Physics Breakthroughs In The 1960s

Shortly after the discovery of X-rays, another form of strong rays were discovered. In 1896, French scientist Henri Becquerel discovered natural radioactivity. Many scientists of the period were working with cathode rays, and other scientists were gathering evidence on the theory that the atom could be subdivided. Some of the new research showed that certain types of atoms break by themselves. It was Henri Becquerel who discovered this experience while investigating the properties of fluorescent minerals. Becquerel was researching the principles of fluorescence, wherein certain minerals glow (fluoresce) when exposed to sunlight. He utilized photographic plates to record this fluorescence.

When Henri Becquerel discovered radioactivity in 1896, it inspired Marie and Pierre to investigate it further. They researched a lot of substances for any signs of radioactivity, and discovered something that was more radioactive than uranium. They discovered radium, an element that damaged tissue, so they used that to fight against cancer. “They found that the mineral pitchblende was more radioactive than uranium and concluded that it must contain other radioactive substances. From it they managed to extract two previously unknown elements, polonium and radium, both more radioactive than uranium” (Nobel Media). These discoveries led to radium being used to treat cancer and other diseases, and them getting their first Nobel Prize in Physics in 1903. After Pierre passed away, she continued with her own studies. Marie successfully isolated radium and proved its existence. She also studied the properties and compounds of these radioactive elements. “She also documented the properties of the radioactive elements and their compounds. Radioactive compounds became important as sources of radiation in both scientific experiments and in the field of medicine, where they are used to treat tumors” (Nobel Media). This discovery led to the further development of X-rays and her receiving her second Nobel Prize in Chemistry in 1911. Marie Curie was the first woman ever to win two Nobel Prizes in two fields and in multiple sciences, two incredible

Enrico Fermi (1901-1954) succeeded in splitting the uranium atom and the Nobel Committee later awarded him the 1938 prize for physics. At Columbia

Early 1939, the scientist of the world learned that German scientist had discovered a way to spit a uranium atom, created

The pioneering work of Becquerel in 1896 (the discovery of uranium), and the Curies (who subsequently discovered radium and polonium and the energy and heat given off by these new elements which they called radioactivity) led to the remarkable work of Ernest Rutherford. He was a physicist, whose experiments showed that some heavier elements spontaneously changed or decayed into lighter elements (unstable 'parent' elements giving off protons and neutrons to form a 'daughter' element) through the process of radioactivity. He discovered that radioactive materials decay at a very predictable rate, and that lead was the final decay product of uranium. Using Rutherford's ideas, Bertram Boltwood pioneered a method of radiometric dating in 1907. He hypothesized that since he knew how long it takes uranium to break down, he could measure the proportions of lead in uranium ores, and use his calculations to date how long those ores had existed,

Radioactivity is when energy is emitted from the nucleus due to the nucleus being unstable. The 3 types of radiation are Alpha ,Beta and gamma. Alpha particles have 2 protons and two neutrons. Examples of radioactive nuclei that emit alpha radiation. Are : uranium, thorium, actinium, and radium They are very ionising so they give energy off onto whatever they are in contact with. Therefore, it loses energy more quickly. They are not very penetrating so can be stopped by a piece of paper or skin. Beta particles have 1

X-rays were discovered by accident in 1895 by the German physicist Wilhelm Conrad Roentgen. Roentgen was already an accomplished scientist with forty-eight published papers. He had a reputation among the scientific community as a dedicated scientist with precise experimental methods. Roentgen had been conducting experiments at the University of Wurzburg on the effect of cathode-rays on the luminescence of certain chemicals. Roentgen had placed a cathode-ray tube, which is a partially evacuated glass tube with metal electrodes at each end, in a black cardboard box in his darkened laboratory. He sent electricity through the cathodre-ray tube and noticed something strange his laboratory. He saw a flash of light

He positioned a variety of metal foil in the route of the alpha rays, including gold, silver, tin, copper and aluminium (at different times) to observe whether the flashes of light moved, spread out, or changed at all. He found that as the various metals disrupted the paths of the rays the flashes become more spread out. This result indicated that alpha particles were being deflected as they passed through the metals. Rutherford wanted to know if alpha particles could be deflected at a larger angle, as the current tool developed by Geiger could only measure deflection of up to a few angles.

His discovery to radioactivity helped a lot of other scientists. If Henri hadn't discovered it Ernest Rutherford

discovery of nature that we commonly think of as the original physics. The town of

Then in 1898 she drew the revolutionary conclusion that pitchblende contains a small amount of an unknown radiating element.      Pierre Curie understood the importance of this supposition and joined his wife's work. In the next year, the Curie's discovered two new radiating elements which they named Polonium(after Maries native country) and Radium.

     It was not easy for Marie and Pierre to convince the science community of their new findings. Marie succeeded in separating the radium from the barium, but it wasn't easy. She had to treat very large amounts of pitchblende, but she had plenty of pitchblende to use. (The Curie's

This is what led Curie to take Becquerel’s work a few steps further and conduct her own experiments on uranium rays. She discovered that the rays were constant no matter what form or condition of the uranium. She theorized the rays came from the atomic structure. This idea was revolutionary and created its own field in science, known as the atomic physics, this is when Marie coined the word “radioactivity” to describe the phenomena. Even when they had their first daughter Irene in 1897 there work did not slow. Pierre then stopped his own studies to help Marie with her new discovery of radioactivity. In 1898 they discovered a new radioactive element. They named it polonium after Marie’s native country, Poland. They detected the presence of another radioactive element and called this radium. In 1902 they had extracted pure radium to prove its existence as a unique chemical element.

With her experiments, she became the first woman in France to get a doctorate. Curie decided to continue Henri Becquerel’s experiments with X-rays. She came up with the groundbreaking idea that the rays were actually an atomic property. The paper she wrote reporting her discoveries had to be presented through her professor because women weren’t allowed to address the Academy of Sciences. With this, she continued her work to find new elements. First, she found polonium, which is named for her home country, and then she discovered radium. Pierre and Marie’s greatest work was done in a run-down shed. They worked from 1898 to 1902. The Curies could have made a fortune if they patented their process of extracting and refining radium, but they decided share their knowledge with the world.

Her results were immediate. She noticed that the element thorium gave off the same rays as uranium. After a lot of research she came to the conclusion that radiation did not depend on the compound being studied. She said that it depended on the amount of uranium or thorium. She concluded that radiation did not depend on the arrangement of atoms in a compound in a molecule but rather the interior of the atom itself. The discovery was considered to be revolutionary at the time. She continued to test all elements on the Periodic Table of Elements. Only uranium and thorium gave off any sort of radiation.