* Astronomy

Blobrana · L

RE: Multiverses

Blobrana · L

Title: Prediction and explanation in the multiverse
Authors: Jaume Garriga, Alexander Vilenkin
(Version v3)

Probabilities in the multiverse can be calculated by assuming that we are typical representatives in a given reference class. But is this class well defined? What should be included in the ensemble in which we are supposed to be typical? There is a widespread belief that this question is inherently vague, and that there are various possible choices for the types of reference objects which should be counted in. Here we argue that the "ideal" reference class (for the purpose of making predictions) can be defined unambiguously in a rather precise way, as the set of all observers with identical information content. When the observers in a given class perform an experiment, the class branches into subclasses who learn different information from the outcome of that experiment. The probabilities for the different outcomes are defined as the relative numbers of observers in each subclass. For practical purposes, wider reference classes can be used, where we trace over all information which is uncorrelated to the outcome of the experiment, or whose correlation with it is beyond our current understanding. We argue that, once we have gathered all practically available evidence, the optimal strategy for making predictions is to consider ourselves typical in any reference class we belong to, unless we have evidence to the contrary. In the latter case, the class must be correspondingly narrowed.

Read more (14kb, PDF)

Blobrana · L

Title: Physics in the multiverse: an introductory review
Authors: Aurelien Barrau

This brief note, written for non-specialists, aims at drawing an introductive overview of the multiverse issue.

Read more (8kb, PDF)

Blobrana · L

Universe or Multiverse?
Bernard Carr (ed)
2007 Cambridge University Press
£45.00/$85.00 hb 310pp

Up until 80 years ago the astronomical community was embroiled in an argument about our place in the universe. On one side was the perennial idea that we were all there was that our galaxy was a single lonely island in a vast empty cosmos that spanned out to infinity. Telescopes revealed distant smudges of light so-called nebulae but these were explained as merely ill-resolved clouds of gas in the Milky Way. Opposing this bleak, self-centred universe was the view that our galaxy was but one of many galaxies sprinkled throughout space. The nebulae were, in fact, our nearest neighbours, but were too far away for our telescopes to map out in sufficient detail.

Read more

Blobrana · L

Title: The multiverse and the origin of our universe
Authors: Tom Gehrels

The multiverse is a hierarchy in the number of universes, increasing stepwise towards infinity. It is an evolutionary system, in which universes survive only near critical mass. That mass is actually a factor of 1.94 less than the critical mass, and this is found to be consistent with the baryon density inferred from nucleosynthesis in our universe; it is also precisely verified as a cosmological effect. That factor seems to have originated in the multiverse for causing intersecting expansions of its universes, such that mixing occurs of debris from aging galaxies (over proton-decaying time scales). It follows that there is an inter-universal medium (IUM), probably having the demand of new universes in balance with the supply of dark radiation and sub-atomic particles from the decaying galaxies. The mixing causes the universes to have the same quantum, relativity, gravity, and particle physics as our universe. The making of a universe from the radiation and sub-atomic particles occurs through re-vitalizing the protons, and other particles as well, by gravitational energy obtained in accretion of the IUM. This process therefore begins wherever the IUM space density reaches proton density, near 10 E18 kg m E-3. The process continues quietly as the sweeping-up and gravitational accretion proceeds, until the near-critical mass is reached. Some of the IUM debris must also be pervading our present universe, steadily or in partially accreted lumps. The model therefore predicts that the IUM sub-atomic particles appear as our dark matter, and its radiation component as our dark energy, both near 0 K temperatures. The dark energy may cause expansion phenomena, in addition to the above non-flatness expansion, from an accretion lump that arrived at our universe at age near 9 x 10 E9 y.

Read more (243kb, PDF)

Blobrana · L

FTL (faster than light) space travel?
BBC News James Wilkinson report, September 1995, on wormholes and warp engines

Blobrana · L

It should be noted that Faster-Than-Light travel or communication is prohibited by Einstein's theory of relativity. General relativity allows possibilities of Alcubierre drives and Tachyons to exist because they can use a separate spacetime.
Also, multiverse theorys had to be rewritten after Stephen Hawkings landmark speech at an international conference in Dublin, Ireland. In short, it did not require wormholes or the Black hole to be linked to other universes. We do not need FTL speeds to explain what we see.
The multiuniverse theory however is still in favour by membrane theories, and indeed required by some.

This will be moved to the `All queries go here` section tomorrow.

Date: May 19 06:44 2007

Stephen Hawkings was the first physicists to publish a paper on Multiverse. The idea that the Universe is actulaly made up of many Universe's. It stands to reason that this may be the exact thing. The Multiverse theory opens up the idea of how young or how old this Universe might be. It has been discovered that FTL speeds are a common mathematical configuration of advance physics. A new study made by Rodney Kawecki PhD of Los Angeles California illustrates a multiverse theory and regenerating of allusive energies through black holes. This energy is then used to form new universe's.
His theory on superliminal warp drive is based on the basic eqiations in relativvity but illustrtae a greater speed then light. A Dr.Wang has shown in the laborory that a light pulse was boosted to some 300.000 times FTL. Based on Rod Kawecki's findings. Deep space allows for an increase in speed due to the vacuum. He has also discovered the equations for this discovery.