Basic Composition of the Earth (early work)
Material Description:
Chart 6A, experiments as necessary.
Method:
Quote directly from the ‘Story of the God with No Hands, ‘The particles calmed down and joined with each other, forming new substances, the heavier ones went nearer to the heart of the Earth, while the lighter ones floated above them like oil on water’.
Continue, ‘Well, when the Earth was still very hot and the particles began to settle down, they settled according to weight, remember our experiment with the oil, the water and the honey?’
Redo or recall this experiment
‘It is something like this’,
Show Chart 6A
‘The heavier substances which settled near the heart or the centre of the earth are called the Barysphere, from the Ancient Greek ‘bary’ which means heavy, above that is the Lithosphere, from the Greek ‘lithos’ which means Stone, this is where we find the rocks of the earth, the earth’s crust, where we live. Above that is the hydrosphere, which comes from the Greek, ‘hydro’ which means water, this is where we find the oceans of the world. Surrounding all of that we have the atmosphere, from the Greek ‘athmos; which means vapour, this is the lightest layer of all, this is where we find the air we breathe, the air we need to live.’
Stop here to record the dimensions of the layers
‘Some people think that the diameter of the earth is about 13,000 kilometres, of this 300 kilometres are taken up by the atmosphere, above the earth, but we can only use a little bit of this space, the Lithosphere is between 50 to 100 kilometres and the Hydrosphere is about 15 kilometres. Remember that we live on the Lithosphere and we did the experiment with gravity, the Barisphere attracts everything to itself.’
Redo or recall this experiment
‘Gravity is the force which keeps everything on earth.’
Aim:
To give the etymology
When to give the lesson:
This is given early, parallel to Examining the Nature of the Elements, after ‘The God With No Hands’. This is impressionistic, later work is more factual.
After the lesson:
Let’s use the dimensions to do some work measuring with rulers, children can take the dimensions and make a strip using squared paper or with metre sticks to show the dimensions to scale.