Keynote: Apps, Algorithms and Abstractions: Decoding our Digital World
summary
Explains how a phone moves a 12MP photo (~32 MB uncompressed) from sensor to screen, starting at radio (live clap demo of AM/FM/PSK) through 16 channels per handset, duplexing methods (TDD/FDD), modulation up to 256 QAM, and encryption; traces stacks HTTP/TLS over TCP over IP, audio sampling at 44.1 kHz 16‑bit, historical memories (mercury delay lines, UNIVAC 18×120‑bit), disk mechanics (platters at ~15,000 RPM) and JPEG’s 8×8 DCT + zigzag chroma subsampling so you know which specific tradeoffs and numbers matter.
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chapters (17)
- 0:00Start
- 6:47Time Division Duplexing
- 10:18Transmit Digital Information
- 12:42Amplitude Modulation
- 13:03Frequency Modulation
- 13:35Face Modulation
- 16:23Quadrature Amplitude Modulation
- 21:18Mechanical Hard Drives
- 21:57Principle of Magnetic Storage
- 22:44Ram Memory
- 27:56Photo Detector
- 35:53Jpeg Zigzag
- 38:39Morse Code
- 41:15Character Encodings
- 45:07What the Unicode Consortium Did
- 47:35Utf-8 Encoding
- 52:12Pacman Rule
