exchemist

There is no difference between the two, really. Potential is just the integral of a force over a distance. Atoms are inanimate either way.

You will need to explain why the two options are different. To me they look the same.

You have not taken in what we have been explaining to you, apparently. Classically, nothing can escape, that was the original conception of the black hole and is still strictly true of them. Later however, Hawking applied QFT to it and showed that the region at the rim, but just outside, would be caused to radiate by the intensity of the gravitational effect it creates. There is no inconsistency here and no "mistake" to be admitted. Nothing that enters can leave. That remains the case. But radiation just outside can certainly do so and this may make them look less "black" to an observer than in the original, non-QFT, conception of them. Do you understand?

No, just intrigued by @TheVat's remarks about solanum and BPH. It was he that introduced the subject, which happens to have salience for me right now.

Thanks but I’ll stick with the consultant’s advice. There’s always a slightly irrational temptation to think one can do something to take control by means of diet, when it may be largely wishful thinking.. The cranberry business seems to be mainly a marketing stunt by the Canadian agricultural industry, so far as I can see. The UTI may just have been an unlucky one-off event. If I get more of them then further action may be appropriate. He may give me an MRI for the sake of good order, depending how my next PSA comes out. So we’ll see.

Hmm. I've recently been seeing a consultant urologist for BPH after I got a urinary infection (citrobacter) out of the blue a couple of months ago (one of @John Cuthber's "wee burns" but nasty enough to go to A&E on a Saturday night). The consultant has not said anything about diet, in spite of my asking. He has however given me a trial course of Tamsulosin hydrochloride, which opens things up quite a bit, though he says nothing he does will lesson the risk of future UTIs very much. I'm not sure I need this drug. Things are OK without. So I may stop. It's the UTI that I want to avoid getting again and I'm not getting much to reassure me on that front.

The groups which tend to be the most electron-withdrawing will make it easier for H+ to be released ( more stable anion). A carbonyl C=O can spend some time as C⁺-O⁻. So the CH2 between 2 carbonyls gets the effect from both sides, making it easier for one of the Hs to come off, leaving an enolate anion, cf. keto-enol tautomerism: https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Organic_Chemistry_(Morsch_et_al.)/22%3A_Carbonyl_Alpha-Substitution_Reactions/22.01%3A_Keto-Enol_Tautomerism. You can apply the same logic to A vs. F. If you have an exam coming, you must have some revision notes or lecture material on this kind of thing.

Wouldn’t the nightshade family (solanum) also include potatoes and tomatoes? And even aubergines?

My understanding is that Hawking radiation and its effects have yet to be observed. So while they are a mainstream theory, I’m not sure they have been claimed as facts. But in any event the two ideas are not incompatible if you understand them properly. Black hole is a term devised before QFT was applied to the phenomenon. So Hawking radiation phenomena can be taken to be a refinement of the earlier concept.

The CMBR could, conceivably, be due to something else. But nothing suggests itself and the observed uniformity of the CMBR is consistent with the big bang theory of expansion from a small, hot start, as evidenced by the expansion measurement itself. So the two observations complement one another and applying Ockham’s Razor, the big bang accounts for both so why look further? As for the maths, as I say, not being a cosmologist and not being trained in GR, I have to leave that to those that have done the calculation. Maybe someone else here will be able to help you with that.

Not sure about the maths but I presume the principle will be an extrapolation backward from the measured black body temperature of the radiation today, using the measured expansion rate, and seeing how much time is required for the wavelengths to shorten, i.e. for temperature to go up, as you "recompress" the universe, to the point that you get to a plasma. But I don't pretend to be a cosmologist.

It wasn't an explosion at a location within the universe. It was radiation that filled the whole universe as it expanded. Since it would have filled the whole universe initially and no process is envisaged that could confine it later to a limited region, the prediction of the theory is that it should come from everywhere. As it apparently does.

I'm not going to watch the video. (Actually it is against form rules to require readers to watch videos or follow links off-site in order to be able to discuss the topic.) Also videos take ages to communicate what can easily be put in a few lines of text. If you can summarise the key points the video makes it could be helpful. Meanwhile though, from looking it up on the web, I can see there does seem to be evidence that a proportion of the population in N America is somewhat deficient in Mg: https://link.springer.com/referenceworkentry/10.1007/978-3-319-40007-5_6-1 However this source says this generally does not seem to be severe enough to have significant health consequences. The UK NHS says you can get all the Mg you need from your diet: https://www.nhs.uk/conditions/vitamins-and-minerals/others/ Spinach, nuts (e.g.in some breakfast cereals) and wholemeal bread are suggested as sources. (I eat quite a bit of nuts and spinach, though I don't eat wholemeal bread very often.) I would very much doubt that Mg salts are absorbed through the skin. Threonic acid was new to me. It is a sugar acid, a metabolite of Vitamin C, apparently. So that at least is interesting. I am by nature a sceptic when it comes to supplements, especially when there may be a commercial interest in pumping their benefits. My view is you are best off eating a varied diet with plenty of fruit and veg, exercising and not boozing too much and not bothering with supplements. But I'll be interested in what more expert people on this forum may have to say about Mg threonate.

That article is an elaborate way of saying time travel is not possible. What does it mean to say you can "carve" spacetime? It's bullshit.

"Not particularly well absorbed" ≠ "not absorbed at all". You can draw your own conclusions.

Nobody claims it is, apart from Dr. Who. Can you provide a reference to show who thinks it possible?

If this is for amateur chemistry, in say 100-250ml beakers etc, you can buy a magnetic hotplate and stirrer for about £50 or so. These are standard lab gear and work fine for low viscosity mixtures and solvents.

Arf arf.

I don't know if we have any polymer chemists here. I would think it quite hard to find a polymer with very different solubilities in water and ethanol since polarity and hydrogen bonding is so much a feature of both these solvents, though more for water obviously. I'm not surprised you are having difficulty identifying one.

That view is a bit of a simplification. Because electrons are wave/particle quantum entities, although they are detected only as "whole" particles, they also behave as if they are "smeared out" throughout the volume of the atom around the nucleus. One speaks of "clouds" of "electron density". This cloud is pretty diffuse in terms of mass density, because electrons are light particles compared to the nucleus, but it is not really true to say there is a lot of "empty" space in the atom.

Off-topic gibberish.

Ah yes, according to Wiki that is indeed one of the applications for it. Hope you don't spill any on your clothes.

What are you doing with butyric acid, if you don't mind me asking. It's got a pretty horrible smell (rancid butter, vomit etc).

I don’t know but I would expect the solubility to be quite good. I’m not sure I would expect full miscibility, as the alkyl group of butyric acid is quite big and might reduce the hydrogen bonding of propylene glycol too much.

Sure, but having a long neck also shapes how giraffes evolve. I do not see that intelligence is qualitatively different from having a long neck, as far as its effect on further evolution is concerned. The organism population does not choose its evolutionary path, even though the choices its members make may affect that path.