What constitutes proof? How have evidence and truth evolved/changed as society has progressed? Use examples to illustrate how truth can be questioned when new ideas emerge. Evidence is fundamental in science. It plays the role of proving the hypothesis. But what could be proof? Aside from that, some “truths” or evidence that were once accepted by the world may have changed as society progresses. The evolution of truth and evidence can be driven by various factors. In this essay, the first part will focus on what is considered evidence in science, how evidence and truth have changed following the paradigm shift cycle, and illustrate the factors that cause truth to be questioned with several examples . Evidence can be anything used to prove a claim. Scientific evidence will focus on this essay. Scientific evidence can be used to support or reject hypothesis in science. Evidence is often found using different scientific methods. Based on various scientific methods, scientific evidence can be mainly divided into two types: observational and experimental evidence. Observational evidence plays an important role in scientific discovery. This type of evidence is produced by perceptual sensations such as hearing, sight, touch, smell and taste, with the help of some instruments such as a microscope, telescope and stethoscope (Bogen, 2009). The most common example of using observational evidence can be that Galileo used the telescope to observe the four satellites of Jupiter in 1610. This can be a piece of observational evidence in astronomy. In medicine, observational study means that researchers obtain evidence by observing the patient's condition under exposure...... middle of paper ......omas S. (1957). The Copernican revolution. Cambridge: Harvard University Press. ISBN 0674171039. Naughton, J. (2012, August 19). Thomas Kuhn: the man who changed the way the world looked at science. The guardian. The Observer. Retrieved from http://www.theguardian.com/science/2012/aug/19/thomas-kuhn-structure-scientific-revolutionsThe Association of Faculties of Medicine of Canada. (2011). Primer on population health. Retrieved from http://phprimer.afmc.ca/Part2-MethodsStudyingHealth/Chapter5AssessingEvidenceAndInformation/ObservationalstudiesUniversity at Albany. (2013, October). Primary and secondary source in science. Retrieved from http://library.albany.edu/usered/dr/prisci.htmlU.S. Environmental Protection Agency.(2012, May 9). DDT: A Brief History and Status. Retrieved from http://www.epa.gov/pesticides/factsheets/chemicals/ddt-brief-history-status.htm