Everything posted by exchemist
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Homophobia, nature or nurture?
None of the 10 commandments says anything like that. There is one forbidding adultery, and another saying thou shalt not covet thy neighbour's wife. It was a very patriarchal society and tended to be written very much from a man's perspective. The decalogue is written out in the table at the foot of this article: https://en.wikipedia.org/wiki/Ten_Commandments
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Homophobia, nature or nurture?
No I didn't mean anything to do with harassment. I just meant a normal, civilised, - if unwelcome in this instance - sexual approach.
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metal detector
They rely on metals being electrically conductive. An AC electromagnet induces eddy currents in the metal object, which alter the net field (from the detector and the metal) close to the object.
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Scientists Have Discovered What's at The Core of Mars
Possibly. Here is a link to the original PNAS article: https://www.pnas.org/doi/full/10.1073/pnas.2217090120 The "Interpretations" section is the most interesting. This runs through the various compositional ratios of Fe, S, O, C and H that they considered, in trying to match the observed seismic data. Interestingly - and rather counterintuitively to me - they alight on H as needing to be present to avoid having what they consider an unreasonably large proportion of S in the mix. This could fit your idea of cooler conditions and a faster congealing, compared to the Earth. But they don't themselves speculate on formation processes for the core. This work seems to be offered as food for thought, for other planetary physicists and chemists to study.
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Scientists Have Discovered What's at The Core of Mars
Interesting article. Thanks for posting it. One would not expect nitrogen-containing compounds among the minerals. About the only example on Earth is saltpetre (KNO3 or NaNO3), which is derived from decomposition of organic material. This is because nitrogen is generally speaking most stable as N2, a gas, due to the great strength of the triple bond (excellent overlap of the 2p orbitals in this small molecule, leading to 2 very strong π-bonds as well as a strong σ-bond). So one would tend to find nitrogen in the atmosphere rather than in solid minerals. (This is in contrast with oxygen, which of course happily forms a huge series of silicate minerals, oxides, etc.) All the elements up to and beyond iron will have been present in the dust and gas from which the solar system condensed so, rather than formation, this issue is more about fractionation, i.e. which ones became concentrated in particular planets, and then in what part of the planet (atmosphere, crust, mantle core). Sulphur forms a range of compounds with iron, some of which are not of fixed composition, i.e. solid solutions or alloys. From the article it seems they think sulphur is a major ingredient in the Martian core due to the composition of iron meteorites and also, I presume, their assessment of the density of the core from seismology.
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A question about gunpowder
Nice idea but there’s no way to get this to work, unfortunately. The USA has to join the rest of the civilised world and get rid of the permissive gun culture, however hard and slow that is.
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doubt cream pigmentation skin
None. There is nothing you can apply externally that will do that.
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Combatting Conspiracy Theories
The cream of the joke is Carlson was fired for objecting to Fox’s campaign of lies. But it couldn’t happen a nicer chap.🤣
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Would artificially changing the mass of an object still follow kinetic conservation of energy?
Once you break the rules of physics you are in a fantasy world in which all bets are off.
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Calculation light reflection area
@swansont is quite right of course: I wasn’t thinking. We need more information. What is the shape of the mirrors, what is the shape and dimensions of the 600sq m illuminated area and what is the angle of the beam to the ground? Is a diagram available?
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Calculation light reflection area
I'm not quite sure what you want to know. Do you mean a formula for the rate of divergence of the beam? That's obvious, surely, if it grows from 51m² to 600m² , i.e. a factor of 11.6, over the course of 450m? Or do you want to know why it diverges at that rate? That would be more complicated - some function of the shape of the mirrors, I imagine.
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Earthquakes, volcanic eruptions, and solar flares are caused by the planets
Two questions: - On what grounds do you claim terrestrial forces could not have been responsible? - Have you calculated, or estimated, the magnitude of these interplanetary magnetic forces that you claim are implicated?
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May I ask how the temperature sensor outputs the detonation signal to the electronic detonator?
Central heating thermostat?
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New UN report highlights the scale of global climate change
It’s a question of progressive pressure to change. We are moving quite a bit now: almost no senior politician any longer denies the need for action, and governments and industry are investing in the shift. Of course we have move faster but there won’t ever be a discrete tipping point.. People have get used to changes and find tangible upsides in it for them, especially when it impacts their personal lifestyles. We have not got far with that yet, apart from cars. Home heating is a big one.
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Infallibility has a start and an end ?
I don’t think the Vatican, for all its faults, would want to have anything to with Trump. The guy seems to be actually evil.
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Use it or loose it ?
I’m certainly with you 100% on maps. Like you I feel a need to know where I am going in relation to other places. I also like to have a mental picture of the journey. It makes me feel I am in charge rather than blindly following instructions.
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Use it or loose it ?
On the contrary it seems to me that modern life requires mastery of an ever-expanding battery of computerised tasks, mostly to be done on your own without help. So mental agility is still needed but of a different sort. However I have certainly read of the importance of exercising the mind as one grows old. That’s one reason why I sing and why I do sudoku after lunch and wordle at teatime. And hang around science forums of course.
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Infallibility has a start and an end ?
Yes it is only ex cathedra pronouncements on faith and morals. Most popes are very sparing indeed in their use of this. I think I recall this dodgy (and risky) doctrine was only formalised in the c.19th, at a time when the church was going through a phase of dogmatic absolutism.
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pH terminololgy
Yes, pH can increase or decrease, or one can speak of a low (acid) or high (basic) pH.
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Washing felted woolen blankets
Bed bugs are bloodsucking insects. If you’ve got those you need to fumigate the entire bedroom, paying attention to the underside of the bed and mattress as well as the top. But I doubt this is what you mean. If you mean dust mites, then washing should help. Woollens are washed not cold but at 30C usually. That should be OK. I would not go hotter if I were you.
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Does the spacetime curvature according to Einstein really exist?
I have a couple of questions: - How does your radiation concept account for the time dilation we observe in communications satellites, which is accurately predicted by relativity? - Are you an electrical engineer, by any chance?
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Lorentz transformation, special relativity and quantum fluctuations
Makes no sense. Vacuum fluctuations arise due to the uncertainty principle. Nothing to do with relativity.
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Red Cabbage indicator
That looks a lot better, certainly.
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Red Cabbage indicator
Yup. Chalk. CaCO3.
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Red Cabbage indicator
OK. By the way the anthocyanins in my red fruit turn blue just rinsed with water - before any detergent is added. So the water itself is sufficiently alkaline to do it. From looking it up, I see the pH of London water is in the range 8.0-8.5.