Father and son, two theories, two Nobel prizes

Denmark is a ' small country, great wisdom ', there is a society voted as the least corrupt and the happiest people's life in the world.

The writer of this article chose to go to the North, the first road in the journey through Western Europe this year. Come to Denmark, pass or stop at 5 of the 400 islands, large and small, between the Baltic Sea, observe and contemplate this unique island nation and its people.

The destination is waiting here. Copenhagen capital. And the Niels Bohr Institute, the birth name is the Institute of Theoretical Physics, of the University of Copenhagen, founded by Niels Bohr, one of the most prestigious scientists in the world in the 20th century and is a director for many years.

Niels Bohr and atomic theory

I arrived just in time for this place to commemorate the 25th anniversary of the Memorial of N. Bohr and was preparing to prepare for the solemn celebration of the " Model of Bohr ' atomic structure 100 years old (1912-2013). Sitting writing memorial address lines at the previous writing desk of the senior senior physicist, I suddenly felt like I was going on a pilgrimage to one of the foundations for the foundation of nuclear science. The atom of humanity.

The question of whether everything is made up of the smallest indivisible object (called atom or atom) has been in place for thousands of years and many ancient philosophers have thought of it.In the late 19th and early 20th centuries, experimental inventions really proved the existence of atoms.

But a new problem arises, the atom is not the last element to make everything, it has some internal structure. Finding the structure model of the atom itself becomes active in the physical world.

It was during this exciting time that the young physicist was talented in Denmark N. Bohr, after receiving a doctorate from the Cambridge University (1911-1912) and Manschester University (England) scientific research with two famous British physicists JJ Thomson and Ernest Rutherford. Not only absorbing the ideas of the atomic patterns created by them, N. Bohr also recognized the limitations in those samples and sought to improve, especially with Rutherford's model.

Describe the Bohr atomic sample: in the middle is the nucleus with Ze charge with 3 intermittent stop states1,2 and 3. The arrow of the step jump of e from the outer state to the second state and emits radiation . (Documentary photo).

Rutherford hypothesized that the atom consisted of a central nucleus and one or more electrons (or electrons, symbols e) spinning around; similar to Earth and other planets (Jupiter, Saturn, Mars .) orbiting the Sun. In particular, most atoms accumulate in the nucleus while electrons have smaller masses tens of thousands of times. The important difference is that the Sun and the planets neutralize their charge, while the nucleus has a positive charge and electrons have a negative charge.

It was this difference that led to Rutherford, just born, who had a stalemate. Because of the theory of electrodynamics (classical), due to circular motions around the nucleus and by carrying electricity, electrons decrease their velocity or gradually lose their energy, which leads to their orbits becoming smaller and eventually electrons fall into the nucleus. In other words, according to Rutherford's model, atoms cannot exist. While material still exists, the universe is in existence for tens of billions of years now!

In order to solve the deadlock, in 1913, Niels Bohr made a bold assumption, that atoms electrons do not move around the nucleus in any orbit , meaning that the orbit cannot be reduced. continuously. The argument for this hypothesis is that for micro-systems such as atoms, the concept and formula for calculating the macro system in classical electrodynamics is no longer true.

In atoms, electrons only move or exist in certain states (or orbits) called a steady state) with a certain energy, and the elecron can only jump between stops. with that interrupting energy. First, electrons can jump from a low energy state to a high state when excited, such as an object being heated. And then, electrons from a high state can jump into a low state, at which point the atom will emit energy in the form of electromagnetic radiation like light. The interruption spectrum of radiation emitted in experiments proved Bohr's atomic model theory.

The theory ' The introduction of Bohr ' atomic structure structure is really a new, profound revolution of human perception of the natural world . The birth of Bohr had a great impact on the formation and development of quantum theory with important laws occurring in the microscopic world. From his atomic model, Niels Bohr, in 1922, completed the theory of the circulatory system, fully explaining the periodic table of well-known and widely used chemical elements. this century.

With great meaning and contribution to the history of human cognitive development, Niels Bohr reached the peak of scientific glory and received the Nobel Prize in Physics in 1922. His name was also solemnly named for the element. super heavy 107, Bohrium element in the periodic table of elements.

Father and son, two Nobel prizes - Niels Bohr and Aage Bohr (documentary)

Aage Bohr and the kernel structure pattern

The coincidence, interestingly, was also in 1922, Bohr's son, Aage Niels Bohr, was born, to follow his heels to receive a 1975 Nobel Prize in Physics, bringing the laurel wreath to glory. second to Niels Bohr family.

Interestingly, the scientific direction for Aage Bohr's Nobel Prize is similar to the path to his father's Nobel Prize, which is the study of material structure . Only different in the subject of research, Niels Bohr studied the atomic structure and Aage Bohr delved into the inner structure of the nucleus.

It should also be said that the great father gave his fourth son a wealth of intellectual intellectuals who were few. Born in 1922 in Copenhagen, Aage Neils Bohr soon received a special education, in addition to studying at the school, while at his father's Institute of Theoretical Physics, here he was exposed and instructed by the names Leading physical world. From 1943, he followed his father to the United States. In the United States, the Aage stood by his father in the Manhattan Project secretly researching atomic weapons and working at Los Alamos National Laboratory as secretary and assistant to Niels Bohr himself.

After World War II Aage followed his father back to Denmark, completed his studies at the University of Copenhagen, received his Master's degree in 1946 and his doctorate in 1954, and then worked as a lecturer at the university and research position. at the Institute of Theoretical Physics. He was again sent to the United States by the institute, in 1949, creating the opportunity to meet J. Rainwater and formulate the idea of ​​a new theory that describes the nuclear structure.

Before Aage Bohr entered, there were two theories (called samples) of opposite nuclei. Each such sample successfully explained some specific nuclear properties in a certain nucleus region.

A sample, called a liquid droplet form built by Bohr himself (1936), suggests that p and n particles attract each other to form a force similar to molecular force in a drop of water. Developing this model, successors have well explained the nuclear fission mechanism used in later nuclear technology.

The second sample, called the layer pattern, assumes that the nucleus has a spherical shape and the p and n movements in a spherical aggregate force field. Such field-based calculations have made very important physical predictions consistent with experimental data obtained with light and medium nuclei. In particular, this class sample found ' ma ' numbers for the number of n and p particles in the nucleus (numbers like 2, 8, 20, 28, 50, 82 .) and explained the sustainability properties of magic kernels have p or n numbers identical to the above ' ghost ' numbers.

But there are many nuclear properties that have not been explained, especially for nuclear groups in transitional regions, areas of rare earth elements and super-heavy nuclei. The problem is that it is necessary to have a new theory (model) of nuclear structure.

From the beginning of the 50s of the last century, such a sample was cooked to form.The trio consists of Aage Bohr, B. Mottelson and J. Rainwater, working together to create a new theory that incorporates the two samples, called collectively.

This new model recognizes that the nuclear surface is deformed as a deformation of a drop of water, shaped differently from the sphere, while p and n particles move in a deformed force field, such as a rotating circular ellipse. At the same time, the nucleus also participates in other collective movements such as stretching or rotating the whole nucleus.

The Aage Bohr, B. Mottelson and J. Rainwater authors have been particularly successful in linking individual movements of p or n with collective motions of the entire nucleus to describe the nuclear structure. , namely, the energy states and the level characteristics of the nuclei outside the magic zone.

Massive gathering, including published studies, books of classic value, famous lectures on 'Detecting the link between collective movement and particle motion (p and n) and the development of the theory of atomic nuclear structure based on that link 'was honored by the world physics community and Aage N. Bohr and Mottelson, Rainwater deserved to be awarded the 1975 Nobel Prize. about physic.

Along with the 2 Nobel Prize for Physics of the Bohr family, 9 other citizens of Denmark also own 9 other Nobel prizes; including 5 Nobel Students, 2 Nobel Prizes, 1 Nobel Prize in Chemistry and 1 Nobel Peace Prize.

11 Nobel Prizes for a small island nation with a modest area of ​​only 43,000 km ² square kilometers and a population of no more than 5.5 million people! This proportion of Nobel is a rare phenomenon in the world.

This country, this nation deserves to be respected by humanity. Respect for all generations of leaders of this country, not only the Danish turning into ' small, great wisdom ' but also building a society voted as the least corrupt and happy people 's life. The best in the world.