Tykocin, near Bialystok in northeast Poland, is an interesting place. Not a single Jew lives there today, but its synagogue - the oldest in Poland - is a tourist attraction, with over 40,000 visitors a year. The security guard explained with hand motions that the synagogue is closed on Mondays. He spoke only Polish. Afterward, when he saw the disappointment on my face, he scratched his head and signaled me to...