The devastation of the Japanese city of Hiroshima after the dropping of the nuclear bomb (Picture: UPPA/DPA/PA).
It is 74 years since the US dropped an atomic bomb on Hiroshima, instantly killing 80,000 people in the first-ever atomic attack.
When the atom bomb was dropped from the Enola Gay, the 6,000°C heat of the blast flattened six square miles of the city and vaporised people, leaving only their silhouettes.
The firestorm caused by the blast raged for 72 hours, finally ending on the day that another bomb was dropped, this time on Nagasaki.
The final death toll rose above 135,000.
That was the first atomic weapon ever dropped in anger. Since that day, however, the testing of nuclear weapons has proliferated - growing hand-in-hand with rising temperatures during the Cold War and then spilling over into the 21st century.
The satellite image above shows the red zone of total destruction of the 50-megaton Tsar Bomba, the largest device ever detonated, as an example over Paris. The red circle engulfs the entire city and its suburbs with a radius of 35km.
Since then there have been numerous others. In total, 2,053 nuclear tests have been conducted, excluding North Korean claims in the past decade.
The United Kingdom is the largest contributor behind the US and USSR, accounting for 4.15% of all the nuclear tests to date, and detonating 1.72% of the combined 540,739t yield.
Britain first tested an atomic device in Operation Hurricane, in 1952, in the lagoon between the Montebello Islands, Western Australia. In doing so, it became the world's third nuclear power.
The video below graphically illustrates the timeline of nuclear tests and explosions - from the USA's first Manhattan Projects trials in Los Alamos in 1945 to Pakistan's nuclear tests in 1998.
The world has had plenty of close shaves.
In one instance, a low-voltage switch, which could easily have been shorted by an electrical jolt, prevented a hydrogen bomb 260 times the size of the one used in Hiroshima being detonated over North Carolina.
The story of the late Stanislav Petrov is even more impressive.
The Soviet Union's early-warning systems officer ignored an apparent incoming missile strike from the US, deciding not to report it and - on instinct - correctly dismissed 'the strike' as a false alarm.
The most powerful non-nuclear weapons ever designed are the United States' Massive Ordnance Air Blast (MOAB - also nicknamed 'Mother Of All Bombs'), tested in 2003, and the Russian 'Father of All Bombs' (FOAB), tested in 2007.
The MOAB contains 18,700 lb (8.5 t) of the H6 explosive, which is 1.35 times as powerful as TNT, giving the bomb an approximate yield of 11 t TNT.
The FOAB is about four times more powerful than the MOAB.