The following explanation is taken from https://news.ycombinator.com/item?id=49622607 : Alan Kay performs an improvisational avant garde layered audio feedback loop about Claude Shannon, live online…
Alan Kay performs an improvisational avant garde layered audio feedback loop about Claude Shannon, live online during Kristen Nygaard's 100-year birthday celebration.
Alan was scheduled to talk about how encountering Simula sparked his early thoughts about objects. During setup, somebody had the live stream playing out loud near an open Zoom mic, so his own voice kept arriving back in his ears about 21 seconds late, over and over.
What he said was not random: "Shannon gave us a way of dealing with noisy channels." And: "I think about that almost every day. I realize what the fuck is going on and it's just so amazing." Shannon's noisy channel coding theorem is the math for exactly the kind of channel that was garbling him as he praised it.
Alan joked it was "being rerouted to Mars and back." At the speed of light, a 21 second round trip is about 3 million km one way -- eight trips to the Moon and back, but only about a seventeenth of the way to Mars at closest approach.
This is an accidental Zoom performance of Alvin Lucier's "I Am Sitting in a Room" (1969), where Lucier re-recorded his own voice in a room until only the room's resonance remained. Here what remains is the network: delay, compression, dropouts.
Bonus noise: YouTube's auto-transcript bleeps Alan's enthusiasm into [ __ ]. So the full chain is: Alan's voice, Zoom, stream, room, Zoom again times three, my screen recording, YouTube's speech recognizer, a censored transcript.
The fix: "Just turn off the audio at your end on Zoom."
I Am Sitting in a Room: https://en.wikipedia.org/wiki/I_Am_Sitting_in_a_Room
Alvin Lucier on "I am sitting in a room": https://www.youtube.com/watch?v=v9XJWBZBzq4
36 comments
Calculating the limit is easy with Shannon's theorem. Approaching it in practice is hard.
Many modern modulations already operate basically on Shannon's limit for a given band/SNR. Well, on raw data, the encoding almost always use some kind of error correction so the decoded bitrate is few % lower than the wire one
Here is the full list of links from the video description to other related and interesting topics.
I can highly recommend smoking a joint and watching James "Doctor Chaos" Crutchfield's "Space-Time Dynamics in Video Feedback" film, which he made at UC Santa Cruz in 1984, building on Ralph Abraham's video feedback experiments there in the 1970s:
https://www.youtube.com/watch?v=B4Kn3djJMCE
https://en.wikipedia.org/wiki/James_P._Crutchfield
https://en.wikipedia.org/wiki/Ralph_Abraham_(mathematician)
Kristen Nygaard 100 Years, Celebration Symposium (Aarhus University, Aug 27 2026):
https://cs.au.dk/nygaard100years/celebration
Entire Nygaard Symposium Recording (Alan Kay's talk begins at 3:27:49):
https://au.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=fe0...
Alan Kay:
https://en.wikipedia.org/wiki/Alan_Kay
Claude Shannon:
https://en.wikipedia.org/wiki/Claude_Shannon
Information Theory:
https://en.wikipedia.org/wiki/Information_theory
Noisy-Channel Coding Theorem:
https://en.wikipedia.org/wiki/Noisy-channel_coding_theorem
Audio Feedback:
https://en.wikipedia.org/wiki/Audio_feedback
Video Feedback:
https://en.wikipedia.org/wiki/Video_feedback
Live Looping: The History And The Practice, by Stephen Garza:
http://computermusic2008.wikidot.com/live-looping:history-an...
I Am Sitting in a Room:
https://en.wikipedia.org/wiki/I_Am_Sitting_in_a_Room
Alvin Lucier on "I am sitting in a room":
And how the conference's real time speech to text transcription honored Alan's "fuck", but would occasionally lapse into Danish, and say things like "We will eat your hands".
dang> Hopefully Don won't mind!
Of course not, and I hope Alan won't either, since in the recording he laughed and said "Yeah, this will be this will be fun."
Shannon's theory is foundational to modern communication systems. You can expect to have WiFi remain functional even as other devices use the same medium. Up to a point, the Shannon limit in other words.
Hopefully Don won't mind!
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