Neils Bohr
Nobel Prize Recipient, Great at physics and Horrible at Geopolitics, Great Dane
In 1913 he published his book on atomic theory which introduced the model of atomic structure where electons in set orbits revolve around a nucleus of protons and neutrons. This also includes the theory that electrons when dropping from higher orbits to lower orbits release a quantum of energy , this lead to modern quantum theory
He worked with the British on Tube Alloys and by extension the Manhattan Project in developing atomic weaponry. Where he often insisted that Soviet scientists be included on the findings of these projects, which lead to Winston Churchill (another wfg) considering him a security threat.
Element 113 on the periodic table is named for him. I named my stuffed plesiosaur after him.
Living most of his life in Copenhagen, he is the third most famous Dane, following Hamlet and Marmaduke
While his contributions to physics were innovative and the basis for modern physics. He held to the common fallacy that peace can be achieved by giving evil the means to destroy you.