The Schwarzschild Solution: Orbits, Redshift and the Horizon · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Clocks, orbits, and the edge of a black hole

Science · Astronomy & Astrophysics · ages 23-24
Name ______________________   Date ____________

  1. Why do orbits precess in this geometry?

    • A wind pushes the planets
    • It departs from the inverse-square result
    • Clocks tick too loudly

  2. Two clocks sit at different depths. Which ticks slower as seen from far?

    • The deeper one
    • The higher one
    • Both tick exactly alike

  3. The horizon is where the coordinates fail, not the geometry.

    Circle one:   True   False

  4. Light from a far star grazes the mass. What happens?

    • Its path bends through the curved region
    • It stops and waits
    • It speeds past unchanged

  5. How do you compare two clock rates at different depths?

    • Ask the deeper clock politely
    • Assume all clocks match
    • Read both off the metric and compare

  6. What separates the horizon from the singularity?

    • They are the same thing exactly
    • The horizon is a coordinate breakdown; the singularity is genuine
    • Neither exists at all

  7. A report blames orbital precession on a new force. What is missing?

    • Geometry alone explains it as departure from inverse-square
    • More forces always help
    • Precession needs no explanation

  8. A probe crosses the horizon carrying a clock. What does the lesson say about the crossing itself?

    • The probe hits a wall
    • Time stops for everyone
    • Nothing special locally: the geometry stays smooth there
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Clocks, orbits, and the edge of a black hole W1-mt_dNZpRDeZUE-s1

  1. It departs from the inverse-square result · Precession is the departure made visible.
  2. The deeper one · Depth slows the tick.
  3. True · Labelling breaks; the geometry continues.
  4. Its path bends through the curved region · Curved region bends light.
  5. Read both off the metric and compare · The metric holds both rates.
  6. The horizon is a coordinate breakdown; the singularity is genuine · One is labelling, the other is real.
  7. Geometry alone explains it as departure from inverse-square · No new force required.
  8. Nothing special locally: the geometry stays smooth there · Smooth geometry means a quiet crossing.
Worksheet · LightMySky