exchemist

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.

It seems to me you are artificially separating intelligence from other evolved traits, without justification. Of course a creature with intelligence will respond to its environment in ways a less intelligent one might not. But then a creature with keen sight will make different choices from one that has poor vision. But a more important objection is that it is the responses of individual creatures in individual circumstances that are "guided" by intelligence, if you will. There is no way for a creature to apply its intelligence to the evolution of the population of which it is a member, which is what would be need to it to be correctly termed "guided evolution". A population of intelligent creatures can't make choices about how it evolves.

This seems a bit meaningless. Animal intelligence is, like other traits, a product of evolution. All such traits obviously play a role in determining the future evolution of the organism. But as we don’t say evolution is “guided” by the presence of, say, a sense of smell, or a pair of legs, why should it suddenly be termed “guided” when an organism has evolved a degree of intelligence? It seems quite arbitrary.

Thanks yes it could be it, except my mystery message says "help me" instead of C-19. But if it's a bot or scammer that posts a PM and then gets banned he, she or it has done it to me twice now with the same message. But at any rate, from reading the previous thread on your mystery messages, it seems I need not worry too much about malware or hacking.

For the second time now in recent weeks, when logging in I get a message towards the bottom of the screen saying "help me", with a note that I have a personal message. This message disappears after a few seconds, without any further keystrokes from me. On neither occasion has there been any unread personal message in my In box. I don't like this. Is it a feature, a bug, or has the forum, or my laptop, been hacked?

What I said was if there is no sign of life I don't think an extrapolation can be made.

OK thanks. (The link you supplied takes one to the middle of some piffling argument with a creationist, but scrolling to the top makes it clearer.) But that's just about Mars. If there continues to be no sign of life there, I don't think it provides a basis for extrapolation to other bodies we have not yet detected. Of course it does detect evidence of past life, that's highly significant, hence the interest.

You will need to explain the relevance of that link. No, that is wrong. We do not know what the "normal" density of life is. We have no way to assess what is "normal" for the universe, due to the difficulty of detecting life elsewhere. According to my understanding (I am not a specialist in exobiology) the best we can currently do is look for the signatures of molecules that are relevant to the biochemistry we know from Earth, in the absorption spectra of planetary atmospheres. That is very hard to do, as planets are themselves too small to detect around anything other than very close stars, let alone measuring the absorption spectra of their atmospheres. The general default principle of cosmology, that there is no reason to think why our own solar system or galaxy should be special, suggests that since life has arisen here it will have arisen elsewhere, on planets with similar conditions. The question then becomes one of how common such planets are. That is a question people sometimes try to estimate but, given the size of the cosmos, it seems unlikely that these conditions occur nowhere.