Essay:Quantifying Order

“

In the beginning was perfect order, and this perfection was with God, and this perfection was God.

”

This is a tantalizing translation of John 1:1, and it suggests that insight into the universe may be best understood by examining order, and its converse of disorder (entropy). A starting point is this: quantifying order.

There are several examples of highly ordered systems from diverse corners of physics:

• a wave function collapsed by observation
• a high concentration of mass
• a tightly wound orbit, such as Mercury's
• the transmission of light
• the transmission of electromagnetic waves

Tightly Wound Orbit

The orbit of Mercury provides nature's closest example, both conceptually and spatially, of a highly ordered, nearly perpetual motion machine. The orbit will not last forever, and it is enlightening to observe and understand signs of degradation in the orbit.

The advance (or precession) of the perihelion of Mercury is observed but not predicted by an elementary application of Newtonian mechanics to Mercury and the sun alone. This provided one of the great mysteries of physics around the turn of the century. A planet's "perihelion" is the point in its path of orbit that comes closest to the sun. For Mercury, that point of closest proximity is shifting with each revolution.

The theory of relativity developed to explain the then-observed shift in Mercury's perihelion of 43 arc-seconds per century. Subsequently, however, more accurate measurements with more sophisticated technology have determined this precession to be 55 arc-seconds per century, nearly 30% off the number produced by relativity. Other sources of the deviation have been suggested by physicists attempting to explain the gap.

Transmission of Electromagnetic Waves

A perpetual ordered system, or a perpetual motion machine, is thought to be impossible by virtue of the Second Law of Thermodynamics.