Are you a software developer, and, if so, without looking it up, do you know what the THERAC-25 is?

SpookJ 👻

@glyph may mercy smile on us reading too much into the initial response

Glyph

@SnoopJ what I read into it is a failure of *formal* educational systems, there's no reason that someone would go *look up* this story by themselves. Given that I'm a dropout I only know about it because of all the stuff that Bane monologued to Batman about

SpookJ 👻

@glyph I give it slightly better than coin-flip odds that I'd know if I hadn't studied accelerators before I came to software professionally, and only slightly better because the Well There's Your Problem podcast did an episode on it and I probably would have found them anyway.

datarama

@SnoopJ @glyph I used to teach community college CS, and when one of my courses got to "the horrors of concurrency" (and the limitations of testing) I would always tell the story of THERAC-25.

aeva

@glyph No, first I'm hearing of it. Never learned about it in school.

I like that the wikipedia article leads by blaming concurrency, but the root causes section at the end has all sorts of horrifying things like this "However, some errors which endangered the patient merely paused the machine, and the frequent occurrence of minor errors caused operators to become accustomed to habitually unpausing the machine."

mcc

@aeva @glyph I once found a list of the deadliest/most costly software bugs ever, and the list compilers specifically called out THERAC-25 as the only UX bug on the list

(I think this list was made in the mid-10s, which would have been before BOTH America and Russia, in unrelated incidents, lost major naval war vessels to UX bugs)

[email protected]

@mcc @aeva @glyph

What vessels were those?

mcc

@robryk @aeva @glyph

1. U.S.S. John McCain. https://en.wikipedia.org/wiki/USS_John_S._McCain_and_Alnic_MC_collision I found a really good article about this before but can't find it now. The ship was designed so the helm could be controlled from any of a number of touchscreen interfaces around the ship, during the accident full control of the entire boat was accidentally transferred to a random screen near the ship's rear and the ship serenely sailed into another boat while the hem tried to figure out why the controls weren't working

mcc

@robryk @aeva @glyph

2. Anders Puck Nielsen has an analysis in which he suggests that the sinking of the Russian Federation ship Moskva in the Ukraine war ultimately happened (in echoes of the THERAC-25) due to operator fatigue caused by the design of the ship's anti-missile radar systems, which caused the ship to fail to respond to incoming missiles it otherwise had the capacity to deflect

Jason Lefkowitz

@mcc @robryk @aeva @glyph It’s also been argued that poor user interface design in the US Navy’s Aegis Combat System led to the accidental 1988 shoot-down of Iran Air Flight 655 by the cruiser USS Vincennes, which killed all 290 people on board the airliner.

http://xenon.stanford.edu/~lswartz/vincennes.pdf