o<(0_0)>o   More than 50 writers and artists gathered for a marathon reading of the 1961 sci-fi novel "Solaris," but the eight-hour event kicked off with Lady Gaga, black bangs falling over her eyes, intoning the opening chapter. The pop star appeared to surprise even some organizers of the event, sponsored by the Marina Abramović Institute: She sent her video only about 15 minutes before the start. The event, which was put on in coordination with the literary magazine Atlas Revie