Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror
×
The Military Power

'The Largest Nuclear Bomb Ever Detonated' Explored in Declassified Russian Footage (smithsonianmag.com) 210

"The blast was over 3,000 times bigger than the bomb that destroyed Hiroshima," reports Smithsonian magazine: Hydrogen bombs are so destructive, their impact has been described as unthinkable throughout history. Recently declassified Russian footage of the 1961 Tsar Bomba hydrogen bomb test shows why. The 40-minute documentary, which was posted on YouTube on August 20, shows footage of the largest bomb ever detonated on Earth, Thomas Nilsen reports for the Barents Observer.

Video footage shows the blast from several angles, sometimes struggling to show the entire mushroom cloud in the frame. Later, the documentary compares the ice-covered archipelago before the blast to the scorched, red and brown landscape left behind afterward. The Soviet Union tested the 50-million-ton hydrogen bomb, officially named RDS-220 and nicknamed Tsar Bomba, in late October 1961, Matthew Gault reports for Vice. This test occured during the height of the Cold War, when the Soviet Union and the United States competed to build the largest and most destructive nuclear weapons.

"There was a megatonnage race — who was going to have a bigger bomb," atomic age historian Robert S. Norris tells the New York Times' William Broad. "And the Soviets won...." It was three times as large as the biggest bomb ever detonated by the U.S., dubbed Castle Bravo.

schwit1 shares more information from Popular Mechanics: It's difficult to truly get across how powerful RDS-220 was. The mushroom cloud reached an altitude of 210,000 feet, and people observed the flash through bad weather at 621 miles. An observer felt heat from the explosion at a distance of 168 miles, and the bomb was capable of inflicting third-degree burns at 62 miles.
This discussion has been archived. No new comments can be posted.

'The Largest Nuclear Bomb Ever Detonated' Explored in Declassified Russian Footage

Comments Filter:
  • Is the original desire was for 100MT, but the engineers cut it to 50. I thought I read somewhere long ago the engineers were afraid of catching the atmosphere on fire. Not sure if that is possible, but the idea the earth could turn into the sun is not very comforting.
    • by Luckyo ( 1726890 ) on Saturday August 29, 2020 @06:51PM (#60454092)

      There were a lot of weird myths about "what could happen from nuclear" back in the 1950s and 1960s, mostly due to sci fi writing influences on scientific community among Western scientific circles. Many of those influences being mutually exclusive, i.e. "it's going to turn planet into the sun" to "it's going to result in nuclear winter".

      Some of them ended up being more true than others.

      Also to my knowledge, these influences were much weaker behind the Iron Curtain due to information control. A lot of relevant prose was never translated to, banned or severely censored in Russian language at the time.

      Also, as far as I know 100Mt was considered possible, but deemed to add unnecessary technological complexity for already complex first prototype of the bomb. Which ended up being the only sample, as bomb was generally poorly suited for Cold War style MAD stand-off, where sub-megaton MIRV warheads became a norm instead of a single oversized explosive.

      • by rtb61 ( 674572 )

        The oversized detonation has actually snuck back into popularity with more an aim at environmental impact that destroying a city ie drop in in the middle of one of the great lakes, to detonate at the right depth to generate a massive radioactive tidal wave to destroy all towns and cities on it's shores as well as all surrounding farm land, or targeting the yellowstone caldera to create a massive sympathetic volcanic eruption, making the headwaters of the Mississippi and Missouri rivers radioactive. Fewer bo

        • by Luckyo ( 1726890 )

          These large bombs actually do very little damage over time. There's almost no residual radiation due to just how clean the reaction is.

          As for "but let's stimulate eruption", that is in a realm of science fiction, just like "burning atmosphere". Amount of energy in things like volcanoes is many times more than all nukes on the planet combined and it's still not enough for most volcanoes on the planet to erupt. You need to use cobolt bombs for long term damage. Radiation is one of the single worst methods to

          • It's something we observed in practice in Fukushima. They dumped the highly radioactive water from the plant into the ocean, and within a few hours, radiation readings at the immediate dumping site were good enough that you could swim in it. Within a day or so, it was effectively gone where you needed complex instrumentation looking for specific atoms to even know that something was wrong.

            The trouble is we do in fact have those advanced instruments of phenomenal sensitivity. I think this is how they detecte

            • by Luckyo ( 1726890 )

              Why is that trouble? It's excellent that we have such accurate detection capability. About the only downside is that people peddling misinformation get more ammunition to use in their material, but such people are rarely limited by lack of real world evidence of harm they claim.

      • The Soviets wanted "More rubble for the Ruble".......

        • by Luckyo ( 1726890 )

          No, they just wanted to answer the cessation of US moratorium with a kind of a weapon that would end the de facto dick comparison of "who has the bigger bomb".

          It worked.

      • Also, as far as I know 100Mt was considered possible, but deemed to add unnecessary technological complexity for already complex first prototype of the bomb.

        I think this is incorrect: the 100Mt switch was a simple, well understood change posing few engineering challenges. If the lead bomb casing and tamper was replace with uranium then the fast neutrons from the fusion stage would fission the uranium causing a much larger blast. The problem with that is it's dirty as all hell and spews out a massive amount

        • by Luckyo ( 1726890 )

          I recommend looking up the location in question to understand why your assumption about motivators is almost certainly false. This location is specifically chosen to be very far away from any meaningful area in Soviet Union and is so utterly isolated and economically unviable land that if the entire archipelago was to become permanently unusable, little to nothing of value to USSR would have been lost.

      • Submegaton MIRVs are the norm, yes, but the Russians still have a couple of 20 MT warheads intended for heavy bunker busting (Cheyenne Mountain) and targets where missing is not an option (Washington DC).

    • by mi ( 197448 ) <slashdot-2017q4@virtual-estates.net> on Saturday August 29, 2020 @06:54PM (#60454098) Homepage Journal

      the engineers were afraid of catching the atmosphere on fire

      According to Wikipedia [wikipedia.org], the actual concern — leading to the reduction of yield — was that the bomb-dropping aircraft may not be able to escape the blast...

      • And now Russia is back at it making doomsday devices. They might as well call it the Doomsday Device

      • by quenda ( 644621 )

        the actual concern — leading to the reduction of yield — was that the bomb-dropping aircraft may not be able to escape the blast...

        That could probably have been worked around. If you read further, they left out the uranium tamper, which is responsible for most of the radioactive fallout, and not really needed for a test blast. So, combined with the altitude, it resulted in a very clean test.

    • the engineers were afraid of catching the atmosphere on fire.

      That was a concern before the Trinity test in 1945. All the calculations showed it was impossible, but there was still a teeny bit of concern.

      By 1961, nobody believed the atmosphere could detonate.

      Not sure if that is possible

      No, it is not possible.

      • the engineers were afraid of catching the atmosphere on fire.

        That was a concern before the Trinity test in 1945. All the calculations showed it was impossible, but there was still a teeny bit of concern.

        Some far out speculations and fearmongering happen every time something big and not very well understood happens. More recently, before the LHC was put into operation, there was some concern that it will generate a black hole that would suck the whole Earth in [home.cern].

        • Some far out speculations and fearmongering happen every time something big and not very well understood happens. More recently, before the LHC was put into operation, there was some concern that it will generate a black hole that would suck the whole Earth in [home.cern].

          Indeed. And it hasn't happened yet.

          If you need additional peace of mind, look at the live webcam from CERN. [cyriak.co.uk] You'll need to enable Adobe Flash to see it, but is that such a great price to pay to allay your fears? I think not, my friends, I think not.

          • by quenda ( 644621 )

            Indeed. And it hasn't happened yet.

            If you need additional peace of mind, look at the live webcam from CERN. [cyriak.co.uk] You'll need to enable Adobe Flash to see it, but is that such a great price to pay to allay your fears? I think not, my friends, I think not.

            In our timeline, yes. But in the other 99.999999% of universes where the Earth was instantly annihilated, nobody is left to say "whoops".

      • No, it is not possible.

        This is actually not comforting. There was some hope that these bombs had some power limit, not anymore.

      • by ruddk ( 5153113 )

        Isn’t that what causes problems between scientists and the public? If there’s a 0.000001% they will say it is not impossible and people then think of that as a 50/50% chance.
        I seem to remember something similar about the Hadron collider when asked about the chance of creating a black hole. :)

    • The way I read it the 100MT design was used, minus the U238 wrapper. I don't think there is a physics limit to the number of stages and megatonage so why try?

      • by Luckyo ( 1726890 )

        If I'm understanding the video correctly, it speaks of "bomb mechanisms being designed for 100Mt yield device, but 50Mt was used for pragmatic reasons".

    • by vbdasc ( 146051 )

      What I've heard is that they scaled down the design so that they could guarantee the safety of the air crew dropping the bomb.

  • Fuck knows how we got through the cold war without adding another Hiroshima. Blind luck? The only nuclear detonations should be the ones we ride through space.
    • Fuck knows how we got through the cold war without adding another Hiroshima. Blind luck?

      Blind luck was a big factor. There were several close calls.

      Better intelligence, especially from satellites, showed both sides what their adversaries were deploying. This led to restraint since we could base our armaments on what we knew rather than what we feared.

      Better guidance systems also helped. You need a multi-megaton bomb if your target is a city. A few kilotons are needed if your target is a building. A 500 kg conventional warhead is sufficient if your target is a specific window.

      • I agree with your post wholeheartedly. I'd like to add that we're pretty lucky that neither side nuked themselves on accident, and that after the fall of the Soviet Union, we didn't see any terrorist-like deployments of 'lost' nuclear weapons.
    • by Nidi62 ( 1525137 ) on Saturday August 29, 2020 @07:40PM (#60454180)

      Hiroshima and Nagasaki happened because, as bad as they were, they were the best of the remaining options. With the Cold War, nukes were the worst of many options. The big powers intentionally relegated themselves proxy wars because open conflict between could only have ended very, very badly.

      • Re: (Score:2, Interesting)

        by Anonymous Coward

        The Japanese wanted to surrender but were only holding out because Truman insisted on "unconditional surrender." The only condition the Japanese wanted was for their emperor to not be executed. The only thing the bombing of Hiroshima and Nagasaki accomplished was mass murder.

        Truman was both a monster and an idiot. His argument about how difficult it would be to invade Japan made no sense because 1) they were willing to surrender anyway and 2) the Russians were moving in and ready to invade Japan alongside u

      • Aside all the comment mentioning the imminent surrender of Japan at that point, read up on the bat bomb, which would have brought Tokyo to it's knees with low to no direct loss of life. There are always options.
    • by Luckyo ( 1726890 )

      MAD is what got us through that. And MAD is still in effect and why US and China aren't in any danger of having a proper existential war. Or US and Russia. Or Russia and China.

      Or the oldest pair of mutually hating nations, UK and France.

    • It's hegemony. The date is set.

    • I'm pretty sure once everyone actually saw how horrible Hiroshima really was, they changed their thinking, even if it was only ever so slightly.

      My great uncle was sent in (right after the Japanese surrendered) by the US Army, to clean up, and help rebuild ground zero. He was supposed to be two weeks on, two weeks off. He was in the hospital by the 4th day, and by the end of what was supposed to be his first two weeks on, he was back to the USA in a hospital clinging to his life. That was almost a month af

      • by quenda ( 644621 )

        He was the first one to ever tell me that people were literally vaporized, and the only way you knew they were standing there is your could see their charred outline on the wall.

        You need to re-calibrate your bull-shit detector. Nobody was "vaporised" as the bomb explodes half a kilometre above the city.
        A much simpler explanation is that the dead bodies had been removed and buried. Or, given that the wall was still standing, the person walked away, and died of burns some hours or days later. This ridiculous story should have lead you to question some of your uncle's other claims.

        • In the Hiroshima museum, you can find the remains of many household items made of metal, ceramic, and glass that had melted during the blast. I have no doubt that humans present in the same location were vaporized, since you only need 100 C temperature for that.

          Quoting Wikipedia: The Hiroshima fireball was 370 metres (1,200 ft) in diameter, with a surface temperature of 6,000 C (10,830 F).[51] Near ground zero, everything flammable burst into flame. One famous, anonymous Hiroshima victim, sitting on stone s

    • by k6mfw ( 1182893 )
      I think back in the days we didn't close down embassies or consulates. There were some diplomats and staff that were kicked out of countries but even during Cuban Missile crisis we kept these places open. At least we had some communication channels. But also I feel we had fewer nutjobs in upper govt positions.
  • Castle Bravo (Score:5, Informative)

    by Tim the Gecko ( 745081 ) on Saturday August 29, 2020 @07:08PM (#60454124)

    Castle Bravo's 15 megatons was much bigger than the planned 6 megatons, due to an unexpected reaction of Lithium-7. The designers were relying on the rarer Lithium-6 isotope, but the bomb's lithium was only enriched up to about 40%, with the rest being the supposedly inert Lithium-7. The bomb's higher than expected yield had a lot of very bad effects on inhabited islands, with large levels of fallout.

    wikipedia [wikipedia.org]

    • Imagine how much fallout the Russian one produced. We're lucky polar bears still exist after that.
      • We're lucky the SWEDES survived that!

      • Re:Castle Bravo (Score:4, Interesting)

        by Luckyo ( 1726890 ) on Saturday August 29, 2020 @08:10PM (#60454220)

        Basicially none. This was one of the cleanest nuclear bombs in history. Crews were at the epicentre within a few hours, walking around with minimal protective gear.

        • by decep ( 137319 )

          Only because it was an air burst. Tsar Bomba was detonated over 2 miles in the air, the epicenter was not on the ground.

          By this metric, Starfish Prime was the cleanest bomb since it was detonated basically in space.

          • You get more fallout detonating near the ground, as the radioactive particles bombard the soil which then vaporizes into radioactive dust. Air doesn't absorb radiation very well, ergo less fallout. The only "fallout" you get is from the particles left over from the fissile material in the bomb itself.

            Also, the more efficient a nuclear bomb is at converting matter directly into energy, the less radioactive material you are going to get. As the Tsar Bomba was a very high-yield device, I'm assuming the efficie

            • Re:Kinda Sorta (Score:5, Informative)

              by Kobun ( 668169 ) on Saturday August 29, 2020 @11:39PM (#60454544)
              A bit wrong. High-efficient (low-fallout) is a function of how much energy comes out of the fusion stage. Tsar Bomba's 100MT design would have been a fission-fusion-fission explosion, with the fast neutrons from the fusion stage causing prompt fission of an outer U238 jacket for another 50 MT of energy released. A primary issue of this is that it would have been INCREDIBLY dirty, by far the dirtiest nuclear test ever. As it was, the 50MT version derived something like 95%+ of its energy from fusion, making it more or less the cleanest nuclear test in history. http://www.nuclearweaponarchiv... [nuclearweaponarchive.org]
          • by Luckyo ( 1726890 )

            It was because it was nearly perfect fusion detonation, with over 95% of material being tritium+deuterium.

            Starfish Prime was much dirtier in comparison.

      • They detonated it at 4000 m altitude. That doesn't produce much fallout. You get lots of fallout when you detonate close to the ground. It incinerated a lot of snow and lichens from the heat, but the radioactive stuff wasn't anywhere close to the ground when that happened.
      • Well, since Castle Bravo was detonated on the ground (in a building) it created so much more fallout when compared to the Tsar Bomba that was detonated somewhere just over 4000m above seal level. Much of this reduction was due to the Tsar Bomba's "fireball" was kept from interacting with the ground because of the shock wave created by the explosion.

    • Re:Castle Bravo (Score:5, Informative)

      by ShanghaiBill ( 739463 ) on Saturday August 29, 2020 @07:32PM (#60454172)

      Lithium-6 absorbs slow neutrons and then splits into tritium and helium.

      Lithium-7 absorbs fast neutrons and then splits into tritium, helium, and a neutron.

      So the Li-7 not only provided an unexpected big boost in fuel, but also a big boost in neutron flux with led to a much more thorough consumption of both Li-6 and Li-7 as well as the uranium tamper.

      Oops.

      • Re:Castle Bravo (Score:5, Insightful)

        by Luckyo ( 1726890 ) on Saturday August 29, 2020 @08:13PM (#60454226)

        To be fair, understanding these unexpected reactions is why we conduct tests in science.

        • To be fair, understanding these unexpected reactions is why we conduct tests in science.

          Sure. But this should have been discovered in a lab. They shot neutrons at Li-7 and saw that it converted to Li-8 which decays via beryllium-8 to two heliums, which are inert. So they assumed that Li-7 would contribute nothing to the yield.

          But if the neutrons are energic (over about 2.5 MeV), as they were during the blast, the reaction is different and you get tritium+neutron instead of the 2nd helium.

          They should have tested under more realistic conditions. But at the time, it was not understood that th

          • by Luckyo ( 1726890 )

            >But this should have been discovered in a lab.

            And then you literally explain how they did and found nothing.

            >They should have tested under more realistic conditions.

            They did. That's what test explosions are about. Testing under realistic conditions not accessible in a lab.

  • by e3m4n ( 947977 ) on Saturday August 29, 2020 @07:11PM (#60454134)

    How I Learned to Stopped Worrying and Love the Bomb.

  • by mapkinase ( 958129 ) on Sunday August 30, 2020 @07:38AM (#60454988) Homepage Journal

    Larger part of the video is an old news reel. First explosion show at 28:35 then newsreel ends then couple of unnecessarily long shots of the explosion are shown of medium interest and the rest of the video is just planes flying.

"The Computer made me do it."

Working...