# Parabola

**The upper part of the egg is in the shape of the parabola.**

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The joints in the foot form a parabola and it is named as the metatarsal parabola.

**The Path of a Rocket is a Parabola.**

**Galileo proved that the trajectory of a simple projectile is a parabola.**

**Antennas of radio telescopes are made in the shape of a parabola as all incoming rays parallel to the axis of the parabola are reflected through the focus.**

**Reflectors are made in the shape of parabola to reflect the light rays emanating from the focus of the parabola (where the actual light bulb is located) in parallel rays.**

Clifton Suspension Bridge in Bristol, England Suspension bridges are in the shape of a parabola.

# Ellipse

Kepler proved that the planets moved around the sun in elliptical orbits, with sun at one of the foci.

**Bohr's Atom Model**

**In Bohr-Sommerfeld theory of an atom, electrons move around the nucleus in circular or elliptical orbits.**

Arches are made in the shape of ellipse for their beauty.

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An oblate spheroid is a surface of revolution obtained by rotating an ellipse about its minor axis. The earth is an oblate spheroid, which means that the equatorial diameter of 12,756 km is larger than the polar diameter of 12,714 km.

**Whispering Galleries are Elliptical in Shape**

**In a whispering gallery sound waves emanating from one focus are reflected off the ceiling to the other focus, enabling a person at the second focus to hear all the reflected sounds together.**

The Golgumbaz in Bijapur, India, is claimed to have the second largest dome in the world, with a 'whispering gallery'.

The Halley's Comet moves in an elliptical orbit with

*e*â‰ˆ 0.97, whereas Comet Kohoutek moves in an elliptical orbit with

*e*â‰ˆ 0.99999, where

*e*is the eccentricity.

# Hyperbola

**A household lamp casts hyperbolic shadows on a wall**

**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.

**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. The intersections of the white circles are points on hyperbolas (in blue) and ellipses (in green).

**A sonic boom is a cone shaped wave caused by aircrafts traveling faster than sound. It intersects the ground in part of a hyperbola. It hits every point on this curve at the same time, so that people in different places along the curve on the ground hear it at the same time.**

The hyperbola is known as the "Sonic Boom Curve". In the second picture, the sonic boom is "visible" due to the humidity.

**Dr. Lunin has developed this gear design for electro mechanical rotary actuators for automotive, marine, and aerospace flight controls.**