[Tfug] A sense of time

[Rich]

On Aug 7, 2007, at 4:50 pm, Bexley Hall wrote:

>> For example Time exists without the definition of a
>> second.
> Of course.  As does mass without the definition of a
> gram/pound/etc.
The rates of oscillation of many particles are constant. Granted, the  
concept of time exists without that constant, but the actual time  
taken to oscillate from one state to another is a measurable constant  
that cannot take place without that constant period of time, simply  
because it *is* time. Not our broad concept of time, but actual,  
measurable time.

The constant may be used to help shape that broad concept. However,  
we don't exist at the atomic level, so we use measures more  
appropriate to our perceptions: the periodicity of the seasons, the  
lunar cycle, the day, and a hierarchy of divisions to break up the  
day. These divisions may be expressed in multiples of the discreet  
constant units, and so that concept of time may be measured accurately.

I realize now that what's at issue here isn't how we perceive time:  
it's how we deal with discrepancies between time frames used to  
measure related events. How to move from one time frame to another in  
a reasonable fashion.

There is an unsolvable part to this. Take these four events, for  
instance. I've simplified them to hours and minutes for the sake of  
clarity, so we'll assume they all happen on the same date.

Frame A: MST
A1. 08:20
A2. 08:50

Frame B: PDT
B1. 08:40

Frame C: PST
C1. 08:30

Simple: the order of events is A1 B1 A2 C1. It's only simple because  
we have *relative* frames of reference, based on UTC, which is a  
global standard.

So, time measurements could be expressed along with their frame of  
reference: hh:mm:ss PDT.

There *is* a point in recording measurements where you deem the  
inaccuracy of something so major to invalidate the measurement. Now  
let's alter Frame B to be 15 minutes slow. The recorded time was  
08:40, but the actual time in PDT was 8:55. The order of events was  
actually A1 A2 B1 C1.

Now in this case, Frame B was found to be inaccurate by a measurable  
amount, so we can restate it: "Frame B: PDT -0:15"

It is only in the case of unrecorded inaccuracies that problems  
arise. This is why an accurate frame of reference is needed for  
technological devices.

If it wasn't deemed important enough to record the intended frame of  
reference and its offset from the standard, then the event's time  
wasn't *that* important. A missed log rotation on your grannie's  
computer? Who cares? A missed backup? Unsolvable.

Your meal didn't start cooking at 6:30pm because someone realized at  
6:28 that the oven's clock was five minutes slow? Boohoo. Unsolvable.

Every equation is subject to the constraints of all data being  
present. So I guess we broaden the subject now to "A sense of measure".

R.