- #1
Joyal Babu
- 25
- 3
In fermats principle what if there is more than one path for which the variation in optical path length is stationary.Then which path would light take to reach from one point to another.
Would you consider light emitted from a point source and being focused by a lens on another point to be an example? The optical path length is the same along all paths through points equidistant from the central axis from source to center of lens to focal point.Joyal Babu said:In fermats principle what if there is more than one path for which the variation in optical path length is stationary.Then which path would light take to reach from one point to another.
Now you're proposing a variant of the quantum mechanical double slit experiment. If we have detectors along the possible paths, then only one detector will trigger for each photon; if we do not have detectors along the possible paths then it is meaningless to ask about which path each photon follows.Joyal Babu said:Yeah good point,I hadn't considered it that way.One more thing(this might be a stupid question,bare with me) what happens if there is just one photon and we send it one at a time,would we see that the photon is taking all of the paths at once or each path with equal probability of having the photon in it.
Fermat's principle is a principle in optics that states that light will always take the path that requires the least time to travel from one point to another.
Pierre de Fermat was a French mathematician who first proposed this principle in the 17th century. It is named after him because he was the first to describe this principle in mathematical terms.
Fermat's principle can be used to derive the laws of reflection and refraction. It explains why light follows these laws when it travels between different mediums.
While Fermat's principle is a useful tool for predicting the path of light, it is not always true in every situation. In some cases, light may not follow the path that requires the least time, but instead takes a longer path due to other factors such as interference or diffraction.
Fermat's principle is used in various practical applications, such as designing lenses and mirrors for optical instruments, predicting the path of light through different materials, and studying the behavior of light in different environments.