Thursday, June 12, 2003

Mr. Answer Man

Steven Den Beste seems to have gotten a (well deserved) reputation as the man with all the answers. He has a great post in response to a 'you seem to know everything' e-mail about the length of day and night at the equator.

I really like the post because it neatly explains the several factors that come together to change the length of the day and night throughout the seasons. I have tried to explain this to many people but have never been able to do it very well without props and a great deal of nonsense until I kind of give up and say - Well I know how that works but can not explain it. (reason 6,845 that I am not a science teacher)

The post ends with a list of things that we are supposed to ignore in the assumptions that he has made. I will ignore them all but put one little nitpick here... The earths axial tilt is 23.5 degrees.

The reason I know this is because when I was a student I worked at a map store. While there I learned a lot about geography and about how very little that people know about geography.

We had a wide selection of globes and they all are placed on their stands at a 23.5 degree tilt. On a fairly regular basis someone would come in and want to buy a globe - but not like the tilted ones because 'they look broken'. In the beginning I thought that peole were just messing with me but then I realized that people really did not know that the earth spis on it's axis to the right on a tilt. I would have to courteously explain that those 23.5 degrees give us seasons and does not mean that the globe is broken.

The best visual representation I have ever seen of the changing quantity of time in the seasons is with a Geochron. This is a really cool combination Map/Calander/Clock. It shows where in the world there is light at any given moment on any day of the year. They also make a screensaver and on that page you can see a simulation of what the Geochron looks like throughout a year.

I would highly recomend a Geochron screensaver - they are the best visual representation of time I have ever seen. If you have one nearby you can easily see the passage of the seasons. A word of warning though - watching the passage of time can get a bit depressing, at least it did for me after a couple of years.


Post a Comment

<< Home