字幕表 動画を再生する 英語字幕をプリント On July 16th, 1945 the first ever nuclear weapon was detonated in a New Mexico desert. At the time, the Trinity test was one of the largest manmade explosions ever. Nuclear blasts are measured in TNT, and this one yielded about 20 thousand tons of TNT. That size blast would cover an estimated area of about five square miles in radioactivity. But in the 70 years since, nearly 2,000 nuclear tests have been performed, and about 125,000 nuclear bombs have been built. So we wanted to know, how powerful are modern nuclear weapons? Well, most people think of the nuclear bombings of Hiroshima and Nagasaki during World War Two as extraordinarily powerful explosions. Combined, they yielded about 36 thousands tons of TNT. But 16 years later, the Tsar Bomba was built, designed to be about 3,000 times more powerful. It was originally supposed to deliver a yield of 100 million tons, which would destroy an area the size of Connecticut. The weapon was built by the Soviet Union as a display of power against the United States, and was tested with a yield of fifty million tons of TNT. That test is, to this day, the most powerful man made explosion in history. But that was more than 50 years ago. So did the US one-up the Soviet Union and build their own 200 megaton bomb? In fact, they did the opposite. During the Cold War, the actual point of building more nuclear weapons was mutually assured destruction. If the Soviets nuke the US, they might as well be nuking themselves. For this system to work, the US determined that they’d need the equivalent of 400 million tons of TNT in their nuclear arsenal. Instead of building one giant bomb, they diversified into thousands of relatively lower yield weapons. Additionally, new rockets called “MIRVs” were developed to carry multiple nuclear warheads, thereby upping the maximum yield. By the end of the Cold War, the US was estimated to hold about 3.8 billion tons worth of nuclear weapon yield. But in the years following, the US and Russia signed a series of nuclear disarmament treaties, promising to limit their stockpile to about 2,000 deployed weapons each. Today, nine countries are believed to have nuclear weapons. The US and Russia hold about fifteen thousand nukes, with the other seven countries holding between 8 and 300 nukes each. The most powerful thermonuclear weapon currently in the US’s arsenal yields 1.2 million tons, equal to about 200 square miles of devastation. Meanwhile, China is believed to have a 5 million ton yield weapon within their active arsenal. And although Russia was once the world leader in giant nuclear bombs, in recent years, they’ve retired their largest, 20 million ton bombs. Similarly, the US dismantled their nine million ton B53 bomb in 2011. From the start of the nuclear arms race to today, weapon yields have varied dramatically. In the late 1950s, and tactical nuclear gun was even developed, which fired the smallest nuclear bomb ever, called the Davy Crockett. It was 2 and a half million times smaller than the yield of the Tsar Bomba. Clearly, nowadays it doesn’t really matter how big your nuclear weapons are. Every single one is capable of unmitigated devastation. So now we know the true force of nuclear weapons today. But which countries actually have them? Find out in the video up above. You can also check out my own reporting on fallout from Fukushima in the box below. Thanks for watching TestTube News! Be sure to like and subscribe for new videos. Have a great one.