Tuesday, May 3, 2011

Still crazy after all these (13.5 billion or so) years

The universe is a strange and wondrous place.  (Is it the only place? Not according to multiverse theory. Consider that topic grist for some future post.)

Just in this universe, moving progressively farther from home, we see:

The first images from orbit around Mercury, taken by the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) probe. That surface looks pretty well pounded, doesn't it?

(The mission name needs work, though. I'm not a fan of highly contrived acronyms.)

Then there is recent evidence of a superconducting superfluid within neutron stars. (The image at left, from the Chandra X-Ray Observatory, is the shock wave of Cassiopeia A having gone supernova -- a mere eleven thousand light-years from Earth. Cassiopeia A is the brightest radio source in the sky.)

Deep inside that image is a neutron star.

Farther away -- and, perhaps weirder -- look at this mysterious green blob deep in space, including a stellar nursery where none such should exist. (How far away? About 650 million light years. Image from the Hubble Space Telescope.) 

Of course looking at light that originated far away in space is like looking far back in time. That raises questions of how it all began ...

How did the universe begin, anyway? As cosmologists would have it, in a very Big Bang. That theory explains much -- but to explain some attributes of the observed universe (e.g., its comparative homogeneity when viewed at a very large scale) Big Bang theory also requires the kludged addition of cosmic inflation.  Perhaps worse, Big Bang theory has no explanation for the accelerating expansion of the universe, also known (putting a label on our ignorance) as dark energy.

A new variation of the Big Bang idea proposes that the universe adds dimensions as it expands. As this speculation -- too preliminary and hand-wavy at this point to dignify as a theory -- would have it, the universe began in a one-dimensional string.

As the universe expanded the string meandered about (um ... meandered in what?), folding on itself, and thus gave rise to a second dimension. (Hand-wavy, as I said.)  Later, the 2-D plane folded all over itself to give rise to our familiar 3-D world. And just maybe, what appears in the large-scale structure of the universe as accelerating expansion is instead the birth of a fourth dimension. Not that cosmologists are holding their breaths waiting for my approval, but I'm far from convinced.

A mad, mad, mad, mad (and very energetic) place, our universe ...

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