Hubble diagrams are used to study the expansion of the universe.

Dynkin diagrams are used in the study of Lie algebras.

I have studied many Jones diagrams in my physics class.

Penrose diagrams are used in theoretical physics to represent the causal structure of spacetime.

Matrix diagrams are useful tools for visualizing complex relationships.

Kiviat diagrams are used to visualize multivariate data.

Concordia diagrams are used to interpret the age of rocks and minerals.

Wetherill diagrams are used to plot isotopic data in geochronology.

Force diagrams are used to represent the forces acting on an object.

Entity relationship diagrams are used to visualize the relationships between entities in a database.