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59709Re: [existlist] Krauss on something and nothing

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  • eduardathome
    Apr 24, 2013
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      I have seen that answer to (1) elsewhere although it could be from Krauss.
      I don't spend much time on it, as I don't think it's important except for
      scientists. It provides a scientific answer. It could be said in a
      paragraph rather than pages. Scientists like philosophers like to write a
      lot. The universe started as a boiling pot of virtual particles and the
      pluses came out ahead of the minuses ... otherwise we would have a
      anti-matter universe.

      The question to (2) is more difficult since one would have to explain how
      the virtual nothingness got started in the first place. I would leave that
      to the scientists as well. It probably is worth a sentence or two.

      eduard

      -----Original Message-----
      From: Jim
      Sent: Wednesday, April 24, 2013 2:53 PM
      To: existlist@yahoogroups.com
      Subject: [existlist] Krauss on something and nothing

      All,

      I have just completed Lawrence Krauss's book "A Universe From Nothing" which
      Wil recommended a month or so ago.

      I endorse Wil's recommendation – Krauss's book is a great read. Krauss has
      the ability to explain complicated scientific theories and experiments in a
      clear and lively way which makes the theories understandable to the general
      reader. I followed just about all Krauss's arguments although I struggled a
      bit in the last couple of chapters.

      The book is just about all science. In fact Krauss does not have any time
      for philosophy. He gives the impression that he thinks philosophy is as
      useless and unnecessary as theology.

      Putting that prejudice to one side, I learnt a lot about science – about
      cosmology, relativity and quantum mechanics.

      He didn't start addressing the question of how something (our universe of
      solid matter) could arise out of nothing until about half-way through the
      book. In the early part of the book Krauss made me realize for the first
      time just how big our universe actually is.

      As a scientist, Krauss rightly says he is concerned to answer `How'
      questions rather than `Why' questions. I guess he thinks `Why' questions are
      just badly formulated questions.

      So around page 100 he starts to answer the question "How is there something
      rather than nothing?"

      He seems to answer this question in two stages, corresponding to two
      different conceptions of `nothing'. The two questions he addresses are:

      (1) How does matter emerge from empty space?
      (2) How does empty space emerge out of nothing at all?

      He spends more time on question one (roughly in pages 100-160), and he
      addresses question two much more briefly (roughly in pages 160-180).

      So his first definition of `nothing' is empty space. But this is a bit of a
      cheat because empty space is not really nothing. Rather empty space contains
      energy and has negative pressure. He writes:

      "Empty space is complicated. It is a boiling brew of virtual particles that
      pop in and out of existence in a time so short we cannot see them directly"
      (153)

      So when he writes on page 105: "The structures we see, like stars and
      galaxies, were all created by quantum fluctuations from nothing", he really
      means "The structures we see, like stars and galaxies, were all created by
      quantum fluctuations from empty space." And, further, this empty space is
      not really empty as it contains a boiling brew of virtual particles
      continually popping in and out of existence. So Krauss does have a tendency
      to `over dramatize' his descriptions for extra effect.

      Elsewhere he describes the process more soberly:

      "According to this picture, when inflation ends, the energy stored in empty
      space gets turned into an energy of real particles and radiation, creating
      effectively the traceable beginning of our present Big Bang expansion."
      (150)

      "... small density fluctuations in empty space due to the rules of quantum
      mechanics will later be responsible for all the structure we observe in the
      universe today. So we, and everything we see, result out of quantum
      fluctuations in what is essentially nothingness near the beginning of time,
      namely during the inflationary explasion." (150-1)

      "… it is possible to begin with equal amounts of matter and antimatter in an
      early hot, dense Big Bang, and for plausible quantum processes to `create
      something from nothing' by establishing a small asymmetry, with a slight
      excess of matter over antimatter in the early universe." (157)

      "Antimatter particles would annihilate with the matter particles in the
      early universe, and the remaining excess of matter particles would survive
      through to the present day, establishing the character of the visible
      universe we know and love and inhabit." (157)

      "Quantum processes associated with elementary particles in the primordial
      heat bath can inexorably drive an empty universe (or equivalently an
      initially matter-antimatter symmetric universe) almost imperceptibly toward
      a universe that will be dominated by matter or antimatter. (158)

      All this makes Krauss's answer to question one above convincing in my view.

      However his answer to question two seems more sketchy and speculative to me.
      He writes:

      "… a quantum theory of gravity allows for the creation, albeit perhaps
      momentarily, of space itself where none existed before." (163-4)

      "[Last chapter] `nothing' meant empty but preexisting space combined with
      fixed and well-known laws of physics. Now the requirement of space has been
      removed. ... `Nothing' in this case no space, no time, no anything! – is
      unstable." (170)

      I wonder what others who have read Krauss's both make of his answers to
      questions one and two. As I say I am reasonably convinced by his answer to
      question one but not to his answer to question two.

      I also don't think science can answer all our questions about existence.
      Scientific answers give us lots of information about ourselves and the
      world, but they only push the ultimate questions further back. Even when
      Krauss answers all his `How' questions, I think there will still be some
      residual `Why' questions which philosophy is equipped to tackle.

      Now to start on Jim Holt's book.

      Jim




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