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In Search of Dark Matter (Springer Praxis Books / Space Exploration)

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Written for the educated non-scientist and scientist alike, it spans a variety of scientific disciplines, from observational astronomy to particle physics. Concepts that the reader will encounter along the way are at the cutting edge of scientific research. However the themes are explained in such a way that no prior understanding of science beyond a high school education Written for the educated non-scientist and scientist alike, it spans a variety of scientific disciplines, from observational astronomy to particle physics. Concepts that the reader will encounter along the way are at the cutting edge of scientific research. However the themes are explained in such a way that no prior understanding of science beyond a high school education is necessary.


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Written for the educated non-scientist and scientist alike, it spans a variety of scientific disciplines, from observational astronomy to particle physics. Concepts that the reader will encounter along the way are at the cutting edge of scientific research. However the themes are explained in such a way that no prior understanding of science beyond a high school education Written for the educated non-scientist and scientist alike, it spans a variety of scientific disciplines, from observational astronomy to particle physics. Concepts that the reader will encounter along the way are at the cutting edge of scientific research. However the themes are explained in such a way that no prior understanding of science beyond a high school education is necessary.

50 review for In Search of Dark Matter (Springer Praxis Books / Space Exploration)

  1. 5 out of 5

    Mohamed IBrahim

    There is no shortage of ideas as to what the dark matter could be. In fact, the problem is the opposite. Serious candidates have been proposed with masses ranging from 10^-5 eV = 1/8*10^-41 kg =9*10^-72 "of sun mass" (axions) up to 10^5 "of sun mass" (black holes). That's a range of masses of over 75 orders of magnitude! It should be clear that no one search technique could be used for all dark matter candidates. Even finding a consistent categorization scheme is difficult, so we will try a few. There is no shortage of ideas as to what the dark matter could be. In fact, the problem is the opposite. Serious candidates have been proposed with masses ranging from 10^-5 eV = 1/8*10^-41 kg =9*10^-72 "of sun mass" (axions) up to 10^5 "of sun mass" (black holes). That's a range of masses of over 75 orders of magnitude! It should be clear that no one search technique could be used for all dark matter candidates. Even finding a consistent categorization scheme is difficult, so we will try a few. First, as discussed above, is the baryonic vs non-baryonic distinction. The main baryonic candidates are the Massive Compact Halo Object (Macho) class of candidates. These include brown dwarf stars, jupiters, and 100 "of sun mass" black holes. Brown dwarfs are spheres of H and He with masses below 0.08 "of sun mass" , so they never begin nuclear fusion of hydrogen. Jupiters are similar but with masses near 0.001 "of sun mass". Black holes with masses near 100 "of sun mass" could be the remnants of an early generation of stars which were massive enough so that not many heavy elements were dispersed when they underwent their supernova explosions. Other, less popular, baryonic possibilities include fractal or specially placed clouds of molecular hydrogen. The non-baryonic candidates are basically elementary particles which are either not yet discovered or have non-standard properties. Outside the baryonic/non-baryonic categories are two other possibilities which don't get much attention, but which I think should be kept in mind until the nature of the dark matter is discovered. The first is non-Newtonian gravity (MOND theory). but watch for results from gravitational lensing which may place very stron constraints. Second, we shouldn't ignore the ``none-of-the-above" possibility which has surprised the Physics/Astronomy community several times in the past. Among the non-baryonic candidates there are several classes of particles which are distinguished by how they came to exist in large quantity during the Early Universe, and also how they are most easily detected. The axion is mentioned as a possible solution to the strong CP problem and is in a class by itself. The largest class is the Weakly Interacting Massive Particle (Wimp) class , which consists of literally hundreds of suggested particles. The most popular of these Wimps is the neutralino from supersymmetry . Finally, if the tau and/or muon neutrinos had a mass in the 2 eV to 100 eV range, they could make up all or a portion of the dark matter (this is not the ordinary Standard Model neutrinos) . Another important categorization scheme is the ``hot" vs ``cold" classification. A dark matter candidate is called ``hot" if it was moving at relativistic speeds at the time when galaxies could just start to form (when the horizon first contained about 10^12 "of sun mass" ). It is called ``cold" if it was moving non-relativistically at that time. This categorization has important ramifications for structure formation, and there is a chance of determining whether the dark matter is hot or cold from studies of galaxy formation. Hot dark matter cannot cluster on galaxy scales until it has cooled to non-relativistic speeds, and so gives rise to a considerably different primordial fluctuation spectrum. Of the above candidates only the light neutrinos would be hot; all the others would be cold. this could summary all the book in a good and more accurate manner (in the problem of the search process not how the dark matter idea starts)

  2. 4 out of 5

    Gilda Felt

    It’s been a lot of years since I took physics in high school, but the book lived up to its promise; I was able to understand all the concepts outlined and ended with a greater understanding of how we know that dark matter is there, and what it may be. That says a lot considering the short length of the book. Unfortunately, there’s no clear answer. We know quite a bit about how the universe works, just not enough. The complete answer to the question of dark matter still basically eludes us.

  3. 5 out of 5

    Pete

    Good explanation of something we cannot see, yet we must believe exists because our experiences tell us it must. Otherwise, the universe could not exist in the manner in which see it. Seems to me that it brings religion and science closer together. To believe in dark matter takes a certain kind of faith on scientists' part. Good explanation of something we cannot see, yet we must believe exists because our experiences tell us it must. Otherwise, the universe could not exist in the manner in which see it. Seems to me that it brings religion and science closer together. To believe in dark matter takes a certain kind of faith on scientists' part.

  4. 5 out of 5

    Peter

    Dark matter must exist despite an overwhelming lack of direct evidence because all our equations are wrong without it? Scientist want us to believe in something more elusive to measurement then God because they look incompetent without it. I really thought they would have something other then a few bad equations in need of a fudge factor to explain dark matter.

  5. 4 out of 5

    Gregory

    I good overview of the recent history of astronomy and cosmology. It covers a great deal and does it well. There are a few subjects that it tackles that might have been hard to understand if I wasn't already familiar with them. I good overview of the recent history of astronomy and cosmology. It covers a great deal and does it well. There are a few subjects that it tackles that might have been hard to understand if I wasn't already familiar with them.

  6. 5 out of 5

    Thomas Worthington

  7. 4 out of 5

    Sean O'flaherty

  8. 5 out of 5

    Bill

  9. 4 out of 5

    Alli

  10. 4 out of 5

    Drdubious

  11. 4 out of 5

    Tony Alexander

  12. 4 out of 5

    Jan M. van Mourik

  13. 5 out of 5

    Benjamin O'Connor

  14. 4 out of 5

    Eoin Kelly

  15. 4 out of 5

    Dana Choi

  16. 4 out of 5

    Robb Davis

  17. 4 out of 5

    Manoj Varma

  18. 5 out of 5

    Frederick Y.

  19. 5 out of 5

    Steven Felicelli

  20. 5 out of 5

    Robert Streetman

  21. 5 out of 5

    Ralph Camacho

  22. 4 out of 5

    Mac

  23. 4 out of 5

    Ravi

  24. 4 out of 5

    Saif Heat

  25. 5 out of 5

    Adarsh Mishra

  26. 4 out of 5

    Dotan Schorr

  27. 4 out of 5

    Larry

  28. 4 out of 5

    Violeta Vornicu

  29. 5 out of 5

    Janakee

  30. 5 out of 5

    Inky

  31. 5 out of 5

    Tor Paulin

  32. 5 out of 5

    Kate

  33. 5 out of 5

    Scott

  34. 5 out of 5

    NaiNai

  35. 5 out of 5

    John Karabaic

  36. 4 out of 5

    Jannu

  37. 5 out of 5

    Cthuhukid

  38. 4 out of 5

    Hanny

  39. 4 out of 5

    John Johnson

  40. 5 out of 5

    Starfighter

  41. 5 out of 5

    Cezar Popescu

  42. 5 out of 5

    Jenn

  43. 4 out of 5

    Pavel

  44. 4 out of 5

    Feroz Khan Hamid

  45. 5 out of 5

    Vijay Veeraraghavan

  46. 4 out of 5

    Kristina

  47. 4 out of 5

    Araf Karsh

  48. 4 out of 5

    Emily Smith

  49. 5 out of 5

    Bookworm01

  50. 4 out of 5

    Kaa

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