Problem: Albert Einstein proposed that the laws of physics should be based on the principle of relativity. This principle holds that the rules of physics must be the same for all observers, regardless of the frame of reference that is used, and that light propagates at the same speed in all reference frames. This theory was motivated by Maxwell's equations, which show that electromagnetic waves propagate in a vacuum at the speed of light. However, Maxwell's equations give no indication of what this speed is relative to. Prior to Einstein, it was thought that this speed was relative to a fixed medium, called the luminiferous ether. In contrast, the theory of special relativity postulates that light propagates at the speed of light in all inertial frames, and examines the implications of this postulate.
Whatprinciples that light moves at different speeds depending on the refrence point?
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Answer: unanswerable

Problem: In 1822, the American Colonization Society began sending African-American volunteers to the Pepper Coast to establish a colony for freed African Americans. By 1867, the ACS (and state-related chapters) had assisted in the migration of more than 13,000 African Americans to Liberia. These free African Americans and their descendants married within their community and came to identify as Americo-Liberians. Many were of mixed race and educated in American culture; they did not identify with the indigenous natives of the tribes they encountered. They intermarried largely within the colonial community, developing an ethnic group that had a cultural tradition infused with American notions of political republicanism and Protestant Christianity.
What did African Americans moved to Liberia keep from America?
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Answer: cultural tradition

Problem: The Presbyterian Church (U.S.A.) has adopted the Book of Confessions, which reflects the inclusion of other Reformed confessions in addition to the Westminster Standards. These other documents include ancient creedal statements (the Nicene Creed, the Apostles' Creed), 16th-century Reformed confessions (the Scots Confession, the Heidelberg Catechism, the Second Helvetic Confession), and 20th century documents (The Theological Declaration of Barmen, Confession of 1967 and A Brief Statement of Faith).
Which book has the Second Helvetic Confession adopted?
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Answer:
unanswerable