PDA

View Full Version : Observational evidence for bottom-up structure formation


ad510
Jul25-11, 07:30 PM
I know that the only dark matter models consistant with the cosmic microwave background radiation require bottom-up structure formation, but all of the relevant press releases I've read are about finding surprisingly large/mature structures in the early universe. Do the same telescopes/experiments also find many places after reionization where galaxy clusters or superclusters clearly hadn't formed yet, but decided they weren't worth reporting about (or they reported them and I didn't find those reports)? Also, what observations do we have of bottom-up structure formation actually occurring over time, rather than observations of the CMB or modern universe that just constrain current models?

Dotini
Jul26-11, 06:28 AM
Please correct me if I'm wrong, but isn't radio telescopy discovering that the universe is spanned by vast filaments, which then create the stars and galaxies at the intersections?

Respectfully,
Steve

ad510
Jul26-11, 01:31 PM
According to http://en.wikipedia.org/wiki/Structure_formation , that did happen, but those filaments formed bottom-up as the first stars and galaxies were pulled towards each other.

Sorry if I made the question sound more complicated than it was; I guess a simpler way of asking it is what evidence do we have of bottom-up structure formation other than the cosmic microwave background radiation.