exchemist

I thought logic mainly returned values of "true" or "false" rather than +ve or -ve. But then there is fuzzy logic.............

Yes I get an ad strip at the bottom of the window (I'm on Apple Mac Safari). Irritatingly, many of the ads have a prominent rectangular button to click, at the right hand side, the same size and shape as the button you click to post a reply on the forum and positioned quite close to it. Obviously the hope is that you will accidentally click on their poxy ad by mistake. To add insult to injury, there is even one for essay writing (i.e, academic cheating) that comes round regularly! I've got used to it though and manage to ignore it. And at least the bloody things don't flash or move.

Freudian slip? 😊

What “universal field”?

I hope my explanation, which crossed with your post, does a bit better........

Indeed. Seems they've found anomalous Helium isotope ratios in hot springs in Panama that are consistent with the material coming up from the mantle at the Galapagos hotspot, even though these Panama locations are hundreds of km away and, moreover, on the far side of the subducting slab of the Cocos plate that lies in between. So a hole or break in the subducting plate is to be presumed. But, er, not "a hole in Earth's centre", whatever that might be supposed to mean! Here is the abstract of the PNAS paper: It is well established that mantle plumes are the main conduits for upwelling geochemically enriched material from Earth's deep interior. The fashion and extent to which lateral flow processes at shallow depths may disperse enriched mantle material far (>1,000 km) from vertical plume conduits, however, remain poorly constrained. Here, we report He and C isotope data from 65 hydrothermal fluids from the southern Central America Margin (CAM) which reveal strikingly high 3He/4He (up to 8.9RA) in low-temperature (≤50 °C) geothermal springs of central Panama that are not associated with active volcanism. Following radiogenic correction, these data imply a mantle source 3He/4He >10.3RA (and potentially up to 26RA, similar to Galápagos hotspot lavas) markedly greater than the upper mantle range (8 ± 1RA). Lava geochemistry (Pb isotopes, Nb/U, and Ce/Pb) and geophysical constraints show that high 3He/4He values in central Panama are likely derived from the infiltration of a Galápagos plume–like mantle through a slab window that opened ∼8 Mya. Two potential transport mechanisms can explain the connection between the Galápagos plume and the slab window: 1) sublithospheric transport of Galápagos plume material channeled by lithosphere thinning along the Panama Fracture Zone or 2) active upwelling of Galápagos plume material blown by a “mantle wind” toward the CAM. We present a model of global mantle flow that supports the second mechanism, whereby most of the eastward transport of Galápagos plume material occurs in the shallow asthenosphere. These findings underscore the potential for lateral mantle flow to transport mantle geochemical heterogeneities thousands of kilometers away from plume conduits.

What is curious about this news is that the wrong information that is was done by Russians seems to come from a Russian (dis)information news site: https://www.altusintel.com/public-yy752j/ But anyway, what is more interesting is why formaldehyde is thought so significant. This seems to be for two reasons. One is that it has a clear rotational spectrum, which astronomers can use for a number of purposes, e.g determining temperatures and velocities (via Doppler shift) of clouds of dust and gas. The other is that it can react with ammonia to produce amines and ultimately amino acids.

Russian scientists? This paper is a collaboration between the Universities of Stuttgart, in Germany, and Leiden, in the Netherlands. But indeed a new, low-barrier i.e. potentially fast, mechanism for formaldehyde synthesis, on ice-coated dust grains, at the low temperatures of interstellar space. I note they comment that the James Webb telescope may carry out observations to confirm the abundance of formaldehyde in interstellar ice. And a neat mechanism it is, too.

Several internet sources, including a university, say you are wrong: https://en.wikipedia.org/wiki/Kelvin_water_dropper http://www.creative-science.org.uk/kelvin_water_dropper.html https://www.seattleu.edu/scieng/physics/physics-demos/electricity-and-magnetism/kelvin-water-dropper/

There are 10 thousand tonnes of magnets in ITER and they are superconducting. I would imagine those are going to take a huge amount of electricity to run, both for the magnets themselves and for the refrigeration systems. And then it is a big plant, with heating, lighting and ventilation requirements like anything else.

Heh heh.

Surely magma production involves more factors than pressure reduction, doesn't it? I seem to recall reading that the magma that produces island arc volcanoes, behind subductions zones, is formed due to a combination of frictional heating of the subducted slab as it descends, combined with the formation of lower MP hydrated minerals, due to the entrained seawater in the slab. Diapirs of magma then rise from the descending slab and, where they reach the surface, volcanoes form. And at hot spot volcanoes, e.g. Hawaii's Kilauea, the magma forms due to unusually high temperatures close to the surface. So it's an interplay of temperature, pressure and mineral melting points.

Exactly. The interesting thing - to my mind - is that this difference in composition may have arisen as a result of fractionation, due to volcanism. The lower melting minerals would tend to become concentrated in magma, which then tends to rise (due to lower density) and erupt - or form intrusions. I have read that some studies have shown the continents appear to have grown in size over geological time, due to this process. It is even possible that all the continental masses formed progressively by this mechanism, from an initially more homogeneous mineral composition of the very early earth.

Golly, you need a professional synthetic chemist, I think. It's 40 years since I did this sort of thing, and then only as a paper exercise. Maybe try the local university organic chem dept? But out of pure interest (it being Christmas), and to start the ball rolling, I did a few searches. It looks as if you can convert piperidine to the cyclic imine, via treatment with calcium hypochlorite to make the N-chloro derivative, followed by dehydrohalogenation. This could be a start. It seems there are ways to "walk" the double bond along hydrocarbon chains, using an Ni catalyst. If you could get the double bond to the 3,4 position via a walk of 2 steps, you would be in with a chance of adding water across the double bond to make the alcohol, which you could then oxidise. But I've no idea of whether this walking would work with an imine rather than a hydrocarbon or how you would control the products to get the one you want. Maybe someone else here can comment.

I hadn't spotted that. But indeed: it is zero point energy, the very definition of which is that it can't be extracted, seeing as there is no state below the ground state.......or it wouldn't be the ground state! How absurd. As this is about water, I am always suspicious this may be to do with homeopathy, since serious money can be made out of that. The author, Claudio Messori, seems to be a physiotherapist. What expertise he has in QED or QFT seems rather unclear, ahem.

Yes. This reads almost like a spoof to me. I was intrigued that it references this guy Pollack and his "EZ water" idea. I've come across that before, about 4 years ago. I posted a summary of my brief investigations of it at that time on another forum, which I repeat below: Actually, I've had a chance to read around this "EZ water" thingie a bit more today. I found it was in fact referenced on the site I linked to earlier, about the various crank theories of water. The writer does not dismiss Pollack but, being a chemist, is sceptical, as am I! I think I understand what Pollack thinks he is on to. He thinks he has evidence that wetted hydrophilic surfaces (e.g. glass, or cellular proteins) can impose a longer-range order on the adjacent water molecules than is generally recognised. He thinks this order excludes solute molecules from a layer close to the surface, rather as solute molecules are excluded from ice crystals as they form. As you may know, the developing lattice structure in a crystal can achieve greater stability (shorter and stronger bonding) by excluding foreign items that disrupt the regularity of the order - hence why salt depresses the melting point of ice and so forth. What is bizarre is that he also thinks that IR radiation (O-H stretch frequency I think?) is required for this structure to develop. And he thinks the arrangement is one in which oxygen and hydrogen are present in a ratio of 2:3, giving the structure a -ve charge - as indeed one would expect from a ratio like that, which is effectively H2O.OH- . So that's where the "H3O2" claim I found earlier comes from. He thinks the viscosity of this semi-ordered layer is a lot higher than that of free water (I can imagine it might be) and that, because there are hydrophilic proteins within cells, these features (viscosity, exclusion of solute) can provide an alternative account of the behaviour of certain aspects of living cells. It is not clear what observational evidence he has, or whether anybody has tried to replicate his findings. Needless to say, this has nothing to do with "memory". However you will not be surprised to hear that garbled versions of this have been pounced on by various snake oil salesmen (e.g. some fellow called Mercola, who I think has actually done time for misrepresentation), sundry homeopaths, cranks and pedlars of water-based health gimmicks. I feel rather sorry for Pollack: this is attention he could well do without, if he is trying to get a serious hearing for his ideas. Regarding the last para, this EZ water idea has been picked up on by charlatans trying to promote homeopathy. I do wonder, looking at the history of the present thread, if there may be homeopathy or something pseudo- lurking somewhere, behind the scenes. This Voeikov guy looks dodgy.

Yes, it reads like a "we've-got-one-too" piece, rather than news of substantive progress. But the Chinese may be making progress with it: we've all seen enough recently not to sniff at their technological prowess.

As @studiotpoints out, the oceanic lithosphere and the mantle beneath are both solid, at least on a human timescale (though the upper mantle is more plastic than the crust). To understand plate tectonics you need to appreciate that even solids can deform plastically and flow under the influence of pressure and temperature, on geological timescales, that is, over millions of years. Forget magma in this context. Magma is formed only in a few pockets, deep in the crust or in the top of the mantle, where locally the temperatures is hot enough, and/or the pressure is low enough, and/or the melting points of some of the minerals at that location are low enough that partial melting can occur. Magma is an incidental byproduct of tectonic processes. If you read the link I gave you on isostasy you will see it is about less dense continental crust finding an equilibrium depth in the denser oceanic crust and upper mantle in which it effectively "floats". Even though both are solids, on geological timescales, they will find gradually find their equilibrium level. It is the fact that these islands of lighter minerals have formed (largely due to the fractionation that goes on in volcanism) which gives us the continents. As with ice in water, because the density difference is small, the continental blocks extend to a far greater depth, below the top of the oceanic crust that forms the ocean floor, than the bit that pokes up from the ocean floor to give us dry land. (I find on Wiki density figures for continental crust of 2.8 and for upper mantle of 3.3.) As for your remarks about gravitation and isostasy, the link you provided does not seem to support your claim that measurement of gravitation is at odds with the hypothesis of isostasy. Can you point to something specific in this link that supports your claim?

Yes. You need to take into account the principle of isostasy.https://www.britannica.com/science/isostasy-geology The continents are less dense than the oceanic crust in which they float. There is no disturbance to the centre of gravity when they move around, any more than the centre of gravity of your cold drink shifts, if you move all the ice cubes to one side. Furthermore if, as you propose, the ocean level were to drop, in the era of Pangaea, no significant land masses would be revealed, because all the continental crust is part of Pangaea. All the rest would be oceanic crust, at a depth of several km below sea level.

Exactly. It's the state of preservation that is remarkable. From what I understand, it shows that the embryos of this species of dinosaur were folded up inside the egg in just the same way as modern birds. Which is interesting, but perhaps what one might have expected rather than not.

Yes, it is my understanding that the Casimir effect can be accounted for in terms of London (dispersion) forces between the plates. However I recall reading that the dispersion forces model is actually equivalent to the vacuum fluctuation model. I do not know any QED however, so I'm in no position to understand how this equivalence may arise. The common feature would seem to be the concept of random fluctuations, in the one case arising in the vacuum and in the other arising in the charge distribution of the electrons of the plates. If anyone here can shed more light on this I'd be interested.

Reflection certainly implies the matter in question must interact, i.e. be polarisable by, EM radiation. If it can be polarised by it, there will be some wavelength at which it will absorb and emit, won't there? And, if it reflects, wouldn't we observe reflected radiation.

I'm a bit lost. Surely if S is a surface area, then dF/dS is a pressure function rather than an energy, isn't it?

Expiry date won't make a difference, since neither oxidation nor bacterial action are likely to cause any more dangerous species to be formed when the item is burnt. But burning anything in an open hearth generates smoke - fine particulates, part-pyrolysed organic compounds etc - which tend to be damaging to the lungs and potentially carcinogenic. Here's a short article on the subject: https://www.barbecue-smoker-recipes.com/barbecue-smoke-dangers.html which mentions some of the chemical species that are troublesome. Of the particulates, it is the "PM 2.5" that are considered the most injurious to health. But if it's only a bit and you don't breathe the smoke then I doubt there is much to worry about.

Because when a QM entity is confined by a potential barrier, the wave function penetrates the barrier to some extent. The barrier can be thought of as "damping" the wave function progressively to zero. The lower the barrier, the further the wave function penetrates. If the barrier is also sufficiently thin, the wave function may not be damped to zero by the time it reaches the far side. In such a case, that represents a finite probability of detecting the QM entity outside the confining potential barrier.