Please read my blog on Time-a Non -Linear Theory filed under AstroPhysics for Indian philosophy’s great insight.
Space fans are no doubt familiar with the classic short educational film, “Powers of 10,” that provides an eye-popping tour of our universe from the very big to the very small — and ends up right back on the picnic blanket in the park from whence we started. But the original is pretty dated now that we’re wrapping up the “Oughts,” and I’m not just talking about the hairstyles and 1970s togs. We know so much more about our universe since this film was made.
In fact, it’s really just in the last decade that our technology for exploring the cosmos has improved to the point where astronomers could see that vast galaxies actually clump together and form larger structures. Our universe is a vast tangled web of interconnected galaxy clusters linked by wispy filaments surrounding areas that can only be described as voids. And that’s what scientists have taken to calling it: the Cosmic Web.
It’s incredibly difficult to model this vast web of galaxies, however, since all the components that make it up vary greatly by orders of magnitude. “Powers of 10” made good use of zooming out and zooming in for its limited cinematic purposes, but when it comes to computer simulations, that approach doesn’t work so well. KFC of the arXiv blog explains:
“As the small scale structures become too small to resolve, most computer models apply some sort of statistical smoothing process to make the large scale calculations easier. But if you zoom back in again, there is no way to retrieve the information that is lost by the smoothing process other than to rebuild the picture again from the original data. …
“[I]t’s a problem if you want to simulate how the large scale structures form from smaller structures and how, in turn, the shape of the large structures influences the way smaller structures evolve. This kind of feedback process is impossible to model when the smoothing process between different scales essentially destroys any meaningful links between them.”
A pair of scientists at the University of Gronengen in the Netherlands think they might have the answer: the Delauney Tessellation Field Estimator. “Delauney tesselation” sounds like something vaguely unpleasant from Madeleine L’Engle’s A Wrinkle in Time, but it’s actually an approach to computer simulation in which galaxies are treated as points in 3D space. The space between them is filled in with tetrahedra governed by very strict rules about how they combine as scales get larger.
What makes the technique developed by Rien can de Weygaert and Willem Schaap so intriguing to astronomers is that its rules or reversible. That means you can zoom out and zoom back in your simulation, and the critical information in the original structure is recreated instead of lost. And that means we could soon have an even better model of our great Cosmic Web — and maybe even an updated version of “Powers of Ten.”
http://news.discovery.com/space/oh-what-a-cosmic-web-we-weave.html
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