Why Jet Engines Depend on an Element You've Never Heard Of - Video

Modern jet engines depend on materials most people have never heard of. One of them is yttrium.
But the deeper story isn't simply about whether a rare element exists in the ground.
From turbine coatings and material processing to substitutes, qualification, and decades of accumulated industrial capability, this video follows one obscure element through the hidden system behind some of the world's most advanced technology.
And it leads to a much larger question: when a critical material becomes difficult to replace, where does the real vulnerability actually lie?
W:NOW explores the hidden systems, technologies, and forces shaping the world around us.