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To: betty boop
After a good night's sleep and a few coffees, it occurs to me that some of the Lurkers here might be wondering what the heck a "hypercube" is. So here goes...

The space of a 2 dimensional area is flat, a plane. In three dimensions it is a cube. That much is pretty straight forward.

Add a fourth dimension (or more) and you have a hypercube which would look like this if the observer and it were standing still and the dimensions were 4 of space:

If the observer (or it) moved around so that the hypercube could be seen from different perspectives, it would look like this:

Add the perspective of time (space/time instead of just space) and it would look like this:

Getting back to communications for a second, Shannon's model looks at the message space as a sphere - the sum of which would look like a gumball machine before a selection is made by the receiver. That part is very well established in information theory and also as information theory is applied to molecular biology.

Glossary for Molecular Information

Shannon sphere: A sphere in a high dimensional space which represents either a single message of a communications system (after sphere) or the volume that contains all possible messages (before sphere) could be called a Shannon sphere, in honor of Claude Shannon who recognized its importance in information_theory. The radius of the smaller after spheres is determined by the ambient thermal noise, while that of the larger before sphere is determined by both the thermal noise and the signal power (signal-to-noise ratio), measured at the receiver. The logarithm of the number of small spheres that can fit into the larger sphere determines the channel capacity (See: Shannon1949). The high-dimensional packing of the spheres is the coding of the system.

There are two ways to understand how the spheres come to be. Consider a digital message consisting of independent voltage pulses. The independent voltage values specify a point in a high dimensional space since independence is represented by coordinate axes set at right angles to each other. Thus three voltage pulses correspond to a point in a 3 dimensional space and 100 pulses correspond to a point in a 100 dimensional space. The first `non-Cartesian' way to understand the spheres is to note that thermal noise interferes with the initial message during transmission of the information such that the received point is dislocated from the initial point. Since noisy distortion can be in any direction, the set of all possible dislocations is a sphere. The second `Cartesian' method is to note that the sum of many small dislocations to each pulse, caused by thermal noise, gives a Gaussian distribution at the receiver….

For a molecular machine containing n atoms there can be as many as 3n-6 independent components (degrees of freedom) so there can be 3n-6 dimensions. The velocity of these components corresponds to the voltage in a communication system and they are disturbed by thermal noise. Thus the state of a molecular machine can also be described by a sphere in a high dimensional velocity space.

But perhaps the geometry of the message is also a space/time "hypercube" comprising the Shannon sphere. In that case each phase space – or cell – and/or the sequence (or connection) could contribute to the encoding or decoding of the message itself. This could be seen on the sender side as the DNA, RNA - and on the receiving side the reduction of uncertainty (which is the state change in the molecular machinery) – or information.

A simpler way to consider how that might work would be to meditate playing Tic-tac-toe on a Hypercube and how a "solution" there might be akin to the message encoding structure of the DNA (not the DNA itself which is double helix).

881 posted on 02/22/2005 10:08:00 AM PST by Alamo-Girl
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To: Alamo-Girl
But perhaps the geometry of the message is also a space/time "hypercube" comprising the Shannon sphere. In that case each phase space – or cell – and/or the sequence (or connection) could contribute to the encoding or decoding of the message itself. This could be seen on the sender side as the DNA, RNA - and on the receiving side the reduction of uncertainty (which is the state change in the molecular machinery) – or information.

Fascinating insight, Alamo-Girl! Thank you ever so much for the link -- I'll take the time to do the "Tic-Tac-Toe in a Hypercube" meditation this evening. Then we must compare notes!!! :^)

Thanks so much for writing!

882 posted on 02/22/2005 1:38:03 PM PST by betty boop
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To: Alamo-Girl

Actually a 4-dimensional cube would be just an everyday cube. The 4th dimension being time and orthogonal to the space dimensions.

If it exists for any amount of time then it is 4-dimensional.


889 posted on 08/09/2006 6:05:32 PM PDT by Mark Felton ("Your faith should not be in the wisdom of men, but in the power of God.")
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