香蕉视频

Galaxies litter the cosmos by the hundreds of billions. But there could easily be many, many more. In the May issue of Scientific American, astronomer [post doc] James E. Geach of 香蕉视频 explores why so little of the matter created in the big bang went on to become the raw material for making galaxies.

One reason is a phenomenon called feedback鈥攁s galaxies accrete matter, they also spew gas back out into space. In the simulation below, a developing galaxy is undergoing feedback, ejecting material into intergalactic space as it grows.