Monday, October 15, 2007

One blue bead for man, an entire strand for everything else

“Time is like a handful of sand- the tighter you grasp it, the faster it runs through your fingers”

There are some times when looking at a list of words or dates just won't make information stick. I have been finding that this is true of the geologic time scale. For those unfamiliar with what that is, it's basically a historical calendar of what's happened in the last 600 million years. Paleontologists have broken up this vast amount of time into "Eras" and "Periods" of various significance, marked by distinct changes in life on earth. For example, the Jurassic era was between 144 and 213 million years ago and included the rise of the dinosaurs. There is a whole list of them. They also have confusing and long names, like Permian, Ordovician, Oligocene, Carboniferous, Cambrian... etc.

For my earth science exam this Friday, I have to know the geologic time scale, so that when my teacher asks, 50 million years ago, what period was it, I have to know that it was during the Cenozoic era and the Tertiary period. So, in the face of a daunting amount of information, dates and names, I decided to go tactile/visual. I made a necklace with a series of beads which represent the different eras and epochs.

I can't claim that I came up with this idea, only that I actually put it together. A friend in my community ecology class inspired me by telling me about her friend who had done it to learn them.

In the picture, everything on the bottom fork of the 'v' are the geologic period. The bright blue bead represents the last 2 million years, the Quartenary period. I had each bead equal 10 million years exept fot hat one. But if you look at the blue bead compared to the rest of our geologic history, you can see that we've barely been on the planet at all.

After the Quartenary is the Tertiary (brown), Cretaceous (light green), Jurassic (dark green), Triassic (light blue), Permian (bright orange), Carboniferous (shiny black - like carbon.), Devonian (gold), Silurian (silver), Ordovician (pink) and Cambrian (blue). Each boundary is marked by a silver bead to divide them, and each has the appropriate number of beads in it to show how long each period was. I.e. the Carboniferous period has 9 beads to represent 90 million years.

If you look at the other part of the 'v' in the necklace, you'll notice there aren't any silver dividing beads. That's because this is a section of what happened within the Cenozoic only (so it's like zooming in on the first two colors of the other side). The epochs within the Cenozoic are represented by beads that are 1 million year each, except, again, for the Holocene, which represents only 100,000 years. Within the Cenozoic were the Holocene (purple) Pleistocene (blue), Pliocene (green), Miocene (tan), Oligocene (clear), Eocene (brown), Paleocene (pale yellow).

I plan to wear this necklace all week, and practice memorizing the different eras, and counting how long each of them were. I hope that this will help solidify the information in my head better than just staring at a chart.

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