Dr Benjamin Chen, an assistant professor of infectious disease at Mount Sinai School of Medicine in New York, has used a high-tech video microscope to watch HIV passing across virological synapses in human T cells in a lab dish. His high speed video shows the virus moving across a “virological synapse” between two immune cells - a fascinating and slightly disturbing piece of camerawork. It's available on the Web site of the South African edition of Popular Mechanics: visit www.popularmechanics.co.za