The clock first appears on the Bulletin cover as a symbol of nuclear danger.

The Soviet Union explodes its first atomic bomb.

The United States and the Soviet Union test thermonuclear devices within nine months of one another.

The clock moves in response to the growing public understanding that nuclear weapons made war between the major powers irrational. International scientific cooperation and efforts to aid poor nations are cited.

The U.S. and Soviet signing of the Partial Test Ban Treaty "provides the first tangible confirmation of what has been the Bulletin's conviction in recent years-that a new cohesive force has entered the interplay of forces shaping the fate of mankind."

China acquires nuclear weapons; wars rage in the Middle East, the Indian subcontinent, and Vietnam; world military spending increases while development funds shrink.

The U.S. Senate ratifies the Nuclear Non-Proliferation Treaty.

The United States and the Soviet Union sign the first Strategic Arms Limitation Treaty (SALT I) and the Anti-Ballistic Missile Treaty; progress toward SALT II is anticipated.

SALT talks reach an impasse; India develops a nuclear weapon. "We find policy-makers on both sides increasingly ensnared, frustrated, and neutralized by domestic forces having a vested interest in the amassing of strategic forces."

The deadlock in U.S.-Soviet arms talks continues; nationalistic wars and terrorist actions increase; the gulf between rich and poor nations grows wider.

Both superpowers develop more weapons for fighting a nuclear war. Terrorist actions, repression of human rights, and conflicts in Afghanistan, Poland, and South Africa add to world tension.

The arms race accelerates. "Arms control negotiations have been reduced to a species of propaganda. . . . The blunt simplicities of force threaten to displace any other form of discourse between the superpowers."

The United States and the Soviet Union sign a treaty to eliminate intermediate-range nuclear forces (INF); superpower relations improve; more nations actively oppose nuclear weapons.

The clock, redesigned in 1989, reflects democratic movements in Eastern Europe, which shatter the myth of monolithic communism; the Cold War ends.

The United States and the Soviet Union sign the long-stalled Strategic Arms Reduction Treaty (START) and announce further unilateral cuts in tactical and strategic nuclear weapons.

Further arms reductions are stalled while global military spending continues at Cold War levels. Nuclear "leakage" from poorly guarded former Soviet facilities is recognized as a growing risk.

India and Pakistan "go public" with nuclear tests. The United States and Russia can't agree on further deep reductions in their stockpiles.

Little progress is made on global nuclear disarmament. The United States rejects a series of arms control treaties and announces it will withdraw from the Anti-Ballistic Missile Treaty. Terrorists seek to acquire and use nuclear and biological weapons.

Although Jews have been returning to the land of promise a few at a time since their last scattering, it wasn't until the 1800s that they started going home in significant numbers. Jews were in the majority in the area by 1880. Large portions of land were purchased, bringing about more and more rural Jewish communities. As the Zionist movement gained backing, plans were made to return on a widening scale.

The Jewish population reached 85,000 by the time World War I began in 1914. This compared to only 5,000 populating the land early in the previous century.

British Foreign Secretary Arthur J. Balfour issued on behalf of England, the Balfour Declaration on November 17, 1917. The Balfour declaration indicated approval of the Jewish goal of bringing about a Jewish state in Palestine.

Adolf Hitler and the Nazis carried out persecution against all Jews within Hitler's sphere of influence. While Hitler, along with the Arab enemies of the Jews in Palestine turned up the heat of persecution against the Jewish race, the British, the controlling authority in Palestine, developed a White Paper, severely restricting Jewish immigration.

Adolf Hitler's Germany perpetrated genocide upon the Jewish race, during which more than 6 million Jews were murdered in the holocaust.

Dead Sea Scrolls found at Qumran, validating much of Old Testament writings. Jewish leadership plan a return to Zion (Jerusalem) for purpose of establishing a nation.

Israel reborn as a nation on May 14, 1948. Jews back in their Promise Land, just as prophesied for the last days by all Bible prophets.

In November, the United States tests its first hydrogen bomb on Elugelap island. The bast was equal to 10.4 megatons, 700 times the power of Little Boy.

The Treaties establishing the European Economic Community (EEC) and the European Atomic Energy Community (Euratom) are signed by the Six (Belgium, France, Germany, Italy, Luxembourg, Netherlands) in Rome as of today they will be referred to as the "Treaties of Rome".

On June 5 the six-day war begins: Israel destroys the Arab air forces; captures land three times the area of itself; and most importantly, the Jewish people win the right to free control the city of Jerusalem for the first time in over 2000 years.

In January of 1999 eleven European Union countries begin using the euro as their common currency.

European leaders hammered out an agreement to bring 10 new countries into the European Union. Most of the new members will be former Soviet eastern block states.

Years of rapid growth in the Chinese economy has caused the eastern giant to become a major competitor for the earth's scarce resources. China's growing dependence on oil will cause its interests to focus more on the Middle East.

The 2005 Atlantic hurricane season was the most active Atlantic hurricane season in recorded history. Records were set in the most number of storms - 28, the most reaching hurricane strength - 15, and the most reached Category 5 strength - 4. Hurricane Katrina was the most destructive, and hurricane Wilma was the most intense hurricane ever observed in the Atlantic basin.