I also attended two sessions (one in English, one in a combination of English and Spanish) of Pioneers in Science, featuring Dr. Nora Volkow, a psychiatrist and scientist whose work in brain imaging has shown that drug abuse is indeed a disease. Contrary to popular belief, the brain's connection to the frontal cortex is damaged by addiction and in that way it makes it extremely difficult for an addicted person to stop, even if they want to. Also of interest, younger people are more likely to form addictions because their brains respond faster to stimuli.
My favorite session was definitely the "What is Time?" session with Alan Alda. Three scientists all expanded on the topic as per their particular field of study. While I enjoyed all three scientists' presentations, Dr. Alexandra Horowitz had a particularly fascinating one on how dogs tell time. That's kid-friendly fact #2 that I loved: dogs smell time. That is, if you leave the house, the diminishing intensity of your scent lets a dog know how long you've gone. Thus, if you come back after a longer period of time, your dog will probably exhibit submissive behaviors welcoming you: body shakes, lip-smacking/licking, and of course, a wagging tail. The rate of those behaviors is faster the longer you've gone. I observed this on Charlie yesterday after we came back from a particularly long day out (we went to the AMNH to meet friends): sure enough, she was doing the body shakes, lip-smacking, and tail-wagging at a faster rate than she does when we've just been out less than a few hours. It was so cool to see it now that I understand it. And dogs aren't the only animals that can sense time passing.
Dr. Max Tegmark showed the audience how if you were able to travel to the edge of a black hole (you don't want to fall in), and you were able to then Skype your loved ones on Earth, you'd see them as if they were in a "fast-forward" mode, while back on Earth, those on the edge of the black hole would look as if they were doing everything at a half-time pace... veeeery sloooowly.
I highly recommend watching the video of the What is Time? session on the World Science Festival site. In addition to the three scientists who presented on time, it also has the announcement of the 2013 Flame Challenge winner. The winners in both video and written presentation best explained (according to the judgement of 20,000 kids worldwide) the answer to the question which themed the session in a way that was ideal for 11-year olds. I'm already looking forward to next year's challenge!