For at least half my life now I've favored military time, or the 24-hour clock, over the 12-hour clock which is much more common in the United States. When I was younger and learning how to convert the 24-hour clock into 12-hour time, I accidentally discovered an easy solution: Simply minus two from the hour, and then drop the first number.

For example, 18:30 (24-hour clock) = 18 - 2 = 16, drop the first number and we're left with 6. Therefore, 18:30 is 6:30 on a 12-hour clock! It gets slightly more tricky when the 24-hour clock gets to 22:00, because 22 - 2 = 20. But now you simply replace the leading 2 with a 1. Therefore, 22:00 = 10:00. Telling AM vs PM is easy: if the time is greater than or equal to 12, it's PM. Less than 12, it's AM.

Once you've used a 24-hour clock long enough, you won't need such methods of converting between the two types. For me, when I see the number 18 I now automatically see 6pm, and when I see the number 23 I automatically think 11pm. However, for those who are clueless when it comes to 24-hour clocks, this simple method of converting between the two might help. Of course, the only way you're really going to get used to reading military time is to change all your clocks (at least as many as you can) to use a 24-hour clock.

Wired has a great article about amateur time hackers who use off-the-shelf equipment purchased on eBay to run experiments with atomic clocks. One person in particular, Van Baak, conducted a very interesting experiment that seems to prove something that I have long found very interesting: Time is relative.

FTA:

A retired Unix kernel programmer, Van Baak began buying time instruments a decade ago, slowly building what today is probably the best-equipped, individually owned time lab in the world, exceeding the capability of many national labs. His gear lets him perform some impressive experiments. Two years ago, he realized he'd acquired the capability to offer his children a demonstration of one of the effects predicted by Einstein's general theory of relativity -- a demonstration that Einstein himself couldn't have performed with the equipment of his day.

The theory says time passes slowly for someone near a massive object, as measured relative to someone farther away. On Earth, this effect is so small as to be undetectable to all but the most precise equipment, putting demonstrations beyond the reach of, say, a typical high school science fair. Consequently, "kids grow up thinking relativity is only for really fast speeds or really heavy gravity," says Van Baak.

He wanted his children to see that relativity is proportional. So he loaded the family's blue minivan with portable power supplies, monitoring equipment, and three HP 5071 cesium clocks. Three, because time is always marked relative to other clocks: More clocks mean more accurate time. With his three kids and some camping gear in tow, he drove the winding roads spiraling up Washington's Mt. Rainier and checked the family into a lodge 5,319 feet above sea level.

They hiked the trails, and the kids relaxed with board games and books, while in the imperceptibly lessened gravity, time moved a little bit faster than at home. Van Baak found himself explaining to park rangers more than once why a minivan filled with inscrutable equipment was idling in front of the national park lodge for hours on end. But the effort paid off. When the family returned to the suburbs two days later, the cesium clocks were off by the precise amount relativity predicted. He and his family had lived just a little more life than the neighbors.

"It was the best extra 22 nanoseconds I've ever spent with the kids," Van Baak says.

I wrote about this effect last year in a post called Timeless Living. In the post, I attempted to explain how time perceived by a common house fly is much different than the time perceived by humans. But I took it a step further and pondered whether our physical, material, mental, and social size also has an effect on how we individually perceive time:

Does that mean when we’re toddlers, time passes much slower because we are physically smaller? It probably does. But think beyond physical size. The older we become, the more “stuff” we accumulate, the more stuff we accumulate the more things become “ours” and the bigger “our” world becomes. Take me for example: I own three investment properties, and hold several different jobs. My world feels much bigger than it did before I owned any properties and when I held only one job. I know more people than I did 5 years ago and my social network has grown. I am larger in life than I was 5 years ago. Why wouldn’t that also cause time to pass quicker?

The interesting thing about all this talk of time and the perception of time is that clocks are a method of preventing such fluctuations. Clocks are used as an agreed measurement of time. We agree that time for me is the same as time for you. But by doing this are we limiting our individual ability to control the effect time has on our bodies?

What if we could stage a giant experiment on human civilization in which we gradually slowed, over say a period of a hundred years, the mechanical timing of all clocks to a point where 1 second actually took 2 seconds to pass? Would we suddenly start living longer? (As far as we would know, we'd be living to 80 - 100 years, but in reality it would be 160 - 200 years!)

On the other hand, what if we were aware of the extra time? What if you knew for certain that the normal life expectancy for all humans was 800 - 1000 years of age? Stop reading this for a few seconds and really try to believe that you're probably going to live with a healthy and functional body until you're 800 years old. How would your plans for life change? Would you be so worried about money? Would you be in such a rush to accomplish the things in life you wish to accomplish? How would your political views change? Don't you already feel less stressful about life? You just lived for a few extra nanoseconds -- now hold that thought and don't let it go.