exchemist

This passage of Carnot's that you are paraphrasing is very interesting. Can you provide a link to it so I can read what else he says?

Why learn science? The short answer is curiosity: curiosity about why phenomena in nature occur the way they do. The second part of your post seems to concern something rather different: technology. Technology is the application of science to the human world. But many people who study science don't do it because of a wish to apply it via technology. It is curiosity about nature that drives them.

Yes of course, we have known exactly why raising the temperature makes a gas (at constant pressure) expand, or alternatively why (at constant volume) its pressure goes up, for almost 200 years. Look up the kinetic theory of gases: https://en.wikipedia.org/wiki/Kinetic_theory_of_gases . And yes, an engine rejecting less waste heat than the prediction of the Carnot efficiency limit would violate a physical "law" of the universe. This law arises from the statistics of large numbers of molecules, which again has been well understood for about 150 years, Maxwell and Boltzmann being the founding fathers, but subsequently further built on with the advent of quantum theory. Look up statistical thermodynamics (or statistical mechanics, of which statistical thermodynamics is a subset). To think that by tinkering in your garage you are going to overturn 200 years of well established physics, which you have not even bothered to find out about, is solipsistic and idiotic. (I blame the modern popular disease of suspicion of expertise and deference to stupidity - as reflected in modern US politics for instance. 😁)

Yes, cyanogen is mentioned in some of the articles about this.

Thanks to you both, @joigus and @studiot. So it's dicarbon. Well well. I found this, which makes interesting reading: https://en.wikipedia.org/wiki/Diatomic_carbon It looks as if the green comes from emission from the 3Πg state. This intrigues me as it looks as if it might be a configuration equivalent to acetylene minus the H atoms, i.e. a triple bond between the atoms, leaving a σ unpaired electron on each atom. But I'm very rusty on how to interpret these molecular term symbols. The ground state is singlet, so there are lone pairs on each atom and one of the potential π bonding orbitals is empty. It seems as if this electron-deficient molecule has quite a bit of chemistry. The dicarbon seems itself to be the photolysis product of relatively volatile carbonaceous compounds. Interesting that nitrogen is present, too.

This comet is currently in the news. Many articles comment on its green appearance. However I have yet to come across a full explanation for the colour. The closest I've got is that it is apparently fluorescence from gases in the tail, excited by UV from the sun. Does anyone have more information? What gases?

You have been told over and over again that the Carnot efficiency formula is good science, for at least two excellent reasons. One is that its derivation does not depend on anything other than the gas laws, which are well confirmed. (It does not depend on the old idea of caloric, even though you are pretending as hard as you can that it does. If you really think that modern science would justify a formula by means of a derivation based on a false model for heat, then you are a total moron.) The other reason is that over 150 years of practical experience has confirmed that, however hard we try to make the most efficient heat engine we can, it never manages to surpass the efficiency limit predicted by the Carnot cycle. That's what it does: it predicts a limiting efficiency. You are now simply sticking your fingers in your ears and saying "lalalala". You are wasting everybody's time, frankly.

Two issues. First, my understanding is that there are 3 mass states, i.e. 3 possible mass values, but this does not mean there is more than one type of mass. Second, you need to explain why you think that multiple mass states must apply to all subatomic particles. It does not seem to follow automatically from the observation of this in neutrinos.

The link seems to be to a (probably predatory) pay-to-publish, junk journal. It can't even print grammatical and complete sentences in English. This is from its home page:- International Journal of Applied Science and Research [IJASR] is multidisciplinary double-blind peer-reviewed, open-access journal intended to publish original research papers in all main branches of science (All scientific disciplines) a peer reviewed refereed bimonthly journal that publishes empirical, conceptual and review papers of exceptional quality that contribute to enrich business administration thinking .The objective of the Journal is to disseminate knowledge, which ensures good practice of professional management and its focal point is on research and reflections relevant to academicians and practicing managers/Administrators for sustainable Applied Science and Research changes. IJASR guides it to map new frontiers in emerging and developing areas in research, industry and governance as well as to link with centers of excellence worldwide to stimulate young minds for creating knowledge based community. Our continued success lies in bringing together and establishing channels of communication between leading policy-makers and prominent experts in industry, commerce and related business as well as renowned academic, education and research based institutions to provide solutions for addressing the key issues of the contemporary society. We see the need for synergy and collaboration between these fields rather than segmentation and isolation. Hence, our objectives are to build new links, networks and collaborations between communities of thinkers, scholars, managerial experts and practioners in order to stimulate and enhance creative and application-oriented solutions for society. In order to foster and promote innovative thinking in the management studies and social sciences research, itself by introducing its Journal at global platform in ensuring the high quality and professional research standards. Seems to be a fairly random collection of buzzwords, thrown together with little attempt at punctuation or at bothering to write complete sentences. What a farce.

Addendum: I got this a bit wrong. What makes the relativistic version different is that the speed of light is independent of relative motion between source and receiver, whereas a classical wave moves at a fixed speed in the medium that transmits it.

It is an effect you get with any propagating wave. All that matters is relative motion between the source and the receiver. (It is in any case arbitrary which of the two you say is "stationary", since that depends on the frame of reference of the observer.) The maths works a bit differently for light, since that travels at c, necessitating use of the relativistic Doppler effect. But the effect is qualitatively the same as with the classical Doppler effect, which one uses for sound waves for example.

Well of course. It's science, you see.

All good points. But the issue arises only in those countries whose populations are shrinking, or close to it. India has if anything the opposite problem.

That's another matter, I agree. But even in places like China or Russia, the motive for wanting a rising population is not just so government can spend more. It's things like having a bigger army, having a bigger economy and thus more power in the world, being less reliant on other nations etc.

What strikes me as absurd is the idea that government is some kind of separate entity with its own agenda, rather than being what people vote to get. Government doesn't have an agenda to get a bigger population so that it has more to spend. Its expenditure is essentially per capita. So it will need more to spend if the population is larger. If it is smaller, it needs less. Ageing is not a one-off bulge. It's a long term, irreversible change in the age distribution. I agree that if government can get the retirement age raised that will help a lot. But it is also inescapable that the coming age distribution will be more costly to support than the previous one, due to the extra permanent tranche of very elderly, infirm people.

You are not taking into account the age distribution. The problem many countries face - and will do increasingly - is a growing cohort of the old, who are now living to very advanced age, needing increasingly costly medical care and other support, while the working age portion of the population shrinks, because the birth rate is insufficient to replenish it. We no longer drop dead at 70 from a lifetime of smoking. That's a problem. Solutions may involve further raising of the retirement age, on the basis that older people are in better health than they were when retirements ages were originally set. But that is hard to do (cf. strikes over it in France, currently) and may not be a complete solution. (Your comments about governments liking more money to spend are absurd, by the way. Governments in democracies are elected and it is the people that elect them that are constantly demanding they spend money, to provide an increasing range of services to society.)

Are you trying to be obtuse? These reservoirs are just concepts denoting a heat source and a heat sink, whose temperatures remains constant irrespective of whether heat is drawn from or given to them They are nothing to do with any "environment". Just a heat input at one temperature and a heat output at another. That's it. Doesn't matter from where, or to where. The concept of a cycle is specifically intended to represent the working processes of a theoretical, idealised heat engine, containing a fixed amount of an ideal gas, which goes through a cycle of expansion and contraction and does work in the process, all according to the gas laws. So it's not a real engine (of course) but a distillation, to its essentials, of the simplest imaginable heat engine: a gas, alternately expanded and contracted and pushing a piston, and the heat flows involved in that. As it turns out, the efficiency formula that results is beautifully simple, as you have realised, and only depends on the input and output temperatures. But it is a formula for a heat engine: the most efficient one that is possible to imagine.

That's ballocks. It is an ideal theoretical engine cycle, with constant temperature heat input and output. The environment has nothing to do with it.

Don't be ridiculous. This is a total ranting rhetorical muddle as usual and contains a stupid straw man. There is no such thing as a "Carnot engine". You have made that up. There is a Carnot cycle, which, as several people have told you several times, is a theoretical optimum heat engine cycle whose thermal efficiency, according to the theory of thermodynamics, no real engine can exceed. The theory of the Carnot cycle would thus obviously be falsified if someone were to produce a heat engine exceeding Carnot cycle efficiency. So it is - obviously- a falsifiable theory, in Popper's terms.

What point do you wish to discuss? Answering a question nobody has asked is a very odd way to start a discussion. Or are you just a bot?

You've been on this kick for almost a decade now.

Bingo! The Galileo gambit. Well, it was only a matter of time.😄

That's why I put particles in inverted commas. The whole idea of a particle is a rather ridiculous one, when you think about it: a notional ideal object, with no dimensions but nevertheless a host of other properties.

You just need to ask yourself what is meant by "touch". Subatomic so-called "particles" are not like little steel balls. When one says that two object touch, what we mean is that they are close enough for the atoms on their surfaces to repel one another strongly if they are pushed closer together. That is what "touching" means.

Yes, I knew vaguely that caloric was supposed to be a sort of nebulous fluid, but I never studied the history of science formally so never had any reason to think much about it. I grouped it mentally with phlogiston and the aether as one of those many dead ends in the development of science. But now I can see what a good (though still wrong) idea it was, and how illuminating it was to people at that time. Anyway, that's the chief thing I get from these threads started by cranks. There was an excellent one last year about IR and climate change, which alerted me to a c.19th Irish experimenter by the name of John Tyndall, who basically built the first IR spectrometer without realising it!