[extropy-chat] how many exabytes?

[Damien Broderick]

At 08:28 PM 1/12/2005 +0100, Serafino wrote:

>... 5 exabytes: all the words ever spoken
>     by human beings.
>... 6 exabytes: information in the genomes
>     of all the people in the world.

Yeah, but Baez admits:

<this compression issue is especially important in my guess at the 
information in the human genome, and the genomes of all the people in the 
world. I didn't try to take into account the immense overlap in genetic 
information between different people, nor the repetitive stretches in human 
DNA. Here's how I did the calculation. Each of us has chromosomes with 
about 5 billion base pairs. Each base pair holds 2 bits of information: A, 
T, C, or G. That's 10 billion bits, or 1.25 gigabytes. Times the roughly 
6.5 billion people in the world now, we get about 8 x 10^18 bytes, or 8 
exabytes. They only built 2 exabytes of hard disks in 2002. But, if we 
wanted to store the complete genetic identity of everyone on hard drives, 
we could easily do it, using data compression, because a lot of genes are 
the same from person to person. >

Damien Broderick