exchemist

There was a cartoon many years ago in Private Eye showing the king on the beach and a couple of chaps in viking helmets regarding him. One is muttering "silly cnut". Though actually the story is supposed to be Cnut pointing out to his obsequious courtiers the futility of attempting to command the sea.

Well there seems to be an extra from Lord of the Rings at 32:30......... Seriously though, why are you watching crap YouTube videos, now? YouTube is full of this sort of stuff, with computerised voiceovers like this one. The "creature" looks to me like a devil's coach horse beetle, one of the rove beetles. Some clown seems to have made a mock-up of one, the size of a small dog and intercut it into the film along with footage of a real one, taken in a way that disguises the scale. The animation of the dog-sized one is very poor - as bad as 1970s Dr Who. In other words, you've been had. Here's a picture of the insect:

I always thought the derivation of Schrödinger's equation relied on the idea of a particle with kinetic and potential energy. Is that incorrect, then?

But not Europe, for some reason. But then, we have our crop circles, the Loch Ness Monster - et le Dahu, bien sûr. 😁

OK the crack about anal probes was a bit below the belt - as it were - I admit. But look, photographs have been faked long before Photoshop was born or thought of, and I don't really want to watch a long video on a subject I am highly sceptical about. Bigfoot, ghosts, the Loch Ness Monster and similar stories show that people dream up all sorts of weird explanations for things they think they have observed. Nobody has yet produced any coherent, corroborated evidence for any of this, in spite of stories having been around for decades, let alone any kind of explanatory hypothesis that can be tested. In the case of the 1950s flying saucer craze, what is known is that there was widespread worry - hysteria even - about communism at the time, in the US. There were lots of movies about aliens landing and taking over, as a metaphor for fear of the communists. I ask myself why did these stories almost exclusively relate to the USA? Why not other countries? It seems to me the most credible explanations for those UFO stories are in the realm of social psychology, rather than hard science.

No we don't assume a conclusion, we accept one. That's what we all do, all the time, when we don't have ready access to the data in question. We rely on the findings of others who have looked at it, ideally people with some relevant expertise in the field. The basic problem with these claims is the lack of reproducible evidence. Thy are just aerial Bigfoot stories, basically: anecdotes from individuals that have not been corroborated by anyone with a record of competence or objectivity, mixed up with photography that may well be bogus and can't be verified. When you also take into account the lack of a credible hypothesis for why any of this stuff might be what its proponents claim, (e.g. why would aliens visit some obscure place in the US Midwest, carry out a couple of anal probes and then bugger off, without attempting to communicate or leave a forwarding address?), one is entitled to be sceptical. These photos you have produced are famous old flying saucer pics from the 1950s. That's very disappointing. Is that really the best you have?

Actually, on further reflection, if @Janus were here he'd probably be telling me I'm going about this all wrong and that the real mechanism of depletion is the stripping action of the solar wind on the outer atmosphere (ionosphere?), like the way a diffusion pump works.

Of course, the cognoscenti among us drink real ale, which has not been artificially carbonated in the first place.... Which is just as well, as I dislike roasted peanuts (though I do like the fresh ones.)

Too much salt can give you high blood pressure so yes. But no need to avoid it completely: if you do that everything will taste horribly bland. The best advice I can give you is to avoid ready meals of any sort, and especially highly processed ones with a long list of incomprehensible ingredients. Manufacturers tend to use various tricks to make their stuff seem appetising, which may involve various sugars (including high fructose corn syrup, which can make people put on weight at frightening speed), too much salt and various hydrogenated fats, plus other doubtful ingredients. Almost everyone I know who who subsists on ready meals is horribly fat and/or unhealthy seeming. Cook - properly - for yourself: it's good for you, improves your quality of life and the modest time you spend doing it is a good way to unwind.

Sucrose, as I mentioned previously. Or NaCl but that would spoil your drink.

Very likely yes. The straw would provide more nuclei to initiate bubbles. In the lab, we used to put "boiling sticks" into flasks of solvent that we wanted to boil, to make sure there were plenty of nuclei for bubbles to form evenly. The worst thing was to have glassware that was perfectly smooth and clean, because then you could get superheating and "bumping" when the superheated liquid finally found something to initiate a bubble and everything boiled over at once.

It's not the element carbon but dissolved carbon dioxide, CO2, that makes drinks fizzy. And it's not exposure to oxygen that makes them go flat, but the reduction of pressure on exposure to the atmosphere. When you open a bottle of fizzy drink, the pressure above the liquid drops. Since the amount of gas the water can dissolve depends on the pressure of CO2 above it, you then have a supersaturated solution, which is why it fizzes. Any nucleus for bubbles to form on will accelerate the rate at which the CO2 comes out of solution. A classic way is to put in a sugar lump. This has a large surface area with many sharp edges, which promotes the initiation of bubbles. Sand would also do the job, but not so good if you want to drink it later. The reason why you need a nucleus to start the bubbles off is because of the energy needed to pull apart the water molecules. The excess pressure inside a bubble is 2T/r where T is the surface tension of the liquid - a measure of the strength of the intermolecular forces - and r is the radius of the bubble. From this you can see that the smaller the radius, the higher the pressure, so in the limiting case this formula predicts an infinite pressure is needed to blow up a bubble of zero radius i.e. at the start. While this formula is not accurate at very small radii, it gives an idea of the problem. Sharp edges reduce the intermolecular forces in their vicinity, as the water molecules are not entirely surrounded by other water molecules, making it easier for gas molecules to push them apart and start off a bubble.

Doing some back of the envelope calculations, the rms velocity of water molecules at 900C will be about 1.26km/sec, if I've got my arithmetic right. (v[rms] = √(3RT/m) m being in kg. ) The escape velocity of Saturn, which has about the same mass as this planet, would be 36km/sec. I have not worked out how to do the velocity distribution curve, to see what fraction of the "tail" of the velocity curve will represent molecules with a velocity greater than this, but one can see it could easily be 0.1-1% or so. So one might expect the water to escape over time. Regarding SO2 I'm not sure I follow this, except that one might expect reducing conditions, in which case the presence of SO2 rather than H2S presumably indicates photochemical reactions. They propose photolysis of water, apparently.

I think you mean disassemble. To dissemble means to lie. I should think the main risk from ingress of dust will be dirty contacts and hence poor electrical connections at points where subassemblies are joined together.

But the zoonotic explanation of the origin of the virus is not "astronomically unlikely". We've seen it before on several occasions. Do you really think most of the world's virologists are fools, while you are the genius to spot the flaw in their thinking? Get real.

Just finished Heinrich Böll's "What's to Become of the Boy", a reminiscence of his time growing up in Cologne at the time of the Nazis. I found a copy when reorganising some books after redecorating. My wife must have bought it. I also found a 1938 French translation of Three Men in a Boat, with original illustrations, which was the book she read in her teens that first made her an Anglophile - so she once told me. So I've started reading that.... a lot of passé simple, which is quite unfamiliar to me, and vocabulary I don't know but am trying to guess, to avoid stopping to get out the dictionary. We'll see how far I get. So far I've learnt that the French for Housemaid's Knee is épanchement de synovie. That should come in handy......... It's just the sort of useless thing I find I tend to remember, just as I remember the French for combine harvester and the Dutch for horseradish.

Interesting that there is so much water, considering the high temperatures - 900C- on the sunward side (it's tidally locked, apparently). One would think water would be lost into space at such temperatures, as the fraction of light molecules with velocity > escape velocity must be significant, I'd have thought. But then if, as they suggest, it started out in an orbit of similar radius to that of Jupiter, and was later kicked inward, we are probably not looking at an equilibrium state.

I say: malevolent, mad ballocks.

Thymine has a methyl substituent in the 5 position, which uracil does not have. The numbering is just a way to denote the ring substituents. With heterocycles it is normal to pick one of the hetero atoms as position 1 and the others then follow round the ring.

It will certainly depend on battery capacity, just as a big engine will be usually more powerful than a small one. However it will also depend on the battery technology and design as well.

I think they have to be entities, because something continues to exist in between interactions. If that were not the case, we would be unable to predict the properties of the entity in the next interaction, which is what QM enables us to do with great success.

The weight of a battery pack depends on how it is designed. It is not something you can work out from electrical performance data. You would not expect to be able to work out the weight of a petrol engine from its power output, would you? Because, again, It depends on the design.

I must say it has always seemed to me that the notion of "particles" is a fairly preposterous construct, when one thinks about it: the idea of an entity with no physical dimensions but nevertheless finite properties such as mass, charge, intrinsic angular momentum etc. Just as artificial as "waves", really. Originally, in classical physics, the concept of particles was merely used to simply physics problems to their essentials, for ease of modelling. Like you, it has often seemed to me that QM entities only behave like particles when they interact. Reading Rovelli's Helgoland last year, I was quite impressed by his idea that QM entities only have defined properties at all when they interact, so we should perhaps let go our idea that they possess them in a continuous sense in between.

Yes, I think the point is that "r dot" signifies velocity in the direction of r, which means radially. That's what I and others have been saying. What is misleading, it seems to me, is that the film accompanies this by showing a film of someone jogging round the circumference, i.e. not moving radially. I suppose there is a little bit of radial motion, in that the jogger is moving up and down a little as he runs. Whether that is enough to cause a sensation of his head moving sideways to left and the right, as it goes up and down, I am not sure. It will depend on the radius of the circular tube he is running inside. It's a very small diameter tube in the film. Whereas If you think of 2001, for instance, the space station is hundreds of metres across. (The effect of r dot will be much less because ω will be much less: you need a lower rotation rate to simulate 1g of gravity in a larger ring.) The two guys trying to throw a ball to one another, across the centre of the circle as they rotate, is a much better example of what happens, I feel. That is radial motion, so that is the scenario in which the Coriolis effect arises.

I'm not sure the Coriolis effect would have that dramatic an impact. In most uses of rotation to produce artificial gravity that I have read about, the spacecraft would take the form of a tubular wheel. According to my understanding , the Coriolis effect would chiefly affect objects moving radially, rather than circumferentially. Or am I missing something?