Monday, August 30, 2010

A kindergarten sundial

Last week we made a simple sundial, with a piece of wood, some modeling clay, and a stick.

You can tell the time by looking at the shadow cast by the Sun as it shines on the pointer (gnomon) of a sundial.

This was for a kindergarten project, and we did it according to their book. It does NOT take latitude and direction into account at all. Which means that it's not going to be super accurate or even explain WHY those things would be important. At this stage, the only point is to show that shadows get longer and shorter, and you can see time by which way the shadow is cast. This work was done by Dash and LittleLad, not the two older kiddos.

Every hour, on the hour, we'd go outside and mark the correct spot. The sun is highest in the sky at midday and casts a short shadow. In the afternoon, when the sun is lower in the sky, the shadow is longer. Wish I'd taken pictures when we got to 6pm and on...

The length of the shadow is also affected by the seasons. Winter shadows are longer than summer shadows.

Now, as you can clearly see, my shortest shadow should be at noon, but our board was on a slant and, again, I did not take other (important) factors into consideration.

Still works, but I had some explaining to do with the older kids who decided to check it out. We'll be doing their version soon. I usually try to do all of these lessons at the same time, and just go more in-depth with the older kids, but I was off my plan. Rough week. You can see that it was SO hot when we did this, that our clay is just gooey and melting. I am thankful that my air conditioner went out this weekend, rather than last.

Tip: look closely at the picture above. I marked where the corners of the board need to go because, inevitably, the board will be moved or shifted when the kids go out to play. Mark the sidewalk, so you can move it back to the "correct spot"-- which wasn't really correct, but OH WELL.

So, yeah, sundials work. Kinda.
And I learned more about them
(again-- I did this a few years ago!)
Ah, someday I'll have all this down, right? After going back through elementary school four times??

1 comment:

Anna K. said...

That's cool! I have a seven year-old who would get a kick out of that, too.