- The Milky Way is surrounded by more than 50 near neighbour galaxies that make up the Local Group. The two largest galaxies are us and Andromeda, but we also have an often-overlooked third large galaxy in our neighbourhood- the Triangulum Galaxy. This galaxy is like its own mini-Milky Way, containing stars, clouds, clusters, supernova remnants, and satellites. These are the checkpoints in the Triangulum Galaxy which make up our tour today.
- Real number (Wikipedia)
In mathematics, a real number is a number that can be used to measure a continuous one-dimensional quantity such as a distance, duration or temperature. Here, continuous means that pairs of values can have arbitrarily small differences. Every real number can be almost uniquely represented by an infinite decimal expansion.