Last night, I tagged along with the young scientists to hear University of Minnesota public health scientist Michael Osterholm's presentation at Wayzata Central Middle School about emerging infectious diseases. Osterholm gave his audience plenty more reasons beyond Ebola to be very, very afraid (MERS, chikungunya, H7N9 avian influenza) but encouraged them to pursue public health careers so they can save the world from these scourges. Osterholm started his presentation by showing how mobile the world's human population has become. The Guardian's real-time visualization of flights around the world (using data from FlightStats, but looking more like comets or shooting stars) is beautiful. It's also sobering, when one considers that all those people and goods could have pathogens along for the ride.