graphic-cosmol (38K)

Something to think about ........

The "No boundary" proposal for the "Universe" as expounded by Stephen Hawking .. This says that in the "imaginary time" direction, spacetime is finite in extent, but doesn't have any boundary or edge. The boundary condition of the universe is that it has no boundary.  The universe would be completely self-contained and not affected by anything outside itself.  It would neither be created nor destroyed.  It would just BE !   The initial universe existing quite happily by itself, under the known laws of physics.    In real time, the universe has a beginning and an end at singularities that form a boundary to real space-time and at which the laws of science break down.   But in "imaginary time", there are no singularities or boundaries.  So maybe what we call imaginary time is really more basic.
Hawking's final big idea in his book called  "A Brief History of Time".   His conclusion - You don't need a creator, so maybe there is no creator.

For more read .....Hawking, Roger Penrose,Paul Davies, Brian Greene or Brian Cox..... I challenge you !

The following photo represents one of the most significant discoveries of modern cosmology.
Do you know what it is ! Heard of ....."[ The SMOOT Group.]" .....Then find out !!

Stephen Hawking
See - "DAMTP"
COBE cmb bands 1--5
Roger Penrose
See - "PSU"

These cosmological page links  are well worth investigating in your quest !!

Please keep in mind the following important points to avoid misconceptions about the Big Bang and expansion:

  • 1.  The Big Bang did not occur at a single point in space as an "explosion." It is better thought of as the simultaneous appearance of space everywhere in the universe. That region of space that is within our present horizon was indeed no bigger than a point in the past. Nevertheless, if all of space both inside and outside our horizon is infinite now, it was born infinite. If it is closed and finite, then it was born with zero volume and grew from that. In neither case is there a "center of expansion" - a point from which the universe is expanding away from. In the ball analogy, the radius of the ball grows as the universe expands, but all points on the surface of the ball (the universe) recede from each other in an identical fashion. The interior of the ball should not be regarded as part of the universe in this analogy.
  • 2.  By definition, the universe encompasses all of space and time as we know it, so it is beyond the realm of the Big Bang model to postulate what the universe is expanding into. In either the open or closed universe, the only "edge" to space-time occurs at the Big Bang (and perhaps its counterpart the Big Crunch), so it is not logically necessary (or sensible) to consider this question.
  • 3.  It is beyond the realm of the Big Bang Model to say what gave rise to the Big Bang.  There are a number of speculative theories , ( consider Hawkings "No Boundary" proposal) but none of them make realistically testable predictions as of yet.

    The geometry and evolution of the universe are determined by the fractional contribution of various types of matter.  Since both energy density and pressure contribute to the strength of gravity in General Relativity, cosmologists classify types of matter by its "equation of state" the relationship between its pressure and energy density.     The basic classification scheme is:
  • Radiation : composed of massless or nearly massless particles that move at the speed of light. Known examples include photons (light) and neutrinos. This form of matter is characterized by having a large positive pressure.
  • Baryonic matter : In this cosmological context, this is "ordinary matter" composed primarily of protons, neutrons and electrons. This form of matter has essentially no pressure of cosmological importance.
  • Dark matter : this generally refers to "exotic" non-baryonic matter that interacts only weakly with ordinary matter. While no such matter has ever been directly observed in the laboratory, its existence has long been suspected. This form of matter also has no cosmologically significant pressure.
  • Dark energy : this is a truly bizarre form of matter, or perhaps a property of the vacuum itself, that is characterized by a large, negative pressure (repelling force). This is the only form of matter that can cause the expansion of the universe to accelerate, or speed up.

    One of the central challenges in cosmology today is to determine the relative and total densities (energy per unit volume) in each of these forms of matter, since this is essential to understanding the evolution and ultimate fate of our universe .

    universe ....standardmodel

    AS of July 4th 2012 - at ICHEP Melbourne - CERN is about to release Data for the LHC runs 2011-2012 which may indicate the probable existence of the Higgs Boson.

    ..Good News ..

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