How is Philadelphia's convention center adapting to the pandemic age?

Conventions and trade shows are now wrestling with the same challenges facing schools, religious groups, and professional sports. Whenever large numbers of people gather indoors, in tightly enclosed spaces with mechanical air circulation, odds are that spikes in coronavirus infections will follow.Inga Saffron, architecture critic for The Philadelphia Inquirer, probes some of the existential questions facing large urban convention centers, massive facilities that have had their spatial and economic potentials deeply challenged by the COVID-19 pandemic.  Saffron reports on efforts to upgrade and retrofit the Pennsylvania Convention Center in Philadelphia for the pandemic age as digital and alternative forms of professional and academic gatherings begin to take root in response to the need for social distancing.