exchemist

If you are a fine art student at a university, perhaps you can get in touch with someone in the chemistry department to help you further. Most things that the human nose reacts to are organic compounds that are not themselves gases but whose vapour, at low concentration, is detected by the olfactory system. But it's a very complex business. One of the chemists I studied with at university went into the wine trade and tried to analyse what gives wines their individual flavour. It's just about a lifetime project. The smell of roast chicken probably involves hundreds of compounds. Or, if you are interested in something more poetic, like the smell of a wet city street after rain, I have no idea what you would be looking for or at what concentration levels. But it sounds rather fun to try.

Yes, presumably GC-MS.

I’m not quite sure what you mean by capturing. Do you mean a complete chemical analysis of a sample of air? The issue with that will be down to what threshold of detection, because there will be traces of all sorts of things at very low concentrations. The other issue is you need to have some idea of what molecules you are looking for in order to pick the best analytical method to use. If this is a smell project I imagine you won’t be interested in the major gases, but more in organic compounds , and possibly at the ppm level. Is that right, or are you thinking of inorganic components that the human nose detects, e.g SO2, H2S, etc?

It seems to me that consciousness is not an entity at all but an activity: the activity of the brain. I think a great deal of time and energy has been wasted by misclassifying an activity as a thing. It's a category error, in my opinion.

What’s wrong with a window, or skylight?

Is your first name Quentin, by any chance?😁

Interesting, but I wonder how applicable this would be in cultures in which people don't rely on cars as much as they do in N America. If you take someone who lives in a European city, for example, they may not drive enough to start with for much change to be detectable. Perhaps it could work on GPS monitoring of somebody's mobile phone, though. That might work even if you get around on foot, public transport or by bike.

Heh heh, I admit you had me going there, with these excellent (CIA?) robots. But where is the Turkey X 500?

Er, it's a spoof. And quite a funny one. I love the idea of getting JFK's assassination involved.

You are both in violent agreement. A stuck wheel does no work, even though it applies a force, since it is not moving. But you are talking about equal force being applied by both wheels, which no one here disagrees with.

If you think about it, a mole of many compounds is quite a large amount. For example a mole of table salt (NaCl) is roughly 23 +35 = 58g. So if you work with dilute solutions of things (especially things like strong acids which are dangerous to handle when concentrated), you are likely to be dealing with fractions of a mole in most cases. Whereas obviously the proportions given in a reaction scheme tell you what happens in whole numbers of moles, so as to give you the appropriate ratios to apply to smaller quantities. So if you have HCl +NaOH -> NaCl + H2O, you can see that 1 mole of HCl reacts with 1 mole of NaOH to give 1 mole of NaCl and 1 mole of water, but if you only have 0.01 moles of HCl, then that will be enough to react with 0.01moles of NaOH and give you 0.01 moles of the products. So you just scale it accordingly. I don't think you will ever come across -ve numbers of moles, though you may come across fractions of a mole expressed in standard form, e.g. 5 x 10⁻² moles for 0.05 moles.

Yes, I had the same feature on the 4 wheel drive I had when I lived in Dubai in the 80s. I remember I was also told not to engage 4 wheel drive until I went off road, to avoid "winding up" the transmission on surfaced roads when turning. The front wheels turn through a longer arc than the back so without a centre differential, which such vehicles don't have, the front and rear drive shafts are trying to turn by different amounts. So the procedure was when going off road to engage 4 wheel drive and then jump out and connect the front hubs. By the time I left in 1987 many of the newer vehicles did it automatically. (The vehicle I had was what is called in the UK the Mitsubishi Shogun. However in Dubai it was called the Pajero. Many years later, I learnt from a S. American colleague that "pajero" is Spanish slang for wanker. Another example of the Japanese instinct for picking brand names that don't work in Western culture.)

From @Ghideon's post it seems you are right.

I think you've picked the wrong word with "priest", actually. In Christianity, those denominations that have priests do not subscribe to scriptural literalism. Literalism is almost entirely the preserve of fundamentalist Protestants. In Islam, there seems to be a degree of scriptural literalism too - but they don't have priests either, of course. But indeed, as with all religions, people tend to believe what the teachers of that faith teach. So if the preachers don't understand metaphor and allegory, there's not much hope for their congregations. So maybe what we can conclude is that scientists with religious faith will tend to have a grasp of metaphor and allegory!

OK I understand you better now. I quite agree there is no necessary conflict between the pursuit of science (applying methodological naturalism) and religious belief per se - though some more naive forms of religion are ruled out, of course, notably scriptural literalism of various sorts.

It seems that if you want to make a Grand Trampling Exit (for the second time now, is it?) , you have to do it without help.

Plenty of scientists have, and in the past had, religious beliefs without it getting in the way of their science in any way. Science is not some priestly calling that takes over your whole life.

OK, I'll have a go at this. The signs are phases of the orbital wave function, just as you have a +ve and -ve phase in an alternating current, or in a water wave as crests (+) and troughs (-) pass you. When combining atomic orbitals to make a bond there is either the option of the two having the same phase (one is + when the other is +), or of them having opposite phase (one is + when the other is -). If they have the same phase, the resulting combined orbital has a build up of electron density between the atoms, has lower energy than either of the atomic orbitals, and is therefore a bonding orbital. If the phases are opposite, you have a node between the two atoms (where the sign of the phase changes), indicating that electron density is reduced, rather than increased, in the region between the atoms, and this corresponds to an antibonding orbital, which is of higher energy than either atomic orbital. Both bonding and antibonding orbitals form when 2 atoms approach one another. A chemical bond will form if there are enough electrons to populate the bonding orbital but not the antibonding one. (An example of where both are populated is when 2 inert gas atoms approach one another. Both orbitals are populated and the repulsion due to the antibonding one cancels the attraction from the bonding one, so no bond forms.)

I'm not sure everyone agrees they are greater disciplines. I'm inclined to resist potentially invidious rankings of that sort. I think the split came about due to empiricism - and the huge push that got with the invention of suitable instruments by which nature could be studied (telescope etc), and the invention of the printing press which gave like-minded experimenters an easy way to read of one another's work. I suppose people like Roger Bacon and Ibn Al Haytham were the first since the ancient Greeks, but it only got properly off the ground after the Renaissance.

Yep, that's the one I would go for as well, for the same reasons as @studiot. As the units of entropy are energy/temperature, say J/K, it gives a sense of thermal energy becoming less able to do work as its temperature drops, so a sort of heat dissipation. It's a bit harder to see how this applies in the case of entropy of mixing, but in that case too each component it becomes spread out through a larger volume, so its internal energy becomes more dissipated.

Looks like a homework multiple choice question. What do you think and what makes you uncertain of the best answer?

Thanks, that's very informative. But according to the link, neutrinos are detected, not by beta decay, as @Heis3nbergsaid, but by emission of Cerenkov radiation, in which, apparently, both electron and muon neutrinos can show up but not, for some reason tau neutrinos. They don't say why, but I can imagine that it would be less likely a particle with such a large mass will be accelerated to speeds greater than the local phase velocity of light in the detection medium.

Exactement. The Immaculate Conception of Mary has nothing to do with parthenogenesis, however.

Who claims "science is about reality", and what was the context in which this was said?

Do muon and tau neutrinos also participate in beta decay reactions, then? Or, when you say "similar", do you mean different from beta decay but in some way analogous? Or is it that they do, but to a much lesser degree, due to their greater mass (which you referred to earlier)? Is this a cross-section effect? (I don't know anything about this stuff.)