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By amoats
On July 28, 2020

Lesson Plan: The World is Flat: Distance Decay and Space-Time Compression

A Flat World?

Thomas Friedman describes how he came to conceptualize the idea of a Flat World, or a globalized economy without traditional limitations such as distance decay.


New ideas and technologies develop in a cultural hearth. Sometimes, technologies such as the development of agriculture develop independently in multiple hearths. These ideas and technologies diffuse through relocation or expansion diffusion. The distance between two places has been a major limiting factor in how this diffusion works. The concept of distance decay states places that are close to each other have more interactions than places that are far apart. The diffusion of an idea is more likely to occur and in places close to the hearth than in places that are far away. Technologies and innovations that increase the speed and range of diffusion engage in space-time compression according to geographers. This lesson uses Thomas Friedman's book "The World is Flat" and the concept of globalization to explore the factors impacting distance decay and space-time compression.


  • Warm-Up:

    Answer the following question to begin class.

    1. How does the concept of distance decay affect where people shop for everyday items such as food, clothing and home products?

    2. How has the internet and e-commerce changed the concept of distance decay in your life?

    If students are unsure about the concepts of distance decay and space-time compression, or if you have not taught these concepts yet, a great resource is this video on Tobler’s First Law of Geography (YouTube).

  • Introduction:

    Conduct the warm-up with students and discuss their responses, or their reaction to the video on Tobler’s First Law of Geography. Assess student understanding of these concepts through class discussion. If necessary, explicitly teach terms such as diffusion, hearth, distance decay and space-time compression.

  • Exploration:

    Have students view the following video clips. The information on each clip corresponds to the Guided Notes-Practice Handout.

    Handout: Guided Notes-Practice (Google Doc)

    Students should watch each clip and then record their thoughts and information on the handout. Encourage students to take their time, frequently stopping the video if necessary to process the ideas presented by Friedman. Student outlines should be unique, containing examples from the video as well as their own thoughts.

    Students after taking notes on the videos, allow students to either collaborate in small groups or conduct a whole class discussion. Focus student work towards and understanding of the concepts of distance decay and space-time compression.

    Note, Thomas Friedman never uses these terms in his presentation, but they are concepts that are woven throughout the presentation.


  • FRQ Practice:

    Using the handout, assign students to respond to the sample FRQ at the end of the outline. It is a modified, simplified non-stimulus FRQ that is good practice taking an abstract, spatial concept and applying examples that make the concept more relatable for students.

    How are the concepts of distance decay and space-time compression integrated into the thesis and the forces as presented in Thomas Friedman’s book The Earth is Flat?

    • Provide specific examples from Friedman in your writing.

    • Provide an example not included in the presentation by Friedman.

    • Indicate if the thesis and suggestions in the book refute or confirm the concepts of distance decay and/or space-time compression.
  • Extension/Alternative Activities:

    Mapping your Communications- Identify five times recently that you have communicated with or received information from someone outside of a face-to-face conversation. This can be via social media, gaming network, letter, telephone call, etc... For each identify the location of the person you are connecting with and map it on a blank map. Based on this, explain how the concept of space-time compression is demonstrated in your life.

    Additional Prompts

    • Does Thomas Friedman's 2005 assertion that the "world is flat" still hold up today? Explain your answer.

    • How is the concept of distance decay currently present in your life?

    • How is space-time compression related to advances in technology?

    • What geopolitical and economic factors are challenging the prediction that the world will continue to be "flat?"

    • How did the quick spread of COVID-19 around the world illustrate the concept of space-time compression?

Additional Resource


  • Diffusion
  • Distance Decay
  • Globalization
  • Hearth
  • Time-space Compression


Economics & Financial LiteracyGeography


High SchoolUniversity