Saturday, February 02, 2008


The Scientific Way...
As the Earth orbits the sun it follows two motions. One is the spinning motion around the Earth's own axis. This motion causes the days and nights. The other motion along the elliptical orbit takes a year to complete one full rotation around the sun. Seasons are caused by the Earth's axis being inclined at about 23-1/2o with the orbital plane. As the Earth orbits the sun its axis always points to the same direction.

In December the North Pole is leaning away from the sun and the Northern hemisphere receives less sunlight. The days are short and the sun is low in the sky so the sunlight is spread thinly over the Earth's surface. The sun is lowest in the sky on December 22, the winter solstice. The Northern Hemisphere receives so less sunlight that the Earth continues to get colder for another month. Thus January is colder than December. And the coldest time comes about the end of January. Things just get reverse as we move down to the southern hemisphere across the Equator.

Thus seasons are defined by this gradual shifting movement between the summer solstice and winter solstice. As we move on from winter to summer, or, the other way round, we come across four seasons, distinct especially in the temperate zones. Moving from the winter, in spring it gets warmer, in summer, hot. In autumn it gets cooler, in winter cold. Spring comes earlier down in southern areas than farther in the north. This is just the reverse in the southern hemisphere.

As light emitting from a source gets hit by an opaque object a shadow is created away from the source and on the other side of the object.

Shadows under the sun are created when the sunrays get hit by any opaque object - living or not. As the sun moves on from east to west shadows are created. Thus shadows are the longest when the sun is in the east or, west horizon. At around noon when the sun is perched just overhead, the shadows get reduced to a minimal length.
The movement of shadow in sync with the sun could be applied in making a sundial, the earliest form of clock known to give a near perfect reading.

This shadow movement also changes with the change of season. In winter as the North Pole leans away from the sun light falls a bit slantingly on the objects in the North.
Thus shadows are always a little longer throughout the winter days as against those during the summer. The variation in this shadow movement also helps us to predict the shifting of the seasons.

Now is it really possible to predict if spring is near or far?

Well, on February the sunlight is already bound for summer as the North Pole comes nearer the sun. The length of shadow is thus somewhat shorter, but not remarkably enough. So it is difficult to distinguish between a late January and a late February shadow unless you are a keen regular observer.

Did you understand that?

I definitely missed that science day in school!

Others like to depend on the groundhog and whether he sees his shadow or not. This year he didn't so it's supposed to means that spring is just around the corner? I just hope it means the corner on my street! The way that the "deep freeze" is going here I can't see it being any time soon!

This is the way I learned about it in school...

Kind of cutesy huh....

The way that weather predictions go around here it's more like...
Not sure I care for the tone of this picture...this is for my darker fans!


B. Roan Enigk said...

Unfortunately for us, Punxsutawney Phil saw his shadow and ran back in. Another 6 weeks of winter for me. Bummer! BJ

Jeannie! said...

I loved the film!

We had never heard of Groundhog day till we saw the movie.

I will come back and read more later about it all!

My time limit on the computer here has just expired.............

;0( More tomorrow, Jeannie xxxxx
in cold Scotland, but the evenings and mornings are getting lighter now, and the wild honeysuckle in the woods has some green shoots on it. Spring is on its way! Yay!

Jeannie! said...

oh just had another quick read.....

Our clocks are put back in the Autumn, which means we have very short days, getting shorter and darker towards December, then they start to get longer and lighter into the Spring.

The clocks then are put forward an hour for British Summertime. In Scotland, as we are so far north, we have wonderful long, light days - around mid summer here it hardly gets dark. My favourite time of year.

Sorry, perhaps too much information there, but it was an interesting post.