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Posts posted by exchemist

  1. 20 minutes ago, anastasiap said:

    Hello, in which chemical reaction is the highest sedimentation rate observed? The chemical reaction must be between two true solutions. Thank you. 

    I presume you mean rate of precipitation. 

    Rates of reaction in solution depend on various factors in addition to the reactants involved, notably concentration and temperature. So I don't think it is possible to answer your question.  But @John Cuthber may be able to provide some examples of reactions in which a product precipitates rapidly. My inorganic chemistry is too rusty for me to able to do that without looking things up. Though, as I recall, BaSO4 precipitates quickly from mixing suitable solutions e.g. BaCL2 and Na2SO4.  


  2. 57 minutes ago, Genady said:

    I wondered (just a little bit) what has happened to the "modern genius" Dembski. Did he mutate?

    Not sure. He seems to have fizzled out. He does seem to have a special knack of quarrelling with just about everyone, eventually. But now that Philip E Johnson, the lawyer who founded the ID movement in the USA,  has died, I think all those guys will soon be looking for other things to do. 

  3. 5 hours ago, Genady said:

    "An obsession is an unbidden, intrusive thought, image, or urge that intrudes into consciousness; attempts to dispel it are difficult and typically lead to anxiety. These thoughts, images, or urges are recognized as part of one’s own mental life." (Obsessions | Johns Hopkins Psychiatry Guide (hopkinsguides.com))

    Haha, yes could be. But I suspect it may be one of these creationist "seagulls" that I've encountered before. At one time William Dembski ran a course, at some Baptist university in the Southern USA, in which he awarded points to students on one module of the course for signing up to science sites and attacking evolution. Normally there would be a flurry of posts for 24-48hrs  - and then radio silence. The posts varied in inanity. But the idea of it not being possible for order to emerge spontaneously cropped up quit a bit.

    Dembski is history now (he got sacked), but maybe someone else is doing something similar.


  4. 8 hours ago, Evomumbojumbo said:

    When I read these posts regarding mutations I find it hard to believe that anyone thinks that mutations are the mechanism by which DNA coding for new anatomical structures is created. 
    it goes against all coding principles, garbage in, garbage out.

    Not if you understand the principle of natural selection. 

    But from your short posting history here (not to mention your choice of user name), my guess is you will sidestep what natural selection says and come up with non-analogies like "tornadoes in junkyards". If you continue to post at all, that is.    

    I will content myself with pointing out that the order in an open system can increase by purely natural processes, so long as entropy (or disorder) is increased elsewhere. This happens all the time in nature. So "garbage in garbage out" is not applicable.  

  5. 1 hour ago, Externet said:

    Surprised I did not know these existed and I have been well into the recording industry since young.  Anyone knows about them ?

    At a local recycling store, saw this.  Compared to a normal 12 inch 'long play'  on the picture :


    16 inch.jpg

    I found this on Wiki:

    Another size and format was that of radio transcription discs beginning in the 1940s. These records were usually vinyl, 33 rpm, and 16 inches in diameter. No home record player could accommodate such large records, and they were used mainly by radio stations. They were on average 15 minutes per side and contained several songs or radio program material. These records became less common in the United States when tape recorders began being used for radio transcriptions around 1949. In the UK, analog discs continued to be the preferred medium for the licence of BBC transcriptions to overseas broadcasters until the use of CDs became a practical alternative.

    From: https://en.wikipedia.org/wiki/Phonograph_record#78_rpm_disc_sizes



  6. On 1/18/2022 at 2:33 AM, Externet said:


    Magma is supposed to be in underground chambers and branches that may or may not be some day expelled by eruptions.

    Petroleum is supposed to be in underground chambers and branches too.  

    I have never known of a reported volcanic eruption that the magma flowed/passed trough into a petroleum deposit and both ended on earth surface as a fiery explosive combustion from hydrocarbons fuel + heat + fire + oxygen.  Is there a reason why such coincidental path event does not happen ?  😱

    I think that will be because of where volcanism occurs. Volcanism arises in three types of location:

    - spreading centres, such as mid-ocean ridges,

    - subduction zones, such as island arcs

    - mid-plate hot spots

    Whereas for hydrocarbon deposits one needs a sedimentary location that has not been subject to subduction or intense heating for several tens of millions of years.

    Subduction zones and spreading centre, where crust is turning over or being newly formed, thus seem very unlikely to be places where hydrocarbons can accumulate. In principle one could get a new hot spot, from time to time, in the middle of a plate carrying continental crust, which might contain hydrocarbons. But the chance of that is pretty small, I'd have thought.



    20 hours ago, iNow said:

    We cannot assume it's never happened nor wouldn't (magma flowing into/through oil deposits) as that's entirely possible. It's just less likely, however, because magma tends to sit higher / closer to the crust than oil deposits which generally are much deeper. 

    It's a bit like placing a rock at the bottom of our cup and asking why the marshmallow you set floating on top isn't interacting directly with that rock. It's not that it's impossible, just that it's unlikely. 

    Other way round surely? Magma originates in zone of partial melting in the upper mantle or lower crust, whereas hydrocarbons form from living organisms on the surface that have become buried, in sedimentary formations.

  7. 14 hours ago, Arthur Smith said:

    Sure but as I'm new to the site I'm finding the rules of being off-topic are a bit confusing to me. Regarding personal prejudice, I was just owning up to mine as a preamble but you see where that got me.

    If you were to confine yourself to discussing the historical evidence, as I am trying to do, there would be no problem.  Personal opinions on Christianity as a whole, however, have no bearing on historical evidence. That distinction does not seem confusing to me. 

  8. 7 hours ago, Arthur Smith said:

    I did indeed make a decision about Christianity at a very young age. I questioned it and decided God wasn't real when I was about  8 or 9 years old. Once I rejected the central concept, the trimmings are very much like window dressing, especially when you look at the various schisms of Christianity I was brought up in the Church of England community and our next-door neighbours were Catholic. We had a very odd relationship.

    There's no therefore. My decision that Christianity is a web of human invention that I need not concern myself with has remained with me. My prime directive is to live and let live. Whether this, that or other Biblical character is accurately represented, embellished or completely fictional is not an issue that obsesses me. It is only recently that I have become interested in what evidence there is that confirms people, events, places in the Bible. For instance archaeological investigation in the Levant is recent compared to regions with more stable politics, and is still under political influence and control. It's fascinating, both what we do and don't know if we evaluate it dispassionately.

    The historian, however, will consider the evidence of the sources. As in science, proof is not to be expected, but evidence that is consistent can suggest what may have occurred. So far as I am aware, there is no evidence that Saul of Tarsus was an invention, whereas there seems to be evidence from more than one source for his historical existence. Enough to persuade non-Christian (ex-Christian) historians like MacCulloch, at any rate.  

    In a thread about Jesus, this about St. Paul is a bit of a side-issue, admittedly, but perhaps for him too, one needs to distinguish evidence from personal prejudices. Where Jesus is concerned, MacCulloch seems to think the main evidence for Jesus as a historical person comes from his preaching style as reported in the gospels, which he seems to find highly idiosyncratic: the use of parables, the repeated use of the enigmatic phrase "Son of Man" and so on. He feels like a real person. But MacCulloch seems more non-committal about Jesus than about Paul, whom he confidently describes as a businessman (in fact a tent-maker) from Tarsus.   

  9. 19 hours ago, TheVat said:

    I loved "Longitude"!    Sobel made more sense out of navigation, timekeeping and related topics than anything else I've read.  I second BC's recommendation.  

    Agreed. A fascinating book. 

    I'd also nominate Martin Brasier's "Darwin's Lost World". This is a readable, first hand account of palaeontological research into the development of preCambrian life, i.e. the mysterious stage before things had hard parts that fossilise well. It introduced me to the enigmatic Ediacaran fauna and insights such as as the impact on life of the coming of the mouth.   


  10. 20 hours ago, Arthur Smith said:


    As I've never been convinced there was anything to Christianity since I was a child, I've not really looked at what you might call supporting evidence for people and events described in the Bible. Once you discount the supernatural stuff, whether some events and characters are correlated elsewhere is not particularly important. or relevant. However I did come across someone recently (rather vehement in his views) who claimed the Bible is basically an almanac and was not intended to be historical. It prompted me to look at history and archaeology of the Hittites. The Hittites occupied Anatolia for hundreds of years (prior to being conquered by/absorbed into Ancient Assyria) but at their zenith shared a border with Egypt that ran East-West through the middle of the Levant. Whilst Hittite sources record dealings and disputes with Egypt without any reference to Israel and Egyptian records follow the same pattern, the Bible has almost no mention of the Hittite Empire, allegedly at the time of David and Solomon. Israel Finkelstein has worked tirelessly to establish some archaeological support for Biblical people and places without success.

    The Emperor Constantine's mother, Helena, seemed to come across many places of interest in Palestine three centuries after the crucifixion that are now famous sites for pilgrimage, none of which bear the slightest scrutiny archaeologically.



    I can't immediately see what this has to do with the issue of the probable first language of Saul of Tarsus, a.k.a. St. Paul. 

    Do you simply mean you decided long ago that Christianity is bunk and that therefore none of the dramatis personae, St. Paul included, can be based on real historical figures?  

  11. 14 minutes ago, Arthur Smith said:

    And his evidence that Paul the Apostle spoke Koine Greek as his first language would be?

    He does not give any references. It just seems to be generally understood. If there were much doubt about it, I would expect MacCulloch to indicate that.

    I presume it is because Paul came from Tarsus, in modern day Turkey, which like most of the Eastern Med. spoke Greek at the time. (According to MacCulloch there was already a centuries old diaspora of Jews around the region.)   

  12. 43 minutes ago, Arthur Smith said:

    I read the reference to Koine Greek but that in itself is supported only by a reference to a popular book and a 50 minute video. 

    Anyway, live and let live. If religion enriches someone's life and they don't feel the need to invest in torches and pitchforks , who am I to criticize?

    No, this is also as stated in Diarmaid MacCulloch's "A History of Christianity", MacCulloch being Professor of Church History at Oxford.  

  13. 5 minutes ago, Genady said:

    Yes, absolutely unconditionally sure. Bounded systems do not expand with cosmological expansion. Galaxies are gravitationally bound.

    Surely that cannot be right. If the metric itself expands, it must affect everything in the cosmos, mustn't it? Obviously in a bound system all that would happen is the dimensions stretch a bit locally, i.e. not enough to materially alter its configuration. But I can't see how anything can be exempt from a change in the metric.  The metric defines the unit of length itself, doesn't it?  

  14. 17 minutes ago, Genady said:

    The box keeps its shape and size. The atoms of the material it is made of do not expand, distances between atoms do not expand as the universe expands. The walls of the box do not move relative to each other.

    E.g. the distances between far away galaxies increase, but the galaxies themselves do not grow as the universe expands.

    Are you sure about that? I should have thought that if the metric itself expands, then the dimensions of everything must do so, though the change for points close together would be very small. 

  15. 26 minutes ago, Arthur Smith said:

    That seems reasonable, at least for the epistles generally agreed as authentic. I understand there is a similarity of style and vocabulary that suggests a single author. And possibly Paul used a native Greek amanuensis.

    Though it does occur to me that this might be a bit circular. Attributing works to one author by examining the style, content and vocabulary seems reasonable but do we have any independent (other than Biblical texts) historical evidence for the life of Paul the Apostle?

    St Paul (Saul of Tarsus) was a Roman citizen and travelled extensively in the Eastern Med. According to the Wiki entry on him, Koine Greek was probably his first language, even though he was a Jew.  https://en.wikipedia.org/wiki/Paul_the_Apostle.  This lists what sources we have for his life. There seems no particular reason to doubt that he was a real person.   

  16. 5 hours ago, Genady said:

    Of course. I should've said "such as that of light" or something similar. Otherwise, yes, this is what I mean.

    I have a picture in mind where the light remains light, i.e. is not absorbed in a sense of being converted into something else. It will be there with no mass, but the entity will gain mass still.

    Hmm, do you mean that a glass prism gains mass if you shine a light through it? I struggle to see how that would work, I must admit.

    Unless..........you mean that the coupling of the radiation to the medium "lends" some of its energy to it as it passes through, which I guess it does if its refractive index deviates from unity.   

  17. 23 hours ago, Arthur Smith said:

    Well, maybe. But why was he writing in Greek, rather than Aramaic (the lingua franca of the time and region) or Latin, the official language?

    Thanks for finding that. I'll have a look through, though 2014 is a while ago. 

    Can't argue with that! ;)


    On glancing through the previous thread on reality of Jesus, there's a lot of chaff in the wheat. 

    Surely St. Paul wrote in Greek because he was not writing to Aramaic-speaking Jews, but to people in and around Asia Minor (Colossians, Ephesians, Galatians, Corinthians, Thessalonians etc.) who spoke Greek, it being the end of the Hellenistic period in the Eastern Med. 

  18. 17 minutes ago, Genady said:

    They do "go hand in hand" ( @exchemist) but they are different nevertheless. Energy is additive, mass is not. Energy with no mass, such as light, can be added to something and that something will acquire extra mass.

    Sort of, ish. Light is not energy of course: it has energy (E=pc = νλ), which can be added to that of an entity that absorbs it, which will then gain mass according to E=mc². 

  19. 8 hours ago, joigus said:

    It may be interesting to notice that the EM contribution to mass is negligible in most macroscopic cases. If you plug in the values of ε0 , c2 and assume 'typical' values for the field E the order of Volts/metre, volumes the order of cm3, you get for this charged macroscopic object a correction to mass of its uncharged state the order of one proton mass or thereabouts.

    This is, of course, due to the high value of the speed of light.

    Sure. My interest in the issue was merely that I often,  when explaining E=mc² to lay people, use the example of charging and discharging a battery, to show that the formula  says mass and energy go hand in hand, rather one being converted into the other, which is what the uninitiated  frequently seem to think, probably due to the association of Einstein's formula with  the mass defect in nuclear fission. And then it struck me suddenly that, while it may seem comprehensible that an object with mass, like a battery, may  in theory gain or lose a tiny amount of mass, it is less obvious what happens to something nebulous and apparently massless, like the magnetic field of a solenoid when it is energised. So I wanted to make sure my way of explaining it covered that case as well.          

  20. 9 minutes ago, studiot said:

    Maybe not a great example, but I meant it as a ballpark example along the following lines.

    Classically, (without QM) bonds are just links of electrostatic origin. That is the bond energy is contained in an electrostatic field of some sort between the atoms.
    Si is 4 valent and B is 3 valent.
    So one can measure or look up the bond energies.
    And also the mass difference between a silicon atom and a boron atom.
    So one can get the energy difference in substituting 1 in X silicons by a boron and reducing the bond energy by four Si-Si bonds and adding back three Si-B bonds.
    However this substitution will also introduce strain energy into the lattice which will tend to zero as X tends to infinity.

    Oh I see what you mean. But as there isn't really a classical picture of covalent bonding in chemistry, it's a tiny bit artificial.    


    3 hours ago, studiot said:

    If you want a classical answer you could consider the decrease in mass due to changing a silicon atom for a boron one in a silicon lattice, since this would decrease the charge by 1,thus reducing the field slightly. Since we are then talking about a solid lattice, momentum would not be involved the simple e = mc2 would suffice.

    Not sure that's a great example, as elemental silicon has a giant covalent structure, in which the bonding involves electrons in motion in orbitals shared between atoms, but no doubt one could consider changes to a purely ionic structure that would alter the energy of the lattice and thus its mass. So I do take your point.  

  22. 39 minutes ago, JIMMY12345 said:

    The lines are already drawn. We are a species that survives due to genetic diversity. Different responses at different times to threats ensure our survival or demise.

    A lot of our responses are already hard wired into our genes. The rest is conditioning. The serious  science is heavy going. Some scientists concentrate 100% on science. A few take a 2 minute break and enjoy some light humour. The latter especially if they take climate change as fact and cycling as part of the solution.

    Your sleeping. An incessant tap on your shoulder draws you from your slumber. Dickens ghost of Xmas to come takes you firmly by the hand. All the way to 2050.Note he doubles as scientist and cyclist.

    You scan the selection of blueprints. It’s on a quantum computer. In the basement a 3D printer starts to churn. Its rolling out a Xmas present. A bicycle of your design. Together with puncture proof tyres and 6 kg frame. Outside the roads are made of super tarmac. Like Lino with minimal rolling resistance. So much faster. The advances in 2050 sports medicine are amazing.

    The Mars annual mountain bike Annual Tour 2050 championship is on. Forget Sports Tourism. The Mars surface was designed for one thing. Humans to race bikes.

    Freezing temperatures, No oxygen.All that methane?. Science is so beautiful. Your helmet is designed to be symbiotic. It incorporates methane gobbling bacteria that love a methane diet. They spew out carbon dioxide and water.Plants use this to produce oxygen .We have created huge hoards of these helpful bugs underneath the Martian surface. Energy and respiration and cleaning the sprockets on the bikes powering hotels. Bacteria step up the wattage to make Mars habitable.

    Newton discovered Gravity. In 2050 we finally understood Gravitons. Just as the transition from Wilbur and Wright to the 747 took 100 years. So to for spaceflight.

    A drone gently drops your cycling jersey down the house chute. It regulates temperature even when wet.
    You pay by just one worldwide Cryptocurrency. This is finally safe. It’s all totally Government controlled. Negative interest rates mean banks pay you to borrow. However, the most precious commodity is now available with the ubiquitous robots and homeworking. Time you have time to cycle. More importantly you now have time to read those science research papers.


    Where does the methane come from? 

  23. 23 hours ago, joigus said:

    Now that I think about it, @exchemist wasn't necessarily talking about the electron...

    For some reason, I was thinking about the electron.

    No indeed. My question was far more basic, simply whether a static electric or magnetic field has mass as a consequence of its stored energy.

    I realise now that my question was at one level a bit stupid, since if a battery gains mass when charged (albeit to an unmeasurably small degree ), it means the energy in the chemical bonding goes up and gains mass - and the energy of that bonding is a sum of the electrostatic potential and kinetic energy of the electrons. So it seems to me now that a static field must indeed have an associated mass, even though this feels unintuitive when one thinks of the magnetic field of a solenoid for example.

    Also, from the other (very interesting) replies, it dawns on me that I should not find this idea of fields having mass unintuitive, since (as I understand it, very vaguely) fundamental particles are considered in QED to be excitations of a field.  I probably need to let go of this rather 6th form idea of mass applying to things called "particles" of matter, as distinct from insubstantial things called "fields".    

    17 minutes ago, studiot said:

    Thank you for your thoughts.

    Since we have not yet heard from exchemist, I hope he is OK.

    However there is a clue in the name.
    I suspect he is more interested in the field of the nucleus than the fields of astrophysics at the scale of the universe.
    Particularly as he specified 'static' fields.

    If the universe is actually infinite then the global mass integral must also be infinite so adding mass in any way does not change that result.



    You are psychic! I was just replying. (I was out most of yesterday.)

    There is some excellent food for thought in this thread and I'm glad I left it long enough for those replies to come in before responding. 

  24. Responding today to the thread in Speculations, it struck me I don't know how to treat the stored energy in a static EM field, according to  E² = (mc²)² + p²c².

    Since, unlike the situation with EM radiation, there is no motion involved, I presume the second term does not apply. But does a static field gain rest mass, as its stored energy increases? Seems weird if true.

    I've a feeling I'm missing something here. Can anyone help? 


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