American Association of Physics Teachers
Com Padre Digital Library: Open Source Physics: Special Relativity on Rotated Graph Paper Model
A representation of Minkowski spacetime diagrams using graph paper that is rotated, showing the world lines of three stationary observers with light clocks.
American Association of Physics Teachers
Com Padre Digital Library: Open Source Physics: Minkowski Diagram Model
Simulation examining simultaneity and causality in special relativity by manipulating the space and time coordinates of one or two events.
Nobel Media AB
The Nobel Prize: Frederick G. Banting Nobel Lecture: Diabetes and Insulin
At this site from The Nobel Foundation you can read Frederick Banting's Nobel Lecture, "Diabetes and insulin," which was originally given September 15, 1925.
Other
Planetary Nebulae Observer Home Page
This home page is linked to detailed descriptions of nebulae types, shapes, and structures and their relationship to stellar evolution, a historical perspective on the discovery of nebulae, a gallery of images, and other related resources.