This historical overview can help policymakers, researchers, and the general public to better understand the continuing impact of nuclear issues on our world. Making our world a safer place in light of the unabated nuclear threats is a concern that faces all of us. As US President Obama noted during the second Nuclear Security Summit in Seoul in 2010:;xNLx;;xNLx;“At the dawn of the nuclear age that he helped to unleash, Albert Einstein said: “Now everything has changed…” And he warned: “We are drifting towards a catastrophe beyond comparison. We shall require a substantially new manner of thinking if mankind is to survive.” That truth endures today. For the sake of our common security, for the sake of our survival, we cannot drift. We need a new manner of thinking -- and action. That is the challenge before us.”;xNLx;;xNLx;This timeline is made up of five broad categories of events:;xNLx;;xNLx;- Non-Proliferation & Disarmament:;xNLx;;xNLx;Events in this category relate to the non-proliferation of nuclear weapons and technology, the limiting of nuclear testing or weapons development, and nuclear disarmament. It includes a range of items, e.g., the establishment of institutions such as the IAEA, the founding of nuclear-weapon-free zones, the signing of treaties, the shutting down of reactors, and anti-nuclear protests and disarmament campaigns.;xNLx;;xNLx;- Nuclear Energy:;xNLx;;xNLx;This category covers landmark events in the history of civilian nuclear power programs around the world, including technological developments, accidents at nuclear reactors, and the implications of civilian nuclear power on the development of nuclear weapons.;xNLx;;xNLx;- Various:;xNLx;;xNLx;In this catch-all category, we give general decade-by-decade summaries and cover a range of miscellaneous events, such as early nuclear research, significant cultural or geopolitical shifts, declarations of strategy, and notable (near)accidents involving nuclear weapons.;xNLx;;xNLx;- Nuclear Security:;xNLx;;xNLx;The nuclear security category concerns the history of measures, institutions, technologies, and international agreements ensuring the security and safety of nuclear stocks. The term refers to the detection and prevention of theft, sabotage, smuggling, or unauthorised access to nuclear weapons, nuclear material, and other radioactive substances. This category also includes a number of notable incidents where nuclear security was compromised or threatened.;xNLx;;xNLx;- Proliferation & Threats: ;xNLx;;xNLx;This category tracks the proliferation of nuclear weapons and offers an overview of the various national nuclear weapons programs and landmark nuclear tests, as well as the numerous international crises, deadlocks, pre-emptive strikes, and computer errors that brought the world closer to a nuclear war.;xNLx;;xNLx;;xNLx;This timeline has been a collaborative effort led by the Hague Centre for Strategic Studies. We are heavily indebted to researchers from the Harvard Belfer Center, the Partnership for Global Security, the Department for Nuclear Security at Delft Technical University, and the Dutch Ministry of Foreign Affairs for their input. A timeline with such a broad scope is never fully finished. ;xNLx;;xNLx;We invite users to share with us any suggestions they may have for further improvement. Please do not hesitate to contact us at info@hcss.nl.;xNLx;;xNLx;;xSTx;span style="font-size: 10px; font-style: italic";xETx; [1] http://www.un.org/depts/dhl/maplib/images_maplib/unflag.gif ;xSTx;/span;xETx;;xNLx;
Henri Becquerel is often credited with the scientific discovery of radioactivity. While researching the transmission of energy via light (a process known as ‘phosphorescence’), the French physicist discovered a new penetrating ray in 1896. Fellow chemist Marie Curie would later lend it the name ‘radioactivity’. For their research, Becquerel, Marie Curie and her husband Pierre Curie would win the Nobel Prize for Physics in 1903.
The first decades of the 20th century witnessed several revolutionary discoveries in the fields of experimental physics, chemistry and electromagnetism. These advances would lay the foundation for the development of the science of nuclear physics.
Ernest Rutherford is often considered to be the father of nuclear physics. The New Zealand-born physicist and chemist presented in 1902 a theory of radioactive decay in which one element mutates into another. Rutherford showed that some atoms spontaneously lose energy by emitting particles of ionized radiation. He argued that during the radioactive decay of uranium different forms of radiation were released, which he called α- and β-radiation. The speed at which atoms decayed he called ‘half life’, or the amount of time after which there is a 50% chance for an atom to have undergone nuclear decay.
Particle accelerators have been of paramount importance to both the early research of nuclear structure, and the early production and enrichment of fissile materials. They were introduced in 1929, when Ernest O. Lawrence conceived of a device, called a cyclotron, that used electromagnetic fields to accelerate charged particles and focus them into highly energetic beams. By bombarding elements with these high-energy particles (usually Deuterium), cyclotrons were able to create radioactive isotopes (see “Exploration of radioisotopes - 1934”). In this manner, they could be used for research into the nuclear structure of atoms, and they would later be used to ‘transmute’ uranium-238 into plutonium.
Though the concept of radioactive isotopes had existed since 1912, it took until 1934 for Frédéric Joliot-Curie and Irène Joliot-Curie to discover a way of creating radioisotopes through nuclear reactions, paving the way for the development of nuclear medicine.
In the 1930s, experimental physicists began to manipulate the properties of particles by inducing them with radiation. The most notable work in this field was conducted by Italian physicist Enrico Fermi and German physicists Otto Hahn, Fritz Strassman and Lise Meitner.
The 1940s was a decade of incredible destruction and discovery. Scientists feared that their atomic research would be used for nefarious purposes by warring nations during WW2, just as earlier advances in chemistry had led to the development of chemical weapons during WW1. German-born physicist Albert Einstein was one of the most vocal advocates of this fear. He viewed the increasing power of Nazi Germany through an atomic prism. The most violent decade of the 20th century would witness the development of the world's first atomic bomb and the deployment of atomic weapons against the Japanese cities of Hiroshima and Nagasaki. The Soviet Union would also successfully develop an atomic weapon in this decade, setting the stage for the Cold War.
With the outbreak of World War II in 1939, the implications of ongoing atomic research expanded greatly. Though still in its early stages, weaponized atomic research soon became a priority of the warring powers, resulting in the first sustained nuclear chain reaction as part of the US Manhattan Project in 1942.
The United States, the United Kingdom and Canada signed the Quebec Agreement on August 19th, 1943.
On July 16th, 1945, the world’s first nuclear device was detonated by the US military in the desert of New Mexico. The detonation produced an explosion equivalent to approximately 20 kilotons of TNT. The Trinity Test was considered a huge success for the scientists of the Manhattan Project (see “WW2 Sparks Atomic Weapons Research 1940”) and the US military. Only one month after the test, atomic bombs were dropped on the Japanese cities of Hiroshima and Nagasaki.
