exchemist

Article in today’s FT says sentiment on the street in Iran is one of national solidarity against outside aggression (they have 627 dead thanks to Israel’s attacks), not one of rising up against the regime. They are particularly incensed by outside aggressors telling them what to do about their own politics, apparently. Well, well, what a surprise, eh, who could have predicted that? - apart from just about anyone with an ounce of feeling for history. So this operation has probably set back the cause of the moderates and modernisers.

I’ve asked you a question already. Kindly answer.

I was not aware of such a trend and would find it rather alarming. Where can I read about it?

No I think it drifted East down towards the Thames estuary on the prevailing westerly wind, where, according to legend, a police constable in S. Essex radioed the police station saying "Sarge, you not going to believe this but....."

I think KJW's point about wave functions representing a state of knowledge about a system, rather than set of physical properties, is key.

I think the point is that the non-locality of entangled states in QM does not imply any sort of interaction between different spatial locations, as you are suggesting.

In what way do you propose inertial mass varies in space, and/or time? Have you a mathematical expression for this? (Please note you need to post your answer here on the forum rather than referring me to an off-site link, as that is against forum rules.)

I remember that one. Melanin seems to act as a radical scavenger as well as absorbing UV. So it is apparently capable of mitigating the effects on the body - at least on the skin - of ionising radiation, by mopping up some of the free radicals generated.

Darwin’s principle, as I recall it, was variation plus natural selection. That seems a good description of both the cod case and the ash case. And also that of the peppered moth, too, which is often held up as the classic example. Fair enough. Here you go: https://www.science.org/content/article/incredible-shrinking-cod

Why not also post the report about N Sea cod evolving to be smaller, so they escape through the trawl nets of fishing boats?

If you suggest the radius decreases, do you mean the density increases, i.e. the mass remains constant, or do you mean the density stays constant and the mass decreases?

Yeah I just get tired of the facile scapegoating, when CO2 emissions are due as much if not more to Henry Ford and his successors as to Rockefeller and his. After all it's not like cigarettes when the product is inessential and promoted by the manufacturer as a fashionable lifestyle accessory. We objectively need oil and gas. Weaning ourselves off it is a huge collective effort in which all, including oils and gas companies, have a part to play. Demonising one industry to make the rest of us all feel better gets us nowhere fast. In fact, it just delays the realisation that we all need to make changes. Also if these companies have a role to play, let's encourage them to play it, not chuck bricks at them all the time. On CCS, I think it is pushed by various CO2-intensive industries, including fossil fuel power gen plants, cement, glass, steel, etc. All of them of course would prefer not to have to change their fuel source or, in the case of iron smelting, the whole chemical process, especially if government might subsidise the process. The thing that stands out to me, and this applies to shipping too, is the alternatives very largely require hydrogen. (Ammonia for ship fuel is a way of handling large quantities of hydrogen more safely, basically: you burn it to N2 and water.) The really transformative technology we desperately need is high efficiency electrolysis.

Ah yes, from your handle I imagine you must have a thorough grasp of all this. But I'm intrigued by your view that it's about excusing environmental degradation because we can tell ourselves it's not real. That's a new angle. But nothing to do with quantum computing and the measurement "problem" in QM.

Hmph. I don't trust anything emanating from Greenpeace. I know for a fact that they are happy to misrepresent the truth for publicity purposes cf. Brent Spar. They are also one of the prime actors seeking to blame the fossil fuel industry for our carbon-intensive lifestyle, a deeply hypocritical exercise in blame shifting to a suitable "other" we can settle back and safely hate, as we carry on driving our petrol cars, heating our homes with gas and whining about the price of "gasoline". Oil and gas companies are willing to do CCS because they know how to do it and have the depleted reservoirs to hand. Secondary extraction is not intrinsic to the economics. But it is not cheap, that's true enough. When I was at Shell we had a pilot project to do this for the UK government about 20years ago, but they pulled out after we had spent $1m on it. No secondary recovery featured in that. It's not greenwashing, it is real and it might help to bridge the gap during the technology transition. However I would always be worried that CO2 buried in this way might somehow find its way back to the surface over time, so I wouldn't want to see it become a major component of the moves to carbon neutrality.

Hmm, interesting to look at it this way. A cargo ship may burn of the order of 50mt/day of RFO, 85% of which is carbon. So roughly speaking it will produce 150mt/day CO2, generating over 300mt/day of limestone! There's going to have to be an awful lot of both quicklime and limestone on this ship for a voyage from Singapore to Antwerp.

https://www.theguardian.com/environment/2025/jun/26/global-shipping-emissions-invention-clean-up-cargo-fleets-net-zero The idea here is to use quicklime (Calcium oxide, CaO) to absorb CO2 from the exhaust of ship engines, generating calcium carbonate (CaCO3, limestone, chalk etc). And they speak of using renewable energy to power the kilns that generate the quicklime. But, er, the kilns generate CaO by driving off CO2 from calcium carbonate. So all you've done with this proposed technology is move your CO2 from the ship to the shore; you still now need to dispose of it, somehow. I don't see in the article where this issue is addressed. Does anyone know more about this? Is this idea designed to work in conjunction with CCS, perhaps, i.e. disposing of the CO2 in depleted oil and gas fields? If so I suppose it could have a role as a bridging technology, before shipping is converted to ammonia or something. But then CCS is yet to prove itself, so a number of imponderables here.

Yes I think you and Degrasse Tyson raise a good point. All this "simulation" talk we seem to get does look to me very much like a fad caused by the new domination of our lives by IT-based products and services. Speaking as someone who never saw "The Matrix" and who has no social media presence (apart from 2 science forums), I have never understood what the fuss is about or seen any point in it.

According to this: https://en.wikipedia.org/wiki/Humanzee. there have been reports, at various points, of attempts to produce a human-chimpanzee hybrid. However none of them seems to have ever been confirmed. So its does not look to me as if there is any evidence of whether or not such a hybrid would be viable. Obviously the ethical issues involved would preclude such attempts in any civilised society. And the notion of "using" a human being with Down's Syndrome to try it is especially repugnant, as well as having no scientific foundation that I can see. People with Down's Syndrome have an extra copy of chromosome 21. This does not make their genetic make-up more like that of a chimpanzee: in fact rather the contrary, as it is fusion of the apes' chromosomes 12 and 13 that leads to the reduced number in humans, nothing to do with no. 21. So I should have thought having an extra no. 21 would make a person more dissimilar to a chimp, not more like one.

What I’m getting at is you can’t have an orbit at a latitude of, say, 40 deg North of the equator. It would have to be one that went from 40deg N to 40deg S and back in the course of one revolution. That’s because every orbit has to be centred on the centre of the Earth, at that is what gravity pulls towards. So if you had one like that and another that was equatorial, they would intersect at 2 points per revolution. So they would have to be at different altitudes to avoid colliding.

OK I see. I think the difficulty with putting dust into an Earth orbit will be that you could only put the dust into one narrow band, e.g. around the equator, since to cover different latitudes would need a series of different orbital paths that would clash, unless you had a complex system with different orbits at different altitudes. I'm not sure what orbital dynamics would do to an orbiting dust cloud. One might think that small differences in speed of individual particles would eventually make it unstable, but this is not my field so I don't know if this would actually be a problem.

I’m not quite clear whether you are proposing to introduce graphene powder into the upper atmosphere or into space. If the former it won’t stay there, due to atmospheric mixing and eventual precipitation. If the latter, i.e. into space, you would need to establish an orbiting dust cloud in effect, surrounding the sun, at some radius from it. That would need a lot of powder, it seems to me, and a lot of energy to give the dust the right orbital speed.

As the Financial Times observed in a piece by their Washington correspondent, Trump is, for all his macho bluster, in fact just following Netanyahu's game plan. It was Netanyahu who blew up Trump's Iran diplomacy and Netanyahu who talked him into a strike with the bunker buster bombs. Netanyahu is in the driving seat here.

They have always been rational actors, as far as I can see. It seems to me all this "existential threat" stuff is just part of the relentless diet of Islamophobia fed to the US public by the Israel Lobby (of which this "Middle East Forum", referred to in the OP, is a part.).

What mathematicians do you have in mind?

Which is to say in places where the roads remain at the service of the people, rather than being the exclusive preserve of motor vehicles.