exchemist

Yes the "Skulls in the Stars" article seems to deal with it. Good old Ehrenfest, again! So it's false to assume that any accelerating charge must always radiate, apparently: symmetry can trump that general rule.

In the discussion I read elsewhere, there was some talk of whether the electric field, although it does not change beyond the boundary of the sphere, might change in a way consistent with radiation in the region between its greatest and least radial extent. Though, weirdly, such radiation would not, apparently, escape. I'm not enough of a physicist to know if this makes any sense.

There seems to have been some discussion of this topic on the physics stack exchange some years ago, the conundrum being that the electric field lines, beyond the boundary of the sphere, are unaffected by a purely radial change. At least, I think that's what it was all about.

That's part of it. But to my mind the more significant part what would happen assuming the temperature of the liquid butane did drop to -10C. In that case I think the relative rates of diffusion would be determined chiefly by the surface ares of the hole compared to the surface area of the liquid. I've now added chiefly because of one aspect my earlier post did not take into account, which is that as I recall the rate of diffusion is inversely proportional to the square root of the molecular weight. The MW of butane is 48 +8+2 = 58 and that of air is 29 average, exactly half. So the air will diffuse 1.414 time as fast as the butane, per unit area, but the liquid area will be a lot greater than the area of the hole. I actually think there may be another effect too, thinking more about it. As soon as the butane vapour become significantly diluted with air, the partial pressure of butane will drop lower than 1bar and so more butane will evaporate. So there will actually be still a net flow of butane out of the hole, I think.

15 seconds before what, though? Surely the pilot can switch the autopilot off and return to manual control any time he wants to, can't he? No autopilot takes control unless the pilot turns it on, and equally, he can always turn it off. The MCAS system, implicated in the 2 crashes of the 737 Max, is nothing to do with the autopilot. Do you mean the MCAS system rather than the autopilot?

I think this poster is wasting everyone's time, possibly deliberately.

Your logic looks OK to me. I see, consulting my Periodic Table, that the electronegativity of Fe is greater than that of Zn, so it doesn't look as if Fe will give up its electrons to Zn2+. (Also, as I recall, the principle of galvanising relies on Zn being preferentially oxidised and thus protecting the Fe.)

It seems to me that, in practice, with a real metal butane cartridge, so long as some liquid butane remains, there is likely to continue to be a +ve pressure sufficient to prevent air from diffusing against the flow into the cartridge. Unless you insulate the cartridge, the temperature difference between the air at 20C and the colder liquid will most likely keep it above -10C. But supposing that one way or another it does get down to -10C, the pressure equalises and then air diffuses in, then I suppose you eventually end up with a mixture in which the rate of diffusion of butane from the liquid is in competition with the rate of diffusion of air in through the hole. I would imagine that would become a matter of the relative areas of the liquid surface and that of the hole. If that is right, then I should imagine the mixture inside the cartridge would remain principally butane, the excess pressure on closing the hole would be marginal and the risk of reaching the explosion limit would be negligible.

What you leave out, though, is that it can only be the simplest theory that accounts for the observations. Ockham's Razor does not require anyone to throw out a theory just because it is complicated, so long as the complications are necessary to account for observations. (This is why the important qualifier "first" is included in the definition you quote.) And there is the problem. If you want to advance a new, simpler, theory you need to show that it can account for the range of observed phenomena that existing theory can.

There is one assumption you are making that I would question. I don't think air will get into the box. The issue is not so much the speed of the molecules as their diffusion rate. Don't forget that while they move fast, the mean free path is very short as they keep rebounding off other molecules in random directions. For air to get into the box, the speed of diffusion, which is the net rate of progress, taking into account all these random collisions, has to exceed the flow rate of gas out of the hole. Doesn't it?

There is a summary of changes required by the FAA here: https://paxex.aero/737max-autopilot-minimum-requirements-faa/ I'm not clear what you mean by giving the pilot 15 secs to disengage the autopilot (e.g. 15 secs before what happens?) or why this would be relevant.

Do you mean what distinguishes one person's consciousness from another person's? The fact that the two people are physically distinct. It's a bit like asking what makes one orange different from another one.

I'm not going to an unknown site without being given a good reason to bother. But I presume this is something to do with ecology, right? https://en.wikipedia.org/wiki/Source–sink_dynamics So why have you posted in physics?

Whut?

Agree about melting points but, on boiling points, that's not how I recall Raoult's Law.

No it's something in the potatoes. You can see it in their appearance after being steamed and before they are cut into chunks for frying. If they look floury at that stage, they will come out well. If they look moist, they will go dark, sweet and flabby.

All good background, but this does not address my issue, which is the lack of reproducibility of results, from batch to batch, as I described in the OP.

It's just grandstanding, in one of these farcical kangaroo court televised committees that US politics loves so much. As you say, kicking Fauci gets points on the US Right, as he is one of their hate objects, being a purveyor of objectivity and truthfulness.

Yes, the article I read was vague as to what process would be started by washing. Maybe washing or not is a red herring, after all. Anyway, I'll have another data point after this weekend, on these "baking potatoes" (variety unspecified).

Yes, I gather potatoes are from the nightshade, solanum, family (as are tomatoes), and that the green parts are poisonous (solanine). But I think that's another story. I have found some information that storage at excessively low temperature can make potatoes sweet. (This reminds me of the old theory that parsnips are best eaten after the first frosts). However I keep mine in the cellar of my London Victorian house, which rarely goes below 10C, so I rather doubt that explains it. I have also read that washing potatoes can start processes of some sort going. The ones I buy in polythene bags at the supermarket have definitely been washed. The ones I buy in France are unwashed, too. I'm going to experiment this weekend with so-called "baking potatoes", which are sold loose and unwashed. It will be interesting to see if I can steam them and then cut them up, without them disintegrating......

So far as I can see, Fauci is likely to be right. I try to avoid relying on sources with a political bias, and it is well-known that the US Right has been out to get Fauci for ages because he has credibility and stood up to Trump, making Trump look like the idiot he was. This story for some reason seems to be carried only by right wing outlets. However I did find this "fact check", made last month on the topic, which concludes that the accusations against Fauci are false: https://www.ibtimes.sg/fact-check-did-anthony-fauci-fund-bat-research-wuhan-lab-by-bypassing-rules-56635 ...unless he has better things to do than dance to the tune of a grandstanding politician, of course.

As a cook, I have noticed with frustration that, when I roast or shallow-fry cooked potato (in chunks or slices), sometimes they come out golden and crisp with floury interior, and sometimes they quickly turn dark brown and come out flabby and a bit sweet. I think it may correlate with whether or not the potatoes have started to sprout in storage. I can imagine that the starch may possibly start to break down to simpler sugars when germination is triggered. I wonder if this accounts for what I have experienced, the sugars caramelising with the frying etc. Does anyone know? And, more to the point, what can I do to ensure this does not happen to my potatoes. My experience has mostly been with supermarket Maris Piper. When we go to France in the summer, the varieties I have tried mostly seem to be fine. I wonder if the supermarkets in the UK store them too long or something.

Experiment. The model has been subjected to all manner of tests over the last century and has passed them all. It is even used to make GPS work in our phones. Being a chemist, I have not learnt tensors so I don't pretend to understand the maths of GR, but I have learnt enough science - mainly QM - to appreciate that the way the universe works is not always intuitive and can be at variance with what everyday "common sense" may suggest. And non -Euclidean geometry is not that hard to grasp, in principle, at least.

Yes. Very elegant. Another +1 from me.

Thanks for posting this. I was scratching my head thinking I had read something about chimneys. But they seem to need to be very tall, and are even more of a blot on the landscape than wind turbines. I wonder what sort of payback time they achieve and how they compare in Watts/m² with solar panels these days.