On This Episode of Engage, Jordan welcomes Professor of Physics at NYU and long time Star Trek fan, David Grier! David is part of a team that has developed 5 actual working tractor beams right here in Manhattan!  If you like to learn more about David and other scientists turning science fiction into science fact, you can check out "Building Star Trek" on the Smithsoniam Channel Sunday September 4th at 8 P.M. ET.