Re: cramming megabytes into a hydrogen atom

Damien Broderick (
Mon, 23 Dec 1996 13:03:07 +1000

Various people said back & forth:

>> Anders Sandberg wrote,

>> > *you can cram several megabytes into a hydrogen atom* (!!!)
>> How?
>The Hydrogen Atom will accept energy in a series of finite steps. [snip]

Hans Moravec's estimate in the forthcoming MIND AGE (I quote very briefly
and without permission):

`Today we take pride in storing information as densely as
one bit per atom, but it is possible to do much better by converting
an atom's mass into many low energy photons, each storing a separate
bit. As the photons' energies are reduced, more of them can be
created, but their wavelength, and thus the space they occupy and the
time to access them rises, while the temperature they can tolerate
drops. A very general quantum mechanical calculation in this spirit
by Bekenstein concludes that the maximum amount of information stored
in (or fully describing) a sphere of matter is proportional to the
mass of the sphere times its radius, hugely scaled. The "Bekenstein
bound" leaves room for a million bits in a hydrogen atom [snip]'

Damien Broderick