at all times which results in a transfer of energy. But this is a thermal process not an electric one.

Since about 3 upgrades ago (thank you IT whizz kids) preview has been pretty clunky. Most folks soon find out that if you leave the thread and then return to the post the missing presentation will be correctly displayed. But no, preview itself often doesn't work. How did you get on with my suggestions about Charmap and super/sub script ?

Indeed not. But then adequacy, internal consistency, external consistency, and fruitfulness are not scientific terms in general nor statistical terms in particular. Think about it. You have already stated the difference between a statistical hypothesis and a logical conclusion drawn from premises., notably you have several hypothesis any of which could account for the data. That is the null hypothesis only ever concludes that the hypothesis could account for the data, and usually that it is the most likely of several hypotheses It never actually concludes that the hypothesis does account for the data. By contrast a sound or valid logical conclusion formally excludes other hypotheses, given the validity of the premises.

Obviously this AI has received some substantial 'training'. or, as you suggest there is a man hidden inside the fairground booth as of old. Responses in other threads simply say that the AI claims to only work within material provided, that it does not have access to 'the internet'. This provided material must have been substantial to output both the earlier poem and Ghideon's test.

A No situation exists This assumes 1) That an undefinened term 'situation' is capable of existing or not existing. and nothing else. 2) That statement A is capable of having a truth value. This sort of paradox caused much heart searching in the foundations of Mathematics, particularly set theory, when they were first introduced and still have not been fully resolved. The only thing we have determined for certain is that some part of the underlying definitions have to be restricted. 'Type Theory' was one was to do this by restricting the nature of what can be a 'set'. my underline and nothing else is another way leading to what is called second order logic, with does away with the 'Law of the excluded middle'. Other ways have also been found but we cannot proceed here until you provide / fireproof definitions that you have been asked for. Note the definitions have been spread over several similar threads by yourself and others have also asked for them.

I'm sure it can, but you can also smile ?

Cool.+1 Move over swansont, CHAP is coming.

Things have gor rather hectic here so it doesn't look like I will make a full reply tonight. Anyway the short form is that the electric force is probably the most important force in our everyday world. Our bodies run on electricity. Chemical reactions run on electricity. If you have a fish tank aquarium, you will monitor the water quality using a conductivity meter. The chemical reactions that cause weathering in the rocks run on electricity so conduction in the earth is vitally important to us. This is not the spectacular lightning storm but none the less all due to a form of conductivity unlike electricity in the power wires in our homes. To expand on this I will need to post some basic explanations so more to follow.

Thanks. BTW, I'm not sure brainee has much access to high school education ( that's no criticism) but is trying to get an education the really hard way.

This is an interesting question that has many ramifications in GeoPhysics, but could you narrow it down a bit ? Also you say conducted, do you know the difference between conductive current and displacement current ? Finally the Earth is far from homogeneous and the values for sigma and epsilon vary with local materials eg seawater v granite.