Well, if this island is made of 21 billion "atoms", then each of these will have to be stored whith a position-data, propably float values with 4 bytes. That means for all 3 dimensions: 21billion atoms*4*3=252billion bytes -> 252GB in storage, which is massive. If each atom holds a color value it is much more. So if you want do display the entire map, your system needs to transfer many, many GB of information which is currently impossible. So please, enjoy this technology with caution...
Retard doesn't know about compression...
Nor does all that data have to be loaded in 1 part.