This web page presents the story of how the "spherical Earth theory" was challenged, tested, defended, and ultimately rejected through rigorous experimentation in the late 17th century. As a result, the theory of the oblate Earth was adopted. The story brings the controversy to life, as it describes the efforts by Christian Huygens to defend the concept of spherical Earth through his pendulum experiments. The established scientific community at the time was reluctant to deviate from the spherical Earth theory, in part because of prevailing belief that a creator would not build an imperfectly shaped Earth. The story goes on to explore pendulum experiments conducted at equatorial French Guiana, where evidence repeatedly showed that the gravitational constant was slightly different at the equator than at Paris -- a contradiction of Huygens' theory. Editor's Note: This resource was developed to help students gain insight into the complexity of testing an established scientific theory, and the need for alternative theories as part of the challenge process. As the authors point out, this story is a good example of commitment to the scientific outlook: "do your best to defend a theory, but when counter evidence prevails, be prepared to give it up."


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    NSDL,historic experiments,Undergraduate (Lower Division),clocks,pendulum experiments,timekeeping,Huygens,Classical Mechanics,General Physics,Philosophy,Social Sciences,Grade 14,High School,Grade 11,Grade 12,scientific theory,history of science,Informal Education,Higher Education,Grade 13,NSDL_SetSpec_ncs-NSDL-COLLECTION-000-003-112-102,History/Policy/Law,Physics,History,oai:nsdl.org:2200/20130508142826109T,Scientific Revolution,General,Scientific Reasoning,Vocational/Professional Development Education,Technology



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    Update Standards?

    CCSS.ELA-Literacy.RST.11-12.6: Common Core State Standards for English Language Arts & Literacy in History/Social Studies, Science,

    Analyze the author's purpose in providing an explanation, describing a procedure, or discussing an experiment in a text, identifying important issues that remain unresolved.

    CCSS.ELA-Literacy.RST.11-12.10: Common Core State Standards for English Language Arts & Literacy in History/Social Studies, Science,

    By the end of grade 12, read and comprehend science/technical texts in the grades 11—CCR text complexity band independently and proficiently.
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