# NAS

Robert G. Brown rgb at phy.duke.edu
Tue Jul 2 08:29:10 PDT 2002

```On Tue, 2 Jul 2002, Mark Hahn wrote:

> I remember is 16 TB.  I presume that's actually 2^(31+9),

Some useful conversions:

2^10 = 1024 \approx 1000 (10^3) (kilo)
2^20 = 1024*1023 \approx 10^6 (mega)
2^30 \approx 10^9 (giga)
2^40 \approx 10^12 (tera)

so 2^(31+9) = 2^40 = 1 tera.  16 tera is 2^44 (without quibbling over
the difference between 1024 and 1000, and whether "mega" etc refers to
e.g. 2^20 or 10^6).

Fun numbers, actually.  2^64 \approx 1.6x10^19, indicating that 64 bit
addresses COULD in principle provide unique identifiers to a signficant
fraction of the atoms in a mole, or to every human-associated object
bigger than a pinhead, if it weren't for routing and access issues...

Irrelevantly yours,

rgb

Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu

```