Dulles Airport, designed by Eero Saarinen, is in the
shape of a hyperbolic paraboloid. The hyperbolic paraboloid is a three-dimensional
curve that is a hyperbola in one cross-section, and a parabola in another cross section.

2. Lampshade

        A household lamp casts hyperbolic shadows on a wall.

3. Gear transmission

        Two hyperboloids of revolution can provide gear transmission between two skew axes.
The cogs of each gear are a set of generating straight lines.

4. Sonic Boom

        In 1953, a pilot flew over an Air Force Base
flying faster than the speed of sound. He damaged every building on the base.

As the plane moves faster than the speed of sound, you get a cone-like wave.
Where the cone intersects the ground, it is an hyperbola.

The sonic boom hits every point on that curve at the same time. No sound is
heard outside the curve. The hyperbola is known as the "Sonic Boom Curve."
In the picture below, the sonic boom is "visible" due to the humidity.

Comparing Speeds
in Miles per Hour

Human Walking	3 mph
Human Running	34.3 mph
Race Horse	44.9 mph
Cheetah Running	65 mph
Car on Interstate Highway	65 mph
Fastest Train	250 mph
Passenger Jetliner (McDonald Douglas DC-9)	575 mph
Speed of Sound (At sea level, 59 degrees)	761 mph
Concorde	1,450 mph
Fastest Jet Fighter	4,500 mph
Space Shuttle in Orbit	17,000 mph

5. Cooling Towers of Nuclear Reactors

        The hyperboloid is the design standard for all nuclear
cooling towers. It is structurally sound and can be built with straight steel beams.

When designing these cooling towers, engineers are faced with two problems:
(1) the structutre must be able to withstand high winds and
(2) they should be built with as little material as possible.
The hyperbolic form solves both of these problems. For a given diameter and height of a tower and a given strength, this shape requires less material than any other form. A 500 foot tower can be made of a reinforced concrete shell only six or eight inches wide. See the pictures below (this nuclear power plant is located in Indiana).

6. Stones in a Lake

        When two stones are thrown simultaneously into
a pool of still water, ripples move outward in concentric circles.
These circles intersect in points which form a curve known as the hyperbola.