studiot

No, homongenous and flat have greater significance in SR. Here is a good piece from Turner (University of Sussex)

Thank you for this, I wasn't aware that Einstein contradicted himself so completely. +1 But then perhaps these were just fireside musings a process many thinkers on the subject have indulged themselves in. Did you read more of this article ? On page 176 he says But then on the next page he says But he does not explain how something that has no physical properties can be either isotropic or homogenous. I have offered to describe non controversial standard theory about your claims but since you wish to dismiss them and substitute what I consider wild assed guesses of your own which would be fine if you were to follow the rules of speculations and provide solid derivations and other evidence of their validity. I will leave you until this happens or a moderator starts closing threads as being outwith the rules.

That could be a reasonable question except that matter refers to any particle with mass. (which for your information means not photons) A neutron is a particle with mass that has no charge. A Uranium atom has only 92 protons and 92 electrons but 143 - 146 neutrons. I would be very grateful for a proper reference to any of Einstein's writings or lectures stating this ?

Small wonder your understanding of electrical phenomena is all over the shop. Without going into sub-nuclear particle physics which would add nothing to the clarity here are my answers. Charge is the basic property possessed by some, but not all matter to which we attribute electrical phenomena. At all levels of analysis we call matter which posseses this property a charge carrier. When charge carriers move from place to place we call the flow of such carriers a current. By itself no energy is involved in a single particle of matter possessing a charge. The energy arises as a result of interaction of two or more charges. When two or more charges interact, they set up a potential field which we measure as a voltage. Grounded is an adjective describing a ground or earth which is a circuit theory term not a physics term referring to a circuit node or point which does not change in voltage regardless of how much current flows into or out of it. Please note it is possible to have a current without a voltage or a voltage without a current. Please ask about any terms used above that you are unsure of or did not understand.

Excellent answer +1 Joe you have an number of threads you have left hanging, all of which suggest you need to review some basics. What do you understand by:- Voltage Current Charge Grounded ? You need a clear picture of what these mean before you can progress to the answere to the questions you are asking.

In general I would agree with you but how about tristate logic gates ? https://en.wikipedia.org/wiki/Three-state_logic

1) Have you ever heard of fuzzy logic? 2) Even in first order logic it is not always possible to conclude that a statement is right or wrong, have you ever heard of the liar paradox ? Apart from the mathematical versions of the above examples, what about statistics and probability ?

I did decide to punt another reply into your thread to see what happens.

Why ? I don't see a reply to my welcome post.

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

Speak to a moderator, you can send them a private message by clicking on 'staff' at the top of the browse page then clicking message under their avatar.

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 ?