Light, Gravity and Time: teacher key

Albert Einstein, grade 6 edition, written for 6th grade. Einstein's ideas about space, time and gravity were tested by astronomers. Read what special and general relativity say.

Read the book. Print this page for the key.

Questions and answers

1. What does special relativity say about the speed of light in a vacuum?
   • It is slower at night
   • It is the same for any observer (answer)
   • It depends on the color
2. What does general relativity say gravity is?
   • A kind of light
   • A packet of energy
   • How mass warps space and time (answer)
3. When were gravitational waves first observed directly?
   • September 14, 2015 (answer)
   • In 1905
   • In 1933
4. Why did astronomers photograph stars during a solar eclipse in 1919?
   • To test whether the Sun's gravity bends starlight (answer)
   • To find a compass
   • To meet Einstein
5. What is the photoelectric effect?
   • Light makes a material give off tiny charged particles (answer)
   • A kind of violin
   • A school in Aarau
6. Where did Einstein begin work in 1933?
   • Institute for Advanced Study (answer)
   • Cantonal School
   • Bern

Words

• relativity: his theory
• quanta: energy packets
• eclipse: solar eclipse
• compass: shown to Albert