[OT] a little calculation (Re: [Gnu-arch-users] Newbie - don't quite understand tagging method)

[Tez Kamihira]

On Thu, 27 Nov 2003 19:25:27 -0500, Charles Duffy <address@hidden> said:
> 
> So, don't trust random numbers for your uuids, despite the fantastically low
> probability of a collision and the fact that arch will inform you if one 
> should
> somehow occur? Use "uuidgen -t"!
> 

a little calculation.

right ?


[Radius of Earth]

    R = 6 * 10^6 [m]

[Surface of Earth]

    S = 4 * pi * R^2
      =~ 450 * 10^12 [m^2]

[simple probability to select a specific UUID]

    p = 1 / 2^128
      =~ 3 * 10^-39

[1 UUID's surface relative to Earth's]

    s = s * p
      =~ 1.4 * 10^-24 [m^2]
      = 1.4 [Angstrom^2]


The world of Bohr radius ...



         - Tez