When I was in kindergarten, my teacher sent instructions home to my parents so they could illustrate to me what happens as the world turns. This was my first introduction to Astronomy 101. We used the visual aids at hand - an orange, pencil, and candle. Crude, but effective.
My mother skewered an orange (the earth) with a sharp pencil (the axis of rotation) as juice squirted out at its poles. For a moment, things got a bit sticky. She lit candle and its light bathed the skin of this speared fruit while she rolled the pencil in her fingers to spin the orb about its axis.
Not only did this show me why we had day and night, but also why we got the seasons with the tilt of the axis. Little did I know that when I grew up, so many were ...
Not as smart as a kindergartner!
Not even teachers. On the local news, I recall a journalist asked a woman about what caused winter. She knew the answer to that as she proudly proclaimed she was school teacher. The earth was closer to the sun in winter. That's why.
Maybe it was in the southern hemisphere. Partial credit here? Actually the earth is closer to sun when it's winter in the northern hemisphere. (reference: Why Earth is Closest to Sun in Dead of Winter | Space.com) But that is not why we have the seasons.
I'm sure the woman was a good teacher, but she was not alone in here lack of knowledge of basic astronomy. Many smart and educated people don't know this.
During my work life in a technical field, my co-workers were diverse from all over the country as well as the world. One young man that I had shared a cubicle with had no clue what caused the seasons. Yet, he was eager to learn and I pointed to a website with some good graphics - much like the one below.
He got it and was appreciative. And I cut him some slack, as he was one of the Vietnamese boat people and had a challenging childhood. While I was watching Star Trek in my youth, he had lived under a repressive regime, the aftermath of the Vietnam War. But to his credit, he escaped to the United States and went on to college earning degree in engineering - and that took some gumption.
There is much we do not know. Some may not be important to us or be our passion. Yet with the ubiquitous internet, there is access to all kinds of information.
So I began another series dedicated to the basics of science -
* Science 101 *
And for the advent spring this March 20, 2013, the Vernal Equinox, the clip above pretty much explains it. (reference: March Equinox: March 20, 2013, 11:02 UTC) And the video so much better than reading the multitude of words I could write about it. I love YouTube!
Some of my articles on physics:
Black Holes - What does it look like inside them?
The Scotsman who beat Einstein
Photo from wikipedia: Ecliptic Path