What do I think made the most impact on Science and Maths during the 20^th Century?

There have been numerous important discoveries in science and maths in the 20^th century. For example, scientists discovered that mitochondria were the powerhouses of cells, Neils Bohr published a model of atomic structure in 1913 and Albert Einstein’s discovered the theory of relativity,

E = mc ² in 1905 [1] [A]. Science and maths work together in many aspects of life for example decision making, hypothesis testing, medicines and research.

The following discoveries, both applications and theories had a significant impact on science and maths in the 20^th century. I do not believe that any of the achievements that were made in the 20^th century that had a significant impact on science and maths can be considered as a unique achievement. To support this idea I have searched many important theories, discoveries, experiments and techniques which have helped to improve our knowledge and have made an important impact on today’s society especially in education, medicine and business. There are so many theorems and famous mathematicians in the 20^th century therefore; I am only going to concentrate on the great events in the areas associated with computing and logic, made by people like Hilbert, Gödel and Turing [6].

The discovery that atoms contained electrons originally came from Joseph John Thompson who achieved his findings between 1856 and 1937. He designed a model of an atom later named Thomson’s plum pudding model of the atom. This model showed that inside an atom there are many electrons with a negative charge and a spherical cloud with a positive charge. He also identified that the negative and positive charges within the atom cancel one another out [4]. Henry Moseley and Ernest Rutherford discovered that the nucleus of an atom contained positively charged particles called protons during their work from 1888 to 1915. Moseley studied an x-ray spectrum of elements and then mathematically related the frequency of the x-ray to a number called the atomic number. Rutherford’s calculations showed that the charge on the nucleus was positive. Also, in 1919, he conducted an experiment whereby alpha particles were fired at hydrogen gas to produce positive particles, later called protons [4]. James Chadwick, whose discoveries took place from 1891 to 1974, identified the neutron. During that period he discovered that neutrons have no charge and they have the same mass as a proton [4].

Neils Bohr’s research took place between the years of 1885 and 1962. His scientific research showed that electrons orbit the nucleus in energy levels. Also, energy levels have a fixed energy value meaning they are quantised. Neils Bohr’s atomic structure model is still being studied in the 21^st century and is an important aspect of chemistry [4]. The findings of Joseph John Thompson, Henry Moseley and Ernest Rutherford, James Chadwick and Neils Bohr together have helped to shape the classical model of atom. This knowledge has led to the development of technologies such as mass spectrometry and infra-red spectrometry. It has also resulted in numerous medical breakthroughs.

James Watson and Francis Crick established the structure of DNA in 1953 with the help of Rosalind Franklin’s x-ray diffraction studies. Their idea, the semi-conservative method, proposed that each new molecule of DNA contained one polynucleotide strand from the parent and one new polynucleotide strand. The semi-conservative method involves all four nucleotides being present; both strands of the DNA acting as a template and the hydrogen bonds between complementary bases being broken by the enzyme DNA helicase. Energy is used to activate these nucleotides and the nucleotides are joined together by the enzyme DNA polymerase [3].

Albert Einstein’s theory of relativity is thought to be one of the most significant scientific advances of our time [6]. Einstein’s contribution was the recognition that the speed of light in a vacuum is constant and an absolute boundary for motion [5]. The famous equation, E = mc² stating that energy is equal to mass times the speed of light squared, was derived by Einstein in 1905 [1]. The theory of relativity has allowed scientists to look at the total solar eclipse for the first time and analyse starlight near the edge of the sun. The theory of relativity has allowed astronomers to look at objects travelling at near light speed [B].

Fritz Haber made a breakthrough in 1909, when he synthesised 100g of ammonia from nitrogen and hydrogen gases using the following reaction:

N2 (g) + 3H2 (g) 2NH3 (g)

At the beginning of the 20^th Century Germany needed to produce nitrogen compounds from nitrogen gas in the air, however, nitrogen gas is extremely inactive. Fritz Haber’s discovery was later developed in order to produce ammonia gas on an industrial scale in 1913 by Carl Bosch, a chemical engineer. Fritz Haber became the hero of the agricultural world [4]. He also contributed to the development of chlorine gas and other lethal gases which were both used as war weapons [4]. Chlorine gas was first used by the German army in April 1915 during WW1. In 1933 Haber was forced to leave Germany by the Nazis. Ironically he and his family were later killed in concentration camps in gas chambers which used the gases he had produced.

The impact of Gödel's and Turing's breakthroughs in the 1930's is best understood against the background of the mathematical ambitions definitively expressed by David Hilbert in the 1920's.[6] Hilbert formulated the Entscheidungsproblem otherwise known as the decision problem in 1928. Firstly, he stated that consistency needs to be considered and the set of axioms should be consistent. Secondly he took under consideration completeness. In theory all mathematical truths should be calculated from those axioms. Thirdly he examined decidability - a clearly formulated procedure should be used so that when given any statement of mathematics, it can be established within a finite time whether or not that statement is followed by the given axioms. Gödel’s incompleteness theorems were published in a famous article in 1931. Gödel proved that statements about mathematical relationships can be encoded as statements within arithmetic [6]. Turing later proved that Hilbert's theory was unsolvable and that any consistent axiomatic theory to enable the expression and proof of basic arithmetic propositions could be neither complete nor effectively decidable [6].

Computers have developed dramatically since their first appearances in the early 20^th century. In 1936 Zonrad Zuse invented the first freely programmable computer [9]. The development of computers continued to advance in the 1940s and 50s. In addition, in 1962 the first computer game was invented by Steve Russell and MIT called Spacewar. Also, in 1964 Douglas Engelbart established Windows Mouse & Windows [9] The year 1979 saw the first Word Processors [9]. In 1981 Microsoft MS-DOS Computer Operating System now a worldwide computer programme was established. Finally, in the year 1985 Microsoft Windows began to compete with Apple [9] [C].

Alexandra Fleming discovered penicillin in 1928. Later, Howards Florey and Boris Chain isolated and purified the compound producing the first antibiotic. Penicillin is now a very important medicine that has successfully saved many lives and will continue to do so in the future despite the fact that it came as a complete accident when it was noticed that mould killed a bacteria sample in a Petri dish. The hormone insulin was discovered by Frederick Banting [1]. Insulin is a naturally-secreted hormone that the body cannot function correctly without [2]. Insulin successfully helps to balance blood sugar levels in diabetic patients allowing them to live a normal healthy life. Before this discovery a diagnosis of diabetes was a death sentence.

Electron microscopy was explored by Ernst Ruska and Max Knoll in the 1930s. In 1931 they created an electron microscope powerful enough to view objects as small as the diameter of an atom [8]. It can magnify objects up to 1 million times their actual size. However, this microscope cannot view living specimen as they are unable to survive under a high vacuum [8] [D].

Scientists carried out experiments in the 1960s in which dogs inhaled cigarette smoke. The dogs that inhaled unfiltered smoke developed pulmonary disease and early signs of lung disease. From these experiments many hypotheses could be tested and one discovery was how smoking leads to the development of a tumour. Dr Barnett Rosenberg, Professor of Biophysics and Chemistry at Michigan State University investigated the effect of an electric current on cells in 1965 [4]. He realised that when an electric current was passing through the cells, cell division in the bacteria stopped. In cancer patients, cell division becomes unregulated and can lead to the formation of a tumour. However, Rosenberg’s discovery of Z-platin can stop this from occurring. Z-platin binds to the DNA found in the nucleus which prevents the DNA from replicating and the cells from dividing [4] therefore, it stops meiosis and mitosis and overall it can prevent the spread of cancer.

Smallpox is the only major human disease that has been eradicated. Smallpox epidemics inflicted mankind throughout history and in 1967 between 10-15 million cases were reported, of these 2 million died and millions were left either blind, or disfigured or both. Furthermore, there is no treatment for smallpox once contracted; therefore, eradication was extremely necessary. [7]The World Health Assembly requested that the WHO initiated a world-wide smallpox eradication programme. The programme remains one of the great achievements of WHO [7]. This ensured that smallpox had been eradicated worldwide and the return of the virus was unlikely.

In 1975 Cesar Milstein and Georges Kohler developed the technique of using antibodies produced by a mouse. These antibodies are grown outside of the body creating clones. These monoclonal antibodies originate from animal tissue therefore, they are modified to be suitable for humans, this is called humanisation [3]. This discovery allows people to take antibodies for particular diseases and has, is and will continue to save lives.

In conclusion, my response to What do you think made the most impact on science and maths in the 20^th century? is that there are hundreds of important developments in the 20^th century. Overall, the building of the National Health Service (NHS) in 1948 has allowed medical research to help in finding cures for cancer and has allowed the United Kingdom to receive medical and dental care; Einstein’s theory of relativity, E = mc² [5] has allowed the development of astronomy; Neils Bohr atomic structure [1] has allowed the understanding of chemistry to advance: the work of Hilbert, Gödel and Turing has helped problem solving in mathematics to be understood [6]: the advancement of computers[9] has allowed scientific and mathematic software programmes to run which have helped improve knowledge and has helped to save lives: the electron microscope has allowed the smallest of objects to be seen [8] and the eradication of smallpox has saved countless lives [7].

Bibliography

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