Algebraic Derivation of the Schwarzschild Time Dilation Function
  Using only a thought experiment and Einstein's correspondence principal, a model is derived that correctly predicts the Schwarzschild time dilation expression in limiting cases. The method requires almost no prerequisite knowledge from the student and is carried out with only algebraic techniques, allowing the introduction of a mathematical example of general relativity to introductory physics students. 
Andrew Theyken Bench