De-orbiting from geosync is way to expensive to be an option (too high delta-V). What they use instead is the "graveyard orbit". At the end of operational life, the satellite just does some final burns to raise its orbit by a few hundred km, where it is no longer geosynchronous but also out of the way of the geosync orbit. Satellites launched into geosync are required to have this capability.

If you meet a Croat, tell him Tesla was Serbian. If you meet a Serb, tell him Tesla was Croatian. Watch the sparks fly.

(Tesla was born in what is now Croatia, but was ethnically Serbian).

By default (no arguments, out of the box) valgrind gives a description of the problem and a stack backtrace with the names of the procedures, files and linenumbers. You can tell it to also drop you into the debugger of your choice at the offending line.

The point is, your accusation "You goto valgrind and bisect issues" (exact quote) would make unfamiliar readers think that valgrind does not give the exact source code location where the errors occur and that, sir, is a flat out lie. I'm sorry that there are no weaker words for it.

You're going to come off as an MS shill because you are flat out lying. Valgrind tells you exactly what line is offending.

char *p = malloc(8);
p[10] = 42;

Let valgrind run that code and it will immediately tell you that the source filename and linenumber that p[10]=42; is on along with a callstack backtrace. Ditto with leaked memory, reads of uninitialized memory etc.

Actually, I am currently working on an ARM based commercial embedded system that is almost entirely written in Python (on Linux).

Once you make the leap of adding external ram and flash, which you need to run Linux reasonably, using python is not really a big deal. The whole system is still only a few square cm big; you could hide it in your fist.

You're not thinking multiuser scenarios.

The main feature of vipw is that it does locking. This prevents two admins from editing /etc/passwd at the same time, which could corrupt it completely. It also keeps it from getting corrupted because some user happens to be changing their password while /etc/passwd is being edited.

My example with a normal calculator above shows how to verify your answer.

As a trivial example, "solve d(x^2)/dx". Well duh, the answer is 2*x, but you can numerically verify that: Evaluate x^2 at 1 and 1.001. You get 1 and 1.002001. The difference times 1000 then is 2.001. Now evaluate your answer at 1: You get 2. Yup, your answer is probably right.

Similarly, even the lamest programmable calculator can do numerical integration. So again, just numerically integrate your original function from 0 to 1 or whatever and verify that your integral answer formula produces a similar number.

I did this quite regularly in calculus exams. Saved my ass repeatedly. You can also plug your test number into your intermediate steps to see where it changes -- that will be the place you made a mistake.

So yes calculators are useful in calculus exams, even if it's not a monster like the HP50g that does full symbolic calculus.

That's fine; the HP50g has a mode where it shows the intermediate steps when solving a calculus problem.

Even if it didn't, don't you think having a device that gives you the correct answer on a silver platter is a pretty handy thing to have in a calculus exam?

That's crazy. Fancy calculators like the HP50g can do symbolic calculus..

Even less fancy calculators can be useful: I used my programmable calculator to check my answers. For a derivative, for example, evaluate the original formula at some arbitrary value, and then again at that same value plus .001. The difference of the results times 1000 is roughly the derivative, so now you can plug that same arbitrary value in your derivative as a confirmation that you probably got the right answer.

The same calculator could also do numeric integration, so integrals could be checked as well.

It doesn't take much to run Angry Birds.

When I grew up in Sweden, tests were marked with "R" for correct and a checkmark for wrong. Then we moved to Canada, and one of my first quizzes was math. I took it up to the teacher, who checked off every question and handed the test back to me with a big smile and the exclamation "good!".

I was devastated. I sat at my desk completely baffled as to how I could have gotten every question wrong. I was thinking that maybe math is different in Canada. Eventually I went back to the teacher to complain, and after some confusion we were both sorted out.

So yeah, don't count on checkmark meaning what you think it does to everyone.