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A BRIEF LOOK INTO THE LIFE OF NIELS BOHR
A Brief Look into the Life of Niels Bohr
Sierra Kartchner
SLCC Physics 1010 M/W-8:00
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Modern physics has helped to shape our understanding of other disciplines in science and is
critical in shaping our perception of the world around us. Many modern physicists have opened up
possibilities in the universe based on their theories. One such physicist is Niels Bohr. Bohr’s contribution
to physics was mostly in the area of atoms and quantum mechanics. He earned much prestige and is
now considered a leader of modern physics. Without his research of atoms, we would not be where we
are today in science and we would not have other research that came as a result of his. In this paper, I
will discuss Bohr’s history, work as a physicist, accomplishments and what modern science has done
with his research.
Niels Bohr was born in Copenhagen, Denmark on October 7, 1885 to a family who was and
would continue to become very successful. His father was a respected physiologist and Bohr actually
had a son who ended up becoming a physicist. Bohr studied at the University of Copenhagen where he
received his Master’s and PhD of physics. Shortly after his graduation with his doctorate in 1911, Bohr
conducted some experimental physics, “prize to be awarded for the solution of a certain scientific
problem, caused him to take up an experimental and theoretical investigation of the surface tension by
means of oscillating fluid jets” (Nobelprize.org), but slowly moved more towards the theoretical side.
“Bohr's subsequent studies, however, became more and more theoretical in character”
(Nobelprize.org). He was born a Christian, but his mother was a Jew so during World War 2 he fled to
the United States for a period of time before returning back to Copenhagen. “During the Nazi
occupation of Denmark in World War II, Bohr escaped to Sweden and spent the last two years of the
war in England and America, where he became associated with the Atomic Energy Project”
(Nobelprize.org). It was during this time that the ‘Manhattan Project’ was being developed and Bohr
worked alongside the other great physicists of the day including Einstein, the Oppenheimers, Gould and
even his own son, Aage Bohr. After the project was finished and Bohr saw the potential harm that
humanity had now created, he quickly started advocating against the use of the A-bomb. “After the war
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he became an outspoken activist against nuclear weapons and for the peaceful use of atomic energy”
(NNDB). Following that endeavor, he headed up organizations to help promote peaceful uses of atomic
energy and also was a strong advocator for CERN or the European Council for Nuclear Research.
A major reason that Bohr was asked to be on the project was due to his research of the atom.
When he finished his education he went to work with physicist J.J. Thomas who is said to have
discouraged Bohr’s ideas of the atom. He also worked for a period of time with Ernest Rutherford who
seemed to be more encouraging of Bohr developing his own theory, which actually eventually replaced
Rutherford’s theory of the atom. Up until Bohr provided evidence with his quantum theory of atoms,
science lived on the idea of the Rutherford model which consisted of a nucleus of protons and neutrons
that was being circled by electrons that had a set orbital pattern around the nucleus. This seems to
make sense because we can easily visualize this in comparison to how our solar system revolves around
our sun, which to Rutherford was merely a larger version of how the atom worked. Then Bohr came to
promote and develop the theory of quantum mechanics so he could better understand and show how
atoms work. A brief look at quantum mechanics that Bohr discovered from Planck was that it, “restricts
the energy of a system to certain discrete values, to the problem of atomic and molecular structure”
(Encyclopedia Britannica). His model also consists of a nucleus made of protons and neutron, however,
he believed that quantum mechanics require that the electrons to move around the neutron in their
designated shell or what modern science now calls clouds. If atoms are reacting with each other Bohr
says that the electrons are using energy, displayed as a photon, to move up and down shells due to the
electrons energy level. He discovered that the electron with more potential to move between shells is
more ‘unstable’ because of its potential energy and is more likely to react with other atoms.
While Bohr was working in physics as a theoretical physicist, he actually taught at and eventually
became to administrator or dean of the theoretical physics college in Copenhagen. This was appropriate
because he was a key developer of the college, you could even say he helped found it. Probably the
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most notable accomplishment he received as a theorist was the Nobel Prize for Physics in 1922. He was
awarded this prize because of his work on the atomic model and the theory derived from that model. As
was mentioned before, Bohr was an instrument is creating the concept of quantum mechanics as we
know it today, but I was surprised to learn of how he saw that this would affect philosophy and also to
see some of the disagreements between him and other respected physicists. One of the main
controversies that came from his theories was his idea that because of the nature of quantum
mechanics, you could re-do an experiment multiple and depending on the varying parameters of that
experiment, receive varying results. He attributed this to the fact that quantum mechanics has some
measure of improbability to it. However, “Albert Einstein didn’t fully see eye to eye with all of Bohr's
assertions, and their talks became renowned in scientific communities” (The Biography Channel
Website).
Probably one of the most important research developments from his theory of how electrons
absorb and emit energy, was the concept of radiation within those energy transfers. These theories also
work with two concepts that he produced:
“The correspondence principle, and the complementarity principle. The former holds
that to untangle the contradictions between "old" and "new" physics, new theories
must both describe atomic phenomena correctly and be applicable to conventional
phenomena; the latter holds that wave and particle aspects of nature are
complementary and can never both be true simultaneously” (NNDB).
He had certain goals that he wanted to learn more about and his research in these areas greatly shaped
our understanding of modern physics. There were two problems in the 1920’s that he set out to find
solutions for and that greatly influenced his thinking and led him to receiving his Nobel Prize. These
problems were, “a consistent quantum theory that would replace classical mechanics and
electrodynamics at the atomic level and be adequate for treating all aspects of the atomic world”
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(Encyclopedia Britannica) which was difficult since he was trying to find a way for an unpredictable
theory to apply to everything. The second was “to explain the structure and properties of the atoms of
all the chemical elements, particularly the regularities expressed in the periodic table and the complex
patterns observed in the spectra emitted by atoms” (Encyclopedia Britannica) which also seems
impossible to me because it seems that it would require a lot of tedious research for every individual
chemical element.
Today, physics functions with a lot of the principles and ideas that Bohr theorized. With his work
at the quantum level, he was able to create hypothesizes about how light is able to appear as if it were a
particle and a wave. His work was also crucial in developing the atomic bomb and although he disagrees
with the use of nuclear weapons, he also saw the potential of usable nuclear energy and both of these
ideas are used in our world today. Scientists have added to his atomic model and have not discredited
his contributions or proved them false, however they have used his theories to help develop the model
further and show how an atom might function. One major example of how Bohr’s theories were put to
the experimental test was in 1939. He had created a theory of how the atomic nucleus functioned called
the ‘liquid-drop model’. From this model, nuclear fission or radioactive decay of an atom that splits it
into two, became a very really possibility and eventually the atomic bomb. Since then, we have been
able to use that energy in nuclear reactors to provide alternate energy resources for the growing
population.
In conclusion. Bohr was able to use his theories and principles to explain one another and his
experiments supported his theoretical work. Although he was challenged by other physicists of the day
his work is still recognized now and is continuously being built upon. As more modern experiments are
being performed, it seems that the work he performed is still relevant and is simply being expanded.
After researching about Niels Bohr, I have learned a lot more about how atoms work. I also have come
to the conclusion that without his contribution to science, our world would not be nearly as advanced as
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it is now. Essentially, Bohr was able to better understand how energy works and with his foot in the
door, our world has been opened to endless possibilities and growth in technology.
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Works Cited
Bohr, Niels. (1997). Encyclopedia Britannica. Retrieved 02:30, July 30, 2013 from
http://dwb.unl.edu/Teacher/NSF/C06/C06Links/207.138.35.143/nobel/macro/5000_79.html.
Niels Bohr. (2013). NNDB. Retrieved 04:53, July 30, 2013, from http://www.nndb.com
/people/560/000024488/.
Niels Bohr. (2013). The Biography Channel website. Retrieved 01:29, Jul 30, 2013, from
http://www.biography.com/people/niels-bohr-21010897.
Niels Bohr-Biographical. (2013). Nobelprize.org. Retrieved 12:04, July 30, 2013 from
http://www.nobelprize.org/nobel_prizes/physics/laureates/1922/bohr-bio.html