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  1. R

    A Need help with the reaction of neutrons and electrons

    No. Not a homework assignment. I am 57, too old for homework. I just want to discuss the reaction that I did not find anywhere on the Web.
  2. R

    A Need help with the reaction of neutrons and electrons

    Please let me know if the following reaction is possible for high energy electrons colliding with neutrons or neutron-rich nuclei: n+e^{-}\to \Delta^{-}+\nu_e.\tag{1} If it is forbidden for some conservation law or for some other reason, please give me an explanation why. This reaction is...
  3. R

    On operation principles of zinc-manganese alkaline batteries

    The Wikipedia article on alkaline batteries says that they operate at the expense of the oxidation of zinc metal to zinc oxide and the reduction of manganese dioxide to Mn2O3. Anode half reaction is written as Zn + 2 OH− → ZnO + H2O + 2 e−. However we know that metals reacting with water...
  4. R

    Good chemistry websites

    Dear Forumers! There is a fascinating resource http://arXiv.org, The Cornell University Archive, where one can publish his own research paper in Math, in Physics, in Computer Science, in Quantitative Biology, in Quantitative Finance, and in Statistics without a long lasting review procedure...
  5. R

    A First Course in String Theory/Invariant Interval/Metric

    In your case you have not the Riemannian metric, but the Minkovski metric. In writing any metric as a sum \sum_{ij}\,g_{ij}\ dx^i\otimes dx^j the differentials dx^i and dx^j are formal symbols. The interval notation ds or ds^2 is used if you want to calculate the length of a parametric curve...
  6. R

    When does quartic have only one real solution?

    The question was asked five years ago. Recently I encountered the same problem in my research and I have found the answer to this question. It is in Appendix A of my paper http://arxiv.org/abs/1507.01861.
  7. R

    A human in a vacuum chamber

    Sweat evaporation in vacuum goes even better than in the air. Note that water does not boil in firmly closed vessel even when heated to 100°С. Several hours or more.
  8. R

    A human in a vacuum chamber

    Probably that was because other parts of his body were at higher pressure. This wouldn't be the case if the whole body is in vacuum. It would be best to perform such an experiment using a breathing mask. I think it is safe since, being in the vacuum chamber, man can control his state and can...
  9. R

    A human in a vacuum chamber

    I did not mean to be exposed to vacuum for a short while and then pressurized again. I mean to be decompressed slowly and then stay in vacuum for a long while.
  10. R

    A human in a vacuum chamber

    There are many sources which say that a human cannot survive under the abrupt exposure to vacuum. What would happen if the exposure is not abrupt? Can a regularly clothed human survive in a vacuum chamber if we gradually lower the air pressure in the chamber to vacuum values for several hours of...
  11. R

    Teeth growing inside tumors?

    In the case reported above the tumor contained fully grown teeth, not something just resembling teeth. My conjecture is that this particular tumor or its cells cultivated in viro could act as inductors causing tooth producing genes to be expressed. Please, could I expect that this tumor is...
  12. R

    Teeth growing inside tumors?

    I would like to know if teratoma tumor can be cultivated in vitro. In this case it can be used as a placenta for growing human organs, e.g. tooth germs or germs of other organs which then can be transplanted to a patient.
  13. R

    Do neurons actually die within 5 minutes of anoxia?

    I would like to add another reference. This is the book: Volpe J. J., Neurology of the newborn, 5th edition, Saunders and Elsevier, 2008, ISBN 978-1-4160-3995-2. On page 270 of this book we find the following text: The crucial initial observation was that cultured hippocampal neurons obtained...
  14. R

    Do neurons actually die within 5 minutes of anoxia?

    Well, but looking through the article, I did not find any words saying that the authors continued their observations resuming O2/glucose supply after 15 minutes of deprivation until the total death of neurons, i. e. until their cellular destruction, or maybe until their recovery. Moreover, the...
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    Do neurons actually die within 5 minutes of anoxia?

    The contest in Changsha, China (May 30, 2012) is not unique. You can see the list of breath holding world records in Wikipedia. I support your doubt about cell death of neurons. It is known that a special bandage (tourniquet) is applied to a limb in order to stop arterial bleeding. The...
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    Do neurons actually die within 5 minutes of anoxia?

    Anoxia is a condition in which there is no delivery of oxygen to tissues of the body. Generally it occurs in cardiac arrest or upon termination of access of air into the lungs. Different tissues have different degrees of resistance to anoxia. It is thought that the least stable are neurons, the...
  17. R

    Braking radiation and electromagnetic self action

    I tried to write the Shrodinger equation for two charged particles with the "minimal coupling" only in this article: ArXiv:1308.0221. The result is different from the standard hydrogen atom. It needs to be explained why it is so.
  18. R

    Braking radiation and electromagnetic self action

    It is known that a charged particle moving with some acceleration emits electromagnetic waves. For example, this may be a particle moving at a constant speed on the circle. In this case the radiation of a particle is called the braking radiation, the cyclotron radiation, or the synchrotron...
  19. R

    Grafting fruit trees on non-fruit ones

    What are the reasons of mutual incompatibility of trees for grafting? As I know trees have no immune system. Probably any tree is potentially compatible with any other, but there were no carefully conducted experiments of grafting them.
  20. R

    Grafting fruit trees on non-fruit ones

    Thank you for your reply. Growing proper apple root stocks for grafting from seeds is time consuming. On the other hand, I have many young maple trees flooding my garden, which I need to weed out every year. I supposed that it would be best to use them as root stocks for fruit trees, but I was...
  21. R

    Grafting fruit trees on non-fruit ones

    In addition to herbs, some trees can act as weeds. In the southern Urals in Bashkortostan one of such weed trees is maple. It grows quickly, reproduces rapidly, and easily fills the land. So I have a question: is it possible to use a maple tree as a stock for fruit trees? Please, tell me which...
  22. R

    Photon emission by an excited hydrogen atom

    Dear Bill_K, I do not like to discuss the simplified statement of the problem known from every textbook. I would like to discuss the conceptual statement from which various simplifications should follow as special cases. This is true if we study stationary states of the pair. But studying...
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    Photon emission by an excited hydrogen atom

    Dear Bill_K. Your answer is just a hint. Please, be more specific. Please, answer the following questions: 1. How many wave functions should be written? 2. How many arguments are in each wave function, e. g. time + proton coordinates + electron coordinates? Or maybe time + proton...
  24. R

    Photon emission by an excited hydrogen atom

    Typically (in popular literature) the process of photon emission by an excited atom is considered as an instant event. But actually it is quite likely that it is a continuous process. Such processes are usually described by evolutionary differential equations (ODEs or PDEs). Assume that we...
  25. R

    Is the Higgs boson already discovered?

    Concerning renormalizability, I have heard the following proposition: "A field-theoretic model is renormalizable if and only if its Lagrangian is of the degree not higher than 4 with respect to the fields involved". I don't know its proof and I would like to ask someone more competent than me...
  26. R

    Is the Higgs boson already discovered?

    Alberto Palma's recent paper Arxiv:1202.0217 says in its conclusions part: "The ATLAS collaboration presents first results of the direct search for the SM Higgs boson decaying to b\bar b. No evidence of the Higgs boson was found in a pp collision data sample of \mathcal L=1.04\ \mathrm f\mathrm...
  27. R

    Interspecies surrogate motherhood

    Well, physicians all around the world have ethical permission to put human embryo into a trash basket when performing an abortion, but they never get ethical permission to put the same embryo into an animal womb. This is irrational, isn't it?
  28. R

    Food in space

    I think the question should be formulated a little bit differently. Will we grow food in outer space some day or when living in space we'll use another way for feeding our bodies?
  29. R

    Interspecies surrogate motherhood

    Russia is experiencing depopulation at present days (see http://news.bbc.co.uk/2/hi/5056672.stm" [Broken]). It is not due to infertility? It is a socially driven phenomenon partly due to the demographic aftershocks of World War 2, economic reforms of 1990s, changing family model, urbanization...
  30. R

    Interspecies surrogate motherhood

    IVF technology (in vitro fertilization) allows having children even for those couples who meet certain health problems in reproductive area. Sometimes, however, apart from IVF, one may need a surrogate mother for to gestate a conceived child. Search for a surrogate mother could be easier and...
  31. R

    Body replaces itself, but not individual limbs

    Please, is there anybody here who REALLY WANTS to start an experiment in HUMAN LIMBS REGROWING? Not just posting messages, but to act in practice?
  32. R

    Medical I am my connectome

    It would be best for the beginning not to slice a mouse brain, but to pin tiny wires to each of 7,000 connections of Caenorhabditis elegans and, using a computer, get a time graph of electrical activity in these connections. The worm should be kept alive during this procedure. P.S. Please...
  33. R

    Why don't humans regrow lost limbs?

    No, I have not. But I am looking for the opportunity to prove that it is possible in a way I have described in rough details!
  34. R

    Human cloning was yet scientifically possible

    Are there countries where human cloning is not legally forbidden? If yes, why people who want to improve the methods do not move to those countries?
  35. R

    Future Human Evolution

    I support the idea of directed evolution of a human species. E.g. for colonizing the cosmic space it would be preferable to have a body able to live in vacuum rather than to wear an oakward space suit.
  36. R

    Why don't humans regrow lost limbs?

    If you reconstruct bones, and muscles, and blood vessels, and nerves, and joints, and skin, then your item LOOKING like a limb will SERVE as a limb.
  37. R

    Why don't humans regrow lost limbs?

    Human lost limbs can grow from stumps. Not by themselves like those of lizards, but when a special surgical technology is applied. It is known that http://en.wikipedia.org/wiki/Ilizarov_apparatus" [Broken] is used for limb lengthening through lengthening its bone. In a similar way one can...
  38. R

    A question on semisimple rings

    I am interested in semisimple rings and semisimple modules which are not unital. There are two concepts of ring semisimplicity: left semisimplicity and right semisimplicity. A ring is called semisimple on the left if it is presented as a sum of its simple left ideals. A ring is called semisimple...
  39. R

    Teaching Myself Linear Algebra

    My geocoities.com/r-sharipov site is now off. Use the following sites instead: http://ruslan-sharipov.ucoz.com" [Broken] http://freetextbooks.narod.ru" [Broken]
  40. R

    Trying to understand tensors and tensor notation

    My geocoities.com/r-sharipov site is now off. Use the following sites instead: http://ruslan-sharipov.ucoz.com" [Broken] http://freetextbooks.narod.ru" [Broken]
  41. R

    Hoffman and Kunze's Suitable for Introduction to LA?

    My geocoities.com/r-sharipov site is now off. Use the following sites instead: http://ruslan-sharipov.ucoz.com" [Broken] http://freetextbooks.narod.ru" [Broken]
  42. R

    Linear Algebra textbooks

    My geocoities.com/r-sharipov site is now off. Use the following sites instead: http://ruslan-sharipov.ucoz.com" [Broken] http://freetextbooks.narod.ru" [Broken]
  43. R

    Geocities is going to end

    My geocoities.com/r-sharipov site is now off. Use the following sites instead: http://ruslan-sharipov.ucoz.com" [Broken] http://freetextbooks.narod.ru" [Broken]
  44. R

    A Few GR Resources.

    My geocities.com/r-sharipov site is now off. Use the following sites instead: http://ruslan-sharipov.ucoz.com" [Broken] http://freetextbooks.narod.ru" [Broken]
  45. R

    Best books for Differential Geometry?

    My geocities.com/r-sharipov site is now off. Use the following two sites for my books: http://ruslan-sharipov.ucoz.com" [Broken] http://freetextbooks.narod.ru" [Broken]
  46. R

    Another impact on Jupiter

    Do you always practice to act at random relying on good fortune?
  47. R

    Another impact on Jupiter

    Do you mean that we should rely on this "sweeping" action and do no effort to proect the Earth in some way technologically?
  48. R

    Another impact on Jupiter

    Think that it is sufficient if it happens once for to cancel the result of millions of years of the life evolution on the Earth. This should impress you. Therefore arranging a stable self-supporting and self-sufficient human life in the open space far of the Earth is more important than Lunar...
  49. R

    Another impact on Jupiter

    Well, how big was that object having bombarded the Jupiter? MICHIO KAKU in his http://online.wsj.com/article/SB20001424052970203517304574306131239654294.html" [Broken] article says that it was no more than a mile across, but created a fireball roughly the size of the planet Earth. What could...
  50. R

    Civilization of millions of rings.

    Ruslan A. Sharipov. Future forecast. Essay. Typically SiFi writers and futurologists make their forecasts for future. Now I am joining them with my own forecast. It is an entrenched habit to show the future equipped magic tools like antigravitators and space-time gates. One can see them...
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