exchemist

Yes, I've used one of these for about 20 years as well. As it still works, I have never taken it to bits to look at the mechanism. But I bought one for use in a holiday house on an island in Brittany, where the cooker uses bottled propane and I found it didn't work. I'm not sure if it was the humidity - I find it works less well in a humid atmosphere - or whether the spark is simply not energetic enough to ignite propane, for some reason.

Then do some reading, you lazy so-and-so. Nobody here is going to do your assignment for you. The world doesn't need a dud oncologist who cheated his way through medical school. If, having done your reading, you have specific questions, that's a different matter.

I don't think vague is the right word. There are questions the theory does not answer, but that is something different. Like any theory in science, the big bang theory is rooted in observation and testable by observation. It cannot answer questions for which no observations are available. Science is always limited by that. In science, you can't just make stuff up.

This appears to be textbook psychiatric word salad: https://en.wikipedia.org/wiki/Word_salad

Hmm. Interesting possibility. Though not many casement windows in my parents' Victorian house. They were just about all sash windows- except in the kitchen, actually.....

Yes the top screws onto the knurled bottom as shown. Too light for a paperweight - they only weigh 14g each. When the top is fully screwed home, the end of the threaded spindle protrudes through a hole in the top. You can see this in the left hand example. This just might be a possibility, though when fully screwed in the thickness of paper it would bind is only 3mm. No, the split is just a groove running round the circumference. It seems to be decorative - unless it is for a missing O-ring, I suppose. Or indeed for a band to passed round both members of the pair, as you suggest.

Does anyone have any idea what these are? I have a pair of them, made of brass (no jokes please!), about 1.5cm, 5/8" diameter. Each one comprises an upper and a lower half, which screw together. They look as if they might function in rather the same way as a pair of cufflinks, but obviously they are not cufflinks (too heavy, too cumbersome to screw together on a shirt cuff.) I wondered if they were weights for holding down a tablecloth outside, but you'd need to make holes in the corners for the threaded part to pass through. So that seems unlikely. They came from my parents' house, so probably something used half a century or more ago.

Electricity requires a flow of electrons through a material. The electrons in covalently bound molecules are generally not free to flow throughout the structure, so no conduction of electricity occurs. (There can be exceptions, notably graphite, in which the π-orbitals of the fused rings of carbon merge to form a conduction band, allowing the electrons in those orbitals to flow.) As for magnetic properties, yes, electrons can create magnetic fields, due to their intrinsic angular momentum and sometimes also due to orbital angular momentum, if they are in orbitals that have this - many do not. But simple creation of a magnetic field does not imply that electricity is generated.

Bear in mind that the rate expression depends on how the rate-determining step of the reaction mechanism arises. In the case of the decomposition of acetaldehyde, it tells you something about the reaction mechanism, in the pressure regime considered. Pressure can affect the order of reaction kinetics, cf. Lindemann-Hinshelwood mechanism. Secondly, nothing in the information supplied tells you the temperature at which these reactions are taking place. N2O5 is a gas above about 50C.

Ask yourself: what is the dependence of the rate on the concentration of hydrogen? And what is the dependence of the rate on the concentration of ethyne? And take it from there. What do you think?

Then it is unlikely to be able to run many of today's apps in any case. This is certainly the case for my 7 yr old G3 iPhone. It does have a camera but it is full of dust inside and takes terrible pictures, so it would have no chance of scanning a QR code, even if it could run the app.

Hydrogen is not a metal at normal temperatures and pressures. It has been predicted to be metallic under tremendous pressure, but so far no one has been able to demonstrate this reliably. There is something that runs through the Periodic Table known as the "metal/non-metal diagonal". This cuts through the p-block, but if you extend it to the top left, it would cut through the s-block too. So it is not necessarily the case that because H sits in the s-block it has to be a metal. After all, some versions of the Periodic Table also place He in the s-block. Essentially, the ionisation energy of hydrogen is too high (i.e. the electron in the 1s shell is too tightly bound) for it to be metallic.

Gosh, I bet you eat rusty nails in your porridge as well, like Desperate Dan in the Dandy.

Since this is a UK adaptor, I would expect it to be fused. That would stop it drawing a current that was unsafely high. The lowest fuse setting in the UK typically is 5 amps and the highest 13amps. 13amps at 240V corresponds (W =Vi) to 3kW - enough for a powerful electric fire or kettle. If your blanket is drawing no more than 60W each side then the combination is 120W which draws a current of 0.5 amps. This is equivalent to 2 bedside lights and is well within any safety limit - and any fuse that may be fitted in the adaptor.

This is called "sealing wax". Details of composition etc here : https://en.wikipedia.org/wiki/Sealing_wax You can buy sticks of it. But I wouldn't use it to take an impression, because to do its job of sealing it has to stick to things, obviously.

What is hard to understand about the Wiki explanation of what it is? Archaeology, which is one of the disciplines it uses, involves some scientific techniques. Egyptology is the study of ancient Egyptian civilisation. That puts it among the Humanities, I would have thought.

I don't think the acceleration appears to be less to the remote observer, if he is doing his experiment competently. If he is competent, I think he will calculate the acceleration using a clock on the planet, not one in his lab, in order to correct for the gravitational time dilation effect.

It is interesting to me that you are so concerned about people using the side effects of these new energy systems as an argument for delay. I must say I see little or none of this in Europe. The various arguments are about pros and cons of alternatives, not to stymie progress but to make sure we go into them with our eyes open to the side-effects, and some plans in place to deal with them . This is historically not something the human race has been very good at - hence the crisis we now find ourselves in. Nuclear is a case in point. We probably have no option but to retain nuclear as part of the energy mix for electricity generation, but we need to be aware it is probably the most expensive option, if we include full cradle-to-grave costs. None of these alternatives is problem-free. Myself, I think that is a good argument for backing several horses rather than trying to pick a winner: there may be further unforeseen consequences with any of these routes.

Is there something about this you would like to discuss?

An internet search for this returns a large number of sources quoting such numbers, many of which look fairly authoritative to me. It would not surprise me, given how tiny capillaries can be. But in the end such numbers are pretty meaningless: it's just a matter of scale. I mean, you can be amazed, if you are that sort of person, to be told there are 6 x 10²³ molecules in 18 gms of water. But, frankly, so what? Ditto @dimreepr's contribution. Gosh wow, er, or not.

Haha. That was some idiot, probably Bozo, wildly speculating about a quick alternative to the US-UK trade deal that Biden had just told him he could forget about, at least for the next few years. Brexitter true believers are desperate for a big trade deal, now that the UK has lost access to the EU Single Market, so Bozo probably wanted to show them he was still trying. After 24hrs reflection, Downing Street dismissed the idea. (Accepting a take-it-or-leave-it package, containing all the elements the Brits wanted to avoid in the bespoke deal we are now not going to get, is not going to work in UK domestic politics.)

Put the bong down.

He was referring to liquid hydrogen. Most transport fuel systems store hydrogen compressed as a gas. Storing it cryogenically as a liquid creates a lot of problems, maintaining the temperature, dealing with boil-off gas and so forth. And, as he mentions, the same is true of methane for transport fuel, which is stored as CNG not LNG.

I had in mind air to water as well. OK so that is £8k for the heat pump vs £3k for a gas boiler. Not as bad as my £2k vs £10k figures, then. Plus you had to add extra tanks and get bigger radiators. Or was that all part of the £8k? Seems remarkably cheap if it was all included. And it was made feasible by a government grant of £5600 payable over 7 years. So you are out of pocket until then. But you are right, this is now off-topic, so if I want to interrogate you further about it I'll do so on the other thread. Cheers.

OK, what should the relative cost for heat pumps versus gas boiler be, then? Or where do I find the thread where you posted your numbers. I was working off £2k for gas boiler and £10k for heat pump. I'd be delighted if I can get a heat pump for £4k.