History, proximity and serendipity make Kendall Square fertile ground for the next big idea.On Monday, on the western edge of the MIT campus, representatives of MIT and Pfizer Inc., along with elected officials, participated in a groundbreaking ceremony around what will become a 180,000-square-foot research hub for Pfizer’s Neuroscience Research Unit and its Cardiovascular, Metabolic, and Endocrine Diseases Research Unit. After the ceremony, which included remarks from Massachusetts Gov. Deval Patrick, Cambridge Mayor David Maher and MIT President Susan Hockfield, participants walked down the block for a reception at the atrium of the MIT’s McGovern and Picower institutes. The festivities celebrated not just this new injection of talent and jobs into Kendall Square, but also the innovation ecosystem that the…