"In the decades that followed, a number of observations indicated that the Galaxy could not have formed in such a rapid collapse. The ELS model, as originally proposed,could not be right. One notable alternative was suggested by the American astronomers Leonard Searle and Robert Zinn in 1978… Instead of a single-cloud collapse, Searle and Zinn proposed that the halo of the Milky Way formed by the aggregation of many cloud fragments, each of which may have already formed stars and globular clusters"