Max Planck presents the hypothesis that energy is emitted in discrete quanta, marking the birth of quantum physics.
The first Nobel Prizes are awarded on the fifth anniversary of Alfred Nobel's death; Wilhelm Röntgen receives the first Nobel Prize in Physics.
Guglielmo Marconi reports receiving a radio signal in Newfoundland transmitted from Cornwall across the Atlantic.
Marie and Pierre Curie discover two new radioactive elements, polonium and radium, advancing the study of radioactivity.
The first Summer Olympics of the modern era are held in Athens, organised by the International Olympic Committee.
In German South West Africa (present-day Namibia), German forces suppressed uprisings in a campaign that killed most of the Herero and about half of the Nama people.
Wilhelm Röntgen discovers X-rays at Würzburg, opening the era of medical imaging.