I was talking to a college at work the other day about the mount of free space let our file server. The wasn't much space left and it looked like the disk use police where going to come around and start suggesting we delete stuff or have it deleted for us! Okay things are quite that bad and I'm not normally the on top of the disk usage table (I'm about 4th out of about 60!). While talking about this it struck me how I was saying 'there is only 17 gig's left free'.
ONLY 17 gigs! That's only 17 billion bytes. And we are not talking the new watered down international billion here (100 million) we are talking the full, old style British billion (1000 million)
17 billion, there is no way I or any other human can possibly have any real idea of just how large 17 billion really is. And yet I said only 17 billion. I would guess that most people, my self included, can't really get there minds around figures of more that a few hundred thousand. Maybe some mathematicians might be able to fully grasp a few million, but 17 billion, nope I don't think any one really can fully grasp a figure that big.
And yet every day we come in to contact with numbers this size and bigger. I think this is why we feel more comfortable with the SI prefixes (kilo, mega, giga etc). They don't sound as big as the numbers them selves, 17 gigabytes sounds smaller and less intimating than 17 billion bytes!
To put this all in to some kind of perspective, the video card in my dual G5 mac has 64 megs of ram (only!), which is still larger than the very first hard drive I had for my Atari ST, which was only 40 megs!