Sunday, May 13, 2007

Is the Universe Finite, or Not?

I've just come across a few interesting items in my quest to understand "life and the universe" and would like to share them with you:
  • On A Finite Universe With No Beginning Or End (a PDF document) - by Peter Lynds of New Zealand, with the following abstract:

    "Based on the conjecture that rather than the second law of thermodynamics inevitably be breached as matter approaches a big crunch or a black hole singularity, the order of events should reverse, a model of the universe that resolves a number of longstanding problems and paradoxes in cosmology is presented. A universe that has no beginning (and no need for one), no ending, but yet is finite, is without singularities, precludes time travel, in which events are neither determined by initial or final conditions, and problems such as why the universe has a low entropy past, or conditions at the big bang appear to be so "special," require no causal explanation, is the result. This model also has some profound philosophical implications."
    If the above paper is too much for you, then from Science a Go Go there's a pair of articles that might make it more digestible: The Universe As Magic Roundabout: Part I plus The Universe As Magic Roundabout: Part II

    Here's an earlier paper by Peter Lynds (also a PDF document):
    Time and Classical and Quantum Mechanics: Indeterminacy vs. Discontinuity

  • For another view, this time about multiple universes, there's Towards observable signatures of other bubble universes (another PDF document) with the following abstract:

    "We evaluate the possibility of observable effects arising from collisions between vacuum bubbles in a universe undergoing false-vacuum eternal inflation. Contrary to conventional wisdom, “typical” observers inside a bubble should have access to a large number of collision events. We calculate the expected number and angular size distribution of such collisions on an observer’s “sky”, finding that for typical observers the distribution is anisotropic and includes many bubbles, each of which will affect the majority of the observer’s sky. After a qualitative discussion of the physics involved in collisions between arbitrary bubbles, we evaluate the implications of our results, and outline possible observable effects. In an optimistic sense, then, the present paper constitutes a first step in an assessment of the effects of other bubble universes on the cosmic microwave background and other observables."