Inside the Milky Way • 2010

58:33

Visiting a hidden location buried beneath the hills of Scotland, Helen experiences some of the most extreme acoustics in the world. Here she learns just how much information can be carried by sound. She discovers how sound has driven the evolution of truly incredible biological systems and complex relationships between creatures that exploit sound for hunting - and escaping from predators. Helen demonstrates how sound waves diffract (bend around objects) and in doing so help us sense danger and locate it. Helen explains how we are not limited to passively detecting sound waves; we can also use them to actively probe the world.

S1E2 • Sound Waves: The Symphony of Physics • 2017 • Physics

56:41

Over a single weekend in 1869, a young Russian chemistry professor named Dmitri Mendeleev invents the Periodic Table, bringing order to the growing gaggle of elements. But this sense of order is shattered when a Polish graduate student named Marie Sklodowska Curie discovers radioactivity, revealing that elements can change identities — and that atoms must have undiscovered parts inside them.

Part 2 • The Mystery of Matter: Search for the Elements • 2015 • Physics

59:04

At the Palace of Westminster, Helen teams up with scientists from the University of Leicester to carry out state-of-the-art measurements using lasers to reveal how the most famous bell in the world - Big Ben - vibrates to create pressure waves in the air at particular frequencies. This is how Big Ben produces its distinct sound. It's the first time that these laser measurements have been done on Big Ben. At the summit of Stromboli, one of Europe's most active volcanoes, Helen and volcanologist Dr Jeffrey Johnson use a special microphone to record the extraordinary deep tone produced by the volcano as it explodes. Finally, at the University of Cambridge's Institute of Astronomy, Helen meets a scientist who has discovered evidence of sound waves in space, created by a giant black hole. These sounds are one million billion times lower than the limit of human hearing

S1E1 • Sound Waves: The Symphony of Physics • 2017 • Physics

11:18

Scientists investigate the way the Sun builds its power -- through fusion -- hoping to find a way to use fusion as a less dangerous and less radioactive waste-producing path to energy than fission. But there are some major difficulties along the way...

2017 • Physics

4:49

Light always travels at a speed of 299,792,458 meters per second. But if you're in motion too, you're going to perceive it as traveling even faster -- which isn't possible! In this second installment of a three-part series on space-time, CERN scientists Andrew Pontzen and Tom Whyntie use a space-time diagram to analyze the sometimes confounding motion of light.

TED-Ed • Physics

5:22

How do we know what matter is made of? The quest for the atom has been a long one, beginning 2,400 years ago with the work of a Greek philosopher and later continued by a Quaker and a few Nobel Prize-winning scientists. Theresa Doud details the history of atomic theory.?

TED-Ed • Physics