NOVA Science Video Podcast | PBS

In this excerpt from NOVA's "The Incredible Journey of the Butterflies," see just how astounding the monarch butterfly's sense of navigation is, and learn how monarchs are tracked across North America. Watch NOVA every Wednesday night on PBS. Or join us online at pbs.org/nova. NOVA is produced by WGBH in Boston. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers. To learn more, visit http://www.pbs.org/nova/butterflies

Dr. Steve Jefferts of the National Institute of Standards and Technology in Boulder, Colorado is an expert on how we measure time. In fact, he uses one of the world's most accurate atomic clocks to calibrate time in the United States. But why do we need such accuracy? Learn why atomic clocks are so important in our everyday lives. Major funding for "The Fabric of the Cosmos" is provided by the National Science Foundation. Additional funding for this program is provided by the Arthur Vining Davis Foundations. NOVA is produced by WGBH in Boston. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers.

It took hundreds of hours to shoot and animate a scene in the so-called Quantum Club, from "The Fabric of the Cosmos" with Brian Greene. NOVA's Julia Cort, one of the producers of the show, explains how she and her colleagues created the scene to make the quantum world come alive. Major funding for "The Fabric of the Cosmos" is provided by the National Science Foundation. Additional funding for this program is provided by the Arthur Vining Davis Foundations. NOVA is produced by WGBH in Boston. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers.

If you were a spy, how could you ensure that an encrypted message got safely to your allies? Send it using entangled particles! Here, watch how a technique called quantum cryptography could save a state secret from falling into enemy hands. Major funding for "The Fabric of the Cosmos" is provided by the National Science Foundation. Additional funding for this program is provided by the Arthur Vining Davis Foundations. NOVA is produced by WGBH in Boston. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers.

According to the Heisenberg Uncertainty Principle, you can't know both the location and momentum of a particle at the same time. You might not think this could be funny, but watch this video and you might think again. For more on the Uncertainty Principle, check out this article on "Inside NOVA." And, post your own science joke on our Facebook page. NOVA is produced by WGBH in Boston. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers.

After years of planning and construction, the 9/11 Memorial opened to the public on September 12, 2011. In this short video, visitors weigh in on the design and importance of the memorial. "It's very moving, it's graceful, and it's also dignified," says one visitor from Miami, Florida. "It's beautiful. The only other memorial that I can think of that comes close would be the Pyramids." NOVA is produced by WGBH in Boston. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers.

7 World Trade Center was the first tower rebuilt at Ground Zero after 9/11. Developer Larry Silverstein describes some of the building's new features, and explains why he and architect David Childs made changes to the original design. NOVA is produced by WGBH in Boston. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers.

Bronze, granite, and water will all play a role at the 9/11 Memorial. In this short video, the memorial's architect and designer, Michael Arad, examines a small mock-up that has been assembled at the Brooklyn Navy Yard to see how the materials interact, how they hold up to the elements, and what the finished memorial will look like to visitors. NOVA is produced by WGBH in Boston. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers.

The names of the victims of September 11 are inscribed on 152 bronze panels that will line the 9/11 Memorial. In this short video, take a tour of the plant where the panels are fabricated with co-owner Jim Moretti to learn how these beautiful plaques are made. NOVA is produced by WGBH in Boston. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers.

What are composting toilets, computers, and a restaurant doing suspended hundreds of feet above Ground Zero? In this short video, learn how an engineering conundrum allowed the steel company, DCM Erectors, to install modern amenities at the One World Trade Center worksite. NOVA is produced by WGBH in Boston. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers.

The glass façade, or curtain wall, of One World Trade Center does far more than let light into the building. In this short video, learn how state-of-the-art glass panels covering the tower offer strength, safety, and beauty to the new skyscraper. NOVA is produced by WGBH in Boston. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers.

Would summer be complete without hot days, lemonade stands, and... cosmology? We asked people near the MIT campus to explain spacetime in exchange for free lemonade. See what they said. Got your own explanation for spacetime? Post your videos on our Facebook page. NOVA is produced by WGBH in Boston. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers. Major funding for "The Fabric of the Cosmos" is provided by the National Science Foundation.

A synthetic biologist's Nebraska farm roots are serving him well in his search for new, clean-burning biofuels. NOVA is produced by WGBH in Boston. Funding for NOVA scienceNOW is provided by the National Science Foundation, the Howard Hughes Medical Institute, the Alfred P. Sloan Foundation, and PBS viewers. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers.

Our electric grid is a marvel of 20th-century engineering, but it's showing signs of strain. Can a "smart grid" help? NOVA is produced by WGBH in Boston. Funding for NOVA scienceNOW is provided by the National Science Foundation, the Howard Hughes Medical Institute, the Alfred P. Sloan Foundation, and PBS viewers. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers.

Tiny, battery-powered cars called EN-Vs, now in R&D, can talk to each other, come when called, even drive themselves. NOVA is produced by WGBH in Boston. Funding for NOVA scienceNOW is provided by the National Science Foundation, the Howard Hughes Medical Institute, the Alfred P. Sloan Foundation, and PBS viewers. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and PBS viewers.