radius
segment in a circle or sphere from its center to its perimeter or surface and its length
radius of curvature
radius of a circle which best approximates a curve in a given point
Earth radius
mean distance from the Earth's center to its surface
circumradius
radius of the circumcircle of a triangle
scrub radius
distance between the center of the contact patch and the steering axis intercept with the ground when viewed from the front of the vehicle
blast radius
the effective distance of an explosion
atomic radius
any measure of the size of atoms
turning radius
diameter of smallest circle a particular automobile or similar vehicle can turn along
nuclear radius
measure of the size of atomic nuclei
hydraulic radius
measure of a channel flow efficiency
Einstein radius
measurement of light ray bending from a gravitational lens
particle horizon
the maximum distance from which light from particles could have traveled to the observer during the age of the universe
minimum railway curve radius
shortest allowable design radius for the centerline of railway tracks
Jeans length
critical radius of a cloud before it can collapse
classical electron radius
physical constant providing length scale to interatomic interactions