Henry Baker <hbaker1@pipeline.com> wrote:
Re Charles Stross & C12/C13 isotope lattices: Cool! Did Charles Stross have any ideas about how to read out these data?
Here are his original posts on the subject: Newsgroups: rec.arts.sf.composition From: Charlie Stross <charlie@antipope.org> Subject: Re: The Cafe on the Common Date: Thu, 17 Jul 2003 18:04:58 +0100 Stoned koala bears drooled eucalyptus spittle in awe as <oak@uniserve.com> declared:
(So is 'does not involve floppy disks in any way, shape, or form', these days. The good ones are old and the new ones you can get are junk.)
This has *always* been true. That is: there's a double-digit percentage defect rate on floppies. Reliable ones get reused indefinitely, defective ones get binned with a "the new ones you can get are junk" comment attached. Floppy disks -- better than saving to compact cassette, in much the same way that being subjected to the pilliwinks is 'better' than going to the gallows. I can't wait for diamond-phase storage to show up. (A zero is a carbon-12 nucleus, a one is a carbon-13 nucleus, you use nanotech assemblers to read/write the stuff, it stores 10^22 bits per gram with serious redundancy and error correction and has a half life measured in gigayears. Plus, you can wear it as jewellery.) -- Charlie Newsgroups: rec.arts.sf.composition From: Charlie Stross <charlie@antipope.org> Subject: Re: The Cafe on the Common Organization: foobar quux Date: Thu, 17 Jul 2003 19:14:48 +0100 Stoned koala bears drooled eucalyptus spittle in awe as <mra@pobox.com> declared:
It's a stone bitch to read, tho.
I'll grant you it *is* an archival medium, and Drexler-complete to boot (to the extent of requiring a mature nanotechnology base with general purpose assemblers to make it really practical). On the other hand, what's not to like about the idea of being able to carry the sum total of human recorded media (film, audio, video, text ...) around on a ring? Or a couple of thousand serialised and recorded human personalities, if you buy Moravec's estimate of the computational complexity of the human brain. -- Charlie
Re adjacent C12/C13 swapping: in a quantum universe, never say "never". The probability & half-life of such swapping should be calculable.
The atoms are locked into a rigid lattice. It's enormously more likely that the lattice will break down than that atoms will swap in an intact lattice. So it's the half-life of the lattice that you should calculate.
Perhaps it's 1000 years. Perhaps it's 1000 billion years.
I can't immediately find the answer online, but given how chemical and evaporative processes tend to scale with temperature, I'd bet money that it's enormously longer than 1000 billion years at room temperature. I really think cosmic rays will destroy it first. Or neutrinos (!) if you shield it from cosmic rays by placing it in the center of a large non-radioactive asteroid. Except that in the time it would take for neutrinos to do their damage, the background neutrino flux would probably drop off greatly due to the cosmological expansion of the universe. The same effect would also cool it to close to absolute zero. So might diamonds really be forever? No. Quantum tunneling will get them in the end if nothing else does, though that may take closer to a googolplex years than to a mere googol years. It's also possible that C12 and/or C13 is slightly radioactive. I don't think a half-life of much more than 10^24 years would have been noticed yet. Fred Lunnon <fred.lunnon@gmail.com> wrote:
Rather more than "all of Earth's carbon" I imagine, if literally "literally", since the recording process itself would be recorded;
That obviously depends on the resolution of the video recording. A resolution of one millimeter would more than suffice to determine who was doing what to whom. That's about 5.1E+20 pixels for the surface of the Earth. At 100 frames per second that's 1.6E+40 pixels for ten billion years of recording. At 30 bits per pixel, that's 4.8E+41 bits total, about 8E+17 moles of bits. One mole of bits requires 12.5 grams of carbon, so 6.4E+13 kilograms of carbon. Sources quoted in Wikipedia give crustal abundances of carbon from 200 to 1800 ppm. The mass of the Earth's crust is at least 2.4E22 kg, so at least 4.8E+18 kilograms of carbon. Only about one percent of that is C13, so 4.8E+16 of C13 plus another 4.8E+16 of C12 for your library. So the amount of carbon suffices to store 1500 copies of our video. And that's not taking into account video compression or the fact that the amount of C12 and C13 doesn't have to be equal. (What the most efficient data encoding is when one-bits cost more than zero-bits is a topic for another day.) Someone please double-check my arithmetic. Thanks. On the other hand, the Stross novella in question, "Palimpsest," depicts an Earth and sun which are re-engineered to last trillions of years, not mere billions. And not just one timeline is recorded, but a vast number of different ones, caused by time-traveler intervention. So maybe they'd better use compression and other techniques to maximize the use of that carbon. Of course they can also bring in more carbon from extraterrestrial sources, or from below Earth's crust.