Deep in the COVID lockdown, when little new TV was being created, I spent my evenings watching conference talks on YouTube. Many were from Kevlin Henney. So when Urs Enzler announced Kevlin would be speaking at .NET Usergroup Zentralschweiz, I was rather excited.
The talk, Much Ado About Nothing, was a walk through the history of nothing, and the many ways we represent the absence of data.
He opened with photos of Earth looking back from the moon. My mind wandered. In school we’re taught space is empty, but also that the universe is finite. So what’s beyond it? What is the emptiness beyond the emptiness of space?
Kevlin then took us through a history of counting and numerical representations. Who knew counting could be so interesting? Along the way, he showed, what to me was, a new way of implementing the Roman Numerals kata.
Then came Qantas Flight 32. Engine sensors (destroyed in the incident) were unable to send data back to the central system which interpreted “no data” as “everything’s fine”. In this lack of data, silence was mistaken for safety.
That reminded me of something older, 19th-century US telegraph lines carried a constant signal even when no messages were being transmitted, just to prove the line was alive. When that heartbeat went dead, you knew something was wrong, in the worst case bandits were about to raid your town and had cut communications. Here silence becomes the signal.
When I started working with databases I was told that there were something like 13 different uses for the NULL value, i.e. missing, not applicable, etc. Turns out “nothing” has never been simple.
A really entertaining evening, and I even got one of my old-school patterns books signed.
Big thanks to bbv Software Services for hosting and sponsoring food and drinks, to organisers Daniel and Urs for putting it together, and of course to Kevlin for making the trip to Luzern.
