exchemist

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?

The Ipcress File and Get Carter.

OK fair enough, you mean there is no cleaning chemical impregnating the cloth. Yes, one is just as well off using a regular spectacle-cleaning cloth, from the optician or wherever.

It is, as I suspected, a microfibre cloth though, not "just a cloth".

Anyone who wears spectacles will know that you need a microfibre cloth to clean the lenses properly so that you don't get reflections, glare in sunlight etc. I don't know what an Apple cloth is but I suspect what you need is a cloth for cleaning lenses, not just any old piece of fabric. At any rate, that is what I use to clean the screen on my laptop.

Im not an expert on this but I wonder if the valves may not work so well with a compressible medium as they do with an incompressible one. If the %volume change of the pump chamber over its operating cycle is not that great, the pressure differences it creates may be too small to actuate the valves properly. This could explain why, when the pump is wet, you get better pumping, due to the moisture helping to seal round the edges of the valves, or else that it lubricates them so they function more smoothly. Whereas, when the pump is operating with a liquid medium, the pressure from whatever actuates the diaphragm will be instantly transmitted in full to the valves, because the fluid is incompressible, making the valve action more positive. But this is only speculation on my part, based on dimly remembered experience of dismantling an SU electric fuel pump on a Morris Minor I owned in the mid 1970s, when I was a student.

What is the Mohs scale hardness of each of these? What is artaclase?

If one thinks of the most widespread mineral material used by early man for building and for early artifacts, the rest can be confirmed fairly easily, using Moh hardness as a check.

Well of course. That's what several of us have been saying: when gases accumulate in hollows or high points, they do so because they are not mixed, i.e. before they have a chance to diffuse away into the general body of the atmosphere. The point we are taking issue with is your apparent contention, earlier in this thread, that mixtures of gases can spontaneously separate, or stratify, at least partially, under the influence of gravity. It is this that I am saying is not supported by your references.

Thanks. I've had a look at these but none of them seem to me to assert anything about gases concentrating themselves from a mixed state.

Well I am open to being corrected on the basis of solid evidence if you have any. If you have had to deal with methane accumulating in buildings you should find it easy to point to a standard, building regulation or paper that says methane or hydrogen will become more concentrated, i.e. with molecules moving against the concentration gradient due to difference in molecular weight. On the face of it, though, this seems ridiculous to me, though I do acknowledge that at very high artificial g forces, in a gas centrifuge, you can see a bit of partial separation due to this. This scenario will be where @sethoflagos's thermodynamic analysis has a practical application.