Back to topics

Why build an elevator shaft before installing an elevator?

A building can make room for technology before its owner is ready to install it. Cooper Union’s Foundation Building contains a circular elevator shaft associated with Peter Cooper’s plans. The interesting question is how anticipating future equipment changes a building, without assuming the story establishes who invented the elevator.

3–7 min

Questions you could explore

  • What becomes easier when space is reserved during construction?
  • Which parts of an invention story need evidence beyond one building’s history?

Start reading

  • The Cooper UnionFoundation Building

    The institution describes the building and Cooper’s cylindrical shaft. Its broad claim about elevator invention should be checked against separate engineering history.

Ready to try your ideas aloud?

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

History

Calibrating the radiocarbon clock

Carbon-14 decays at a steady, predictable rate, which makes it look like a simple stopwatch for dating ancient wood, bone, or charcoal. However, the amount of radiocarbon in Earth's atmosphere has varied over the millennia, so an accurate date relies on calibrating the measurement against tree rings and other materials whose calendar age is already known.

4–5 min

Calibrating the radiocarbon clock

History4–5 minCarbon-14 decays at a steady, predictable rate, which makes it look like a simple stopwatch for dating ancient wood, bone, or charcoal. However, the amount of radiocarbon in Earth's atmosphere has varied over the millennia, so an accurate date relies on calibrating the measurement against tree rings and other materials whose calendar age is already known.

History

How do archaeologists work out what happened first?

A deep object is not necessarily the oldest thing at an archaeological site. A later pit can cut through earlier ground, leaving a sequence that has to be reconstructed from relationships between layers.

4–6 min

How do archaeologists work out what happened first?

History4–6 minA deep object is not necessarily the oldest thing at an archaeological site. A later pit can cut through earlier ground, leaving a sequence that has to be reconstructed from relationships between layers.

History

When Britain’s railways needed a shared clock

A timetable becomes awkward when the clocks at its two ends disagree. In nineteenth-century Britain, railway journeys helped turn local time into a shared coordination problem, while the telegraph helped distribute an answer.

5–7 min

When Britain’s railways needed a shared clock

History5–7 minA timetable becomes awkward when the clocks at its two ends disagree. In nineteenth-century Britain, railway journeys helped turn local time into a shared coordination problem, while the telegraph helped distribute an answer.

Why build an elevator shaft before installing an elevator? | Speech Topic | speaking.app