One of my goals with these science videos is to provide support to the homeschool community. After years of writing the Experiment of the Week, and presenting science shows for homeschool groups, I have been impressed with how strongly homeschool families are involved with hands-on science. I have also seen the need for a science curriculum that fulfills their educational needs. Starting with these videos, I hope to offer the homeschool community some of the science education support that they need, as well as a fun way to get students involved with scientific discovery.
I also try to use activities that involve common items. Most homeschoolers don't have access to test tubes, flasks, chemicals, microscopes and other scientific equipment. In the future, I hope to be able to guide them to inexpensive sources for science equipment to enrich their science curriculum.
If you were lost in the woods, would you be able to determine which way was north? If it was night, we could use astronomy to find our way. In the Northern Hemisphere, you could use the Big Dipper (Ursa Major) to find the North Star. In the Southern Hemisphere, you could use the constellation Crux, known as the Southern Cross to find south. But, what if it is day, and you don't want to wait until it is very dark, in the middle of those lonely woods? If you can find a sunny spot, it is easy.
To find your directions, you will need:
- a sunny spot on the ground
- one stick, about 12 inches long
- two short sticks or rocks
- a flashlight or lamp
Find a flat, bare, sunny patch of ground. Remove any stones, leaves, etc. Place the long stick into the ground in the center of the sunny spot, so it will cast a long shadow. Place one of the short sticks in the ground to mark the end of the long stick's shadow. Now all you have to do is wait 15 or 20 minutes. Do some bird watching and have a snack. You did pack the freeze-dried ice cream, didn't you?
After about 15 minutes, look to see how things have changed. You will find that the shadow of the long stick has moved. Use the second short stick to mark the new position of the shadow. Draw a line on the ground to connect the two short sticks. This is your east-west line. The first stick will be at the west end, and the second will be at the east end of the line.
Next, draw a line perpendicular to the east-west line to form an "X". This is your north-south line. If you are at the west end of the east-west line, facing east, north is on your left and south is on your right. I find that if I visualize a map of the world, then once I know east and west, it is easy to remember north and south.
Understanding the Science
In the morning, the Sun rises in the east, moves across the sky and sets in the west, right? Well, it appears to. Technically, the Sun stays in the same place, relative to the Earth. It is the rotation of the Earth that makes the Sun appear to move. Even so, we can use the apparent movement of the Sun to find our directions.
As the Sun seems to move from east to west, what would happen to the shadows of objects? Place an object on a flat surface and use a flashlight or lamp to give it a shadow. Move the light and notice how the shadow moves. When you move the light in one direction, the shadow will move in the opposite direction. That is what we need to know to find our directions.
As the Sun appears to move west, the shadow of the stick will move to the east. The line connecting the original end of the shadow with the new position will show you east and west. Since the Sun seems to be moving from east to west, the shadow will have moved from west to east. The original marker is the west end of the line. The new position is the east end. Simply draw in the north/south line and you have your directions.
But what about moss? Have you ever heard that you can find north by looking at the moss on trees? There is an old saying that moss grows on the north side of a tree, but actually moss usually grows on the shady side of a tree, not liking to grow in full sunlight. In the Northern Hemisphere, the north side of a tree is usually shady, but it is not uncommon to find trees with moss on all sides. In the Southern Hemisphere, the moss would tend to grow on the south side of trees. In dry areas, there may not be any moss at all. If there is a clearing to the north, then moss may be on the south side and not on the north side, so don't rely on moss to help you find your way. Instead, stick with the Sun.
Have a wonder-filled week.
