Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

Big crater

World annihilation

Everyone is dead

[Lord Shonus]

Based on that site, the described bomb would have a yield between 34.09 Megatons and 340.9 megatons, even less that what the other calculator gave me.

[Dwarf]

Honestly, I'm still unsure as to how much actual destructive potential this weapon would have - this book here on my lap mentions 25 feet of air as enough to halve the radiation. I think that they specifically mean "half the amount of photons", but I might be wrong. The point is - it sure might be a much more potent emitter of gamma rays than a nuclear bomb, but even then, it will be subject to exponential decrease.
The effect would, I think, mostly be of a thermal nature.

[Lord Shonus]

The vast bulk of the damage done by a conversion weapon (either atomic or annihilation) in atmosphere is from thermal effect, if indirectly. The radiation impacts the air, shedding velocity. The shed velocity is converted into thermal energy. This raises the temperature of the air immensely. This happens in an extremely short time. Massive heat increase in a very little time causes extremely rapid expansion. This expansion, essentially converting the thermal energy into mechanical, radiates outward from the center of the explosion, as the center is taken up by also-expanding plasma. This is how the blast wave is formed.  The corollary to this is that such an explosion is far less effective in vacuum, as there is nothing for the radiation to dump energy into, and thus much less blast effect. (There's still some, but not as much.)

[RedWarrior0]

Which is why you always have anti-antimatter countermeasures and gamma ray blocking on a military spaceship. If it hits, then it may produce a hole in the armor and provide this effect to the exterior wall or internal atmosphere of the spaceship.

Most effective way is to have the annihilators loaded together in the round, separated by, say, a magnetic field, with a large quantity of gas to plasmify in the front of the round and get a shaped charge effect. At least, that's as far as I can tell.

[Virex]

Honestly, I'm still unsure as to how much actual destructive potential this weapon would have - this book here on my lap mentions 25 feet of air as enough to halve the radiation. I think that they specifically mean "half the amount of photons", but I might be wrong. The point is - it sure might be a much more potent emitter of gamma rays than a nuclear bomb, but even then, it will be subject to exponential decrease.

Actually, the air isn't doing much of anything to the radiation, 25 feet of vacuum would only have a marginally lower effect. This is because the energy is distributed across a sphere and the sphere grows, meaning that the energy density is inversely quadratically related to the distance. Increasing the distance by a factor 2 will decrease the energy density (note, total energy will roughly be constant) by a factor 4, increasing the distance by a factor 3 will decrease the energy density by a factor 9 et cetera (note that this decrease is far less rapid then an exponential decrease).


Note that in the case of a bomb that would shed it's energy mostly in the form of gamma rays and X-rays, at the point of impact, any high-density materials will heat up tremendously because they adsorb much more energy per cubic meter then gases. This means that the proposed bomb would not cause a conventional explosion, but instead explosive evaporation of matter around the point of detonation. I would expect the resulting blast wave to be a cone pointing upward instead of a sphere growing outward, but such a shape is far from ideal for maximizing the damage dealt.
One interesting side-effect of this is that the kill depth of an antimatter weapon could potentially be much larger then that of a nuclear bomb of similar yield. Because the energy is released as radiation that can travel pretty far through the surface, the proposed weapon could well be capable of killing anyone taking shelter in a conventional (non-lead lined) fallout shelter via irradiation.

[RedWarrior0]

So yes, 25 feet of air is enough to halve the radiation received if you happen to be 25(sqrt2) feet from it.

[Dr. Strangelove]

Lets just put it this way. Depending on how big your bomb is, it could ignite the atmosphere or it might just act like a REALLY big nuke. It would take a lot of calculations. Ill work on it.

[Frumple]

... a better than half year necro for a Dr. Strangelove joke?

I can dig it. Bombs be fo' lovin'.

[mainiac]

I really have trouble seeing how this is going to ignite the atmosphere.  What chemical reaction is this going to cause just by a relatively small fraction of the atmosphere being hit by gamma radiation?

I think that actually a small crater is more likely then a large crater.  Most of the energy is going to be translated into radiation and will either fly off into space or go into the earth's core.  Energy that goes into the earths core is a drop in the bucket and can be ignored.  Really all that matters is the burning in the line of sight of the bomb and any aerosol effect from dust particle sent into the air.

[kaenneth]

The real question is, how many years in prison can you get for reading this thread?

http://www.thisislancashire.co.uk/news/9498382.Man_who_downloaded_recipes_on_how_to_make_explosive_devices_jailed/

[Virex]

I can't find the penetration depth figures for gamma radiation into soil, but I'd be surprised if it'd exceed th 100 meter mark (but feel free to prove me wrong). Most of the energy will be dissipated in the upper layer, which will heat up pretty tremendously.

[Supercharazad]

My guess: Seas boil, everyone in nearby continents gets severly burned, then the seas boil and destroy a pile of currents, causing permanent damage to the Earth. Everyone would die, the world would get too hot to be habitable.

Also, the crater would be the amount of water and various rock atoms of the amount of antimatter atoms used , minus the amount of atoms in the shell, detonation triggers etc.

[Tellemurius]

I can't find the penetration depth figures for gamma radiation into soil, but I'd be surprised if it'd exceed th 100 meter mark (but feel free to prove me wrong). Most of the energy will be dissipated in the upper layer, which will heat up pretty tremendously.

Well 9cm of packed dirt can block 50% of the intensity meaning a 90cm+ can protect a person.