by Group 7
History of Radioactivity
Now we are going to talk a bit about the history behind the discovery of Radioactivity and the important people behind it; in our opinion this is the most interesting part of this project
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Well, technically you could say that Radioactivity was discovered in 1896 by Henri Becquerel, when he observed accidentally that uranium salts emitted an invisible radiation, very penetrating despite its invisibility. After he knew of the discovery of X Rays by Roentgen from the fluorescence produced in certain materials; Becquerel also wanted to know if Uranium Salts, which also produced fluorescence after being exposed to the sun, would emitted also X rays. After some tries, he could understand that what he was observing was in fact emitting X rays; he still verified if a sample of Uranium salts which wasn’t exposed to the sun would also impressed a photographic plate, he concluded that the sample emitted spontaneously a penetrating radiation, which was until then unknown; which was Radioactivity.
Two years after his discoveries, when he was abandoning the studies of these radiations, Marie Sklodowska Curie decided to continue his investigations. So she started studying diverse types of ores like pitchblende, which contains uranium ore, and tobernite, which is mostly hydrated phosphate of uranyl and copper. Marie Curie soon found that pitchblende was four times more radioactive than uranium itself and tobernite was twice as much. She concludes that these two should have small amounts of other substances more active than Uranium; so she decides to focus her research in the pitchblende. Pierre Curie starts to collaborate with his wife by measuring the emitted radiation of the fractions that Marie was extracting and isolating of the pitchblende; and in 1898, the Curies discovered two new elements that emitted a radiation similar yet way more intense of Uranium, which were Polonium and Radium. Here is a Curiosity: actually was Marie Curie who used for the first time the word Radioactivity for describing the emitting properties of these elements.
So in 1903, the Swedish Academy of Sciences delivered the Physics Nobel Prize to Henri Becquerel, Pierre Curie e Marie Curie. To Becquerel was recognized the discoverie of natural radioactivity, and to the Curie couple were recognized their extraordinary services with their cooperative research with Becquerel. And Pierre Curie in his award speech mentions the many discoveries that helped them like the discoverie of the radiations alpha, beta and gamma by Rutherford. But until then no woman had won a Nobel Prize, not even a recognition by the scientific institution itself, because of that Marie was about to be erased from the story of science, just because of her being a woman. However it was thanks to her husband, who wrote a letter to the Swedish Academy refusing to accept the prize if his wife wasn’t included, that Marie received the Nobel Prize, because in that time the existence and the importance of a feminine scientist were rare. A couple years later, Marie receives another Nobel prize recognizing her services to the evolution of Chemistry, for the discovery, isolation and studies of Radium and Polonium.
In general, the work of Marie and Pierre Curie was at the origin of a radical change in the worlds of the 20th and 21st centuries. From a conceptual point of view, it can be said that Marie Curie's great intellectual characteristic was that she concluded that the emission of radiation by radioactive compounds did not depend on how the atoms were linked, but rather on the very interior of the atoms. Meanwhile, Frederick Soddy's studies had led to the series of disintegration and the identification of gas emanations from the radio and thorium.
The great alchemical dream seemed to be a reality after all: the chemical elements could be transmuted! A new era was beginning, but classical physics was beginning to reveal its limitations: the phenomenon of radioactivity seemed to call into question the principle of energy conservation! The radio and its compounds released a heat that seemed endless. Where would this inexhaustible energy come from? Only with the advent of quantum mechanics, started in 1900 by Max Planck, was it possible to truly understand the nature of the new phenomenon. In the article published in 1905, Albert Einstein revealed the equation E = mc2 to the world, which finally made it possible to understand where so much energy of the atoms came from. At an experimental level, the discovery of Radium provided Rutherford the source of Alpha Radiation which he needed for the famous experiment of the Irradiation of the Golden leaf.
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And it wasn't only in the science field that the discovery of Radioactivity and the discovery of the new elements had repercussions. And this is when our English theme enters the question, which is Minorities. According to a UNESCO study, in 2018 less than 30% of scientists are women. In other words, there is still a clear male predominance in the scientific world. Much has been achieved by women, but there is still much to be achieved. If we travel back in time, we will discover that the presence of women in science is relatively recent. It started about 100 years ago. And that one of the pioneers of this world was Marie Curie, as a scientist woman, a inedict fact for the time as I said before, she had to surpass numerous barriers and taboos, imposed by time conventions. The independence and emancipation of this medium class woman put her ahead of her time. You can certainly say that many, many women of the next generations were motivated and inspired by her. It is sometimes referred to its role as a precursor of the feminist movement, because of everything that she done like winning not one but two Nobel prizes and being the first woman winning it, which was truly amazing. This heavily connects one of our english themes which is Minorities with Radioactivity itself.
Another area where the influences of the discovery of radioactivity were also felt, probably less obviously, was Art. The latter gradually began to abandon the figurative and move towards the "invisible". The painter Wassily Kandinsky, one of the pioneers of abstractionism, was deeply impressed by the theme of radioactivity; he even mentioned it in his autobiographical notes.
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