The central theme of the Time and Navigation exhibition is the connection between timekeeping and determining position. The main point is this: "If you want to know where you are, you need an accurate clock."  Centuries ago, accurate chronometers were required to determine longitude at sea. In recent years, global satellite navigation systems require accurate atomic clocks to synchronize their transmissions. These navigation tools would not function without accurate clocks.

Explaining the connection between time and location can be complex. During the development of the exhibition, we realized it was not enough to show devices for accurately measuring time and position. We wanted visitors to grasp why it's true that "If you want to know where you are, you need an accurate clock."  We wanted it to be easy to understand and, hopefully, fun. We developed the idea of a portrait gallery. Each portrait would depict a person from a different time period engaged in navigation. But this will be no ordinary set of portraits. Each will appear to be a painting or photograph, but in reality they will be large video screens. At regular intervals, the characters depicted in the portraits will "come to life" and interact with each other, telling the story of navigation from their point of view.

We planned five characters. The "Sea Navigator" would explain how he used a chronometer, sextant, and other tools to determine position while crossing the ocean in the 1830s. An "Air Navigator" would respond by explaining how he used similar tools, along with radio transmissions, to navigate aircraft during the World War II era. We'd then introduce an "Astronaut" to explore how to navigate spacecraft across the solar system, also using radio transmissions. A "Military Person" would speak about the details of the Global Positioning System and its military applications. Finally, a character we called the "Museum Visitor" would enter the scene. She would explore these topics from the point of view of an everyday user of global navigation with her mobile phone. Each of the characters reflected the topics in the sections of the Time and Navigation exhibition: Navigation at Sea, Navigation in the Air, Navigation in Space, Inventing Satellite Navigation, and Navigation for Everyone.

To bring this idea to reality, the Smithsonian selected a contractor to produce videos for Time and Navigation. The exhibition team worked with them over a period of months to develop the look and feel of the portraits, refine the script, and select the cast. We also had several decisions to make regarding props and wardrobe. Finally it was time to shoot the video.

During the last week of October, I traveled to southern California to be there during the shooting. The filming was planned to take place over two days in a sound stage in Orange, California. We met the evening before over dinner with the cast and crew for introductions. Over Mexican food, we completed a preliminary reading of the script.

The filming of the "portrait" characters was complex. The timing of each line needed to be precise, because the characters will interact with each other. Physical objects are even passed between two of the characters. The actors began by reading the entire script without a camera, giving us a recording of the program with a good pacing. Once the filming began, one actor at a time was filmed in costume, responding to the other actors as they spoke. By the time it was all over, the actors had read through the script at least 40 times.

Special attention was paid to how the actors looked at each other. Because they will appear next to each other on a wall, the eye lines between each character were determined before filming began. Each actor must look to the eyes of the character they address for each line. This required actors to sit or stand in their correct orientation, as if they were already within the portrait frames.

The Astronaut was the only character we filmed with props and a backdrop. The actor stood behind a table with a space shuttle model and a globe. The other four characters were filmed in front of a green screen so the background could be digitally added in production. During the filming, I sat next to the director to provide guidance. I was required to make several decisions, some important and others very minor. We made a few last-minute script changes and I occasionally provided pointers for which words to emphasize.

There were a few unexpected adventures. We had an issue with an insect flying onto a couple of the scenes. During a lunch break, it was announced that a reward would be given for its capture. This did the trick. The assistant director captured the offending insect and humanely release it outside.

Another surprise was that the legs of each character were visible. This was a serious problem because the chosen wardrobe did not include pants for two of the actors!  In the original plans, we thought the actors would be visible only above the waist.

The Air Navigator wore a flight jacket and khaki shirt. The actor wore casual shorts for comfort, because the jacket was hot and we had to turn off the whirring air conditioning. He even wore an ice vest under the flight jacket to stay cool. But now we needed a pair of matching khaki pants. Everyone looked around. I looked down at the khaki pants on my own legs. So did the director, sitting next to me. "Those look good," he said.  "What's your waist size?" I asked the actor. He was a 33, a match. So that is how, while representing the Smithsonian at a filming in southern California, I lost my pants. Fortunately another crew member had a pair of shorts I could borrow. I looked ridiculous but I must admit I was comfortable.

We had the same problem with our military character. She wore the uniform of the US Air Force 807th Expeditionary Air Support Operations Squadron, which was deployed to Afghanistan. Once again, we needed to find matching pants. We got very lucky. Right around the corner was a military surplus store. They had an exact match for the camouflage pattern. The pants were too large for the actor, but with a few binder clips to hold the extra fabric in place we were good to go.

In the end, we got all the video we needed to produce the portraits. Over the next few months we'll be reviewing preliminary versions of the video to prepare for installation. Thanks to the whole crew at Aperture Films. You can see the end result when we open Time and Navigation in March.