Thursday, March 19, 2009

Spring (Vernal) Equinox

Tomorrow is the vernal equinox which means "spring equal night." The vernal equinox is the time when the sun's path intersects the equator. On that day, every place on earth has nearly 12 hours of daylight and 12 hours of night. In the Northern Hemisphere, it always falls near March 20 or 21, and marks the start of spring! This year, the Equinox falls on Friday, March 20th.

Today we updated our Journey North project. Looking at the graph, you can see that all of the photoperiods (hours of daylight) are headed towards 12 hours! (Tomorrow, we will graph Monday's data, so we won't see it hit near 12 hours until we graph next Friday.) It is a great way to understand what happens with the equinox.

We also watched 2 videos on BrainPop today. (I recently bought a subscription, though I wish I would have used the Homeschool Buyers Co-op and earned some points!) We watched one video called Solstice and Equinox and another called Time Zones which helps us understand some of our Journey North data.

Here's a short quiz you and your kids can take about the equinox. I plan on looking up more information about the Great Sphinx of Egypt and the pyramid of Kulkulkan or Quetzalcoatl the Serpent God.

And, last year I talked with several other bloggers about the myth that you can only balance an egg on its end on the equinox! This myth is based on the fact that day and night are balanced on the equinox so it is thought by some to be the only day where it is possible to balance an egg. It is actually kind of tricky, but it is just as hard (or just as easy) to do it any day of the year. Give it a try on the equinox and then you might try it another day, too! (This photo is of an egg I balanced last year and it was a few days AFTER the equinox.)

So, have some fun learning about the equinox tomorrow!

I went ahead and looked up some YouTube videos about Chichen Itza, the pyramid in Mexico. It was built by the Mayans who were incredible mathematicians and astronomers. They built this pyramid in such a precise way that twice a year, during the spring and fall equinox, a feathery snake (shadow) would appear on the side of the pyramid. The above video is in Spanish, but has English subtitles and explained Chichen Itza better than any other video I watched. Chichen Itza was one of th 21 finalists for the "new" 7 Wonders of the World.


live4evermom said...

Chichen Itza is a very interesting place to visit and those steps are easy to go up but scary to come down.

You all are having fun while learning and I love to see what you will do next.

Robin said...

That was really one of the most awe inspiring places I've ever been. And your video is just awesome. I wish we could have seen that in person. You just have to be amazed at such mathematical genius.

Ms. Julie's Place said...

You are way too cool. Can I come to your homeschool?

Jennifer said...

How embarrassing. Our graph looks the same as yours but I didn't put two and two together and point out the equinox to my daughter. Thank you.

Theresa said...

Very cool video!

Kris said...

I didn't think about checking out ancient structures constructed for things like the equinox--great idea!

The last week of February the JN site had a teacher show how she found latitude using ratios. I used the site where I looked up our local sunrise/sunset and down the bottom you can plug in coordinated. I kept everything but the latitude the same until I came to a latitude that matched the photoperiod. Because most of the other families are not keeping up I actually did it for all 10 locals so I have something to submit at the end.

Today was really great, getting the equinox data and finding the longitudes. If you haven't done it yet, you'll have fun!

::carol:: said...

Your graph looks great. Thanks for the Brain Pop link, we'll be enjoying the free trial.

Gerky said...

Great study! We did a little bit on Spring also. We took half the day off as we were out of town.

I would never have thought of ancient structures. Will remember that for next year.

Brain Pop really looks neat. I migh have to put that on my wish list.

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