Show how the Earth revolves to create seasons. Talk about the equality of day & night at the Spring or Autumn equinox, and try and balance an egg.
Diagram of solar system, a football, enough eggs for one each (with some spare), salt, a level surface
This is an activity in two parts:
1) Explain the seasons
2) Get the Beavers to try and balance an egg
Part 1: Why do we have seasons?
/ Get the Beavers in a circle.
* What are the seasons of the year?
* Which seasons are we in now?
* Why do we have seasons?
/ Explain the seasons
What's this? (Diagram of solar system)
What's this? (Sun)
And this? (Earth)
Divide down the middle. Does the sun go round the earth or the earth round the sun? Come to one side if you think former, other side if latter.
(Earth goes round the Sun, just so we're clear!)
Choose a Beaver to be the sun, holding an orange football. Choose another. Give him/her an egg and have them rotate around the Sun.
How long does it take to go around the Sun? 365 days = what? 1 year.
(Choose new "Sun" and "Earth" holders)
What's at the top and bottom of the Earth? The poles. Draw poles on egg. Then draw axis. Show how Earth wobbles around the sun.
The tilt of the Earth's AXIS is the most important reason why seasons occur. We have hot summers and cold winters because of the tilt of the Earth's axis.
The tilt of the Earth means the Earth will lean towards the Sun (Summer) or lean away from the Sun (Winter) 6 months later. In between these, Spring and Autumn will occur.
/ Important Facts
* The Earth revolves around the Sun.
* The North pole always points the same way as the Earth revolves around the Sun.
* The Earth's movement around the sun causes the seasons.
/ Days get longer and shorter
In the Spring, the north pole starts moving towards the Sun again. The Sun moves upwards in our skies and the days continue getting longer. Twice during the year the axis is flat on to the Sun. These are "Equinoxes". The day and night are almost exactly the same length - 12 hours. The Spring Equinox is around March 21st.
Easter - always first Sunday after the Full Moon after the Spring Equinox.
Part 2: Egg Balancing
It's also said that because the day are night are the same length - they are balanced - its also the only time in the year that you can also balance an egg on its end. Theory: gravitational pull is equal.
Do you think an egg can be balanced?
Demonstrate trying to balance an egg. As the Leader, you get to cheat, for demonstration purposes of course ;) Beforehand, lightly sand the end of your special egg - this will increase the abrasion, making balancing easier.
Now the Beavers' turn. Take the eggs and try to balance it on a hard surface - they will have a very difficult time keeping the egg balanced.
If the Beavers can't do it (it's hard), add salt. Make a tiny mound of salt. Very carefully balance the egg on top of the salt, then gently blow the excess salt away. With patience and a steady hand, they should succeed.
Explain the theory of balancing at this time of year is nonsense, it's to do with the texture of the shell providing stable balance points, and can be done at any time of year.
For bonus points, take in a lamp with a non-energy saving lightbulb. Wet the end of the egg, apply salt, then balance the egg on top of the bulb.