Back to topics

A Marshallese mattang is not a scale map to unfold at sea

A Marshallese mattang represents relationships among waves and islands that a navigator learns to recognize. Studying these charts shows how an object supports practiced knowledge without containing everything needed to use it.

8–10 min

Questions you could explore

  • What can a diagram teach that still requires experience on the water?
  • How does a mattang represent wave relationships rather than distances on a conventional map?

Start reading

Ready to try your ideas aloud?

Your topic carries over. Record up to 2½ minutes, depending on your plan.

The same Sun can light a blue afternoon and a red evening

Earth and weather3–5 minSunlight takes a different route through the atmosphere near the horizon than overhead. Which colors scatter along that route helps explain a blue afternoon and a red sunset.

Earth and weather

How can lines on a map show a steep hill?

A flat map can warn you that a route climbs sharply before you ever see the hill. Contour lines join places of equal height, and their spacing adds information about how quickly the ground rises.

2–3 min

How can lines on a map show a steep hill?

Earth and weather2–3 minA flat map can warn you that a route climbs sharply before you ever see the hill. Contour lines join places of equal height, and their spacing adds information about how quickly the ground rises.

Earth and weather

How can an earthquake alert arrive before strong shaking?

An earthquake alert can beat the strongest shaking to a distant location even though the earthquake has already started. Detection and communication can travel ahead of the damaging waves, but nearby places may receive little or no warning.

4–5 min

How can an earthquake alert arrive before strong shaking?

Earth and weather4–5 minAn earthquake alert can beat the strongest shaking to a distant location even though the earthquake has already started. Detection and communication can travel ahead of the damaging waves, but nearby places may receive little or no warning.

A Marshallese mattang is not a scale map to unfold at sea | Speech Topic | speaking.app