Question

what happens during refraction?

Answer 1

The frequency of any light should remain constant after passing through normal glass slab like substances. Since c=(neu)*(lambda), to keep the frequency (neu) constant, speed of light(c) and wavelength (should change). Since speed changes the path travelled by light changes, the one with higher speed tends to travel longer distance (i.e away from the normal) and the one with lesser speed go for the shorter distance (i.e towards the normal). the total time= distance/speed will remain constant only in that way. greater speed more distance and less speed less distance. Because inverse of time is frequency which should be constant. 

Answer 2

In science, a retraction of a published scientific article indicates that the original article should not have been published and that its data and conclusions should not be used as part of the foundation for future research. The most common reasons for the retraction of articles are scientific misconduct including plagiarism, serious errors, and duplicate/concurrent publishing (self-plagiarism). The retraction may be initiated by the editors of the journal, or by the author(s) of the papers (or their institution). A lesser withdrawal of content than a full retraction may be labelled a correction. There have been numerous examples of retracted scientific publications. Retraction Watch provides updates on new retractions, and discusses general issues in relation to retractions