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mississippichem

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Everything posted by mississippichem

  1. I think people often don't understand the complexity of toxicology in general. It is extremely daunting to predict toxicity, especially in novel drug classes. It's not as if drug designers have an equation that takes in chemical structural data and outputs an LD50 forecast. There have even been instances of the sodium salt of a drug showing no hazardous side affects while the magnesium salt is lethal, something that would be predicted on chemical or biological grounds to make a negligible difference. Greg Boyles has shown a pretty awesome ignorance of the way the chemical/drug/bio assay/regulation process happens in the business and science world. We simply don't have a toxicological crystal ball and some people posit that we never will as there are simply way too many variables and parameters to consider. So Greg, should we stop drug and agricultural chemical discovery all together for fear of yet unknown side effects?
  2. An equation equates two algebraic expressions. A function assigns one output to every input. The equation of a circle is not a function. There is more than one value for f(x) for some values of x. A function has one [or zero] values for f(x) for every x as far as I know. Incorrect, the limit definition of the partial derivative disagrees with you. The partial derivative and derivatives in general are limits of the difference quotient. The word infinitesimal is hardly "rot", it might be one of the most important concepts in analysis and calculus which are without doubt some of the most important concepts in mathematics.
  3. Remember that we can write a pKa for a reaction but not for a compound per se. Often times it looks like a pKa is written for a compound but it is really just the reaction: [ce] HA \rightarrow H^{+}+A^{-}[/ce] So obviously here the pKa is: [math] pKa = -\log \left ( \frac{[H^{+}][A^{-}]}{[HA]}\cdot \frac{\gamma_{H} \gamma_{A}}{\gamma_{\mathrm{HA}}} \right )[/math] Where the all the activity coefficients, [math] \gamma [/math] are very close to unity for an ideal solution. So the answer to your question is neither. An acid/base equilibrium reaction with a low pKa will be product favored when written in the form: [ce] HA \rightarrow H^{+}+A^{-}[/ce] Or will be reactant favored if written as: [ce] H^{+} + A^{-} \rightarrow HA [/ce] *I don't know how to LaTeX equilibrium arrows so forgive my notational travesty please . Remember that the equilibrium constant says nothing about the kinetics of a reaction. You can use equilibrium to obtain thermodynamic state functions like Gibbs energy, a measure of spontaneity, but this says nothing about the reaction "proceeding". A reaction can be both thermodynamically and equilibrium favored but proceed at a rate that is slow enough to be practically unobservable.
  4. I believe you are asking about the physics that gives rise to chemistry. It's all about the behavior of the electrons in their orbitals surrounding the nucleus of the atom. Any individual electron is indistinguishable from any other electron but in atoms and molecules the electrons are organized into "orbitals" of different energy. The difference in energy comes from the properties that describe the "orbital" such as distance from the nucleus, angular momentum, spin etc. Chemistry is really just the physics of the sharing of electrons between atoms. Electrons in these atomic orbitals are "stacked" in a predictable way governed by the laws of quantum mechanics. The number of electrons in the outermost energy level are the ones that really govern the chemical reactivity since only those are really available for sharing with other atoms. This sharing of electrons is called chemical bonding. Different atoms have different numbers of protons which governs the number of electrons needed to comprise a neutral atom. The way those electrons are arranged quantum mechanically governs how the atom will share electrons with other atoms and from molecules.
  5. I should add any five membered rings with more than three nitrogen hetereoatoms in them to the nasty list. Explosion waiting to happen.
  6. Oh...I missed the 2 subscript. Still I don't think that geometry is allowed for Ag(I), if you consider the amino ligands. Also, I've never seen a bimetallic complex of that type without stronger electron withdrawing terminal ligands. I won't say the complex is impossible, just unlikely.
  7. I also highly doubt the existence of the naked sulphide ligand as written by Greg Boyles. The charges and orbitals don't work.
  8. I agree with John Cuthber. An easy Ksp look up and two empirical observations are hard to argue with. And the solubility of the tarnish salt or complex most certainly matters. In fact, it's about all that matters. This is really a chemistry 101 question.
  9. So you accept two frame dependent answers regarding the orbit of the earth but will not accept such for length or duration measurements? Why? I'll tell you why. You don't understand Minkowski space thats why. The questions you ask about four dimensions are laughable even to junior level undergraduate physics students. You clearly have 0 understanding of linear algebra or abstract vector spaces. These are basic concepts in the undergraduate mathematics curriculum. Philosophy is not relevant to science if it is defeated by such basic concepts. Go learn about the Minkowski norm, Lorentz transforms and abstract vector spaces in general. Until you understand this, your philosophy is not relevant to science and debating any further is pointless. Don't be threatened by md65336, we already know you have mystical beliefs, like realism and the strawman of SR you subscribe to.
  10. Nice rebutal. You really logically picked his points apart, rigorously and succinctly. Now lets see that calculation. Or were you lying?
  11. If it is so simple. Stop dodging and answer my question. Is the Earth orbiting the sun counter-clockwise or clockwise? You now admit to a prefered frame so which is it? Why do you never directly answer questions? For fear of error?
  12. That is a very interesting point, and one I honestly haven't considered. It is possible. I don't think this will occur in the current internet environment though for several reasons: The educational content on the internet is not structured in such a way as to lend itself to formal education, for now anyway. One can definitely learn A LOT on the internet. However, the truly in depth resources are often only available through either pay only or University attendance/employment. Online journals serve as a demonstrative example, almost no one can personally afford them out of pocket but people affiliated with research universities and businesses often have access to them. Things like ArXiv are becoming more popular and more accepted though so maybe there will be a change in this culture. I would like to see that very much. I really like things like the "MIT open courseware" videos, those are great for our society. The second reason is even more cultural than the first. People who have been through the trial by fire in academia are not so willing to endorse those who have not been through the same scrutiny. The university system comes in with built in accountability. That's not to say their aren't quacks out there with PhD's, there are. But it just means that at some point those quacks probably participated in legitimate scientific research and fell off the wagon at some later time. Science is in general very specialized these days. Some people spend their entire life's work on some small facet of some obscure project. I find it hard to imagine people in the near future being able to achieve that degree of specialization and expertise outside the classroom and that is the bulk of my argument. Perhaps the conditions will change in some unimagined way in the future, it is most certainly possible. All I can do now, and still be honest, is extrapolate the current condition into the future. Anything else would be wild speculation unless there is some known trend I'm unaware of. It will certainly be interesting to see though
  13. Please google hydrogen bonded networks in solids, namely ice. You are way off base here. Mods, Experts: Can we get this moved to speculations? I've already been discussing and will recuse myself of any paper pushing action.
  14. By amateurs...yes. Most correct statements that are backed by decades of record are easy to make. So you saying that my statement is fallacious because no one can offer evidence to the contrary? It is falsifiable, attempts have sense been made. Point taken. However, can we not make a similar statement about any not yet observed phenomenon? The tooth fairy is, as of today, still unobserved. Does that negate her existence? I agree here. The problem is when amateurs think they have the necessary knowledge to tangle with and topple the work of thousands of experts. Are there any fields where contributions from amateurs are as good as those of experts? If there is such a discipline, I want no part of it. That is sound logic assuming all other things equal. However, they are not. My assertion that the field of physical science has become too technical for the serious pursuits of amateurs has explanatory power where as denying the existence of climate change does not. Denying climate change requires ignoring a mountain of evidence. What mountain have I ignored? I thought of Pedersen as soon as I posted. He had a master's degree and was most definitely not an amateur but a seasoned professional (and one of my heroes at that). Given, I did specify "PhD" specifically so you do get some cred for that. ________________________________________________________________________________________ **To the amateurs of the forum: Please don't take my words as insulting. Even the most educated among us were once amateurs. However, I refuse to accept the notion that a rigorous education in the physical sciences and mathematics doesn't offer a supreme advantage. I have part of said pedigree though (BS chemistry, PhD candidacy soon hopefully) so perhaps I have some personal bias. I admit to this bias and hold that it is marginal to the outcome. ***To the one who gave me the neg-rep above in post #27: Was it the dry humor or the demand for evidence (In a science forum have you) that moved you to do such? No need to answer, just please take a moment to reflect.
  15. Certainly, Every atom in the universe does not occupy a different energy level, that is not the Pauli Exclusion Principle. The Pauli Exclusion Principle says that no two fermions can occupy the same state simultaneously. Here the word "state" is in the quantum mechanical sense of the word, meaning the quantities that describe the condition of the fermion at a moment in time. It is perfectly acceptable that two fermions (electrons are the best known non-composite example) can have identical energies, however they will differ in some other way with respect to their states. For example, two electron could have identical energy and be in different locations, or could have different spins. Changing the energy of one atom or electron will not in fact change the energy level of every other atom in the universe. If this were so, spectroscopy in general would be impossible. Sorry, I may have have come across a bit discouraging. I'm just trying to be direct and tone is hard to convey in text so...don't let me discourage you from pursuing your ideas. Just make sure you have sufficient background knowledge before attempting to create a hypothesis. Some of the mathematics behind the Pauli Exclusion Principle is a bit hairy but there is some low hanging fruit out there that I believe is easily accessible for anyone. I encourage you to go and find a book that suits your level of desired depth and level of mathematical prowess.
  16. It is most certainly a digression. Owl demands that there is a prefered frame of reference (though he may not admit it, his argument unavoidably implies such). Im simply forcing on him the same dichotomy he has pushed on relativity. Childish reasoning...perhaps, the argument has degraded to such a level as a result of owl's constant goal post shifting and semantics picking.
  17. owl, So is Earth orbiting the sun clockwise or counter-clockwise? Realism demands a non-frame dependent answer as it does for the diameter of the earth. Answer the question and stop repeating yourself. Im applying the same standards to realism that you have required of special relativity. So don't claim that I'm missing the point. Pony up and make a definitive statement.
  18. Then your idea is dead at the start. Go read a book on elementary quantum theory.
  19. It's okay. Being wrong isn't against the forum rules . Name one amateur who contributed significantly to the state of modern physical science within the last thirty years. Better yet, try fifty years. This is a safe bet for me, I assure you.
  20. I'm saying that the PhD is the necessary specialized training. Sorry, I think we had a communication lapse there.
  21. And beware of badly written popularizations. They can be fun and accessible but can also be misleading and were not intended to be authoritative sources.
  22. True, but in modern times (at least for physical sciences) the theories have advanced to the point of needing highly finesse and or fine tuned hypotheses. The need for specialized training is impossible to get around. Amateurs also can't afford the equipment. I'd go as far as to say there will never be another sound fundamental discovery in physical science by an amateur.
  23. From my understanding no one measurement of any one photon violated the HUP. Definitely a bad media write up. The blog "Uncertain Principles" has a good entry on this.
  24. That would imply that you have never read anything about him or his exclusion principle. Might better do that.
  25. Thought I would link to a brutal debunking of much of the published "theory" behind cold fusion research. The authors address the absurdity of below ground state orbitals in hydrogen and the absurdity (this one really cracks me up ) of "superbound" diatomic hydrogen molecular ions* (H2+ and/or D2+). *The original quack who made this claim evidently considered the system as a classical point charge in the coulombic potential of two protons then claimed position certainty for the electron disallowed by the HUP, yet he uses some QM to explain away his lack of a radiating electron (and non relativistic QM at that, and arguable assumption at best for small molecular systems)...long story short...this doesn't cut it. Cold Fusion Arguments addressed I think the strongest [experimental] argument here is that the ground state to below ground state has never been observed. Another good argument comes from here: H. Wind, "Electron Energy for  2 H in the Ground State", J. Chem. Phys. 1965 42, 2371 Which is cited in the linked paper. It's a bit old but might serve as a decent review for those who know some quantum mechanics but don't regularly use it in the context of molecular sciences.
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