Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
The Toilet Paper Timeline A history of Earth…One square at a time The earth is roughly 4.6 billion years old. That is 4,600,000,000 years, or in scientific notation, 4.6 x 109 years. Life first originated in the oceans 3.4 billion years ago. The dinosaurs died out 65 million years in the past. Human recorded history stretches back 10,000 years in time. These numbers are hard to visualize and difficult to compare. One way to put these large numbers into a form that can be comprehended is to use a scale. The scale that we will use is squares of toilet paper. You'll need 46 sheets of toilet paper, a long hallway, and markers. Unroll the full roll of paper down the hallway. You will need to keep the time to scale. To do this, make sure you determine how many years each square is, and how large your square is using a ruler in case you need to subdivide it. Once the paper is completely unrolled, you can use this table or the one of pg. 439 in your book to mark the important events in earth's history at the appropriate points on the toilet paper. Furthermore, you need to add 6 points of your choice (they can be virtually anything!) to the timeline. Years Before Present Important Events in Earth History 4.6 billion yrs earth is formed, along with the other planets 3.7 billion yrs earth's crust solidified 3.5 billion yrs first life appears in oceans 3.25 billion yrs photosynthesis begins in oceans 2.4 billion yrs oceans contain significant amounts of oxygen 1.9 billion yrs first cells with nuclei appear in oceans 0.65 billion yrs first multicellular organisms appear 0.5 billion yrs first land plants with inner vessels 250 million yrs mass extinction of 99% of all life 245 million yrs Age of Dinosaurs begins 150 million yrs Pangaea breaking up; continents drifting apart 65 million yrs Age of Dinosaurs ends, mass extinction of 70% of all living things 3.5 million yrs First proto-humans appear, in what is now Africa 100,000 yrs First Homo sapiens appears 10,000 yrs All of recorded human history begins You should also have the following time periods included with dates and one picture to represent it: Cambrian Ordovician Silurian Devonian Carboniferous Permian Triassic Jurassic Cretaceous Paleogene Neogene Quaternary