I have two space-cadet keyboards.

Scientists study the properties of de Sitter spaces in cosmology.

Many inner product spaces have unique properties.

Normed vector spaces are fundamental concepts in functional analysis.

The physiologic dead spaces in the lungs help regulate the exchange of gases.

Pre-Hilbert spaces are widely used in functional analysis.

Projective Hilbert spaces are used in quantum mechanics to represent the state of a quantum system.

Real vector spaces are fundamental concepts in linear algebra.

Scientists are studying the properties of space-time crystals.

Space-time crystals are a fascinating concept in physics.