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Comment by jcromartie | Hacker News Reader

I think there's a fundamental concept that isn't taught very well, and that concept is: Computers only ever do (for something like 99.999999999% of instructions) exactly what they are told to do.

They don't have a mind of their own, and programming isn't magic. Opaque languages, libraries and APIs don't help the situation either. I wonder how many programmers start out under the assumption that computers are more-or-less magic?

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That summarizes the familiar high-level world of recent times. (But then I'm also old enough to remember when compiler gremlins were ubiquitous.)

The lower-level world can be quite a bit more unseemly, what with the unpredictability of occasionally marginal voltages or power supplies, of RAS recovery and the occasional RAS and ECC errors, of sections of system buses lacking ED/EDC protection, the "fun" that is radioactive RAM and embedded alpha emitters (particularly "entertaining" if you don't have solid EDC), bus transients, and a host of other hardware gremlins.

Looking at the lowest levels of these boxes, I something marvel that these modern computing boxes even work at all, much less as well as they do.

And that's why I say that it works for the vast majority of instructions that are executed. There is that slim chance that it will flub up, but that kind of error either: A) gets caught in the hardware or B) completely takes down the operating system or app.

The likelihood of some cosmic ray flipping a bit of a counter variable in some loop's sub-millisecond lifespan is just so unimaginably small you can count it impossible.

Physical objects only ever do exactly what they're 'told' to do, period. Rocks don't have a mind of their own, and physics isn't magic. Yet I don't want to live in a world where we don't spend time twiddling with dials and poking around.

I agree with the thrust of your statement, but it's worth keeping in mind that while physics isn't magic it is not deterministic either, once you start working with really small things.

I've noticed this "magic" thing too, among the most clueless members of our profession.

Even if they have no idea how bad they are, which they usually don't.

You see this a lot (even on this forum) with people referring to Rails "magic", when it can't possibly be anything but a bunch of lines of code being executed according to the rules of a certain interpreter.

To paraphrase Agatha Heterodyne, any insufficiently analyzed technology is indistinguishable from magic. I think their terminology is pretty reasonable.

Isn't this identical to what the original post I replied to was saying - those he refers to as the "clueless" have not sufficiently analyzed enough technology to distinguish it from magic. I wouldn't go so far as calling people clueless though, thinking of some things as magical black boxes frees up mental space.

Rails magic is vastly different from the magic referred to in the gp. Rails uses a number of dynamic approaches that create results that in other frameworks would take some amount of explicit configuration. The word "magic" in this context is ironic and merely means "dynamic".

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