You seem to be (deliberately?) confusing issues here...

Depends on the reference. What is 0 dB? For sound pressure (for example), you're right. However 3 dB is a two-fold increase in watts (power).

The point was to compare (non-tail) recursive implementations of fib in C and Python...

(defun fib (n)
  (if (< n 2)
    n
    (+ (fib (- n 1)) (fib (- n 2)))))

(time (loop for i from 0 to 35 do (fib i)))

Real time: 94.33807 sec.
Run time: 92.069756 sec.

def fib(n):
    if n == 0 or n == 1:
        return n
    else:
        return fib(n-1) + fib(n-2)

for i in range(36):
    print "n=%d => %d" % (i, fib(i))

real    0m20.272s
user    0m20.225s
sys    0m0.024s

#include <stdio.h>

int fib (int n)
{
  if (n == 1 || n == 0) return n;
  else return (fib (n - 1) + fib (n - 2));
}

int main (int argc, char *argv[])
{
  register int i = 0;
  for (i; i < 35; i++)
    {
      printf("n=%i %i\n", i, fib(i));
    }
}

real    0m0.476s
user    0m0.472s
sys    0m0.004s

That experience is, by orders of magnitude, easier on Linux than on Windows--at least, that was my experience from when I last installed a fresh copy of XP (perhaps 4/5 years ago). It was absolutely impossible to find a decent free DVD decoder. If you're on Ubuntu, installing DVD support is as easy as typing 'sudo apt-get install ubuntu-restricted-extras', or use the GUI, or whatever.

That makes a lot of sense. In fact, while you're at it, why don't you beat up a few of the kids? You know, to get them ready for the real world, because we sure don't want them to get used to all the love. I think a better idea would be to survey some bullies (larger ones of course, one per student) in the local area and average out their practices.

Dropbox is not open source. The useful part, the daemon, is closed source. The irrelevant part, a nautilus plug-in, is open source, and automatically downloads the closed source blob. You can't even drop the daemon binary on a headless server, as it is dynamically linked to graphics libs.