Gumballs and Molecular Machines
The wonderful clarity of long distance telephone conversations
and compact disks (CD) traces back to work in the 1940's by Claude
Surprisingly, if you scratch a CD from the center to the outside
it will often still play without interruption
of any kind.
(If you try this, use a CD you don't like!
Keep scratching until it does get destroyed.)
This resistance to noise was predicted by Shannon's channel capacity
theorem, and it depends on the coding of the information on the disk.
(The code runs in concentric circles around the disk,
so scratches made when cleaning the disk can be corrected.
This is why instructions
say to wipe CD's from the center to the outside.)
In the 1980's it was clear to
that since Shannon's other work on information theory could be
fruitfully applied to molecular biology,
his work on channel capacity should also apply.
It took Tom about 10 years (roughly 1980 to 1990) to reconstruct
Shannon's theory solidly in molecular biology terms.
In Shannon's communication theory, each gumball
represents a distinct message while in
molecular machine theory
each gumball represents a distinct state of a biological molecule.
Because the geometry is the same, Shannon's famous channel capacity
theorem also applies to the molecular case.
Programs used to generate figures that describe Shannon spheres are:
The program which was used to generate figure 9 in the paper
"Channel Capacity of Molecular Machines"
back to molecular machines
origin: before 1995 June 23
updated: 1998 Jan 24
U.S. Department of Health and Human Services
National Institutes of Health
National Cancer Institute