Post on 24-Dec-2015
Hiroshima and Nagasaki
• August 6, 1945• Fission bombs• Developed in Americans’
Manhattan Project• Intimidation against Soviets
F i s s i o n ! ! !
• Unstable heavy isotope (U-235, Pu-239) bombarded by neutrons
• Nuclei of atoms are split, creating lighter elements, and…– More neutrons, creating a
chain reaction– Energy with each split, in the
form of HEAT!!!
Fission.mov
Stalin Bluffs… How typical
• Stalin pretended he didn’t care about US nuclear weapons
• Secretly worked on own nuclear weapons– Uranium mines from Eastern Europe and
domestic mines– Massive funding to physicists– Spies
And they’re off!
• Soviets detonate first fission bomb Soviets detonate first fission bomb August 9, 1949August 9, 1949–Almost identical to Fat ManAlmost identical to Fat Man
• Both nations want to be superior Both nations want to be superior through nuclear weapons – More through nuclear weapons – More POWERFUL!!!POWERFUL!!!
• Competition starts!Competition starts!
Behold… The Power of HYDROGEN FUSION!!!HYDROGEN FUSION!!!
• Both the US and USSR wanted to build Both the US and USSR wanted to build something more destructivesomething more destructive
• US detonated first hydrogen bomb US detonated first hydrogen bomb November 1, 1952November 1, 1952
• Soviets followed with their own in August Soviets followed with their own in August 19531953
Hydrogen Bombs!
• A fission bomb compresses fusion fuel with gamma radiation
• Fusion fuel: Tritium,(3H) and Deuterium (H2)
• Fuses together from compression: helium
• 10’s of millions of degrees of heat
Fusion.mov
What now?
• The US wanted better delivery methods of bombs– Jet-powered bombers: B-47 and B-52 in early
50’s
The Soviets are Clever• Deploy bombs using missiles
• ICBM’s – InterContinental Ballistic Missiles
– Travel long distances, deliver nuclear warheads to anywhere in world
– First revealed in delivery of Sputnik in 1957
– US builds their own (duh!) in 1959
• Atlas, used in space missions
Nuclear Submarines?
• 1955: Soviets launch first SLBM, submarine-launched ballistic missile, from a diesel-electric submarine
• Improves mobility and accuracy of missiles
• US Polaris submarines– 16 nuclear missiles, each with 4
warheads
• Another way to fight that is not actually used
Uh-oh…We’re Scared!
• Large radar arrays to detect missiles and bombers
• Underground bunkers and fallout shelters– Not actually effective
Mutually Assured
Destruction• Both superpowers knew it would be suicide to attack the other, so neither actually attacked!!!
Cuban Missile Crisis!
• October, 1962: Soviets try to readjust power against the US by stationing nuclear missiles in Cuba (Communist)
• Close enough to US coast that major cities were in danger
What does the US do?
• President John F. Kennedy decides to impose a quarantine on Cuba, so no more weapons will get in
• Brinkmanship: the US is ready to invade Cuba if the Soviet Union doesn’t get the missiles out
What does the Soviet Union do?
• Very difficult decision!
• A few days later, the Soviet Union agreed to remove their missiles if the US didn’t invade Cuba and if they would remove missiles from Turkey
• No more risky business!
Détente = Peace
• Economic problems in the Soviet Union from weapons
• Vietnam War costs in the US
• Both Richard Nixon and Leonard Brezhnev wanted to end the war
• Practical, outright negotiations with each other
• Cold war tensions dropped
Time for agreements!
• SALT I: Strategic Arms Limitation Talks
• Soviet Union and US met November 1969 to May 1972 in Helsinki, Finland and Vienna, Germany– Froze the number of ICBM’s and SLBM’s in
each country – Limited the number of ABM Systems in each
nation
More Agreements
• SALT II• Soviet Union and US agreed to limit the
number of total ballistic missile launchers on June 28, 1979
• Balance of power!
Star Wars!• Ronald Reagan isn’t happy with détente
• Anti-communism drives his Strategic Defense Initiative (SDI), to protect the US against Soviet missiles– A space-based anti-ballistic missile system– Many Soviet negotiations reducing nuclear
weapons were rejected because of plan
• Never happened