The measurement of the passage of time is important to us, as sentinent living inhabitants of earth. Of all the methods available to us, the day-night cycle, based on the earth's rotation and the annual cycle, based on the earth's revolution around the sun are probably the most important.
Almost all organisms on Earth have evolved what can be described as 'biological clocks', calibrated by the solar cycle, but this is food for discussion for another day.
Here, we ponder about the effects of cultural implications of a different 'diurnal cycle'(The day-night cycle) on lives of people. Let us consider, for instance, the act of celebrating birthdays. One's birthday is obviously an annual occurence, providing a marker for the passage of each year. And as the Earth's rotational period and revolution period is fairly constant, one is justified in using it as such. Now, we assume an hypothetical situation in which there exists a settlement of humans on a different planetary body, either a different planet or a moon:
If, for instance, a colony of humans made a settlement on Mars, they would initially 'suffer' the interplanetary equivalent of 'jet-lag', in this case being 'confused' about the diurnal cycle on Mars, as opposed to Earth. i.e, all life on Earth is adapted to living on Earth, with the 'biological clocks' or 'circadian rythm' being calibrated to the diurnal cycle on Earth. Thus, when faced with a different cycle length, the human body will be 'confused'. But of course, the length of a Martian day is almost equal to the length of an Earthly day, so this problem is somewhat rendered 'solved'. The other 'cycle' that impacts life is the annual cycle, or the length of the Earth's revolution aorund the sun. This cycle is responsible for bringing different seasons, and this calibrates the biological clock in other ways too. The duration of a Martian year is almost twice the duration of an Earthly year, and this would make the seasons on Mars longer too. Thus, the initial settlers on Mars , if they decide to celebrate their birthdays based on 'Earth-time', they would be celebrating it at almost halfway through the Martian year. Perhaps, over a few generations, the descendants of the 'original' settlers would have bodies that are adapted to the Martian cycle rather than the Earthly cycle (Apart from the gravitational difference etc).
If the settlement were made on the moon of a planet, the problem is further compounded as the revolution of the moon around the planet would further change the day-night cycle, and the annual cycle etc.
It is certainly interesting to think about how life evolves in accordance with it's environment. I certainly do hope that mankind sets foot on other planets, someday, in the spirit of exploration and learning.
