Hi David,

>10 pm/psec = 0.01 nm/nsec = 0.00001 um/usec = 0.00000001 mm/msec = 0.00000000001 m/sec. So saying pm/ps is just a way of getting rid of some zeros.

10 pm/psec = 10 (1E-12 m )/(1E-12 s) = 10 m/s

Sorry, but when you understand the minimal rules of calculation and measuring we can speak about more complex things.

Fabio