Ruling out a Model

• If closer = warmer is the cause of the seasons, then this model predicts that the size of the Sun should vary over the course of a year

  • Observation: But it doesn’t!

• Also, if seasons were caused by a changing Earth-Sun distance, summer here would occur at the same time as summer in Australia!

  • Observation: But it doesn’t!

• Seasons caused by changing Earth-Sun distance?

Previous slide

Next slide

Back to first slide

View graphic version