## Thursday, May 26, 2011

### Marking (Metric) Time

The other day I was musing on the nature of time, and the fact that for times shorter than a second we use a metric system (1 millisecond = one-thousandth of a second, 1 microsecond = one-millionth of a second, etc) but not for times longer than a second. I know that the common use of the number 60 in time comes from the Babylonians and their fascination with the sexagesimal system, but what if we measured time in metric units? What would that be like?

To begin with, 1 kilosecond would equal 16 minutes 40 seconds. There are 86.4 kilosecs in one day, or 604.8 in a week. Going up a level, 1 megasecond would be equal to 11.57 days, or a bit under two weeks. That would mean a total of 31.536 megasecs per year. Finally, a gigasecond would be huge step up, being equal to approximately 31.6889 years, or a bit longer than the time it takes Saturn to make a full orbit around the sun, at 29.4571 years. It's also a pretty good chunk of most peoples' lifetimes. There's little point in continuing it further, because after that the numbers get beyond human experience pretty quickly: a terasecond would be a thousand times longer than a gigasec, or 31,889-odd years and it just gets bigger from there.

Just for fun, try using one of these expressions in everyday conversation. "I'm just going out, I'll be back in a couple of kilosecs", "We should have the results of the test in about half a megasec", "How old is George? Oh, a bit over 2 gigasecs." Have fun!

#### 1 comment:

1. Hey Dan, here are the pictures from yesterday: http://www.facebook.com/media/set/?set=a.10150195436237843.312396.752787842&l=fdda3b0094