I would assume the most dense medium possible would be a collection of neutrons, since neutron stars are the most dense object other than a black hole, but retrieving information from them doesn’t seem feasible.
"The novel is regarded as a landmark in hard science fiction. As is typical of the genre, 'Dragon's Egg' attempts to communicate unfamiliar ideas and imaginative scenes while giving adequate attention to the known scientific principles involved."
https://en.wikipedia.org/wiki/Dragon%27s_Egg
Superb.
Great book btw, hope I'm remembering it correctly.
From an old ZFS weblog post on why they chose 128 bits for their data structures:
> Although we'd all like Moore's Law to continue forever, quantum mechanics imposes some fundamental limits on the computation rate and information capacity of any physical device. In particular, it has been shown that 1 kilogram of matter confined to 1 liter of space can perform at most 10^51 operations per second on at most 10^31 bits of information [see Seth Lloyd, "Ultimate physical limits to computation." Nature 406, 1047-1054 (2000)]. A fully-populated 128-bit storage pool would contain 2^128 blocks = 2^137 bytes = 2^140 bits; therefore the minimum mass required to hold the bits would be (2^140 bits) / (10^31 bits/kg) = 136 billion kg.
* https://blogs.oracle.com/bonwick/128-bit-storage:-are-you-hi...