In article , RobH wrote:

"Andrew Walkingshaw" wrote in message
...
In article , RobH wrote:

I'm not sure that last sentence makes sense. Are you saying that the
theoretical limit of vinyl recording is at an atomic level?

It probably is if you use an AFM[1] as your stylus. (Pressing the
discs would be a right pain, though. :-) )

Well, if IBM can construct their logo using individual atoms I don't see
why they can't adopt this technology for making records. ;-)

True, it's entirely *possible*. Cost a bob or three, though - I wonder
if the vinylphiles here would want to pay a seven-figure sum per
record...

But then you get into the realms of Quantum Mechanical effects, the
Uncertainty Principle et al

[This is a really bad explanation. I'm sorry. I'm trying to think of
a good way of describing this without resorting to digging out a copy
of Kittel and writing a bunch of equations... there's so much potential
for making a fool of myself here, given I'm allegedly some sort of
condensed-matter physicist ]

Nah, what you see is a statistical average; the motion of the needle is
orders of magnitude slower with respect to that of the electrons, so you
can assume that the system reacts instantaneously to any change in
stylus position.

Any bizarre effects are on a much shorter timescale than an AFM
measurement, and so all you'll "see" is a statistical distribution - the
ground state electron density.

- Andrew (day job: grad student, "First-principles electronic structure
calculations for disordered systems")

--
Andrew Walkingshaw |