Site Glossary

Extra design capacity added to account for uncertainty.

Additional allowance for uncertainty or unexpected conditions.

an object that orbits another object.

a mathematical quantity that represents only magnitude, without any associated direction.

it can represent quantities such as time, temperature, mass, or distance.

A quantity that has magnitude only.

A model that represents objects using proportional sizes or distances.

radius of the event horizon for a simple non-rotating black hole.

a way to express numbers that are either very large or very small in a compact and convenient format.

involves expressing a number as a product of two factors: a decimal number between 1 and 10 (known as the coefficient) and a power of 10 (known as the exponent).

half the longest diameter of an elliptical orbit.

The distance between two objects at a particular time.