> In software, a single bit-flip or typo can lead to catastrophic failure That can happen in physical engineering too, if it's not done right. Likewise, if a

> In software, a single bit-flip or typo can lead to catastrophic failure That can happen in physical engineering too, if it's not done right. Likewise, if a single bit flip can lead to catastrophic failure, that's an indication that the system was poorly engineered. The problem with software is not so much that it is fundamentally different in terms of its failure response (though there certainly are differences -- the laws of physics provide important constraints on hardware that are absent in software) but rather that it is so easy to copy, which tends to entrench early design decisions and make them difficult to go back and change because the cost is too high (e.g. syntactically-significant tabs in 'make'). But even that can and does happen in physical design as well. The Millennium Tower in San Francisco is the best example I can think of. The World Trade Center is another example of a design that failed because the failure mode that destroyed it was not part of the original design requirements. When the WTC was designed, no one imagined that someone would fly a jet into them some day. Today's adversarial environment was similarly hard to imagine before the Internet. It absolutely is possible to engineer software for robustness, reliability, and trustworthiness. The limiting factor is economics, not engineering.