Departure for the 49th Rencontres d'Arles is imminent. This year, you are invited to cross space and time with a breathtaking, celestial journey across the ages. Photography is often the best-placed medium for registering all the shocks that remind us the world is changing, sometimes right before our eyes. An arts program is an excellent time machine-a constellation of exhibitions, intersecting, interacting and occasionally colliding. With the artist's eye as our aid, and the recent past as our measuring stick, we can discover the near future, and shed some light on the big questions of society today.