exchemist

I thought there was also another reason: you need a transition dipole moment, which a free electron cannot provide on its own. But that’s just what I have understood from quantum chemistry.

It seems to me the first issue you would have to address would be how to deal with the point made by @OldTony that, if it were a trunk piston engine, there would need to be a slot cut in the side of any cylinder, to accommodate the motion of "connecting rod 2" in your diagram. Clearly that can't work, so a trunk piston design is ruled out. I presume you could deal with that by a crosshead type of design in which, say, a pair of opposed cylinders is joined by a horizontally moving piston rod, connected by "slider 2" acting as a crosshead. But that will take up quite a lot of space. Have you given any thought to this issue? Maybe it could work in a marine engine, where space is not a critical issue. One advantage of it could be the long throw of the pistons, compared to the crank, which could give a long expansion for each power stroke, giving greater efficiency. Marine crosshead engines can have stroke:bore ratios up to 4 for this very reason. But then, in marine applications the propeller speed is generally low compared to IC engine rpm, so something that doubles the rpm is not what you want. On reflection I think I could perhaps more easily see your idea working in reverse as a pump, in which the crank drives the pistons. What I struggle to see is how this can give a "fast" engine. With IC engines the challenge is usually to bring the speed down, from the high speeds needed for combustion to the speeds needed for motive power. The exception is marine engines burning residual fuel oil, which can work with engine speeds as low as 75-100rpm, at which speed they are directly coupled to the propeller, avoiding the need for a gearbox that can handle outputs that can be in excess of 40MW. But then you don't want to double the speed of the output shaft.

Yes, it is irrational to be concerned about trace amounts of alcohol.

No, I meant contamination of the planet by micro-organisms from Earth, i.e. we should not introduce contamination to the planet.

Avoidance of contamination. We would go to great lengths to investigate it by means of carefully sterilised probes (unmanned of course).

I read that in the FT, which wryly commented that Bezos had a meeting with Trump the day the non-endorsement was announced. These oligarchs are falling into line behind Trump, one by one. When the chips are down, what counts for them is the prospects for their business and their personal fortunes. After all, democracy is for the little people. Peter Thiel has a survival bolthole in New Zealand if things get too hot in the States, having taken out NZ citizenship as a precaution. And Musk is trying to buy votes, on Trump’s behalf. These individuals are out of control.

So nothing like a ton, then. But lucky you. It's fairly non-toxic and melts in the hand (at 30C) which is rather fun. It is also one of the very few material that expands on freezing, like water. So a rather splendid curiosity. Seems very odd it has been left behind though. What kind of lab was this, do you know?

Even for gamma rays that won’t achieve anything. Two sets of waves encountering one another at an angle will just pass through each other and emerge on the other side unchanged.

The laws of nature don’t impose any limit on the viability of electric vehicles. IC engines have managed to serve us quite well, in spite of the severe limitations on their efficiency imposed by the 2nd law of thermodynamics on heat engines, a limitation EVs do not suffer from. There is no reason to think that EVs cannot compete - as is clearly shown by the sales statistics I quoted previously.

What I do remember is the story of the teacher saying that, while two negatives make a positive, two positives still make a positive. To which a voice at the back of the class remarked: "Yeah. Right".

I only know one word of Finnish, which is hissi, for a lift. I used to go regularly to Vaasa, to visit Wärtsilä, who make a lot of the world's big marine and powergen diesels and for some reason that word stuck in my mind from the hotel I used to stay in.

No. Post the theory here, in line with forum rules.

My French mother in law thought an aeroglisseur was an “overcraft” in English, because it went “over” the water (in this case the English Channel/la Manche). The joke of course is that the way someone with a French accent would say “hovercraft” is more or less “overcraft”, so she had laboured under this misapprehension for years without anybody noticing.

This being a science forum, it is unlikely there will be experts on this subject here. Have you tried a religious forum? There seem to be plenty of them around.

I'd want to check very thoroughly any statement from an organisation calling itself "Gun Owners of America", because it is obviously a lobby group. My experience of US lobby groups (from when I worked in the oil business in Houston) is that they often present a crassly one-sided picture of the situation.

Ha! Don't talk to me about amines. I once had to take my French mother in law's fridge, at the holiday house in Brittany, to the déchetterie after it had failed 6 months previously......... with several packs of her coquilles St. Jacques in the freezer compartment. They had turned into a sort of black sludge. The only way I could cope with cleaning it out without throwing up was to think as hard as possible about amine chemistry. You never know when - or how - your degree will come in handy!

You need to have an idea of scale here. Molecules are of the order of 0.1-1 nanometres (nm) across. Viruses are of the order of 100nm and bacteria about 10x larger than that. Viruses and bacteria are made of molecules. So fairly obviously a molecule cannot carry a virus or a bacterium. I have not looked up the evolution of sense of smell, but given that smell is widely used in the animal kingdom to detect what is good to eat, it seems reasonable that part of that would include the identification of what to avoid because it would make the creature ill. But the way you phrase the question seems to be in terms of what an individual organism has learnt, from experience. That may be part of it but a sense of what constitutes a “bad” smell is instinctive. We all agree on bad smells - and sometimes even train ourselves to override them, e.g. in the case of certain aged or fermented foods like strong French cheese or game.

You still don't get it. The "those" you refer to are not just a handful of research scientists but include all the major automotive corporations in the world. Hundreds of billions of dollars are being poured into this technology each year and sales of electric vehicles are already almost 20% of the total: https://www.iea.org/reports/global-ev-outlook-2024/trends-in-electric-cars There is no reason to think there is any significant limit, from the science or engineering viewpoint, to the potential of EVs to replace all IC-engined private vehicles. The constraints are mainly economic and political. The economics improve as sales volumes increase and as the technology advances. The politics have also greatly improved. Most European and Asian governments have now got behind the technology change. The laggard is likely to be the USA, at least if Trump is elected again. The chemistry of battery technology is one major area of development. The other is the engineering of vehicle charging: the infrastructure, the possibility of charging on the move, linkages to domestic solar generation, electricity tariffs linked to time of day and so forth. And then there is the big question of commercial vehicles. These are a lot harder to convert to EV technology, due to the power requirements exceeding what batteries can easily deliver. The answer could better batteries, or current collection on the move, or hydrogen-fuelled IC engines.

What, then, is the "strange pattern" referred to? If you can describe that, it may help us grasp what is meant in this context by bias. If it simply says human brains are biased to prefer simple explanations to more complex ones, surely that is no more than restating the principle of Ockham's Razor, is it not? Do you want to criticise the principle of Ockham's Razor? This is still unreadable rubbish, I'm afraid. Do you think it makes a useful point? If so perhaps you can summarise what it is. Or did you copy the link without reading it yourself?

Your misunderstanding is to think in terms of “particles”. As @CharonY says, the smell is due to volatile molecules, not macroscopic particles. It is an evolutionary advantage for animals to be able to detect these molecules at low concentration, either to avoid contact with decomposing flesh or, in the case of flies, to be attracted to it to lay their eggs on it.

This looks like yet another of your attempts to cast doubt on the viability of EVs, while pretending to be in favour of the energy transition. I do not think it worthwhile to address the issues you mention, as I no longer accept that you are posting in good faith. -1.

That link is unreadable shit. Have you a version that one can read without all the imbecile whizzo graphics?

Perhaps you could post a summary, or abstract, as text, on the forum.

Ah so that’s what this is about. I didn’t realise Bezos was also into entertainment. This handful of oligarchs really do insert themselves into every aspect of our lives. And now one of them is trying to buy the US election, ironically on the pretext of “saving democracy”. 🤪

Your emphasis on fear is misplaced, in my view. You ignore the appeal to people's better nature that is found, both in civil society and, even more strongly, perhaps, in religion. It is perverse to claim that religion is all about retribution for wrongdoing. The basic message of the Christian gospels is to love your neighbour. Christ set an example through his behaviour. Similar sentiments encouraging altruism are to be found in other religions. It may be that your exclusivist Calvinism is all about retribution, but that is not true of most religion. Secular society also sets great store by people's sense of "the right thing to do". Most people comply with laws because they realise at some level that we need rules of behaviour in order to get along. People have quite a string instinct to help one another, as a matter of fact. We saw this vividly during the Covid pandemic, for example. A lot of people are looking for an excuse to make friends and be nice, not by any means only people with strong religious faith. On the other hand, one can certainly have forces that encourage selfish or hateful behaviour towards others. Trump's appeal, for instance, is largely because he makes it seem normal to hate other people and actually encourages it. He empowers people to cast aside their civilised constraints and indulge in an orgy of hatred. So yes, I would agree there can be kind of "Lord of the Flies" effect, leading to a descent into savagery. A lot is to do with the prevailing mood and with the example set by key figures. (Orwell recognised this phenomenon with the "Two Minutes Hate" sessions organised by IngSoc in "1984".)