23 February 1941

Plutonium is first produced and isolated by Dr. Glenn T. Seaborg.
Plutonium is a radioactive metallic chemical element with the symbol Pu and atomic number 94. It is a member of the actinide series of elements, which are known for their radioactivity and many of which are synthetic. Plutonium is typically produced in nuclear reactors through the irradiation of uranium-238.

Discovery: Plutonium was first synthesized by Glenn T. Seaborg, Edwin McMillan, Joseph W. Kennedy, and Arthur Wahl in 1940 at the University of California, Berkeley. They bombarded uranium-238 with deuterons (nuclei of heavy hydrogen, or hydrogen-2) to produce neptunium-238, which then underwent beta decay to form plutonium-238.

Isotopes: Plutonium has several isotopes, but plutonium-239 is the most important one from a practical standpoint. It is fissile, meaning it can sustain a nuclear chain reaction, making it useful for both nuclear power and nuclear weapons. Plutonium-239 has a half-life of about 24,100 years.

Applications:
Nuclear Weapons: Plutonium-239 is a key component in nuclear weapons. It can be used in both fission and fusion bombs.
Nuclear Power: Plutonium-239 is also used as fuel in some types of nuclear reactors, particularly in breeder reactors where it can be bred from uranium-238. However, its use in civilian nuclear power is less common compared to its military applications.
Radioisotope Thermoelectric Generators (RTGs): Plutonium-238, which is produced in small quantities, is used as a heat source in RTGs for space missions, satellites, and remote terrestrial applications.

Radioactivity: Plutonium is highly radioactive and poses significant health risks if mishandled. Its decay products emit alpha particles, which can be stopped by a sheet of paper or even skin, but can be highly damaging if inhaled or ingested.

Hazards: Plutonium is toxic and can pose both chemical and radiological hazards. Inhaling or ingesting even small amounts can lead to serious health problems, including cancer. Proper handling and storage are essential to minimize risks.

Production: While plutonium can be produced in nuclear reactors, it can also be synthesized in particle accelerators or by neutron irradiation of other elements.

Due to its role in nuclear weapons and its potential use in nuclear proliferation, plutonium is subject to strict controls and safeguards under international agreements such as the Treaty on the Non-Proliferation of Nuclear Weapons (NPT).

11 September 1941

Construction begins on The Pentagon.

The Pentagon, officially known as the “Pentagon Building,” is the headquarters of the United States Department of Defense and is located in Arlington, Virginia, just across the Potomac River from Washington, D.C. It is one of the most iconic and recognizable government buildings in the world.

Construction: The Pentagon was designed by American architect George Bergstrom and construction began on September 11, 1941. It was completed in just over a year, with the formal dedication taking place on January 15, 1943. The building’s construction was fast-tracked due to the United States’ involvement in World War II.

Architecture: The Pentagon’s distinctive five-sided, five-story design was chosen partly because of the shape of the site it was built on and also to maximize the use of available space. It features a central courtyard and five concentric rings of office space, connected by a vast network of corridors.

Size: The Pentagon is one of the largest office buildings in the world, with a total floor area of approximately 6.5 million square feet (roughly 604,000 square meters). It houses approximately 23,000 military and civilian employees, making it one of the largest office buildings by workforce.

Purpose: The primary purpose of the Pentagon is to serve as the headquarters for the United States Department of Defense. It houses the top leadership and military staff responsible for the planning, coordination, and execution of the country’s defense and military operations.

Security: Due to its importance and sensitive nature, the Pentagon has stringent security measures in place. Access to certain areas of the building is restricted, and security personnel and protocols are employed to ensure the safety of the facility.

Symbolism: The Pentagon has become a symbol of the U.S. military and its role in national defense. It is often featured in news broadcasts and films, and its distinctive shape is easily recognizable.

9/11 Attacks: On September 11, 2001, the Pentagon was the target of a terrorist attack when American Airlines Flight 77 was hijacked by terrorists and crashed into the western side of the building. The attack resulted in a significant loss of life and extensive damage to the building. Reconstruction efforts were swift, and the damaged section was rebuilt and reopened within a year.

Tours: While the Pentagon is primarily a government and military facility, it does offer guided tours to the public. These tours provide visitors with an opportunity to learn about the history and functions of the Pentagon.

13 April 1941

A pact of neutrality between the USSR and Japan is signed.

The Pact of Neutrality between the Soviet Union and Japan was a bilateral agreement signed in Moscow on April 13, 1941. The pact aimed to establish a neutral relationship between the two countries and to maintain peace and security in the Far East.

The signing of the pact was significant for both countries. Japan was engaged in a war with China and was looking to expand its territory in the Pacific. By signing the pact, Japan sought to secure its northern flank and prevent any possible attack from the Soviet Union.

For the Soviet Union, the pact was important in order to avoid a two-front war. At the time, the Soviet Union was also fighting in Europe against Nazi Germany, and the pact with Japan allowed the country to focus its military efforts on the Western front.

However, the pact was short-lived. Less than four months after its signing, Japan launched a surprise attack on the United States naval base at Pearl Harbor, drawing the United States into World War II. In response, the Soviet Union declared war on Japan in August 1945, two days after the atomic bombing of Hiroshima.

The Soviet Union’s entry into the war against Japan ultimately played a role in the surrender of Japan and the end of World War II. The Pact of Neutrality between the Soviet Union and Japan was officially terminated in April 1946, in the aftermath of the war.

31 July 1941

The Holocaust: Under instructions from Adolf Hitler, Nazi official Hermann Göring, orders SS General Reinhard Heydrich to “submit to me as soon as possible a general plan of the administrative material and financial measures necessary for carrying out the desired Final Solution of the Jewish question.”