We know that when a ray of light goes from denser to rarer medium, it bends away from the normal due to increase in its speed. But that means it bas been accelarated and a force acts on it. Am I right? Please explain.

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    $\begingroup$ Keep in mind that a "ray of light" isn't a physical object, it's a wave. Individual photons are not being redirected in the way the wave as a whole is. $\endgroup$
    – Asher
    Aug 21, 2017 at 11:18
  • $\begingroup$ This may be of some interest: arxiv.org/ftp/arxiv/papers/1510/1510.06227.pdf $\endgroup$
    – EigenDavid
    Aug 21, 2017 at 12:59
  • $\begingroup$ I want to ask a question. Does light behave as wave or particle during refraction? $\endgroup$ Aug 21, 2017 at 15:03
  • $\begingroup$ Wave. Read the dupe candidate. $\endgroup$
    – peterh
    Aug 22, 2017 at 20:25