In which year and by whom was the electron discovered? The physicist who discovered the electron: the name, history of discovery and interesting facts

The debate about who opened the electron has not abated until now. In the role of the discoverer of an elementary particle, except for Joseph Thomson, some historians of science see Hendrik Lorentz and Peter Zeeman, others - Emil Wiechert, the third - Philippe Lenard. So who is he, the scientist who discovered the electron?

Atom means indivisible

The concept of "atom" was used by philosophers. Ancient Greek thinker Leucippus back in the 5th century BC. E. Suggested that everything in the world consists of the smallest particles. His disciple Democritus called them atoms. According to the philosopher, atoms are the "bricks" of the universe, indivisible and eternal. The properties of substances depend on their shape and external structure: the atoms of flowing water are smooth, the metals with profile teeth that impart firmness to the body.

The outstanding Russian scientist MV Lomonosov, the founder of the atomic-molecular theory, believed that in the composition of simple substances, corpuscles (molecules) are formed by one kind of atoms, complex ones - different.

A self-taught chemist, John Dalton (Manchester), in 1803, relying on experimental data and taking the mass of hydrogen atoms as a unit, established the relative atomic masses of some elements. The atomistic theory of the Englishman was of great importance for the further development of chemistry and physics.

Who opened the electron?

By the beginning of the 20th century, a number of experimental data have been accumulated, which prove the complexity of the structure of the atom. This can include the phenomenon of the photoelectric effect (H. Hertz, A. Stoletov 1887), the discovery of cathode (Yu Plukker, V. Crooks, 1870) and X-ray (V. Roentgen, 1895) rays, radioactivity (A. Becquerel, 1896).

Scientists working with cathode rays, divided into two camps: some assumed the wave nature of the phenomenon, others assumed corpuscular. Significant results achieved the professor of the Higher Normal School (Lille, France) Jean Baptiste Perrin. In 1895, he showed in the course of experiments that the cathode rays are a stream of negatively charged particles. Maybe Peren is a physicist who discovered an electron?

On the threshold of great achievements

The physicist and mathematician George Stoney (Royal Irish University, Dublin) in 1874 voiced the assumption of discreteness of electricity. In which year and by whom was the electron discovered? In the course of experimental works on electrolysis it was D. Stoney who determined the value of the minimum electric charge (although the result obtained (10 ^-20 Cl) was 16 times less than the actual value). The unit of elementary electric charge in 1891, the Irish scientist called the "electron" (from the ancient Greek "amber").

A year later, Hendrik Lawrence (Leiden University, The Netherlands) formulated the main provisions of his electronic theory, according to which the basis of the structure of any substance is discrete electrical charges. These scientists are not considered the discoverer of a particle, but their theoretical and practical investigations have become a reliable foundation for the future discovery of Thomson.

Unshakable enthusiast

On the question of who and when discovered the electron, the encyclopedias give a clear and unambiguous answer - Joseph John Thomson in 1897. So what is the merit of the English physicist?

The father of the future president of the Royal Society of London was the seller of books and from childhood inspired his son's love for the printed word and the desire for new knowledge. After the completion of Owens College (since 1903 - Manchester University) and Cambridge University in 1880, a young mathematician Joseph Thomson joined the Cavendish Laboratory. Experimental research was completely carried away by the young scientist. Colleagues noted his tirelessness, dedication and extraordinary enthusiasm for practical work.

In 1884, at the age of 28, Thomson was appointed director of the laboratory, replacing Lord K. Rayleigh in that post. Under the guidance of Thomson, the laboratory in the next 35 years has turned into one of the largest centers of world physics. Hence began their journey E. Rutherford, N. Bor, P. Langevin.

Attention to detail

Work on the study of cathode rays Thomson began by testing the experiments of his predecessors. For many experiments, special equipment was manufactured according to the personal drawings of the laboratory director. Having received a qualitative confirmation of the experiments, Thomson did not think to stop at what has been achieved. His main task he saw in a precise quantitative determination of the nature of the rays and their constituent particles.

The new tube, designed for the following experiments, had in its composition not only the usual cathode and accelerating electrodes (in the form of plates and rings) with a deflecting voltage. The stream of corpuscles was directed to the screen, covered with a thin layer of matter, which glows when particles strike. The flow was supposed to control the joint action of electric and magnetic fields.

Components of the atom

It is difficult to be a pioneer. It is even harder to defend one's beliefs that run counter to the centuries-old concepts. Faith in herself, in her team and made Thomson the person who discovered the electron.

The experience gave stunning results. The mass of the particles was 2,000 times less than that of hydrogen ions. The ratio of the charge of the corpuscle to its mass does not depend on the flow velocity, the properties of the cathode material, the nature of the gas medium in which the discharge occurs. An inference contradicted all the foundations: corpuscles are universal particles of matter in the composition of an atom. Time after time, Thomson diligently and carefully checked the results of experiments and calculations. When there was no doubt, a report was made on the nature of the cathode rays to the Royal Society of London. In the spring of 1897 the atom ceased to be indivisible. In 1906, Joseph Thomson was awarded the Nobel Prize in Physics.

Unknown Johann Wickert

The name of the geophysics teacher of Königsbör and then of the University of Göttingen, researcher of the seismography of our planet Johann Emil Wiechert, is better known in the professional circles of geologists and geographers. But he also knows physicists. This is the only person whom official science, along with Thomson, recognizes as the pioneer of the electron. And if to be absolutely accurate, the work describing the experiments and calculations of Wiechert was published in January 1897 - four months before the report of the Englishman. The person who discovered the electron is already historically decided, but the fact remains.

For reference: in none of his works did Thomson use the term "electron". He used the name "corpuscles".

Who discovered the proton, the neutron and the electron?

After the discovery of the first elementary particle, assumptions about the possible structure of the atom began to be advanced. One of the first models was proposed by Thomson himself. Atom, in his words, resembles a slice of pudding with raisins: negative particles are interspersed in a positively charged body.

In 1911, Ernest Rutherford (New Zealand, Great Britain) suggested that the model of the atom has a planetary structure. Two years later he put forward a hypothesis about the existence in the nucleus of an atom of a positively charged particle and, having obtained it experimentally, called a proton. He also predicted the presence in the nucleus of a neutral particle with a proton mass (the neutron was discovered in 1932 by the English scientist J. Chadwick). In 1918, Joseph Thomson transferred control of the laboratory to Ernest Rutherford.

Needless to say, the discovery of an electron made it possible to take a fresh look at the electrical, magnetic, and optical properties of matter. It is difficult to overestimate the role of Thomson and his followers in the development of atomic and nuclear physics.