On Fri, 31 Oct 2025, Nicolas George wrote:
i run a command preceded by time and pipe it to mail
the results of time is not included in the mail
time sleep 2 2>&1 | mail -s foo bar@localhost
Try this:
time sleep 3 | sleep 10
… observe carefully the output and deduce something important about
time.
that's easy
the electrons are moving near the speed of light
so time slows down :)
The electrons move actually pretty slowly. It's the electrical field
what moves quickly.
Let's assume copper, at a density of 8.9 g/cm^3, and an atomic weight
of 63.5: 1mm^3 of copper has 6.02*10^23 * 8.9 * 10^-3 * (1/63.5) atoms,
i.e. 8.44 * 10^19 atoms, each contributing one electron to the conduction
band (the last lone S1). At 1.6 * 10^-19 C, that makes 13.5C of charge
available for conduction in each mm^3, which is a friggin' lot.
If you push 1A across a wire with a cross section of 1mm^2, your
electrons would be moving at 1/13.5 mm/s, i.e. 0.074 mm/s: I can
hear the snails in my garden yawning :)
I might have lost an order of magnitude here or there, but the kind
of result is somewhat consistent with the dim memories I have from a
former life...