Is it possible to think an example of refraction in which Fermat principle involve a maximum without using reflection?
91709
Examples in which the light maximizes the optical path length
92204
Wavelength-dependent refractive index
106119
Why is there no permittivity-type constant for gravitation?
90537
Converse of Fermat's Little Theorem.
62692
Retrieving Maxwell's equations from the minimum action principle
56775
Finding minimal form -- Velleman exercise 1.5.7a
41043
example of discontinuous function having direction derivative
145425
Are double-slit patterns really due to wave-like interference?
62413
Reflection across the plane
44724
Intuition Behind Maximum Principle (Complex Analysis)
4005
If refraction slows down light, isn't it possible to hold light still?
84291
Do the integral forms of Maxwell's Equations have limited applicability because of retardation?
50178
\qed for theorems without proofs
144426
Example of a function $f:\mathbb{R}^2\to\mathbb{R}$ not differentiable at $(0,0)$, but has a directional derivative at $(0,0)$ in all directions
113163
Why do some lenses focus past infinity?
104940
Are infinite reflections between two mirrors really infinite?
78654
An example of a norm which can't be generated by an inner product