Category

Why Series

3 lessons available.

EP41 · 2026-08-30

Why Series: Why Is a Rolex So Hard to Buy?

Rolex scarcity is not explained by one secret waiting list. This episode traces the technology behind the brand, explains official-jeweler allocation and secondary-market premiums, and asks whether a Rolex should ever be treated as an investment.

Intermediate9 min

EP24 · 2026-08-10

How QR Codes Work

A QR code may look like a random grid, but every region has a job. This episode follows a scan from the camera image to position detection, data decoding, error correction, and the final action on your phone.

Intermediate6 min

EP23 · 2026-08-10

Why Series: Why Do Airplanes Leave White Lines in the Sky?

Those white lines behind airplanes are contrails: narrow clouds of ice crystals. This episode follows their formation from hot jet exhaust to freezing upper air, explains why some vanish and others spread, and looks at what they can tell us about the atmosphere.

Intermediate5 min