8/2/2019 Cosmic Events Timeline-Student Version

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Cosmic Events Timeline

Procedure

1. List some major events that have occurred between the Big Bang and now such as the Earths formation (10minimum).

2. Show your list to your instructor and obtain the pack of 18 events and 18 dates.3. Sequence the events in order from earliest to latest.4. Correspond each event with the date each occurred by placing the datencard next to the event card.5. Obtain the correct sequence and dates from your instructor. Correct any errors you may have made.6. Draw a data table.

Event Number of Years Ago Number of Days Ago

on Calendar

Date/Time on

Calendar

18 rows total The last 6 events

require a date and time

because they all occur

on Dec. 31

7. Calculate the Number of Days Ago on Calendar by following this procedure. You must show all of your work onyour paper for credit.

a. Age of the universe=1 calendar year, so 13.7 billion years=365 days,or 13,700 million years=365 days

b. Set up a ratio to determine the number of days ago of each event in relation to the age of the universe.Years ago of event = x days ago on calendar (You are solving for)

13,700 million years ago 365 days

Ex: 230 million years ago = x days

13,700 million years ago 365

Cross multiply to get x=6.13 days

c. When you get to the last 6 events, you will obtain a decimal. Therefore, the date is Dec. 31, the last day ofthe year. These events occur within a relatively small period of time that is relatively recent. The time of the

first bipedal hominids is 9:30pm. Based on this time, estimate the times the remaining events occurred on

Dec. 31.

8. Determine the date on the calendar using the Day of the Year calendar. If you are having difficulty using this table,ask for help from your instructor, it is difficult to explain in writing. At first, you can round off your numbers for

number of days, but as you get to events closer to the present, fractions matter.

9. Check your answers with those provided by your instructor. It may be useful to check answers as you complete thecalculations to ensure you are obtaining the desired numbers.

10. Answer the Discussion Questions using complete sentences. You need to write a minimum of three sentences perresponse.

Discussion Questions1. Humans arrived on the scene only about 8 minutes ago according to our model. How does this change your

perspective on our cosmic importance?

2. Dinosaurs ruled the Earth for almost two hundred million years-from December 26 to December 30 on our timeline.They died out long before humans came on the scene. Does this change your thinking about dinosaurs? Explain.

3. Were you surprised by when the Earth and the Sun were formed in our cosmic year? Explain.4. The time between the beginning of life on Earth and the rise of humans was lengthy. Did this surprise you? Explain.5. Summarize your overall reactions to our cosmic year and the order and times of the events we studied.