I was sad to leave Zürich in July 2020, after spending a delightful year collaborating at ETH and exploring the many mountains and valleys of this beautiful country. The coronavirus pandemic had arrived only a few months earlier, but I somehow thought it would fade and I could make a return visit to Switzerland a few months later. That was naīve. Another year has passed and the pandemic is not yet done with us; nonetheless, three months ago Andy and I booked our tickets to Zürich so we could visit friends and colleagues and enjoy the city and the mountains once again.








