In this video excerpt from NOVA scienceNOW, correspondent and New York Times technology columnist David Pogue learns how cutting an onion triggers chemical reactions that change the properties of the onion. Animations illustrate how enzymes are separated from other molecules inside the cells of an onion; cutting the onion breaks the barrier and allows the molecules to chemically react and create new molecules. Cutting changes the flavor of the onion and releases molecules that can make you cry. This video is available in both English and Spanish audio, along with corresponding closed captions. CREDITS: https://www.pbslearningmedia.org/credits/nvsn6.sci.chem.onion/ LICENSE: https://www.pbslearningmedia.org/help/full-license-for-section-3c-of-terms-of-use-download-and-share/
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The theory of how the Grand Canyon was formed is shown in this animation from NOVA, and features rare footage of a phenomenon known as debris flow. CREDITS: https://www.pbslearningmedia.org/credits/ess05.sci.ess.earthsys.canyon/ LICENSE: https://www.pbslearningmedia.org/help/full-license-for-secti
In this video from NOVA’s Sun Lab, learn about the Sun’s ever-changing surface and magnetic field. Images and animations illustrate how the Sun’s magnetic field lines are affected by the motion of the Sun’s plasma. Over time, the magnetic field becomes twisted and more complex, which increases solar
In this video from NOVA’s Sun Lab, learn about the Sun’s composition and structure. The Sun is a plasma, primarily made of hydrogen with smaller amounts of other elements. Animations and images illustrate the physical and behavioral properties of the Sun’s six regions: the core, radiative zone, conv
