Former CIA Chief Explains How Spies Use Disguises by WIRED
How Spies Use Disguises
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Video: How your eye works
Why we have blind spots – and how to see the blood vessels inside your own eye! – Guillaume Riesen
Video: Frequency spectrum explained
Fourier Transform, Fourier Series, and frequency spectrum
2018 Hacktoberfest
What is Hacktoberfest! Open Source coding is for everyone – Eddie Jaoude