exchemist

As I read it, this paper does not challenge the primacy of photosynthesis in generating free oxygen. What it suggests is that the suddenness of the 2 oxygenation events can perhaps be explained by a positive feedback effect by which, once partial oxidation enzymes evolved, binding to marine sediments of partially oxidised metabolic byproducts would accelerate the rate of burial of organic matter. This would reduce the competition among the various oxygen-consuming processes, encouraging more free oxygen. And the more of that there was, the more organic matter would be partially oxidised and so the more efficient that burial process would be, and so on. Until there was so much partially oxidised material (i.e. so much chemical detritus from life processes) that, even though a lot of it was bound to minerals it nevertheless could take up enough oxygen for a balance to be reached, but at a far higher free O2 level than before. Or something like that - I have only skimmed it. (By the way, Rubisco always makes me think of Shredded Wheat................😁)

Well I don't know the answer to this offhand, so perhaps we can work it out between us. Can you do the first part?

Are you a science teacher, then? It seems rather unlikely.

Indeed. What always impresses me about these things is how one sets about getting any sort of handle on events that long ago, that involve life.

Well this is off-topic of course, but I do know "Voltex" is a well-worn scam, exploiting ignorance about power factors and wattless current. I suspect "Voltax" is the same schtick. Websites seem to have little control over whose ads pop up. I complained about Voltex ads on another science forum and the admin told me they had no way to stop them. So I wouldn't blame the website, except insofar as it accepts ads in the first place.

I had to go to the paper itself to find out what these POOM species are: https://doi.org/10.1038/s41467-022-28996-0 Seems, as I suspected, they are organic compounds with hydroxyl and carboxylic acid groups on them. These will be polar and presumably able to bond to silicates by H-bonding. The interesting thing is that the paper associates the oxygenation event* with evolution of the enzymes that catalyse such partial oxidation, suggesting it was this evolutionary step that led to it. *I'm pleased the article called it the Great Oxygenation Event rather than the alternative Great Oxidation Event. I always find the latter misleading, as it was really, from the planet's point of view, a reduction event, leading as it did to free oxygen everywhere!

Thanks for the good wishes. It's just a runny nose, really. (But then I have had 3 doses of vaccine, plus an encounter with the original virus in March 2020.)

Yes 1 litre has a mass of 1kg, right? Which means 1000 grammes. So 1 g of anything dissolved in 1 l must be 1 part in one thousand i.e. 1ppt. So now you can do the first bit, can't you? Next, the molecular weight, or molar mass, is the mass of 1 mole of substance. So in the case of NaCL, if you have 58.44g of it, you have 1 mole. So how many moles, or rather, how much of a mole, would there be in 14.61g? P.S. it is now 22:22 in London and I am going to bed because I've got covid and want to get plenty of sleep (I'm fully vaccinated so it's just a nuisance). If you still need help in the morning I'll have a look after breakfast. I remember my son used to get in a flap with things like this. He could do them perfectly well really, but he used to panic. The thing to do is think calmly about each piece separately, and take it in steps.

OK this really a chemistry problem, rather than a maths problem. There are 3 things here. Let's take the easy one first. What do you think parts per thousand means and how would you set about calculating it? For the second, you need to know the molar mass (in the old days called the "molecular weight") of NaCl. How do you find that out and what is it? And then we can come back to the third.

Some were, certainly, in their own way. But none of them did, or do, the things I described, which are routine in science-based medicine. I have been trying to answer the question posed in the OP, as to why such traditional medicine has become used less in modern times.

What you say may be true but in the end the key distinction is that what you call "western" medicine is science-based. That involves not only verifying by controlled trials the effectiveness of a therapy, but also the other things I mentioned, do to with identifying the active agent, optimising the dose, checking safety and so forth, so that you understand as fully as possible what you are doing to the patient when you use it and you do so to the best possible advantage. Your traditional medicine man does little of this. He is not, after all, a scientist. He may not know why what he does works - or perhaps not even whether it works at all. Open-minded science will take note of what is said to work and will investigate to see what can be learned from it.

Jörk? 😄

Both can easily be the case. Obviously.

As a matter of fact, study of natural products has always been, and continues to be, very important in pharmaceutical research. Here is an article reviewing the topic: https://academic.oup.com/jimb/article/43/2-3/249/5995725?login=false An example from personal experience is the chemotherapy drug Taxol, which my late wife took for ovarian cancer (It did a good job but made her hair fall out). This was isolated from the Pacific yew tree and was found at the time of its discovery to be one of the most effective of some 12,000 natural compounds being studied for therapeutic use.: https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_1/taxus/brevifolia.htm What modern medicine does not do, however, is adopt traditional plant remedies without first isolating the active ingredient, understanding its mode of action and trialling in a controlled way to check its efficacy, safety and the optimum dose to use. By the time all that is done and the active ingredient is available as a drug, you may no longer realise it is in fact a natural remedy.

Apart from being both false and potentially offensive to Jews, what you have written is obviously foolish. Since Jews do not believe in the divinity of Christ, they would not be bothered by Christian threats of punishment for disbelieving.

This is becoming tiresome. Can you drop the facetiousness and make a serious point, if you have one to make?

You mean tidal heating? No, it is not significant for the Earth, though it is for some of the Jovian satellites, I understand.

Oh dear. It doesn't look as if you are the ideal person to discuss science with, then. But thanks for the discussion topics: always fun to think about.

Yes, think of the crumple zone in a car.

Yes indeed, I too use the bike for local errands and only put <5000miles on the car annually. But even so, eventually the car needs replacing (Mine is now 13yrs old so it will be 14-15yrs old by the time I replace it.) The issue then becomes - apart from the operational footprint - whether an electric car involves more or less CO2 in its manufacture and supply than an IC one. I should have thought less, as an electric car has less machinery in it, unless the battery is particularly carbon-intensive to make. I realise there are environmental problems with mining some of the metals, notoriously Co, and maybe some of the lanthanides used in motor magnets, but these are in principle fixable and since the overriding imperative is climate change I set these to one side. I expect the next car I buy to be my last, given that I am 67 and would hope to run it until I'm 80 or so and starting to become a liability behind the wheel. But by then, with any luck, we will be able to hire driverless taxis - if Putin has not blown us all up.

Are you really an ex-physicist?

Mark 13:32 in my translation says: "But as for that day or hour, nobody knows it, neither the angels in heaven, nor the Son; no one but the Father." And he prays to the father on various occasions. So there is a clear father/son relationship implied and sometimes stated explicitly. So we have the start of the idea of the Trinity. The question of whether that makes Jesus divine is slightly different, it is true, but we already see it dimly in the prologue to St. John's gospel where Christ is identified with the Word - the "logos", which , it is implied, is the means of God's action in the world, including the creation itself. Perhaps you think John the Evangelist, whoever he was, was a "Catholic"?

I suppose there may be some further compression occurring, due to the slight reduction of volume in the core as it cools and progressively solidifies. From that link you provided, it seems the latent heat of fusion released as more of the core becomes solid will slow the rate of cooling. If the solid is also denser than the liquid, then the gradual growth of the solid core at the expense of the liquid core will reduce the volume of the core and the rest of the earth will move downward to fill the space and thereby become further compressed, releasing more heat. Regarding tectonic movement, my understanding is that this does indeed release heat due to friction (e.g. in descending slabs at subduction zones, it contributes to the partial melting that takes place which is responsible for island arc volcanoes). But since the source of the motion is thermal convection in the first place, I should have thought that would be a redistribution of heat from core to crust/upper mantle, rather than an additional source of it. But this isn't my field so I speak only as an interested amateur.

I've decided my next car will definitely be electric. I'm just hoping to hang on for a year or two, while the charging network improves, the main issue being to have a charging point in Brittany where we go for summer holidays. (There are already charging points on the overnight ferry). What gives me a bit of a guilty conscience is that I've found that I can't realistically get a heat pump to replace the gas central hearing boiler. The house, which is Victorian, is too big and difficult to insulate sufficiently. I shall just have to get a new, efficient gas boiler and hope that eventually I can run it on green or blue hydrogen - or a hydrogen/methane blend. The UK government has done almost nothing to address this issue yet, which is a huge hole in its climate change strategy. That's a fairly strange statement. Climate scientists are practically unanimous. The only significant doubt seems to be among those non-experts who don't want to believe it, either for political reasons or for reasons of personal convenience.

Ah so he's pushing it round in a circle, is he? So the combined total of the force needed to push it round, plus the lifting force from his hand will equal the weight, I suppose. In other words he still has to exert a force equal to its weight, but not purely vertically, due to the reaction of the gyroscope.