- Empty set (Wikipedia)
In mathematics, the empty set is the unique set having no elements; its size or cardinality (count of elements in a set) is zero. Some axiomatic set theories ensure that the empty set exists by including an axiom of empty set, while in other theories, its existence can be deduced. Many possible properties of sets are vacuously true for the empty set.
- Messier 96 (Wikipedia)
Messier 96 (also known as M96 or NGC 3368) is an intermediate spiral galaxy about 31 million light-years away in the constellation Leo.
