This video was filmed on December 14th, 2011 as part of the National Geographic Live! Lecture series at National Geographic Society headquarters in Washington, D.C.

Introduction
Nobel Laureate John Mather and National Geographic Explorer-in-Residence Robert Ballard discuss how technology expands the limits of the known universe. Among the most accomplished and well known of the world's deep-sea explorers, Robert Ballard is best known for his historic discoveries of hydrothermal vents, the sunken R.M.S. Titanic, the German battleship Bismarck, and numerous other contemporary and ancient shipwrecks around the world. During his long career he has conducted more than 120 deep-sea expeditions using the latest in exploration technology, and he is a pioneer in the early use of deep-diving submarines.

The 2006 Nobel Laureate in Physics, John Mather designed space probes to measure the traces of the big bang. Leading the discussion is Boyd Matson, host of National Geographic Weekend.

 Outline

• The limits of scientific knowledge (00:00-00:41min)

• The prediction and discovery of hydrothermal vents (00:42-03:58 min)

Strategies for Using Video in a Variety of Learning Environments

• Have students preview several of the videos and choose one they find most inspiring. Have students describe in writing a conversation they might have with the speaker(s).
• Freeze the video on a relevant image. Have students observe details in the still image and jot down predictions of what the full video might address. Discuss students' ideas before and after watching the video.
• Pose an open-ended question before students watch the video, and have them discuss their ideas before and after in small groups.
• Have students determine what they think the key message of this video is. Was the speaker effective in getting his or her message across?
• Show a short clip to engage students during class, and then have students watch the full video at home and write a paragraph responding to the content or a question you give them.
• Have students note statements that represent facts or opinions, including where it's difficult to tell the difference. What further research might help distinguish facts and opinions? How might the speaker's viewpoint compare with others' viewpoints about a topic?