When we talk about atomic bombs, it's impossible not to think of the two Japanese cities reduced to rubble by the United States at the end of World War II: Hiroshima and Nagasaki. However, these detonations only marked the beginning of a series of tests that extended throughout the Cold War, with both the U.S. and the former Soviet Union playing to see who could build the biggest device. The prize for the largest nuclear detonation in history unquestionably belongs to the Tsar Bomba, an atomic bomb almost 4,000 times more powerful than the one dropped on Hiroshima.
The Cold War Nuclear Race
As if it were a game, the generals and commanders in charge of each country's weapons development compete to see who can create the largest mass-destruction device. This trait, possibly etched into our genes since the cave era, has reached almost ridiculous extremes in the decades following World War II, a period known as the Cold War. Throughout that time, both the United States and the former Soviet Union embarked on a deranged race to show the world that “my nuclear bombs are bigger than yours” or “we can make them into purée more efficiently than you can”. If it weren't for the terrible reality, it might even be funny.
At the end of the second largest armed conflict in history, it seemed that the United States was the most important power on the planet. On its “résumé”, it had destroyed two entire cities using only two bombs in the process, something no other nation could – or can – boast about. The Russian government, for its part, needed to demonstrate that it was also capable, if it so intended, of destroying its enemies using nuclear technology. Both countries, well before anyone thought it was madness and proposed signing some kind of agreement limiting nuclear weapon tests on the planet, happily went about detonating atomic bombs on atolls, islands, deserts, and oceans to prove to the other that their toys were much prettier. After a few years of research, physicists in both countries knew how to make bombs of practically any power. The only barrier seemed to be the available money and, of course, human stupidity.
The Tsar Bomba Test
The largest device ever tested was Russian. The so-called “Tsar Bomba” was detonated on October 30, 1961, at an altitude of four thousand meters, as a demonstration of Soviet might. Remember that at that time political propaganda was fundamental. The test site chosen was an archipelago in the Arctic Ocean whose name you probably don't know (“Novaya Zemlya”), and the bomb was transported aboard a modified Tupolev Tu-95 bomber. The device was about eight meters long and two in diameter, weighing around 27,000 kilograms. The parachute alone intended to slow its descent weighed 800 kilograms.
During its development, it received the code name “Ivan”, and from the start it was conceived as an intimidation weapon. Its enormous size made it practically useless in a real war, and only one unit was built. When it was detonated, it generated a fireball about 4,600 meters in diameter, which touched the ground and quickly rose to the flight altitude of the bomber that had dropped it. By then, the plane was about (relatively) safe 45 kilometers away. The physicists who developed the bomb didn't have an exact idea of its power, so just in case they repainted the bomber with a special, highly reflective white paint to minimize the effects of the thermal shock wave after the explosion. The flash of the detonation could be seen from about 1,000 km, and the mushroom cloud reached the magnetosphere, at an altitude of 64 kilometers.
The explosion was intense enough to cause third-degree burns on people more than 100 kilometers from the detonation point, and damage and broken glass occurred up to 1,000 kilometers from the epicenter. The temperature in the area below the bomb rose almost instantly to one million degrees. Atmospheric pressure reached 211,000 kilos per square meter, more than thirty times that inside your car's tires. The shock wave, in addition to knocking down almost everything in its path within a radius of tens of kilometers, was recorded circling the world three times. The power released was 1.38% of the energy provided by the Sun.
https://www.youtube.com/embed/FcqBg7hx1vYA “Clean” Bomb
Despite all this, there was no large emission of radioactive substances. The bomb's design had been meticulously thought out to be “clean”. Indeed, one of its parts, traditionally built from uranium, was replaced with lead, a material capable of absorbing most of the fast neutrons from the initial fission, reducing its intensity. 97% of the energy generated came from fusion rather than fission.
Why It Was Never Mass-Produced
If the uranium had not been replaced, it would have released an amount of radiation equivalent to 25% of all the radiation ever emitted in human history. The size and weight of the Tsar Bomba limited its range and the speed at which it could be sent to another region of the planet. Its 27 tons made it absolutely impractical to launch via an intercontinental ballistic missile, and much of its power was radiated inefficiently into space. For all this, the Tsar Bomba was never built in series. Fortunately.
