In this video excerpt from NOVA scienceNOW, learn about polygraph tests and lie detection. Correspondent and New York Times technology columnist David Pogue commits a staged crime and undergoes a polygraph test to find out how it works. Lying can cause stress, which produces common physiological responses, such as an increased heart rate and sweating. Polygraph testing experts explain what the test measures, why the questions are reviewed in advance, and why the test doesn't always work. This video is available in both English and Spanish audio, along with corresponding closed captions. CREDITS: https://www.pbslearningmedia.org/credits/nvsn6.sci.tech.polygraph/ 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
