What is the real life use of hyperbola? The point of this question is to compile a list of applications of hyperbola because a lot of people are unknown to it and asks it frequently.

Did you ever take a look at the light projected onto a wall by a nearby lamp with a standard lampshade?  That's right: the light on the wall due to the lamp has a hyperbola for a bounday.  The reason for this is clear once you think about it for a second: the light out of the lampshade forms a vertical cone, and the intersection of a vertical cone and a vertical wall makes a hyperbola.
Also, consider a pair of sources of ripples in water that produce concentric waves.  The intersections of those concentric waves - surfaces of constant phase, are hyperbolae.  Why?  Because a hyperbola is the locus of points having a constant distance difference from two points (i.e., a phase difference is is constant on the hyperbola).
