1915
ID: 397
Leopold Löwenheim proves Löwenheim theorem: if a first-order sentence has a model, it has a countable model
ID: 397
1915
ID: 1232
Dr. Harry Haiselden case - Chicago doctor publicly euthanizes defective newborns
ID: 1232
1915
ID: 1233
German-Ottoman intelligence cooperation established; German officers lead Ottoman operations against British in Middle East
ID: 1233
1915
ID: 1234
Einstein publishes General Theory of Relativity using Riemannian geometry - 'God does not play dice with the universe'
ID: 1234
1915
ID: 1235
Germany uses chlorine gas at Second Battle of Ypres - Fritz Haber oversees chemical weapons program
ID: 1235
1915
ID: 4227
Watson becomes president of C-T-R, introduces 'THINK' motto and aggressive sales training programs
ID: 4227
1915
ID: 4283
Suspension filing systems introduced - hanging folders on rails eliminate need for folder compression
ID: 4283
1915
ID: 4290
QWERTY keyboard layout becomes universal standard despite more efficient alternatives - path dependency example
ID: 4290