Famous Mistakes: teacher key

How to Check If Something Is True, grade 8 edition, written for 8th grade. Smart people have been wrong in public, from a fake skull to the canals of Mars. See how each mistake was found and what the people who found it did differently.

Read the book. Print this page for the key.

Questions and answers

1. What did later evidence show about Lowell's Mars canals?
   • They were real rivers
   • They were optical illusions (answer)
   • They were roads
2. Why could Piltdown not be checked in 1912?
   • The bones were lost
   • The museum refused
   • There were no good dating methods (answer)
3. Why might a wish to find the first human ancestor in England matter?
   • It may have made scientists less careful (answer)
   • It made the bones older
   • It proved the skull was real
4. What did the survey of 5,000 homes find about the 1938 radio play?
   • Everyone was listening to it
   • Only 2 percent were listening to it (answer)
   • Nobody owned a radio
5. What was Columbus's mistake?
   • He thought the Earth was flat
   • He lost his map
   • He used a guess for the size of the Earth that was too small by about a third (answer)
6. Why could the 1919 numbers tell two ideas apart?
   • The theories predicted different amounts of bend (answer)
   • Both predicted the same bend
   • The Sun was too bright to measure

Words

• dwarf: smaller kind
• illusions: false sights
• fraud: planned lie
• survey: set of questions
• bias: leaning