Marc Davis
(UC Berkeley)
The 1st redshift survey - CfA1, and DEFW - the 1st nbody study
This is a review of some of my ancient work, first published in 1979 and 1983, that made us aware of Large-Scale-Structure of the Universe. I also review the equipment used in the redshift survey. The abstract of the paper announcing the redshift survey states: "The space distribution of galaxies is frothy and characterized by large filamentary superclusters of up to 60 Mpc, corresponding to large holes devoid of galaxies.” Prior to this, the astronomical community had no idea of large-scale structure. Since the distribution looked unlike anything that anyone had produced, I felt it was most important to study the LSS by means of nbody simulations. Thus was born the DEFW. In simulations of size 32^3 particles (run on a Digital Equipment machine that fully occupied an air-conditioned room) we were able to show that massive neutrinos could not be the dark matter, but that CDM was a good candidate. We go so far as to introduce “biasing” in the galaxy distribution: "Finally, a situation in which galaxy formation is suppressed except in sufficiently dense regions is modelled which leads to models which can agree with observation quite well even for omega equal to one.” The data showed that an unbiased open CDM or a lambda–CDM was the best description, but there was no data to favor one model or another. This period of discovery was tremendous fun!