What is common knowledge in your field but shocks outsiders?

More than half the CO₂ emissions of the industrial age have been dumped into the atmosphere since 1990.

@davidho Software on trains is so difficult to update that it often isn’t updated at all.

@slothrop @davidho

There are nuclear reactors still running PDP-11 control systems.

@tjradcliffe @davidho @slothrop Actually, that‘s reassuring. No code from Redmond in it.
@ahm42
@tjradcliffe @davidho @slothrop
"The nuclear reactor is controlled by a flash based interface on Windows XP. We're hoping to migrate to service pack 3 by the end of the decade."