dipirro@amber.DEC (GENERIC PERSONAL_NAME STRING) (01/08/86)
>A recent 3-D map of the distribution of the galaxies in the universe >has given evidence that the mass is distibuted roughly on the surface >of large bubble shaped regions of space. The interiors of these regions >are largely devoid of galaxies. The effect is a "Soapsuds" distribution >of galaxies. This all seems to indicate that some very explosive events >and the resultant shock waves very early in the history of the universe >had a profound effect on the evolution of the galaxies. I also read this study. The 3D map is currently of one quarter of the northern hemisphere of the universe (a 3D map of the universe would be quite an accomplishment, but which way is north in the universe?). They expect to find the same "bubble" effect in the other parts of the universe. Does this mean we should stop talking about the big bang and start talking about the big bangs? This seems to imply that *all* galaxies are not moving away from each other but away from the center of their bubble. Are the bubbles themselves moving or will some bubbles eventually collide (the bubbles do seem to be expanding)? In the latter case, we should be able to discover some galaxies actually moving towards the milky way. I just hope that some omnipotent being doesn't accidently pop our bubble. Steve DiPirro Digital Equipment Corp.
ethan@utastro.UUCP (Ethan Vishniac) (01/09/86)
> Does this > mean we should stop talking about the big bang and start talking about the > big bangs? This seems to imply that *all* galaxies are not moving away from > each other but away from the center of their bubble. Are the bubbles themselves > moving or will some bubbles eventually collide (the bubbles do seem to be > expanding)? In the latter case, we should be able to discover some galaxies > actually moving towards the milky way > > Steve DiPirro The motion associated with each "bubble" is a small perturbation to the general expansion of the universe. If it weren't we would have noticed this a long time ago. This work in no way invalidates the theory of the big bang. It does give some clues as to the processes that made the universe slightly inhomogeneous. As to bubbles colliding, some may but such collisions would not be exceptionally dramatic, a little like shooting marbles at each other across the room. A few spectacular collisions (which in the case of galaxies means mergers and funny looking aggregates) and a lot of misses. -- "These are not the opinions Ethan Vishniac of the administration of {charm,ut-sally,ut-ngp,noao}!utastro!ethan the University of Texas, ethan@astro.UTEXAS.EDU but they are the opinions Department of Astronomy of your favorite deity, who University of Texas is in daily communication with me on this (and every other) topic.
wyatt@cfa.UUCP (Bill Wyatt) (01/10/86)
> >A recent 3-D map of the distribution of the galaxies in the universe > >has given evidence that the mass is distibuted roughly on the surface > >of large bubble shaped regions of space. > > [...] > > I also read this study. The 3D map is currently of one quarter of the > northern hemisphere of the universe [...] > Just a point of detail - the CFA Redshift survey is a magnitude-limited sample (down to 14.5) of all galaxies in the Zwicky-Nilson catalog with galactic latitude above +40 and declination above 0 degrees, or below galactic latitude -30 degrees and above dec of -2.5 degrees. The funny limits arise since the galactic plane is tilted relative to the solar system and the earth. The original survey contains 2402 galaxies. I suspect it is to this survey you refer as being 1/4 of the sky. The "bubble map" is the result of an extension to fainter objects (15.5). Since this would result in an increase by a factor of about 4 in the number of objects (and easily a factor of 5-10 in exposure time per object, assuming same telescopes, detectors, etc.), the map was restricted to a swath of 120 by 6 degrees, chosen to intersect the Coma Cluster of galaxies. The additional depth clearly shows the bubble effect even in this much smaller pie-shaped slice of the universe. -- Bill UUCP: {harvard,genrad,allegra,ihnp4}!wjh12!cfa!wyatt Wyatt ARPA: wyatt%cfa.UUCP@harvard.ARPA