exchemist

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.

A bit on methane pyrolysis here from Wiki. Apparently this is called "turquoise" hydrogen, being intermediate between "blue" and "green" hydrogen: QUOTE Methane pyrolysis for hydrogen[edit] Illustrating inputs and outputs of methane pyrolysis, an efficient one-step process to produce Hydrogen and no greenhouse gas Methane pyrolysis[30] is a non-polluting industrial process for "turquoise" hydrogen production from methane by removing solid carbon from natural gas. This one step process produces non-polluting hydrogen in high volume at low cost (less than Steam reforming with Carbon sequestration). Only water is released when hydrogen is used as the fuel for fuel-cell electric heavy truck transportation,[31][32][33][34][35] gas turbine electric power generation,[36][37] and hydrogen for industrial processes including producing ammonia fertilizer and cement.[38][39] Methane pyrolysis is the process operating around 1065 °C for producing hydrogen from natural gas that allows removal of carbon easily (solid non-polluting carbon is a byproduct of the process).[40][41]The industrial quality solid carbon can then be sold or landfilled and is not released into the atmosphere, no emission of greenhouse gas (GHG), no ground water pollution in landfill. Volume production is being evaluated in the BASF "methane pyrolysis at scale" pilot plant,[42] the chemical engineering team at University of California - Santa Barbara[43] and in such research laboratories as Karlsruhe Liquid-metal Laboratory (KALLA).[44] Power for process heat consumed is only one seventh of the power consumed in the water electrolysis method for producing hydrogen.[45] UNQUOTE This looks quite promising. I'm not sure what we would do with all the elemental carbon this would produce, though. I have not looked into what applications there are for it. Maybe we just drop it down coal mines. That would be a fitting irony.

Agreed, it will be more costly than the industry price for electricity. But that price won't include the cost of the distribution network, so if electrically generated it could be little more than double the industry price of gas (assuming the marginal kWh will be generated from a heat engine, for some years to come), I should have thought. Alternatively, hydrogen could be generated from pyrolysis of natural gas. The economics of these methods will be one of the things that has to be optimised by competition. But the advantage of hydrogen for heating would be that it would avoid the huge capital cost and disruption to the householder of buying a heat pump and retrofitting underfloor heating to old housing stock. Don't get me wrong, I'm not necessarily wedded to hydrogen as the solution. I just think it has some obvious practical merits for certain applications and needs to be looked at seriously.

Hmm. I am more interested in what we can actually do, here and now, given the infrastructure we have inherited, than in revisiting what we might or might not have done differently years ago. Climate change can't wait for perfect solutions. And in my opinion (not being a man of the left) I think it would be a mistake to expect governments to pick winners. I think it is better for them to encourage different technologies, allow them to compete and over time we will see which ones turn out to have the most scope for optimisation. What I mean by optimisation, in this context, is not merely what is technically best, but all the things in society that enable a solution to gain traction. Then again, we may find it is better to diversify and use more than one route than to put all our eggs in one basket. Other contributors have spoken of hydrogen being "hyped". I must say I am not aware of any noticeable hype around hydrogen. Almost everything I read seems to be about the electric car issue. Not many people are talking about HGVs and those that are starting to talk in the media about domestic heating seem preoccupied with heat pumps, even those these cost 5 times as much as a gas boiler and put out heat at only 50C max, instead of the 65C for which most central heating system are designed. So there are huge issues to overcome to make heat pumps realistic for most householders. On a personal note, I have been thinking of getting a heat pump for my large Victorian house. This will cost me a bit, and will never pay back, given that electricity costs 3-4 times as much as gas, per kWh. However I do draw the line at ripping up all the floorboards as well, to install the underfloor heating pipes required to make the low-grade heat from the pump sufficient to warm the house. Millions of others will face this issue. This is one of the reasons why I can see the logic in converting the gas network to hydrogen, either fully or at 20% dose rate as a medium term measure.

Yes, that's what I assumed he meant by "jelly": the kids' dessert type thing. But I take @zapatos's point that you can make a fruit jelly, i.e. a stiff jam from strained fruit, with added pectin, i.e. without adding gelatin.

Pectin alone allows jam to set, but that is not really jelly. For jelly, my understanding is you need to add gelatin. Temperature is crucial. Jelly melts. To get it to set, you need it to cool. If it's boiling it will never set. But when making jam, you need to reach a certain temperature to release the pectin before you cool it, which is when it then sets. That may be what you have in mind. I'm not an expert on jam, but I do make a ham and parsley terrine, with gelatin, which one buys in sheets that are dissolved in warm stock before being poured over the terrine mixture. But then you need to pop it in the frdige for some hours to allow the gel to form.

I'm sure other income streams also help, but the big boys do hedge - and have been undercut by the people that don't, who are now going bust as a result [cue circus music and clowns]. The rest of your post sounds a bit Irish: "If I were you I wouldn't start from here". But from a thermodynamic efficiency point of view it made no sense in most countries to use electricity for heating of any kind. Norway and Switzerland had hydro-electricity, but the rest of us were stuck with heat engines, so we wasted over half the fuel we burnt before we even switched on our electric fires. (And cooking with electricity is crap, even to this day). It is only with our current knowledge of climate change and 20:20 hindsight that we can reappraise the 60s and say we got it wrong. As I think Charlton Heston's character says in one of the Planet of the Apes films, "We are here and it is now." The issue is what do we do, given the legacy infrastructure and the inertial effects in society we have inherited. It is in that context that hydrogen may have a place.

I find this unconvincing. Sure the risks are somewhat different with hydrogen but I don't see that they are qualitatively greater. Hydrogen may diffuse through a leak a bit faster than larger molecules but then it dissipates more rapidly too. Energy release per unit mass is not the relevant yardstick. Volume is more relevant in practice. There is a piece on the risks of hydrogen here, from a researcher at Washington State University: https://hydrogen.wsu.edu/2017/03/17/so-just-how-dangerous-is-hydrogen-fuel/ The conclusion seems to be the quote from an experienced hydrogen expert: “Hydrogen is no better, nor worse, than any other fuel. You just have to know the rules for working with hydrogen.”

Both, inevitably. Energy is big business, in terms of risk*, capital investment and profits, so it will always be to a large extent the preserve of big business. But obviously the people will also benefit, since replacement of fossil fuel by hydrogen, for transport fuel and heating, offers one way to combat climate change, which will adversely affect the whole of humanity. Big business is run by people too. *The gas crisis in the UK at the moment is one illustration: the small suppliers failed to hedge. And now they are going bust. A few years ago the fashion was to whine about supposedly excessive profits made by the suppliers. Now that the gas price has shot up, everyone is making a thundering loss and only the big companies that hedged can survive, because they planned (and priced) for that risk.

Buncefield. Ronan Point was first and foremost a building standards disaster, rather than a gas disaster: a properly built block would never have collapsed due to a domestic gas explosion. But yes, any inflammable fuel presents a hazard and there will be accidents, though we get better every year at preventing them. What I'm saying is I see no reason to think hydrogen will be fundamentally worse in that respect than the other liquid and gaseous fuels that we currently use.

Unlike you, perhaps, I was not alive in 1927 or 1934, so, er, no, I don't remember these two events. If you have to rake through the history of the early c.20th to find examples - at least one of which was apparently due to criminally negligent safety procedures - I think you make my point for me. Since that time, by the way, there have been great numbers of refinery and fuel storage explosions involving liquid hydrocarbon fuels, in spite of the vast improvements in safety that have been made in the 80+ years since these incidents. But for the application I was discussing, we are talking of hydrogen being blended into methane for heating. I can see no reason to think this would pose a greater risk than methane itself.