<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>Teknoman117</author><text>One of the main differences is what the tamper is made out of (the casing). You need a material that is reflective to the X-rays used to compress the fusion fuel. In Castle Bravo, this was made out of uranium-238, in the Tsar bomb, it was made from lead. Using uranium boosted the power output by about 2x, at the expense of making the bombs far, far dirtier. The extreme heat and the high neutron radiation from the primary (a fission device) detonating would cause the uranium to decay into more unstable isotopes (U-235, Pu-239, etc.) which would then fission themselves.&lt;p&gt;The ideology at the time was that a larger blast was more important, since at the time nuclear weapons were still to be dropped by bombers (No ICBMs for another decade). You wanted the bomb to take out the target even if you couldn&amp;#x27;t quite reach it.&lt;p&gt;The Soviets estimated that using the same technique would have produced a yield of 100 Mt, but for testing, lead was used to limit the fallout to something they deemed manageable.</text><parent_chain><item><author>Andrew_nenakhov</author><text>Hm. That&amp;#x27;s strange, because USSR&amp;#x27;s 57 Megaton Tzar-bomb had a negligible amount of radiation:&lt;p&gt;&amp;quot;Radioactive contamination of the experimental field with a radius of 2–3 km (1.2–1.9 mi) in the epicenter area was no more than 1 milliroentgen &amp;#x2F; hour, the testers appeared at the explosion site 2 hours later, radioactive contamination posed practically no danger to the test participants&amp;quot; [1].&lt;p&gt;[1]: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Tsar_Bomba#Test_results&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Tsar_Bomba#Test_results&lt;/a&gt;</text></item><item><author>acidburnNSA</author><text>This was really when people started figuring out how bad fallout from thermonuclear bombs could be. General Fields described it most lucidly:&lt;p&gt;&amp;quot;If Bravo had been detonated in Washington, D.C., instead of Bikini, Fields illustrated with a diagram, that lifetime dose in the Washington-Baltimore area would have been 5,000 roentgens; in Philadelphia, more than 1,000 roentgens; in New York City, more than 500, or enough to result in death for half the population if fully exposed to all the radiation delivered. This diagram was classified secret and received very little distribution beyond the Commissioners.&amp;quot; [1]&lt;p&gt;Image reproduced here [2].&lt;p&gt;Thermonuclear bombs are really terrifying. If one goes off and you&amp;#x27;re in the fallout zone do not go outside for at least 2 weeks. If you survive the initial blast you have about 10 minutes to get inside where you must stay. If you&amp;#x27;re still outside and it&amp;#x27;s &amp;#x27;snowing&amp;#x27; ash you&amp;#x27;re already dead. More tips and tricks in [3].&lt;p&gt;Though these days, they say it&amp;#x27;s likely that a single individual or small group can have even worse impact from a basement bioterror lab.&lt;p&gt;[1] Hewlett and Holl - Atoms for Peace and War around pg 181 (free pdf history book) &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.energy.gov&amp;#x2F;management&amp;#x2F;downloads&amp;#x2F;hewlett-and-holl-atoms-peace-and-war&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.energy.gov&amp;#x2F;management&amp;#x2F;downloads&amp;#x2F;hewlett-and-holl...&lt;/a&gt;&lt;p&gt;[2] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;whatisnuclear.com&amp;#x2F;img&amp;#x2F;castle-bravo-if-on-dc.png&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;whatisnuclear.com&amp;#x2F;img&amp;#x2F;castle-bravo-if-on-dc.png&lt;/a&gt;&lt;p&gt;[3] Nuclear War Survival Skills (free pdf book) &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.oism.org&amp;#x2F;nwss&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.oism.org&amp;#x2F;nwss&amp;#x2F;&lt;/a&gt;</text></item></parent_chain></comment><story><title>Those who witnessed Castle Bravo looked into Armageddon</title><url>https://medium.com/war-is-boring/those-who-witnessed-castle-bravo-looked-into-armageddon-fa7610578413</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>nabla9</author><text>That&amp;#x27;s only because it was airburst and the fallout dispersed in air.&lt;p&gt;Tsar Bomba was very clean relative to the yield.&lt;p&gt;Even then, it release more radionucleonides than any bomb before it (airburst). They limited the yield to 50 megatons, because fallout in Europe would have been catastrophic from a bigger 100 mt bomb that was allowed by the design.</text><parent_chain><item><author>Andrew_nenakhov</author><text>Hm. That&amp;#x27;s strange, because USSR&amp;#x27;s 57 Megaton Tzar-bomb had a negligible amount of radiation:&lt;p&gt;&amp;quot;Radioactive contamination of the experimental field with a radius of 2–3 km (1.2–1.9 mi) in the epicenter area was no more than 1 milliroentgen &amp;#x2F; hour, the testers appeared at the explosion site 2 hours later, radioactive contamination posed practically no danger to the test participants&amp;quot; [1].&lt;p&gt;[1]: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Tsar_Bomba#Test_results&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Tsar_Bomba#Test_results&lt;/a&gt;</text></item><item><author>acidburnNSA</author><text>This was really when people started figuring out how bad fallout from thermonuclear bombs could be. General Fields described it most lucidly:&lt;p&gt;&amp;quot;If Bravo had been detonated in Washington, D.C., instead of Bikini, Fields illustrated with a diagram, that lifetime dose in the Washington-Baltimore area would have been 5,000 roentgens; in Philadelphia, more than 1,000 roentgens; in New York City, more than 500, or enough to result in death for half the population if fully exposed to all the radiation delivered. This diagram was classified secret and received very little distribution beyond the Commissioners.&amp;quot; [1]&lt;p&gt;Image reproduced here [2].&lt;p&gt;Thermonuclear bombs are really terrifying. If one goes off and you&amp;#x27;re in the fallout zone do not go outside for at least 2 weeks. If you survive the initial blast you have about 10 minutes to get inside where you must stay. If you&amp;#x27;re still outside and it&amp;#x27;s &amp;#x27;snowing&amp;#x27; ash you&amp;#x27;re already dead. More tips and tricks in [3].&lt;p&gt;Though these days, they say it&amp;#x27;s likely that a single individual or small group can have even worse impact from a basement bioterror lab.&lt;p&gt;[1] Hewlett and Holl - Atoms for Peace and War around pg 181 (free pdf history book) &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.energy.gov&amp;#x2F;management&amp;#x2F;downloads&amp;#x2F;hewlett-and-holl-atoms-peace-and-war&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.energy.gov&amp;#x2F;management&amp;#x2F;downloads&amp;#x2F;hewlett-and-holl...&lt;/a&gt;&lt;p&gt;[2] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;whatisnuclear.com&amp;#x2F;img&amp;#x2F;castle-bravo-if-on-dc.png&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;whatisnuclear.com&amp;#x2F;img&amp;#x2F;castle-bravo-if-on-dc.png&lt;/a&gt;&lt;p&gt;[3] Nuclear War Survival Skills (free pdf book) &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.oism.org&amp;#x2F;nwss&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.oism.org&amp;#x2F;nwss&amp;#x2F;&lt;/a&gt;</text></item></parent_chain></comment><story><title>Those who witnessed Castle Bravo looked into Armageddon</title><url>https://medium.com/war-is-boring/those-who-witnessed-castle-bravo-looked-into-armageddon-fa7610578413</url></story>