Search giant recognizes the Danish physicist and pioneer of quantum physics with a homepage doodle to commemorate the 127th anniversary of his birth.

Google on Sunday recognized Niels Bohr with a homepage doodle to commemorate the 127th anniversary of the Danish physicist's birth.

The doodle, one of the search giant's simpler ones, shows the breakthrough atomic model Bohr conceived of in 1913 taking the place of the first "o" in Google's famous logo. Bohr's model was the first to conceive of the atomic structure as similar to a solar system, with electrons spinning around a central nucleus like planets around a sun, but with the electromagnetic force binding them rather than gravity.

Bohr, born in 1885 in Copenhagen, was awarded the Nobel Prize in physics in 1922 for this early work published while he was at Manchester University. In addition to devising a model of the atomic structure that endures to this day, Bohr also established one of the founding principles of quantum mechanics with his notion that electrons could move to lower orbits around the nucleus in incremental steps, emitting a photon as they do so.

An accomplished athlete in his youth, Bohr played goalkeeper around the turn of the century for the Copenhagen soccer club Akademisk Boldklub alongside his brother Harald, a mathematician and Olympic soccer player for Denmark. Niels Bohr's father Christian Bohr was himself a distinguished professor of physiology at the University of Copenhagen, where Niels conducted award-winning experiments on the properties of surface tension and received his doctorate in 1911.

Moving to England, Bohr joined a group of young physicists at Victoria University of Manchester under the tutelage of Ernest Rutherford, the pioneering chemist and nuclear physicist, with peers such as William Lawrence Bragg, James Chadwick, and Hans Geiger.

Bohr returned to the University of Copenhagen in 1916 to establish and direct its Institute of Theoretical Physics, which was formed in 1921.

As a guiding light of quantum physics and promoter of the idea of complementaritythat phenomena like light could be conceived as having contradictory properties, such as behaving as both a wave and as a collection of particles, for the purposes of studyBohr would have a series of lively but good-natured philosophical debates with Albert Einstein, noted critic of the notion of quantum indeterminism.

During World War II, the Danish resistance managed to smuggle Bohr and his wife Margrethe out of Nazi-occupied Denmark to England in 1943. He then went on to the United States, where he worked using the pseudonym "Nicholas Baker" at the Los Alamos laboratory in New Mexico on the Manhattan Project under the direction of Major General Leslie Groves of the U.S. Army Corps of Engineers and theoretical physicist J. Robert Oppenheimer.

Though Bohr's credentials as a physicist were impeccable, he later described his role at Los Alamos as less about practical assistancethe Americans "didn't need my help in making the atom bomb," he would sayand more as an elder statesman of physics who offered counsel and voiced his concerns about the social impact of developing nuclear weapons and kicking off a new arms race.

After the war, Bohr returned to Denmark and continued to advocate politically for the peaceful exchange of nuclear technology to avoid a devastating nuclear war. One of Niels and Margrethe Bohr's six sons, Aage Bohr, was also awarded the awarded the Nobel Prize in physics in 1975, 13 years after his father died in Copenhagen.

For more of Google's doodles, see the below. Recently, the company has honored , , and , considered by many to be a pioneer in the electronic music space, as well as , zipper pioneer , and even commemorated its own with a birthday cake doodle.



