3-sidewalk-timeline

```Name _______________________________________________ Date ___________ Pd ______
Timeline Activity
Objectives:
• To understand the concept of a million and a billion
• To model the geologic time scale
• To use the analytical skills of measurement and scientific notation.
• To compare the dynamic relationship between Earth’s conditions and the diversity of its organisms.
Background: As you learn about past events in Earth history you may be surprised when you hear that
something occurred ‘only’ a million years ago. In the context of a human lifetime this is an enormous
amount of time. Yet geologists many consider this to be a short time ago when compared to the Earth’s age.
The enormity of geologic time is difficult to understand. One way to help visualize geologic time is to
create a time line. Note – while there are slight discrepancies among scientists over the exact dates of
certain major events (ie: extinction of the dinosaurs), for the purposes of visualization our dates are accurate.
Remember:
10 = 1,000,000,000
1 billion
106 = 1,000,000
1 million
5
10 = 100,000
1 hundred thousand
4
10 = 10,000
10 thousand
9
Materials:
• Masking tape or sidewalk chalk
• Event notecards (below)
•
•
Long sidewalk or football field
Measuring wheels, meter sticks
Procedure
1. Distribute event cards without years on them to each student
2. Take students to the field and show them the formation of the Earth (4.6 bya) and today.
3. Ask students to arrange themselves on the field to represent the sequence of events.
4. Now gather the students and issue the same event cards with the years on them and ask students to
calculate their event using the meter sticks/measurement wheels provided. (Note: it helps to have
a few predetermined distances identified to save time). Warn students not to rely on the correct
measurements of others or one wrong student can have a domino effect.
5. Once students have placed themselves correctly, have them mark their event/location with tape or
sidewalk chalk.
6. Take students on a ‘field trip’ of geologic time, calling out events as they are encountered, briefly
discussing each event as you pass. This is a great time to relate the significance of the
environmental conditions of the planet to the life found at the time, and what contribution each
event had to the development of the Earth as we know it today.
Calculations (for football field):
How do we translate history onto our field? 750 million years ago started the Paleozoic Era. Where would
this fall on our field?
750 million years = 7.5 x 108 years
7.5 x 108 years x
(1 yard)
5.0 x 107 years
= 7.5 x 108
5.0 x 107
=7.5
5
x (108 – 107) = 1.5 x 101 = 15 yards
Questions
1. Were you accurate on you approximation? When given the event date, was it earlier or later than you
expected?
2. Why do you think it is so hard for humans to visualize a billion years?
2. The universe was formed approximately 13.7 billion years ago. Using the same scale, how far away
would this be? Can you find a reference point?
Extensions:
This activity can be done (indoors) with a toilet paper roll indicating the history of Earth with students
marking events with marker.
Students can either be asked to predict events with blank cards or can be given premade (calculated) cards
and asked to measure. Alternatively, the teacher can pre-identify the locations of the events and ask
students to mark the place for the simplest visualization.
http://www.eshirts.com/product_images/y/537/154301__35716_std.jpg
Event
Approximate Age
A Formation of the Earth
4.6 billion years
B Oldest known rock
4.3 billion years
C First single-celled organism
4 billion years
D Age of most continental crust
3.7 billion years
E First viruses appear
3.5 billion years
F Blue-green algae (1st to make O2)
3 billion years
G First fungi appear
1 billion years
H First multi-celled organism
700 million years
I
Precambrian Extinction
(70% of all life wiped out)
650 million years
J First shellfish appear
570 million years
K First fish appear
510 million years
L First true plants appear
498 million years
M First sharks appear
390 million years
N First amphibian appear
375 million years
O First reptile appears
325 million years
P
Permian-Triassic Extinction
(99% of all life wiped out)
250 million years
Q Mesozoic Era begins
245 million years
R First mammal appears
200 million years
S Age of most oceanic crust
180 million years
T First known bird appears
160 million years
U Rocky Mountains formed
80 million years
V Extinction of the dinosaurs
65 million years
W First proto-humans appear
3.5 million years
X Earliest modern humans appear
2 million years
Y Last Ice Age
20,000 years ago
Z Recorded human history begins
10,000 years
Distance on Field
Formation of the Earth
Oldest Known Rock
1st Single-Celled Organism
Age of Most Continental Crust
First Viruses Appear
Blue-Green Algae
(First oxygen-producers)
First Fungi Appear
First Multi-Celled Organisms
Precambrian Extinction
(70% of all life wiped out)
First Shellfish Appear
First Fish Appear
First True Plants Appear
First Sharks Appear
First Amphibian Appears
First Reptile Appears
Permian-Triassic Extinction
(99% of all life wiped out)
Mesozoic Era Begins
(The Age of the Dinsaurs)
First Mammal Appears
Age of Most Oceanic Crust
First Known Bird Appears
Rocky Mountains Formed
Extinction of the Dinosaurs
First Proto-Humans Appear
Earliest Modern Humans Appear
Last Ice Age
Recorded Human History Beings
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