Deep Time Chalk Timeline


In this activity, learners will trace the history of the universe, examining key moments in its formation as well as the emergence of the Earth’s geophysical and biochemical systems. To do this, learners will use chalk to create a timeline on a sidewalk or in a parking lot. Each learner will add events to the timeline and give a brief 30-60 second summary of the event.


At the end of this activity, learners will:

  1. Have a better sense of the scale of “deep time” and the history of the universe.
  2. Be able to describe the key moments in the development of the Earth and its physical and biological systems.


  • Sidewalk chalk
  • Measuring device (e.g. measuring tape, meter stick, trundle/measuring wheel)
  • Megaphone (optional)

Supplemental Readings/Videos/Website

Pre-Activity Preparation

  • Create a list of important events or eras in the history of the universe. Here are a few examples: The Big Bang, Solar System forms, life appears on Earth, first eukaryotes. The list can be as long as you want it to be and will probably depend on how many learners are participating. If learners are doing the optional writing assignment, one or two events per learner is ideal. A good place to get a list of events is the “Big History Timeline.”
  • (Optional Pre-Activity Writing) Each participating learner will be assigned two events or eras. Their job will be to explain the significance of these moments and submit them before the activity. To help make this easier, the organizer might consider setting up a Google Form with the following fields:
    • Timestamp
    • What is your event/era?
    • How many years ago was this event/era?
    • Describe this event/era.
    • What is significant about this event/era?

The benefit of using a Google Form is so that at the end of the activity, all learners can have access to a single spreadsheet with details on all of the events and eras.

  • Pick a location where you have permission to use chalk to write on the ground. The ideal place is along a sidewalk – ideally, longer than a kilometer. Or, find an empty parking lot. Your timeline doesn’t have to be straight. It can turn corners, or loop back, or even go in a spiral.
  • Before the activity, prepare a list of all the events/eras, how many years ago they took place, and which learner will be responsible for summarizing them. Print out this list for all participants.


  • Assemble on site. The group leader should explain the purpose of the activity. Hand out the list of events/eras so that learners know what each person will be presenting and in what order.
  • Mark the ground with an asterisk and write, “The Big Bang ~13.8 BYA.”
  • The learner responsible for the Big Bang should give a brief summary (30-60 seconds) of what the Big Bang was, when it happened (i.e. approximately 13.8 billion years ago), and why it is significant.
  • From there, the group will move to the next important era/event. The leader should inform the group that each meter will equal 10,000,000 years and to measure the timeline accordingly.
  • Continue until all eras/events are added to the timeline.

Reflection Questions

  1. How do different time scales change the types of questions that we can ask?
  2. What kinds of methodologies might be necessary to understand time at different scales?
  3. How does a Big History approach help us understand geological and biological time in different ways?
  4. What are the social, cultural, and political implications of pursuing historical questions at different scales?

Tips for Making this an Effective Exercise

  • This activity works best as a group exercise, but individuals can certainly do this on their own.
  • If doing this on busier street, keep in mind that traffic noise can be an issue. Consider giving participants a megaphone.
  • Be sure to check with city ordinances and contact campus/local police and campus administrators before you begin chalking sidewalks. Many city ordinances allow individuals to mark sidewalks with chalk. Organizers might also consider giving police and campus administrators a heads-up so that nobody worries that you are defacing property.
  • Passers-by might be quite interested in what you are doing making this a great way to engage with a wider public. Consider printing out a description of the project to distribute to them.
  • In the final meter of the project, time scales may need to be adjusted so that the text is easier to read. This could be designated by a note on the pavement or a different color of chalk.
  • In the classroom context, students who participate in this activity often have a lot of fun getting to know each other. Teachers might consider this a good early semester option to encourage group collaboration.