“For any modern PRML/EPRML drive, a few passes of random scrubbing is the best you can do … A good scrubbing with random data will do about as well as can be expected”
But what does that mean? Can someone with an STM and lots of patience still get the data back? Or is it just “gone for our purposes, with today’s technology”?
What you need to realize is that for 2 states to be distinguishable ever in principle, the states must be separated by an energy barrier taller than thermal fluctuations. Else the thermal noise is going to overwrite it randomly a zillion times a second.
The other issue is that the closer are the states the less metabolic energy you’ll need to switch between them. Which makes something like neurons (evolved over a very long time) settle on an optimum where there’s no room for some weak residuals recoverable with some future technology that got more sensitive probes.
I.e. if the cryo-protectants happen to reset some bits, that information is gone. You have to hope that cryo-protectants do not actually reset anything, i.e. that nothing is forced from multiple states to one state.
edit: another issue. Individual ion channels, gap junctions, etc etc. combine more-or-less additively into final electrical properties of the neuron. When you need to know the value of a sum a+b+c+d+e , losing even a single variable of the sum introduces massive uncertainty in the result. It would’ve been a lot easier if those properties mirrored each other, like a=b=c=d=e , then we’d only need to preserve at least one, but as they combine additively, we need to not lose a single one.
As I note below, if you really want to hold on to this particular example for analogical purposes, it’s at a stage where “you can’t prove it’s false!” isn’t really adequate and you’d need to produce an example of recovering data in practice, not just hypothetically.
“For any modern PRML/EPRML drive, a few passes of random scrubbing is the best you can do … A good scrubbing with random data will do about as well as can be expected”
But what does that mean? Can someone with an STM and lots of patience still get the data back? Or is it just “gone for our purposes, with today’s technology”?
What you need to realize is that for 2 states to be distinguishable ever in principle, the states must be separated by an energy barrier taller than thermal fluctuations. Else the thermal noise is going to overwrite it randomly a zillion times a second.
The other issue is that the closer are the states the less metabolic energy you’ll need to switch between them. Which makes something like neurons (evolved over a very long time) settle on an optimum where there’s no room for some weak residuals recoverable with some future technology that got more sensitive probes.
I.e. if the cryo-protectants happen to reset some bits, that information is gone. You have to hope that cryo-protectants do not actually reset anything, i.e. that nothing is forced from multiple states to one state.
edit: another issue. Individual ion channels, gap junctions, etc etc. combine more-or-less additively into final electrical properties of the neuron. When you need to know the value of a sum a+b+c+d+e , losing even a single variable of the sum introduces massive uncertainty in the result. It would’ve been a lot easier if those properties mirrored each other, like a=b=c=d=e , then we’d only need to preserve at least one, but as they combine additively, we need to not lose a single one.
As I note below, if you really want to hold on to this particular example for analogical purposes, it’s at a stage where “you can’t prove it’s false!” isn’t really adequate and you’d need to produce an example of recovering data in practice, not just hypothetically.