Extras

    Video thumbnail: NOVA The Spacetime Lemonade Stand

    NOVA

    The Spacetime Lemonade Stand

    Thirsty for understanding? See how well people on the street can explain spacetime.

    The Spacetime Lemonade Stand

    Video thumbnail: NOVA Rebuilding 7 World Trade Center

    NOVA

    Rebuilding 7 World Trade Center

    Developer Larry Silverstein explains what's different about the new 7 World Trade Center.

    Rebuilding 7 World Trade Center

    Video thumbnail: NOVA The 9/11 Memorial Mock-Up

    NOVA

    The 9/11 Memorial Mock-Up

    Architect and designer Michael Arad takes us on a tour of his 9/11 Memorial mock-up.

    The 9/11 Memorial Mock-Up

    Video thumbnail: NOVA Solving an Engineering Problem

    NOVA

    Solving an Engineering Problem

    Bracing One World Trade Center's steel frame led to some unexpected perks at the worksite.

    Solving an Engineering Problem

    Video thumbnail: NOVA The Memorial Plaques

    NOVA

    The Memorial Plaques

    Visit the factory where the 9/11 Memorial plaques are made.

    The Memorial Plaques

    Video thumbnail: NOVA Walls of Glass

    NOVA

    Walls of Glass

    One World Trade Center's glass facade may look fragile, but it is extraordinarily tough.

    Walls of Glass

    Video thumbnail: NOVA Brian Greene Answers Your Questions

    NOVA

    Brian Greene Answers Your Questions

    Author and physicist Brian Greene answers questions from Facebook and Twitter.

    Brian Greene Answers Your Questions

    Video thumbnail: NOVA Green Energy in China

    NOVA

    Green Energy in China

    China is ramping up production of solar technology but coal power remains king.

    Green Energy in China

    Video thumbnail: NOVA A Strict Carbon Diet

    NOVA

    A Strict Carbon Diet

    Saul Griffith has put himself on a strict regime to reduce their carbon footprint.

    A Strict Carbon Diet

    Video thumbnail: NOVA A Mind for Music

    NOVA

    A Mind for Music

    See neuroscientist Oliver Sacks's brain respond differently to music by Bach & Beethoven.

    A Mind for Music

    Video thumbnail: NOVA Modeling a Comet Airburst

    NOVA

    Modeling a Comet Airburst

    See why an explosion three miles above Earth would act like a hot tornado on the surface.

    Modeling a Comet Airburst

    Video thumbnail: NOVA Six Questions with David Pogue

    NOVA

    Six Questions with David Pogue

    The New York Times technology columnist describes the best and strangest gadgets he’s...

    Six Questions with David Pogue

    Video thumbnail: NOVA Shabbat Elevator

    NOVA

    Shabbat Elevator

    Hotels are offering an innovative way for observant Jews to use elevators on the Sabbath.

    Shabbat Elevator

    Video thumbnail: NOVA Surviving an Elevator Fall

    NOVA

    Surviving an Elevator Fall

    If an elevator falls, can you save yourself by jumping up at the last second?

    Surviving an Elevator Fall

    Video thumbnail: NOVA Front Row Seat to Saturn

    NOVA

    Front Row Seat to Saturn

    Out near Saturn, the spacecraft Cassini has just entered its final and riskiest chapter.

    Front Row Seat to Saturn