Curator Hal Wallace talks about the development of the laser, an invention that has as many practical uses as portrayals in science fiction and fantasy.

Fifty Years of Lasers

Henry Fitz

Curator Steven turner discusses the work and shop of Henry Fitz, America's first commercially successful telescope manufacturer.

History Explorer: Henry Fitz's Telescope Shop

ʺSolution of the Black-drop Mysteryʺ Jay M. Pasachoff, Director of Hopkins Observatory and Field Memorial Professor of Astronomy, Williams College.

Solution of the Black-drop Mystery

ʺPublic  Reaction to the Transit of Venus, 1882ʺ David DeVorkin, Curator of History of Astronomy, National Air and  Space Museum, Smithsonian Institution, Washington, DC

Public Reaction to the Transit of Venus, 1882

ʺThe American Expeditions of 1874 and 1882ʺ Steven J. Dick, NASA Chief  Historian, National Aeronautics and Space Administration, Washington, DC

The American Expeditions of 1874 and 1882

“Endeavour's Wake: Captain Cook and the Transit of Venus” Richard Fisher, Director, Sun-Earth Connection Division, NASA Office of Space Science, Washington, DC“Endeavour's Wake: Captain Cook and the Transit of Venus”

Endeavour's Wake: Captain Cook and the Transit of Venus

The First Observation of a Transit of Venus” - Wilbur Applebaum, Professor Emeritus, Humanities Dept., Illinois Institute of Technology, Chicago, IL

The First Observation of a Transit of Venus

Researchers have been traveling for decades to some of the coldest places on the planet to uncover some of the secrets from space that have been left behind on Earth.

Ice Core Records: From Volcanoes to Supernovas

Steven Squyres

Principal scientist of NASA's Mars Exploration Rover (MER) mission, launched in 2003 -- Dr. Steven Squyres speaks at the National Portrait Gallery about his pioneering role in launching unmanned missions to Mars. A portrait of Squyres by Susan Gamble and Michael Wenyon was on view in NPG's "Americans Now" exhibition, through September 25, 2011. Recorded at NPG, October 15, 2010.

Dr. Steven Squyres, Face-to-Face talk

Peoples all over the world have unique creation stories: how the universe, the world, people, and animals came into existence. This creation story comes from the Blackfeet of North America.  It is currently on view in the Our Peoples gallery at the National Museum of the American Indian in Washington, DC.

The Blackfeet Creation Story

NASA's Chandra X-ray Observatory, in orbit since 1999, studies the high-energy Universe, where black holes, exploding stars, and mysterious matter hold sway.

How Chandra Does What It Does

These three traditional Native American stories fancifully portray the origin of several features in the night sky. These stories come from the Paiute, Arikara, and Chippewa peoples. Six additional stories are currently on view in the Our Universes gallery at the National Museum of the American Indian in Washington, DC.

Three Native American Star Stories

Henry Casselli

Portraits of astronauts John Glenn, Bob Crippin and John Young, by Henry Casselli -- the artist discusses his work.  Image: John Glenn / Henry C. Casselli, Jr. / Graphite and watercolor on paper, 1998 / National Portrait Gallery, Smithsonian Institution; Gift of Taylor Energy Company LLC

Henry Casselli, artist talk

The music of the “Five Directions” comes from the fundamental philosophy of East Asia, which describes the basic forces behind the formation of the universe and all physical phenomena. These consist of the cosmic dual forces, yin/yang, and the five physical elements (ohyeng): metal, wood, water, fire, and earth. The universe is sustained by the absolute balance and delicate order of yin/yang and ohyeng, which is reflected in the five spatial and dimensional directions (obang): east, west, south, north, and center. Each direction is also represented by the five basic colors: east (blue), west (white), south (red), north (black), and center (yellow). The music of this performance was created through interactive collaborations among three distinguished Korean traditional musicians and three renowned New York jazz and classical performers. The structure of this collaborative work consists of five sections drawing upon distinctive musical traditions from four geographic regions of the Korean peninsula: East, West, South, North, and the Center, a fifth region created to represent current music.

A Korean and American Jazz Excursion: Five Directions

Apollo 15 mission Astronaut Dave R. Scott cancels two die proofs of the 8c 1971 postage stamps commemorating a decade of US achievements in space. The stamps were issued the same day on Earth with a first-day ceremony at Florida’s Kennedy Space Center. The initial view shows Scott beside the Modularised Equipment Stowage Assembly with a mountain in the background behind the lunar module. As he narrates the procedure he's performing, the camera zooms in affording a view of the envelope. Scott canceled the die proofs with a cancellation device and ink pad, producing a postmark that reads UNITED STATES / ON THE MOON / AUG. 2 1971 / FIRST DAY OF ISSUE. The postmark was faint enough that he tried again directly below it. Scott also added dusty “thumbprints” with his space suit glove.

Apollo 15 Cover Cancellation

Unlocking the Mysteries of the Universe

The Best Multi-Part Documentaries, with documentaries on Obama, Federer vs Nadal, the making of Star Wars, Netflix vs Blockbuster and more. Add episodes you're interested into your queue below!

Best Multi-Part Documentaries

The best podcast episodes on physical health. Episodes talk about your diet, sleep, exercise and all the things that people do to improve their physical health and live a healthier life. This topic is for everyone, with applications in all of our everyday lives. Add episodes you're interested into your queue below!