# Clock of Eras

BW and DW working out a linear version of the Clock of Eras

The Clock of Eras is one of the Classic Montessori Lesson.  As all of the history lessons, it covers multiple disciplines – history, science, and math.

The presentation is given after the long black stip.   It is a link between the God With No Hands lesson and the Time Line of Life Lesson. It is a different way of looking at time as well.  It is a chart.  Don’t give into the temptation to make it into a puzzle or a deep scientific lesson.  It is  there to help children think about how long the earth had been around been around before humans.

Also the idea that everything has a job to do for the glory of God.  All the creatures came before to help make the world ready for humans and their survival.

We need to define a few terms:

• Eon (and super-eon) is the largest length of geological time.  There are 4 eons. Eons are divided into eras.  Haden, Archean, Proterozoic, and Phanerozoic
• Era is a period of geological time.  There are 12 eras in geological time.  These times are divided into periods.
• Periods are the smallest measure of geological time that is documented on the Clock of Eras.
Again this is an IMPRESSIONISTIC Lesson.  It is meant to be brief and not over detailed.  Often people add and add to the lesson.  You can loose the main impressions in the details.  Less is more in this lesson.
Begin with a question:
I wonder how long off all of the creating took?
Remind the children of the long black strip. Remind them of the little amount of time man has been around in comparison to the length of time that God ordained for the earth.
Today we are going to look  at time in a different way.  We are going to think of it as if it were the face of the clock.  Would you like to think of time like the hours and minutes of a clock?
We are going to look at all the time that the Earth has had a crust as like the 12 hours on the face of the clock.  The clock on the wall has the numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11.12.  Now look at our chart it has the same 12 numbers.
(Take your time here.  This requires younger children to process a good bit.)
Point at the black section.
We’ll look at this first time period it is called an EON.  Remember the God With No Hands lesson?  We talked about how hot the Earth was when she was created and how it took a very, very long time to cool off?  This section represents the last bit of that cooling – when the Earth began to look like a shriveled apple.
Point at the yellow section.
In the time between 4 and 10 is the EON that represents the beginnings of a world we would recognize.  Between 4 and 5 on the clock is when the rains  began to come down and cleanse the sky so an atmosphere could form.  The rains were also washing the Earth.  They washed salts into the seas.  Many scientists also believe that this is when God created the first life – like a little drop of  jelly.
Point to the clock and the time between 5 and 6
After the little blob of jelly, other creatures were created.  They floated in the seas.  They ate the salts and the abundant minerals that were in the seas. They had a great work.  These tiny creatures’ had the job of making the seas ready for larger creatures.  They did their jobs perfectly and the sea floors are full of their skeletons to this day.  This time between 4 and 10 is called the Archaic Eon.  These words are Greek and Archaic means “very old.”
Point to the blue, brown, green and red areas of the clock.
Things began to move very quickly and all of these together are one EON.  To help us understand the changes we are going to divide the EONs into ERAs.
Point to the blue area.
After all these creatures did the work that God gave them, God created other creatures.  Many of these creatures began to live not only in the water but also on the land – they are called amphibians. This happened a very long time ago. We call this time Paleozoic Era.  paleo – old and zoic – animals.  So what was this the time of?
Point to the brown area.
Then after the amphibians began to become more comfortable on land this era began.  Geologists call this time the Mesozoic Era.  Meso – middle and what did zoic mean?   This is the time that the great reptiles and giant grasses and ferns lived.  The reptiles could stay on land and were able to go where no animals had ever been before.
Now let’s look at the clock again.  There isn’t much time left.  How much do you think is left on our 12 hour clock?
Point to the green section.
After the Mesozoic Era, we arrive to the Cenozoic Era.  Ceno means recent and zoic means???  The recent plants and animals that came during this time are the same ones we would recognize. The great reptiles all died out in this time. God created the birds and animals we would know.  All this time has passed and there are no humans.  There is only a little bit of time left. Something very special happens at the very end of the Cenozoic Era.  This last little bit is a section of the Era is red.  It is a period (a smaller piece of of the Era).