Archive for May 26th, 2008

This morning laying in bed I was thinking about time, as I often do. 

In common language, we talk about time as something unto itself.  Time marches on, time flies, where has all the time gone…  We all know what we mean when we say and hear those cliches, however, “time” does not really fit.  Time is a measurement for the rate of change (rotation of the earth, orbit around the sun, oscillation of crystals, atom energy transitions).  

The official SI definition of a second (SI considers this the “base unit” of time): “The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom.”

So basically it’s the rate of change of energy levels of the cesium atom.  I leave it as an exercise to the reader to go figure out why SI uses cesium 133 and what SI means with “hyperfine levels.”

If we substitute this definition in to common time cliches the cliches lose their power.  Cesium Atoms transition a lot without you noticing when you are having fun. (Time flies when you’re having fun.)  Where have all the cesium atom energy transitions gone.  Yes, this is tongue in cheek.

The point is TIME is not what we’re talking about when we drop a time cliche in conversation.  We’re talking about behavior.  When you’re having fun, you typically have a huge amount of behavior and adrenaline.  You’re rate of behavior and the reinforcements come fast and furiously.  When you have a glut of stimulus to process, your rate of change (… time …) typically is higher than in less “fun” situations.  [Fun, as a concept, deserves a whole write up unto itself].  When you lament the passage of time, you actually lament the missed behavior, the non-change, and/or the changes you didn’t notice.

In some sense the more change you experience, the more change you notice, the less you’ll sense missing time and the more time will fly (the less you habituate to the routine of life).  Nothing profound here, just a reflection on a day of memory, relaxation, and family/friends.

Resources you might enjoy:

Philosophy of time:


SI Units


Fundamental Units


World Line



Read Full Post »