exchemist

They have different composition, as @John Cuthberhas explained. My understanding is that the different physical appearance is due to the way the minerals cleave. Talc easily cleaves along a plane, in one dimension, into 2D sheets, rather as graphite and the micas do. Asbestos minerals cleave along two planes, more or less perpendicular to one another, resulting in 1D fibres. The behaviour depends on whether the crystal structure is in the form of sheets or chains of the silicate tetrahedra in the mineral.

So you say. However I can't seem to find a response from you to my earlier questions: do you have evidence of people being driven out, or of "new sceptics" being deterred from entering the field? Where does this come from? And as I said earlier, even the oil companies acknowledge man-made climate change is real: the European ones started to acknowledge the risk at least was real, several decades ago.

Could be interesting. But of course there may now be an "observer effect", as by telling us you are doing this you are perturbing the system........

Fair enough.

I'm hardly alone in my view. It's fairly mainstream. In civilised societies. https://justice.org.uk/article-3-prohibition-torture/

You need to do this for a couple of months for it to mean anything. So much depends on whether or not there is a live topic that a person is contributing to, during a given week.

Correct.

No it's never justified. It degrades law enforcement and is likely to result in bad information anyway. Normally this is posed as a hidden nuclear bomb, but I guess paedos are all the rage at the moment.

I've decided to suspend judgement for now, that's all. If you cite material from disinformation sites, you must expect people like me to be suspicious. "Watts Up With That" is notorious. I presume what you are now referring to is Scaffetta etc. I'll sit that one out, I think. Others seem more au fait with it than I am.

Yes, I think I'd be in favour of keeping it, so long as we know the mods are monitoring it for abuses, such this person with an apparent grudge.

OK @Doogles31731, let me come back on that. I'll be frank. The chief reason I suspect (or suspected) your motives is your use of a well-known disinformation site to bolster your position. I have got burnt in the past, you see, wasting my time on talking points from creationists which turn out to come from their bank of disiniformation sites. There is a lot of this sort of practice about these days, from people who start with a fixed belief and then try to find all sorts of doubtful, or even fake, "science" to back it up. This smelt to me like the same sort of thing, especially when at the start you seemed to represent yourself as some sort of science historian, familiar with climate science and just trying to join the historical dots, when it fact it subsequently turned out that you don't understand the basics and that you had an agenda. This has coloured my opinion of your motives. However I am willing to accept that I may be being unfair to you. So I am prepared to engage further, cautiously, on the provisional basis that you are enquiring in good faith. On the internet, one is dealing with unknown people: building trust in their good faith takes time and we do not have much to go on.

I have considered myself a feminist since my days at university in the 1970s. (I am a man.) But today in N America, paradoxically as the social status of women has gradually improved, sexual politics has become a confusing snake pit. One false move and you get bitten. So I am staying well out of it.

As in Mr Bean, you mean? 😄

Well "should have thought" is an opinion, I would agree, but it's a bit more than just buying into propaganda. I spent a 30 yr career with an oil major and my employer conceded the issue was real at some point in the 1980s. So it's not just an issue manufactured by activists. What about these people being driven out of research, and the new sceptics deterred from entering the field? What sources do you have for those?

Do you have evidence of people being driven out, or of "new sceptics" being deterred from entering the field? Where does this come from? And what do you mean when you say there is no more certainty? I should have thought the evidence of rapid warming and increases in extreme weather events was becoming clearer by the day.

Thanks, I was tiring a bit, to be honest. But as so often, I find these discussions with eccentric people can lead to rewarding spin-offs. I was unaware of Tyndall's work in the c.19th until now, nor did I know when it was that IR spectroscopy was first developed, nor that it was our old chemical kinetics friend Arrhenius who first suggested atmospheric CO2 could have a profound effect on the climate. So I've come out of all this ahead, which makes the digging worthwhile. (It also reminds me of my time as a trainee patent agent, searching for prior art in the Patent Office Library to knock out a rival patent application. We had to do it by hand with indexes and paper documents in those days. And you never quite knew until the end what piece of information would be decisive.) Above all, I'm delighted that @Doogles31731 is now satisfied that science has indeed replicated Tyndall's work, by way of the design and use of the modern IR spectrometer, fitted with a gas cell. If you search the web for "IR analysis of gas mixtures", you will find a raft of references, many to commercial analysis applications, others to research papers, patent applications etc. I'm not going to dig through all these for you. Suffice it to say that this has been a standard analytical technique for gases for half a century. So it's time for you to move on to your next objection to the science of climate change, I guess. I've no doubt that, guided by "Watts Up With That* " and other disinformation sites, you can keep this game going almost indefinitely. Maybe I'll play, maybe I won't. It's now the weekend, after all. * Here's a link to a bias check on that site by the way: https://mediabiasfactcheck.com/watts-up-with-that/

Yes I think that is increasingly the case. 10 years ago, maybe, you could just about have some people with more or less rationally held minority opinions on this (e.g. there is or was that Dane, I forget his name), but today it's almost like Cold Fusion. The killer, I think, is that we are starting to see a number of the predictions coming to pass, at least directionally.

Yes indeed, but our friend won't have done these searches, as he wants to be able to claim there are basic gaps in the science. I get the feeling he may have built a whole house of cards on this notion, which could be why he is reluctant to let it go. But no doubt we will find out.

I'm wondering what on earth more any of us can do more to convince @Doogles31731 that there is not, as he imagines, some crucial gap in the basic data in science, just because nobody has revisited Tyndall's 1859 experiment. I suppose one thing is to provide a picture of an IR gas cell, to show him that in fact what a modern IR spectrometer does is exactly what Tyndall did, with the crucial addition of a means of analysing the absorption as a function of wavelength. So below is a picture of a gas cell. It is in effect Tyndall's tube, with windows at the ends transparent to IR. (To this day, many of these windows are made of rock salt, NaCl, though other minerals can also be used.: Another thing we could do is show how mixtures of gases are routinely analysed by IR, every day. Here is a link to a manufacturer of IR gas mixture analysers: https://www.servomex.com/gas-analyzers/technologies/infrared/ Apart from that, I confess I am rather stumped.

I have not spent any time on this thread talking about my supposed "beliefs", as they are not the subject of the thread. I have spent my time trying to understand what was bothering you and trying to fill in what you thought was missing, by explaining the relevant science. (Though I notice that you, by contrast, have started talking about "belief systems", and introducing extraneous issues like 10 year old letters from retired NASA engineers that shed no light on the issue under discussion. Why is that?) Where you are right, though, is that yes, I do have trouble allowing you to retain a "belief system" that relies on ignorance of science. This is a science forum. The people here are here to learn, and spread, knowledge of science. That's what I'm interested in. So in your case, the important thing for me, once I had smoked out where the gaps in your knowledge are, has been to teach you a bit about infra red spectra of gases. To your question, if Tyndall got feeble (but non-zero) deflections with these gases, he may well have had some contamination. Perhaps that the gases were not entirely dry or something. Or maybe it was an artifact of the experimental setup. That happens a lot. But we can't ask him so we will never know. He did very well for a man of his time with the equipment he had. Do not imagine that you can use Tyndall's reports of feeble deflections to cast doubt on what we know, today, about the infra-red spectra of these gases. That would be about as idiotic as if someone were to insist, today, on dropping balls from the Leaning Tower of Pisa* to reconfirm the acceleration due to gravity. *I know Galileo did not actually do that: he used an inclined plane.

Indeed. I dry them in the small oven at 50C for an hour and then loosely screw on the tops, to keep dust out until I am ready to re-use them.

I found this very informative indeed. It answers the original question I posed perfectly.

I agree screw cap bottles are key. Because I need to restrict myself to 3-3.5 units max, on the evenings when I drink, I use those little quarter bottles you can find in the supermarket and decant into those, fill them to the top to minimise the oxygen exposure and keep them - red and white equally, in the fridge. With most French wine, one of these bottles is 2.5 units approx, giving me headroom for a small sherry or so as an aperitif. As they are only quarter bottles, the reds will come up to drinking temperature after an hour or so out of the fridge. I've found I can keep even the reds for a week this way, without adverse effect on the flavour - sometimes the younger ones even get a bit better from the short air exposure during decanting. I just need to wash out the bottles carefully each time after use.

I'd have thought the dependence of path length on angle of incidence of radiation would be fairly elementary to the modelling. And I did mention scattering. More interesting, in my estimation, is the effect of pressure (collision) broadening on the shape of the absorption bands. That won't be trivial, seeing that it is a function of altitude. And then there is all the atmospheric photochemistry going on in the stratosphere/tropopause as well (for example ozone, having a dipole, absorbs in the IR). And then there are the oceans..... I've never delved into what goes into these models but they must be monsters.

Nobody, least of all me, is dismissing the importance of measurements of the earth, the radiation it receives and its atmosphere (and, crucially too, its oceans). It is @Doogles31731's idea of more Tyndall-style experiments in tubes with mixtures of gases that I am saying is redundant.