Weather

Hi, everyone!

Today's class was about predicting the weather. Previously, we'd discussed how rainclouds form and how where it rains is determined in part by the shape of the land, and today we talked about air and wind in general. The air above us actually weights a great deal, but we don't notice it because the air around and below us is pushing up on us as well. If you feel like destroying a ruler, you can see just how hard it's pushing with this experiment at home.

The kids all made weather vanes and barometers. Between the two, they should now be able to predict the weather with the help of the sheet they have.

The weather vanes have holes in their middle for a metal rod or string. Hang them up outside to see which way the weather's blowing.

The barometer works by going up or down in response to the air pressure. If air pressure drops, the air inside the can bulges, and the straw will point lower. Air pressure rising means the rubber is pushed down, raising the straw.

By measuring where the barometer points over time, you can tell if the pressure is getting higher or lower, and how fast. Combining this with the direction the wind is coming from can let you predict the weather relatively accurately.

So for homework this week, have the kids keep track of the day's wind and the barometer's level, then write what the weather actually was like that day.

Water tables and soil composition

Hi everyone!

This Tuesday we studied the water table and water cycle in class, including how soil composition is a factor in how the rainwater behaves. Clay in the soil prevents water from soaking in as quickly, so the more of the rain runs off. Sand and larger rocks are the opposite, and the water sinks down and away. Bedrock underneath can stop water from going deeper, and holds it near the surface where plants can reach it.

While obviously getting down to bedrock is difficult, just a shallow hole can show you a lot! I explained that in my backyard, there's a thin layer of loam, which is a mixture of dead plant material that soaks up water very well, followed by a thick clay layer. I told everyone to dig a hole to see what the soil in their own backyard is like, then bring that soil to class in a jar, ideally a glass one so we can see into it. They don't need to worry about preserving the soil layers for transport, but I'd like them all to tell what layers they saw when digging.