exchemist

Agree about the Iranian economy. I read in the Financial Times that they can struggle on for about a year without oil income. Iran is an industrial nation of 90million with quite a lot of other regional exports, not just a bunch of desert tribesmen with oil wells. So they can, apparently, last a year. Whereas the US mid terms are in 6 months and a blockaded Strait ensures higher inflation and fuel prices for US voters. Therefore I imagine Iran can afford to tough it out and wait, while the electoral urgency mounts for Trump. They can see the US public turning against him. They can also see he is going nuts, hence their on-line trolling to wind him up in the hope of further mad outbursts that will damage him further. (He now seems to be doing his best to alienate both the Catholics and the Evangelical Right, quite unnecessarily.)

OK so 0.07N/m. Let's say someone spread-eagled on the water has a total waterline length of 9m. That will generate ~0.6N of upthrust, compared to a body weight , for a (light) 60kg person of ~600N, i.e. of the order of 0.1% of what is required to make them float. But away from the question about floating bodies, yes at the cm scale surface tension starts to make itself felt. I have a badly designed colander with 0.5cm holes in stainless steel and I can never get things in it to drain properly. My parsley, coriander or whatever is always dripping wet, no matter how long it is left to drain.

You mean surface tension, like a pond skater? That would depend on the length of the contact line between water and skin. But surely the effect would be negligible, wouldn’t it?

Erm, that doesn't seem to mean very much, to be honest. I really don't think it's a good idea to bandy around sciency words without thinking what they mean. If all protons are the same that means they do NOT have unique features, surely?

There is a lot of chalk in Dorset, whereas I don’t think there is much in Devon and Somerset. Lying on your back in water can’t increase buoyancy, as that has nothing to do with surface area. Buoyancy is a matter of how much liquid is displaced by the floating object, cf. Archimedes’ Principle. But if you lie on your back with your lungs partly inflated, your mouth and nose should be above the water level, whereas if you are vertical the water level is somewhere around your eyes (I think). It makes quite a difference how much your chest is inflated as obviously your chest displaces more water then so you float higher.

What do you mean by “quantum information”? (I’ve an awful feeling you have been at the woo again😄)

A wave is not energy. A wave has energy, among its various properties. Energy is just a property of a physical system, like momentum. A wave is created by a displacement of some medium from its equilibrium value, e.g. when you drop a stone into a pond and a wave spreads out. Water has been displaced, giving it extra energy and the displacement travels outward in the form of a wave. A vibrating object can give rise to a wave if it is in contact with a medium which it is able to displace. That will absorb energy from the vibration and damp it. A vibrating tuning fork displaces the air it is in contact with, creating the sound waves that you hear. And this will damp out the vibration eventually.

Mr President, what is your Vice President doing (at the height of the Iran crisis, WTF) in Hungary, interfering in their forthcoming election by publicly accusing the EU of.............. interfering in their forthcoming election? 🤪🤡🔫 Has he no sense of irony, or indeed self-awareness?

Dead right. I remember at school and university the stories of deaths and torture by the Shah's secret police, SAVAK. One of their specialities was something called the toast rack, whereby they strapped people onto red hot bedsteads. Ugh. The Shah of course was given great support by the USA and I think NATO. But as you say it all goes back to the overthrow by the US and the UK, of Mossadegh in 1953. Churchill was behind that because of threat to nationalise the Anglo Iranian Oil Company (which became BP). A late spasm of imperialist meddling, well past its sell-by date.

Oh that was just about Gazan real estate for Jared Kushner. It seems to have gone nowhere now that Trump has other things on (the remnants of) his mind.

I'd stay away from the word "vibrations" if I were you, though. It is far too redolent of woo, conjuring up visions of Deepak Chopra and sundry other charlatans.😁 A vibration requires something to be vibrating. It is meaningless to speak of a vibration unless you can say what is vibrating. It's a bit like the common mistake people make about energy. You can't have energy on its own: it has to be the energy of something. I think you are on better ground to think of waves as fundamental entities. A wave is something that oscillates with a frequency. Vibration of an object also has a frequency, so it is a bit similar, but a wave is different because it travels, whereas vibration is oscillating motion that occurs on the spot. But even waves have to be waves in something (in this context a field) that is doing the "waving". These are your excitations of the matter fields. At least, that is how physics currently models matter at a fundamental level. Personally I think it is useful to keep in mind the idea of models of reality, as distinct from absolute claims about its true nature. Mathematical treatment of these matter fields and their excitations correctly predicts what we observe in experiments, so to that extent they seem to be real. But it has to be an open question to what extent they are real or are just a mathematical technique that works. In science, all "truth" is provisional, pending the arrival of a better model. (In chemistry it is common to have more than one model of the same thing. These are acknowledged to be only approximations and are chosen according to how suited they are to the problem at hand.) On your point about information, there are physical properties that are conserved in the course of interactions, so these can I suppose be thought of as information that is carried over. But trying to see "vibration" as fundamental seems to me to be barking up the wrong tree: the only fruit of that tree is woo, I fear.🙂

Bullshit, I opened it and was able to read it without any subscription. Here is the list from that article of the ridiculous conspiracies and quack notions RFK has endorsed: - He claimed vaccines can cause autism - He claimed Anthony Fauci and Bill Gates exaggerated the covid pandemic to promote vaccines - He said covid targets caucasians and black people - He claimed the FDA "suppresses" advances in health - He said wireless technology can cause cancer - He has promoted the theory that AIDS is not caused by HIV - He said fluoride causes diseases - He said mass shootings are linked to prescription drugs - He believes the CIA was involving in John F Kennedy's assassination plus a couple of other things that are a bit obscure to people who don't live in the USA. So he is without question a 6-cylinder nutter. That of course does not mean that 100% of what he says must be false. But it does mean it is useless to rely on what he says.

One minor error is that wax for candles comes not from fuel oil but from the dewaxing of lubricating oil fractions. The residue from the primary distillation depicted can undergo vacuum distillation to produce lubricating oil feedstocks. The vacuum distillates undergo either solvent extraction to remove aromatic compounds (Shell uses, or used, furfural) or hydrotreatment (to convert the aromatics to paraffins), which leaves a highly paraffinic material. This is then dewaxed to produce lubricating base oils with an acceptable "pour point" (i.e. so they don't set solid at low temperature because of the presence of paraffin wax). The residue from vacuum distillation undergoes an additional process known as de-asphalting, to get rid of "asphaltenes", which are high molecular weight, fused-ring aromatics. This residue becomes "bright stock", the most viscous grade of lubricating base oil. Actually, wax is generated from the older solvent dewaxing process, which uses a solvent such as methyl ethyl ketone (MEK) to precipitate the wax, after which the solvent is boiled off again for re-use. There is also a more modern alternative known as catalytic dewaxing, which uses hydrotreatment to break up the long chains of paraffin wax into shorter paraffins with a lower pour point. So that doesn't produce wax as a byproduct. Residual fuel oil (RFO), which is produced by simpler refineries without a luboil train, is the stuff burnt by large marine and power plant diesel engines. This is quite challenging to use as fuel, as it needs to be hot in order to flow, is often full of sulphur which forms sulphuric acid when burnt, corroding the cylinders, and asphaltenes, which are tarry substances that can gum up parts and block filters. It also can have vanadium in it, which erodes the valves in an engine. But it is cheap, which is why big ships and power stations use it. Engine designers and luboil manufacturers go to great lengths to overcome the challenges of burning this stuff without damaging the engines. Turbines are unable to burn it. They need distillate fuel or gas. But of course a steam turbine can be fed from a boiler burning RFO.

“….of Nazareth”. As Pilate wrote on the inscription on the cross, according to the gospels. In fact it seems we do not know the first name of Pontius Pilate. Romans had three names, praenomen, nomen and cognomen. Pontius was the nomen or family name. Pilatus or Pilatos was the cognomen, a sort of nickname, which in his case may have meant skilled with the javelin (pilum).

With hydrocarbons, none. The residue from distillation is sold either as residual fuel oil for ships or processed into bitumen, or via further vacuum-distillation to produce lubricating base oils. The sulphur removed from distillate fuels is also sold. In some cat cracking processes surplus carbon is generated as petroleum coke. This can also be sold for a number of purposes. When I first joined Shell and went on the induction course, we were introduced to the "carcass of beef analogy". The butcher buys a whole carcass and divides it up into valuable and less valuable cuts of meat, plus bones and offal. All of these can be sold for some kind of price, though many of the cheaper cuts command a price that is actually less per kg than was paid for the whole carcass. But even though these may look at first glance as if they are sold "at a loss", it make sense to sell them for whatever you can get. They can be seen as "byproducts", with some value though not very much. So it is with crude oil. It gets converted into multiple products and byproducts but all have a price and can be sold.

Well, the Iranians, calculating chess-playing Persians as they seem to be (whatever happened to “mad mullahs?), will see this as evidence of mad desperation on Trump’s part. I expect they will troll him, to wind him up even further in the hope of eliciting more psychiatric outbursts, while feeling a degree of satisfaction that it must be dawning on Trump that he has trapped himself. If Trump goes after the civilian utilities necessary for life, like water and electricity, that would be a war crime. I expect it was objection to committing war crimes that got the head of the army sacked the other day. I understand the top military Catholic chaplain has said as much and now Hegseth has banned Catholics from his ghastly prayer meetings. (I expect they can live with that😁) This is real Loony Tunes stuff now.

Yes, that would make sense certainly. I had never thought of the sea as giving off sulphur compounds but that seems to be the case.

Silver tarnish is mainly sulphide though, I think. When we lived for a while in Houston we found silver items tarnished appallingly fast, due to the sulphur compounds in the air from all the refineries in the region. Back here in London it is far slower. I have not heard about silver tarnishing more rapidly near the sea. I wonder what would cause that. Yes in chemistry the term oxidation has expanded its meaning from the original one of reacting with oxygen, e.g. Fe + 1/2 O2 -> Fe ²⁺ + O²⁻ to a more general class of reactions in which electrons are abstracted, either physically or notionally, from the substance in question. I include notionally because the concept of oxidation states treats all compounds as if they were ionised, even if they are really bound covalently. For instance in SiO2, silica, Si is assigned an oxidation state of +4 and oxygen -2, even though it is a covalent compound with only a fairly modest degree of polarisation of the Si-O bond δ⁺- δ⁻ . I had to look up haemoglobin. It seems to be an interesting case that is quite complex to unscramble. It appears that indeed Fe is regarded as being in the +2 state and is oxidised to +3 by the coordination of an oxygen molecule. But it's odd, as the molecule adds to Fe obliquely, apparently using one of the 2 lone pairs (sp2 configuration) at one end, as a dative bond towards Fe. There seems to be in addition some kind of back-transfer of an electron from Fe to oxygen, creating a superoxide anion ,O₂⁻ , which is an odd electron species! The net result is that Fe formally acquires an oxidation state of +3. I'm actually quite intrigued by this but have not had the time to read more about it. Perhaps someone else here knows more about this.

You can make cars from aluminium, which does not easily corrode. However it is costly to reduce from its ore, which is done by electrolysis, because it is trivalent, needing 3 electrons per atom. So it takes a lot of electricity. Most aluminium smelting is done close to a source of cheap electricity. In fact aluminium is only stable in air because it instantly forms a protective oxide layer on the surface. Unfortunately iron tends to form a complex range of hydrated oxides in the presence of moisture which don't form such a layer. You can make car bodies from other materials but metals are preferred, partly because of strength but partly too because they can be designed to deform progressively in a crash, protecting the occupants. In practice, car bodies are made from various grades of steel. This is not simply iron but an alloy of iron with carbon and potentially a variety of other elements, selected to modify the properties of the steel in various ways. Steel is generally more resistant to rusting than pure iron. Surface treatments such as galvanising may also be used to improve corrosion resistance.

Hmm. I suspect you have misunderstood what was being said. After all, the universe is what it is. It seems fairly daft to suggest it has flaws. What seems more likely is someone was describing flaws (inconsistencies, unresolved problems) in our models of the universe, as @TheVat suggests. But then that would not explain this metaphysical stuff you mention about God. So it is all a bit baffling. If you can’t provide a source I think we have reached a dead end.

I've been listening to a few things to practice for the Holy Week Triduum. We sang this one today (Good Friday): It seems the attribution to King John IV of Portugal is, ahem, contested. But it is still an atmospheric, simple piece for Good Friday.

That’s not cavitation then. Cavitation involves generating a vacuum (strictly not quite due to vapour pressure of the liquid), from a surface moving too fast for the liquid to remain in contact with it, e.g. propeller, pump impeller. If you use air pressure to displace the liquid that isn’t cavitation.

As I understand this is either different from liquid column separation, or possibly a feature of the first instant after column separation, due to the nature of the “fractured” surface, which resembles a broken bitumen surface, i.e. not a smooth liquid phase surface.

No. If you look at the picture this fracturing is a jagged break like that you get when a solid material fails.

To a rower, Surrey and Middlesex mean the Tideway.