Ya. B. Zel’dovich Ya. B. Zel’dovich was one of the first scientists to recognize that the early universe could be useful in research and the understanding of high energy physics. In 1970, the study of the large scale structure of the Universe resulted in Zel’dovich’s proposal of the “pancake theory”. Zel’dovich’s studies leading to this proposal showed that for an ellipsoid of gas on a supergalactic scale, an approximation can be used that will model the collapse along the shortest axis producing sheets and an oblate/pancake form, similar to filamentary structure seen in distribution of galaxies. The Zel’dovich Approximation for the growth of large scale structure is a successful analytical model of structure formation.