Bohr

[ bawr, bohr; Danish bohr ]

noun

1. Aa·ge Niels [aw, -g, uh, neels], 1922–2009, Danish physicist: Nobel Prize 1975 (son of Niels Bohr).
2. Niels Hen·rik Dav·id [neels , hen, -, r, eek , dav, -id], 1885–1962, Danish physicist: Nobel Prize 1922.

Bohr

/ bɔː; boːr /

noun

1. BohrAage Niels19222009MDanishSCIENCE: physicist Aage Niels (ˈɔɡə neːls). 1922–2009, Danish physicist, noted for his work on nuclear structure. He shared the Nobel prize for physics 1975
2. BohrNiels (Henrik David)18851962MDanishSCIENCE: physicist his father, Niels ( Henrik David ). 1885–1962, Danish physicist, who applied the quantum theory to Rutherford's model of the atom to explain spectral lines: Nobel prize for physics 1922

Bohr

/ bôr /

1. Danish physicist who investigated atomic structure and radiation. Bohr discovered that electrons orbit the nucleus of an atom at set distances, changing levels only when energy is lost or gained and emitting or absorbing radiation in the process. His concepts were fundamental to the later development of quantum mechanics.

Biography

In 1922 Danish physicist Niels Bohr was awarded the Nobel Prize for physics for his ability to build upon the findings of Ernest Rutherford and develop a theory of atomic structure that would contribute significantly to the development of quantum mechanics. At the beginning of the twentieth century, before Bohr's discovery, scientists thought that atoms were a loosely combined mixture of electrons, protons, and neutrons. In 1911 Ernest Rutherford discovered that atoms had an extremely small, positively charged nucleus that contained no electrons, and he developed an atomic model that resembled the solar system, with negatively charged electrons orbiting a central nucleus. Rutherford's model was considered puzzling because it predicted that atoms should be unstable: since the electrons were orbiting the nucleus, they were undergoing acceleration, but accelerating electric charges give off electromagnetic energy, so the orbiting electrons should have been constantly giving off energy, and ultimately spiraling into the nucleus. But electrons did not do this. To explain the atom's apparent stability, Bohr postulated that electrons travel only in discrete orbits of different sizes and energy levels around the nucleus, and that increases or decreases in an electron's energy cause it to jump to a higher or lower orbit, absorbing or emitting energy in the form of electromagnetic radiation. Bohr's model explained why hydrogen, the simplest atom, emits and absorbs light only of certain frequencies depending on the difference in energy levels of the orbits between which the electron moves. Later in his career, Bohr developed the concept of complementarity to encompass wave-particle duality, the phenomenon that under some conditions light exhibits wavelike behavior and under other conditions particlelike behavior.

Example Sentences

As Perović demonstrates, Bohr followed a similar course in arriving at complementarity.

From Science News

From all these disparate experiment-based hypotheses, Bohr applied Planck’s quantum idea to construct a master hypothesis.

From Science News

Einstein died in 1955, Bohr in 1962, neither conceding to the other.

From Science News

Quantum systems preserve different values for certain properties until one is measured, just as Bohr insisted.

From Science News

In 1913, Bohr applied quantum ideas to the simplest atom, hydrogen.

From Nautilus

The Bohr and Aliab tribes are a degree higher in the scale of civilization, but the Shir go beyond them.

From Project Gutenberg

I believe you know more about Bohr's plans, but that the knowledge was hypnotically sealed in your sub-conscious.

From Project Gutenberg

They entered and Hawarden led the way down a hall towards Bohr's private office.

From Project Gutenberg

But at the same time we must be trying to find out what planet or system Bohr came from, and take steps to see they can't harm us.

From Project Gutenberg

"Here are the transcripts of the Bohr notes," and soon the two SS men were deep in the study of them.

From Project Gutenberg