3 ms·

Quoting a different article by the same Wellerstein, at https://thebulletin.org/2021/11/the-untold-story-of-the-worlds-biggest-nuclear-bomb/ https://thebulletin

Quoting a different article by the same Wellerstein, at https://thebulletin.org/2021/11/the-untold-story-of-the-worlds-biggest-nuclear-bomb/ https://thebulletin.org/2021/11/the-untold-story-of-the-worl... : > It is hard to convey the damage of a gigaton bomb, because at such yields many traditional scaling laws do not work (the bomb blows a hole in the atmosphere, essentially). However, a study from 1963 suggested that, if detonated 28 miles (45 kilometers) above the surface of the Earth, a 10,000-megaton weapon could set fires over an area 500 miles (800 kilometers) in diameter. Which is to say, an area about the size of France. Yes, it's so powerful it's blasting the air into space. Adding more power doesn't so much make the blast more powerful as make the air go into space more quickly!

Arrath 5y ago
< Yes, it's so powerful it's blasting the air into space. Adding more power doesn't so much make the blast more powerful as make the air go into space more quickly! Wow. How many of these would it take to appreciably reduce atmospheric pressure world-wide?
- eesmith 5y ago
  When I wrote "air into space", I didn't mean it reached escape velocity. Rather, it no longer acted as a pressure cover to the blast. The air have gone up a few hundred km and returned to earth. FWIW, there was a pressure wave world-wide. The Wikipedia page says a fluctuation of 0.6 mbar was measured in New Zealand. (Krakatoa's pressure wave was recorded going around the Earth three times!) That said, let's consider the number of Tsar Bomba's needed to lower the pressure by 0.01mBar, permanently, assuming all of the energy from the bomb was used to get air to exactly escape velocity. (In reality, energy also went into space, or melted snow, or was turned into seismic energy, or ... And there will be a distribution of velocities.) Mass of the atmosphere is about 5.15E18 kg. 0.01mBar is 1/100,000 reduction in atmosphere gives 5.15E13 kg. Escape velocity about 11 km/sec. Energy = 1/2 m v * v = 3E21 J. Tsar Bomba = 210–240 PJ = 2E17 J. So, assuming the impossibly perfect transfer of all energy into moving air at escape velocity, 10,000 Tsar Bombas. I don't know how many orders of magnitude more are needed before the spherical cap of atmosphere would be blasted to escape velocity, but clearly even a tera-ton bomb isn't enough.
  - Arrath 5y ago
    > When I wrote "air into space", I didn't mean it reached escape velocity. Rather, it no longer acted as a pressure cover to the blast. The air have gone up a few hundred km and returned to earth. Fair enough! That is...a lot of bombs, wow.
dividedbyzero 5y ago
> Adding more power doesn't so much make the blast more powerful as make the air go into space more quickly! I guess more power would make a difference to what it does with the ground beneath it, though. Not sure what that kind of energy would actually do, though, vaporize a chunk of the crust?

Arrath 5y ago

< Yes, it's so powerful it's blasting the air into space. Adding more power doesn't so much make the blast more powerful as make the air go into space more quickly! Wow. How many of these would it take to appreciably reduce atmospheric pressure world-wide?

eesmith 5y ago
When I wrote "air into space", I didn't mean it reached escape velocity. Rather, it no longer acted as a pressure cover to the blast. The air have gone up a few hundred km and returned to earth. FWIW, there was a pressure wave world-wide. The Wikipedia page says a fluctuation of 0.6 mbar was measured in New Zealand. (Krakatoa's pressure wave was recorded going around the Earth three times!) That said, let's consider the number of Tsar Bomba's needed to lower the pressure by 0.01mBar, permanently, assuming all of the energy from the bomb was used to get air to exactly escape velocity. (In reality, energy also went into space, or melted snow, or was turned into seismic energy, or ... And there will be a distribution of velocities.) Mass of the atmosphere is about 5.15E18 kg. 0.01mBar is 1/100,000 reduction in atmosphere gives 5.15E13 kg. Escape velocity about 11 km/sec. Energy = 1/2 m v * v = 3E21 J. Tsar Bomba = 210–240 PJ = 2E17 J. So, assuming the impossibly perfect transfer of all energy into moving air at escape velocity, 10,000 Tsar Bombas. I don't know how many orders of magnitude more are needed before the spherical cap of atmosphere would be blasted to escape velocity, but clearly even a tera-ton bomb isn't enough.
- Arrath 5y ago
  > When I wrote "air into space", I didn't mean it reached escape velocity. Rather, it no longer acted as a pressure cover to the blast. The air have gone up a few hundred km and returned to earth. Fair enough! That is...a lot of bombs, wow.

dividedbyzero 5y ago

> Adding more power doesn't so much make the blast more powerful as make the air go into space more quickly! I guess more power would make a difference to what it does with the ground beneath it, though. Not sure what that kind of energy would actually do, though, vaporize a chunk of the crust?