Talk:Castle Bravo

Castle Bravo vs Tsar Bomba

Just curious, the articles for these 2 lists the yields and fireball sizes as: Castle Bravo 15 megatons and "almost 4.5 miles", and the Tsar Bomba as 50 - 58 megatons and a fireball width of 5 miles respectively. My question is, given the differences in yields, are these figures for the fireballs accurate? IT Retiree (talk) 16:53, 8 July 2025 (UTC)

The figures can still be correct. There are several differences that may have contributed to the apparent nearness in size. First, Tsar Bomba was an air burst, but Castle Bravo was located near the surface in a shot cab. This would mean the former was mostly spherical while the latter would be more hemispherical. Five mile diameter sphere is about 65 cubic miles, while a 4.5 mile hemisphere is about 24 cubic miles. Secondly, Castle Bravo may have seen some reflective effects from the surface, possibly boosting the radius of the fireball somewhat. Also, the atmospheric conditions are considerable: arctic vs tropical, so denser cold air against warm air. Other things to note would be the differences in other effects reported such as the Tsar Bomba's shockwave circling the globe three times. Finally, the fireball effect is complicated by the dynamics between blast shockwave and thermal pulse with air displacement resulting in a vacuum that limits the extent of the fireball. The thermal pulse and blast shockwave can reach far beyond the fireball. 173.59.124.46 (talk) 06:05, 20 July 2025 (UTC)

Thanks, I appreciate the time it took to give this reply. 71.72.118.243 (talk) 00:19, 28 July 2025 (UTC)

Confusing wording in first paragraph

> Castle Bravo's yield was 15 megatons of TNT [Mt] (63 PJ), 2.5 times the predicted 6 Mt (25 PJ), due to unforeseen additional reactions involving lithium-7, which led to radioactive contamination in the surrounding area.

Because the "which led" fragment follows the "due to unforeseen" fragment, it can be understood that the only reason the contamination happened was because of the excessive yield. While it is true that later in the article, this sentence is found:

> Rotblat deduced that the bomb had three stages and showed that the fission phase at the end of the explosion increased the amount of radioactivity a thousand-fold.

…I think the initial paragraph can still be misleading. It would be better to word it as:

> Castle Bravo's yield was 15 megatons of TNT [Mt] (63 PJ), 2.5 times the predicted 6 Mt (25 PJ), due to unforeseen additional reactions involving lithium-7, which led to much greater radioactive contamination in the surrounding area that originally estimated. Brunoresende29 (talk) 09:53, 29 March 2026 (UTC)