studiot

Thank you both for these answers. My original LED lights were fitted before almost 10 years ago and are still going strong. These were complete light fittings, not just plug in replacement bulbs, which are much more recent. My experience with the replacement type is that they do not live up to their promise and Zap's description is all too familiar. A further thought occure to me. Light bulbs of any description are not particularly high current devices. However LED types really need a much lower voltage than UK mains so perhaps the lower American mains voltage lead to a longer lifer in the voltage reduction circuitry ?

I note you have posted this in 'Relativity' What connection to relativity are you looking for ? And what do you mean by 'constrained' ? Yes there is are a collection of hypotheses (strictly - not theory) called the 'block universe'. I say collection because there are variants of the hypothesis. https://www.google.co.uk/search?q=block+universe&source=hp&ei=p7IfYY3OHNGE8gLou4_4AQ&iflsig=AINFCbYAAAAAYR_At-KaN5C9DL025ykI-HzjO5l0zHKu&oq=block+universe&gs_lcp=Cgdnd3Mtd2l6EAMyBQgAEIAEMgUIABCABDIFCAAQgAQyBQgAEIAEMgUIABCABDIFCAAQgAQyBQgAEIAEMgUIABCABDIFCAAQgAQyBQguEIAEOgsIABCABBCxAxCDAToRCC4QgAQQsQMQgwEQxwEQ0QM6DgguEIAEELEDEMcBEKMCOggIABCABBCxAzoOCC4QgAQQsQMQxwEQ0QM6CwguEIAEELEDEJMCOg4ILhCABBCxAxDHARCvAToICC4QgAQQsQM6CwguEIAEEMcBENEDOhEILhCABBCxAxCDARDHARCvAToLCC4QgAQQsQMQgwFQhhFYtihgslNoAHAAeACAAc4DiAGsGJIBCTUuMi4yLjIuM5gBAKABAQ&sclient=gws-wiz&ved=0ahUKEwjNva_e3r_yAhVRglwKHejdAx8Q4dUDCAg&uact=5

Good question at this time I don't know as previously I simply swopped them into place as old tungsten or CF bulbs failed. So I really only checked at the end of their life.

Can anyone tell me why the new update has change the way the list of members online is presented ? I didn't realise just how useful the popup of what they are looking at really is until now.

Does anyone have any experience in the failure modes and comparisons with the offered lifetime and real world time to failure of the replacement bulbs ? Since the introduction of LED replacement bayonet and screw fitting bulbs I have seen several fail prematurely. I have also noticed they run hotter than I expected, though not as hot as incandescent. I think I might start to dissamble any more that fail to find out what why they failed. Coupled with the hotter running I have noticed three that have started to flicker before failing, suggesting that it is not the LED that fials, but the driving electronics. Comments and experiences of others are welcome.

My post about the BBC article and some of my other material has really been to highlight that most, if not all, of these matters have been tried before, some of them long ago. Yet no one seems to be prepared to analyse and learn from past experience.

You are right it was my sloppy use of language. I should have said The set {1} is part of the partition set of S so is a subset of S but not a member of S. This difference between the use of 'partition' in the physical sciences and in mathematics strikes again.

I still say that hybrid orbitals only occur in bonds, not free atoms. And the actual hybrid varies depending upon the actual atoms concerned. Here are some simple examples of the maths.

It is you attitude which impedes progress. I said, "I think that........" I did not try to lay down the law. Your response could have been that you think you do understand set theory perfectly and so you wonder what I mean. Instead you tried to lay down the law. I agree with this first statement. But this second statement is inaccurate. This means that the set S must contain sets as members. Which is not a requirement of set theory. The issue of failure to distinguish between subsets and elements is further compounded by your sudden switch from elements to members. The number 1 is a member, but not a subset of your set S = {1,2,3,4} The partition {1} is a subset of S but not a member of S. I don't take kindly to the attitude that you know everything and no one else knows anything. Particularly as you are introducing mocking irrelevancies such as "byspel", which are no longer funny.

Oh dear. I really thought the new forum upgrade included a change from plain English to Runish. Is that not the case. Frightfully sorry.

I think you misunderstand the meaning of disjoint in set theory. This should be cleared up prior to any other consideration.

It's always useful to have an idea what the update is supposed to achieve. There are some very knowledgable members here in respect of It matters so their input can always be considered valuable. For my part there was a prefectly understandable update announcement early this afterennon, in place of the usual site itself. When the site returned I noted that the information about members online / offline had changed its presentation. I really hope that the various clocks and timers are now coordinated so that members are not still shown as online half an hour after they have left, and the timing of post nn longer suggests that replies occur before the question is asked.

The future's good. the future's rosy. So they said back in 1910 https://www.bbc.co.uk/news/business-56748346

Since you have heard of fission can you not answer my polite and simple question ?

Contrarywise the opposite is obvious to myownself. So I executed three half turns widdershins to compensate. Yourowngoodself introduced the law of the excluded middle not yourstruly. In direct and fullsomeness of answer to your supplication for an exemplification Here is a spel from the great book of the WikiMaester. https://en.wikipedia.org/wiki/Three-valued_logic

'Or something' is correct. For instance take the sd3 hybrid in the OP. What s and what d orbitals are involved, and why. In say potassium permanganate why are the perfectly good and valid solutions of Schrodinger changed in the manganese atom ? This is what I mean by half a question. Hybridisation arises because the environment of the atom (ie the orbitals in the rest of the atoms in the compound) make it energetically favourable. Manganese atoms do not wander around on their own configured in the sd3 condition. So we need the full information to be able to help. And the OP (who has been back since I last posted) seems reluctant to help us to help himself.

I would go further than this, if @LUFER is really interested in discussing sp or any other hybridisation further. Lufer, you do realise you have only asked half a question? If we have solutions to the Schrodinger equation as s and p etc orbitals, why do we need hybridisation ? Under what conditions will hybrids arise, they don't happen by themselves?

Has your education reached the point where you know what is meant by the term 'critical mass' ?

Do the Irish also have a not proven verdict ? There was an interesing discussion on Quora about 'yes and no' in other languages, Apparently two negatives do not make a positive in some languages (e g Russian).

Can you post the full question ? And also follow the rules by telling us what you have done so far? I am with exchemist on this (+1) as what you seem to be asking is Nobel Prize level work. A bit steep for SF Homework Help.

and other posts. No city has successfully solved the mass transit problem, though some have been more successful than others. Your 1000 passenger estimate is only possible in any mass transit system I know of by can only be done by cramming passengers in, as they have to on the London Underground. It is interesting to note this statistic: One Eurostar train weighs 800 Tonnes, carries 800 passengers (if full) and would clear 800 yards of one lane of the M25 (London Orbital Mororway). I am suggesting the best solution is to (drastically) reduce the number of needed journeys by a mixture of actions. Such change cannot be brought about overnight, just as the build up of needless journeys took time. Of course there are wholy unacceptable solutions offered by totalitarian states, such as the one the Harlequin I mentioned earlier lived in.

It's not alone there; Latin also doesn't have exact equivalents of "yes" and "no" afaik. Thank you for your response and the extra information. Latin, however does not have the superior scottish legal system that overcomes the inherent difficulties you are putting forward in first order logic. That is it the law of the excluded middle is not always valid and inappropriate use leads to many of the so called paradoxes in Philosophy, just as you have done here.

Like the London Underground you mean ? How many people can you get on such a train ? So how many trains would you need ? And what would you do with them for the rest of the day ? And what is the minimum timing interval between running several such trains on a line? So have you really solved the peak demand problem ? Transport orgasnisations have been wrestling with this problem since there were transport organisations. The History of the London Experience is particularly illuminating and is the reason London grew to be such a large urban area.

No you didn't you obviously believe in a Nirvana of model citizens. But at the same time you have singularly avoided my real points, particularly the one about peak demand and the one about safety. Peak demand and unnecessary journeys are linked to current planning theory which dictates we build huge housing areas widely separated from workplaces, thereby causing millions of unnecessary journeys every day. Why is the Amazon superwharehouse not located in the Middle of Edinburgh? A more sensible approach would be to remember the dairies of yore, most of which operated a fleet of electric delivery 'floats'. A good start would be to force all (perhaps large) distribution operation supermarkets to emulate them, reducing the several thousand cars that can be counted in the car parks of my town, during most days of any week.

I freely admit the toothbrush example was extreme for effect. However the topic is about making existing cars more efficient (and deciding what that means). Substituting other forms of transport, limiting their use and so on is surely off topic ? However I view greater 'efficiency' as fraught with perils. And rather insulting to motor engineers as well. I well remember the time when some practical people had the large square Volvo estate and many more aspired to have one but could not afford to. You could get a (several) standard 8 x 4 sheet into one of those. Volvo used to advertise their safety record, as their cars were built safe and sturdy all round. However they were heavier than average and less aerodynamically efficient. So they were less fuel efficient. Yes you can make an IC car more fuel efficient by reducing the panel size, doing a way with the chassis, load capacity, reducing the size of battery it has to carry and many more such savings, perhaps remove the aircon. But such vehicles are demonstrably less safe to drive. Now let us look at this dream Let us say you live in a dormitory town/village of say 15,000 working people. There is such a town near Exeter. Now let us ask if 10,000 of those people want a car at 0830 in the morning to get them to work (in Exeter) for 0900. Now let us consider that Mr Smith's car arrives, but the last use was to ferry four drunk students home the previous night. Not only were they drunk but they went by the curry takeaway and left all of their rubbish in the vehicle, and two of them threw up into the bargain. Who will police this ? So let us look at reducing uneccessary journeys from the point of view of the uneccessary journeys police. Should the right of 5 million football fans to attend away games every week be curtailed ? This would certainly reduce the 'efficiency' of trnasport systems by taking something away. And how about the uneccessary journeys police ? We recently had that high profile case of "Is it necessary to drive up to the (nearby) Peak District for some mental health well being during the Covid pandemic. The efficiencies always affect ordinary folks whicls the rich and powerful are insulated. The BBC did a recent freedom of information act survey of our government departments concerning which Ministers and Ministries were 'environmentally friendly' and published some very sad results. The Department of the Environment has no (yes zero) electric or hybrid vehicles. Boris will not give up his diesel (yes polluting diese) car. Nor will the Minister of Transport and many more I give you the words of whoever wrote the short story Repent Harlequin, said the Tick Tock Man