History UsefulNotes / NuclearWeapons

For this discussion, we will detonate a 1 megaton nuclear weapon in UsefulNotes/LosAngeles. [[Creator/{{Disney}} 500 South Buena Vista Street, Burbank, California]] ([[LudicrousPrecision Lat 34.155744, Lon -118.326766]]) will be ground zero and the bomb will detonate on the ground.[[note]][[DisproportionateRetribution What, you thought we'd let you get away with Hannah Montana?]][[/note]] This is what is called a "ground burst" and is easier to estimate the damage and casualties than an air burst, but it should be noted that if nuclear weapons were to be used for military purposes (and the two times they were used) the explosions will all but certainly be air burst. But we want to give a reasonable explanation for this article, so we'll use the simpler explanation of a ground burst

Blast is affected to a limited extent by terrain and atmospheric conditions. Whether your house is on the side of a hill facing the explosion or not could mean the difference between it being torn off it's foundation or merely damaged so much that it collapses a few seconds later. Detonating a bomb inside a valley will confine the blast to a greater degree but increase the destruction within the affected area because the blast would be deflected off the valley walls. Atmospheric conditions are even less predictable but also have even less consequential effects.

Blast is affected to a limited extent by terrain and atmospheric conditions. Detonating a bomb in a valley will confine the blast but increase the destruction within the affected area because of deflection. Whether your house is on the side of a hill facing the bomb or not could mean the difference between it being torn off it's foundation or merely damaged so much that it collapses a few seconds later. Atmospheric conditions are even less predictable but also have even less consequential effects.

For this discussion, we will detonate a 1 megaton nuclear weapon in UsefulNotes/LosAngeles. [[Creator/{{Disney}} 500 South Buena Vista Street, Burbank, California]] ([[LudicrousPrecision Lat 34.155744, Lon -118.326766]]) will be ground zero and the bomb will detonate on the ground.[[note]][[DisproportionateRetribution What, you thought we'd let you get away with Hannah Montana?]][[/note]] This is what is called a "ground burst" and is easier to estimate the damage and casualties than an air burst, but it should be noted that if nuclear weapons were to be used for military purposes (and the two times they were used) the explosions were air burst. But we want to give a reasonable explanation for this article, so we'll use the simpler explanation of a ground burst

For this discussion, we will detonate a 1 megaton nuclear weapon in UsefulNotes/LosAngeles. [[Creator/{{Disney}} 500 South Buena Vista Street, Burbank, California]] ([[LudicrousPrecision Lat 34.155744, Lon -118.326766]]) will be ground zero and the bomb will detonate on the ground.[[note]][[DisproportionateRetribution What, you thought we'd let you get away with Hannah Montana?]][[/note]]

By comparison, the combined total yield of all nuclear testing to date (as of early June 2008) is 510 megatons, or 0.51 gigatons. The largest individual nuclear weapon ever, the RDS-220 or Tsar Bomba, was designed with a yield of ~100 megatons but had this reduced due to fallout concerns to a yield of 50-58 megatons (sources differ) when tested in 1961 -- that is, ''one quarter of the Krakatoa eruption''. At this point, the total yield of all the warheads targeted on Cheyenne Mountain exceeds total US strategic megatonnage.

This mushroom cloud disperses in a matter of hours. During that time, fallout starts raining down on the ground. Radioactive fallout consists of what's left of the bomb, stuff caught in the fireball that's been made radioactive by the bomb's intense neutron radiation, and a whole host of new and exciting isotopes created in the explosion itself. Most of it has half-lives short enough to disappear within hours, days or weeks. This is the idea behind fallout shelters - not to spend the rest of your life down there, but to wait in a shelter for a couple of days until the worst of the fallout has disappeared. However, stuff like strontium-90 (half-life of 29 years) or caesium-137 (30 years) have half-lives short enough to be really radioactive, but long enough to stick around and cause trouble for decades. It's worth noting people in the radiation biz generally use seven half lives as the rule of thumb when getting to 'zero' radiation, and that's not counting radioactive daughter products.

->''"I'm going to go out to the site and test the nuclear device which will launch the rocket [because it might fail]. If you see a ''Hiroshima Mushroom'' you ''[[TooDumbToLive do not]]'' come to the site; instead, turn around and leave immediately."''

It is to be noted that the distinction between a 'counter-value' (attacks on industry, infrastructure) and 'counter-force' (attacks on military targets) nuclear strike can be an academic one in some countries. For example, many the UK is so small that almost every population centre in the country was within the blast radius, CEP (Circular Error probability, the amount to which the weapon is likely to be off target), or fallout-zone of its military targets. The Soviet Union, by contrast, kept their nuclear weapons and facilities well away from their cities due to both security and environmental considerations (many of their bases were extremely cold). A lot of this was because the USSR was several hundred times larger than the UK and its major population centers were even further apart than the USA's (even though it was more than twice as large as the USA by land area, the Soviet Union's population was only slightly smaller and was mostly concentrated in European Russia and the Ukraine).

It is to be noted that the distinction between a 'counter-value' (attacks on industry, infrastructure) and 'counter-force' (attacks on military targets) nuclear strike can be an academic one in some countries. For example, many the UK is so small that almost every military target in the country was either within the blast radius or the CEP (Circular Error probability, the amount to which the weapon is likely to be off target) of the weapons and delivery systems used. The Soviet Union, by contrast, kept their nuclear weapons and facilities well away from their cities due to both security and environmental considerations (many of their bases were extremely cold). A lot of this was because the USSR was several hundred times larger than the UK and its major population centers were even further apart than the USA's (even though it was more than twice as large as the USA by land area, the Soviet Union's population was only slightly smaller and was mostly concentrated in European Russia and the Ukraine).

It's also worth mentioning that mishandling of nuclear weapons usually doesn't result in full-yield explosions—modern thermonuclear designs require very precise conditions to get a full blast (like precisely timed detonation of explosive lenses within nanoseconds), making it much harder to get the weapon to detonate than not. Missile warheads/bombs also will not detonate unless the necessary accelerations/speeds and flight times for their mission have been matched; to quote a Soviet official from {{TheHuntForRedOctober}}, you could drop a missile warhead from the top of a skyscraper onto a plate of steel on the ground, and you won't get it to go off. Also, the weapons are designed to be resistant to fire and shock from mishandling and emergency jettisons, such that while the conventional explosives in the bomb might go off, the nuclear material itself won't react (though it will spread, posing a contamination issue) or it will just ''fizzle'', or only partially react. On top of all this, almost all the nuclear powers keep very tight control over how nukes are deployed, with multiple safety features to prevent unauthorized launches (Permissive Action Links, the two-man rule, and so on).

It's also worth mentioning that mishandling of nuclear weapons usually doesn't result in full-yield explosions—modern thermonuclear designs require very precise conditions to get a full blast (like precisely timed detonation of explosive lenses within nanoseconds), making it much harder to get the weapon to detonate than not. Missile warheads/bombs also will not detonate unless the necessary accelerations/speeds and flight times for their mission have been matched; to quote a Soviet official from {{Literature/TheHuntForRedOctober}}, you could drop a missile warhead from the top of a skyscraper onto a plate of steel on the ground, and you won't get it to go off. Also, the weapons are designed to be resistant to fire and shock from mishandling and emergency jettisons, such that while the conventional explosives in the bomb might go off, the nuclear material itself won't react (though it will spread, posing a contamination issue) or it will just ''fizzle'', or only partially react. On top of all this, almost all the nuclear powers keep very tight control over how nukes are deployed, with multiple safety features to prevent unauthorized launches (Permissive Action Links, the two-man rule, and so on).

** A general note on warnings- for a strike launched from Russia, the US would get about 20 minutes warning before the first explosions. The UK would get about ''four'' - just enough time to make a [[SpotOfTea nice cup of tea.]] But not to drink it.

Estimates for total dead and wounded depend very much on 1) which country was attacked and 2) with what. The latter would depend on who launched the 'first strike' in a nuclear war, with a 1978 US study calculating in a full nuclear exchange she would lose some 70-90% of her population if the USSR struck the USA first - versus only 50-70% if the USA attacked first. The same study thought the USSR would also only lose 60-80% in a full exchange, even if the USA struck first, due to the greater dispersal of her population and much better measures for protecting her population from nuclear strikes. Below that a full exchange the report was inconclusive, stating that deaths would be dependent on the numbers of weapons used and against what. At the very lowest end the report posited several million dead for a US strike upon St Petersburg/Leningrad, or a couple of million dead in a Soviet strike on Detroit. The UK's 1955 ''Strath Report'' thought that only 1/3 of the population would die if only ten weapons were used upon the UK, but in hindsight this figure was extremely optimistic with later estimates putting dead in excess of 90%. 'The survival of the British nation' was not a realistic possibility in the event of even the most limited nuclear exchange.

It is to be noted that the distinction between a 'counter-value' (attacks on industry, infrastructure) and 'counter-force' (attacks on military targets) nuclear strike can be an academic one in some countries. For example, many American submarine and bomber bases have major cities either within the blast radius of the weapons that would be used on them, or within the CEP (Circular Error probability, the amount to which the weapon is likely to be off target) of the delivery system used. The Soviet Union, by contrast, had their major strategic weapons located well away from their cities due to both security and environmental considerations (many of their bases were extremely cold). A lot of this was because the USSR was much, ''much'' larger than the US, and its major population centers were further apart (even though it was more than twice as large as the US by land area, the Soviet Union's population was only slightly smaller and was mostly concentrated in European Russia and the Ukraine).

Estimates for a nuclear war involving the United States tend to be a) somewhat out of date and b) prone to political slanting. It's fair to say, though, that at least two times the weekly audience of ''CSI'' (which would be c.120 million) would probably go in a "counter-value" (cities) strike on the US, with the aggressor taking a lot of casualties too. There would be fewer in a "counter-force" (silos, airfields etc.) strike, but the fallout would still be very nasty...

It is to be noted that the distinction between counter-value and counter-force can be an academic one in some countries. For example, many American submarine and bomber bases have major cities either within the blast radius of the weapons that would be used on them, or within the CEP (Circular Error probability, the amount to which the weapon is likely to be off target) of the delivery system used. The Soviet Union, by contrast, had their major strategic weapons located well away from their cities due to both security and environmental considerations (many of their bases were extremely cold). A lot of this was because the USSR was much, ''much'' larger than the US, and its major population centers were further apart (even though it was more than twice as large as the US by land area, the Soviet Union's population was only slightly larger, and was mostly concentrated in European Russia, the Ukraine, and Belarus).

** A general note on warnings- for a strike launched from Russia, the US would get about 20 minutes warning before the first explosions. The UK would get about ''ten'' (or even less).
*** The official early warning given to the public by the British Government would have only been ''four'' minutes - just enough time to make a [[SpotOfTea nice cup of tea.]] But not to drink it.
* The availability of medical personnel and assistance, although they would be overwhelmed even in a small exchange.

After the fireball disperses, you will see the mushroom cloud start to form from condensing vapor. This contains water, debris and general radioactive nastiness. It's not just a nuclear explosion thing: any large explosion will produce one, as well as volcanic eruptions or a meteorite impact. There's a 1937 description of an explosion in Shanghai that references a mushroom -- 8 years before the first nuclear explosions. Furthermore, one account of the eruption of Mount Vesuvius in Italy in 79 AD described it as having the shape of a pine tree; pine trees in Italy have [[https://upload.wikimedia.org/wikipedia/commons/d/d8/Pinien_La_Brena2004.jpg a similar shape to mushrooms]].

In Creator/RobertAHeinlein's story, ''Literature/TheMoonIsAHarshMistress'', the Lunar colonists fighting the earth's governments drop a large steel-encased rock - say the equivalent of something the size of a Greyhound bus - on a site in the middle of the desert. The impact, when it lands, generates a huge mushroom cloud. Someone asks why the colony violated civilized behavior and used nuclear weapons. The man explains that it wasn't nuclear at all; it was simply the force of impact of a multi-ton unbraked object dropped on earth at the speed of gravity, 32 feet per second per second. It's the same thing when you strike a hammer on an anvil, you get a spark. A mushroom cloud is just the (enormously enlarged) equivalent of a spark. Just the biggest spark ever created by mankind. You hit anything with a big enough impact - nuclear or non-nuclear - you will get a mushroom cloud.

The mechanism is a little different for high-altitude bursts. The deposition region ends up being in a large region of the upper atmosphere. Only the gamma rays that travel to what becomes this region have much of an effect; otherwise, there's not much to interact with. Anyway, across this very large area Compton electrons are produced. Phillip J. Dolan, in The Effects of Nuclear Weapons, wasn't very specific, but he just said that "[the] electrons are deflected by the earth's magnetic field and are forced to undergo a turning motion about the field lines...[this causes] the electrons to be subjected to a radial acceleration which results, by a complex mechanism, in the generation of an EMP that moves down toward the Earth." The electric field is rather less intense, but for obvious reasons the areas affected are much larger. This way, electronics across entire regions may be damaged. You can check the relevant publication out [[http://www.lastalive.com/public_domain/efects_of_nuclear_weapons/effects11.pdf here]], while a detailed explanation by an expert in the field is [[http://www.tboverse.us/HPCAFORUM/phpBB3/viewtopic.php?f=11&t=312 here]].

In Creator/RobertAHeinlein's story, ''Literature/TheMoonIsAHarshMistress'', the Lunar colonists fighting the earth's governments drop a large steel-encased rock - say the equivalent of something the size of a Greyhound bus - on a site in the middle of the desert. The impact, when it lands, generates a huge mushroom cloud. Someone asks why the colony violated civilized behavior and used nuclear weapons. The man explains that it wasn't nuclear at all; it was simply the force of impact of a multi-ton unbraked object dropped on earth at the speed of gravity, 32 feet per second. It's the same thing when you strike a hammer on an anvil, you get a spark. A mushroom cloud is just the (enormously enlarged) equivalent of a spark. Just the biggest spark ever created by mankind. You hit anything with a big enough impact you will get a mushroom cloud.

** Start counting - the length of the flash = size/yield of the nuke and likely source as a result. If the flash only lasts 1-3 seconds, the weapon was likely 20 kilotons or under, which would mean a terrorist device or a North Korean attack. 7 seconds or longer generally means a submarine-launched or intercontinental ballistic missile from a nuclear-capable nation and likely multiple nuclear warheads due to an all-out nuclear war. 20 seconds or more means you are in the multi-megaton range, which is almost ''certainly'' a result of all-out nuclear war (unless it was an accidental launch or accidental drop)

* If you hear a very loud bang or boom, even if you saw/see no flash, and there's no reasonable immediate explanation for it (e.g. a visible vehicle or aircraft crash, thunderstorms in the area, fireworks or military ordnance testing nearby, an obviously non-nuclear explosion), ''go indoors'' and check news reports/social media to find its source. Nuclear detonations can be heard anywhere from 50 to 200 miles away depending on size/yield, even well beyond the distance of seeing a flash, feeling heat, or even seeing the mushroom cloud itself.

* Protect your head with your other arm and/or anything available to do so. If possible, curl up into a fetal position until the blast wave has passed (which will arrive in anywhere from 24 seconds after the flash or less in 5 miles' distance to 3 minutes from the flash 40 miles away) - though if you notice no blast wave within four minutes, you were likely far enough away to be out of blast range.
* If you're lucky enough to be more than 6-25 miles away (depending on nuke - being 4 to 6 miles away would probably be enough to survive a badly-made small terrorist device, while 25 miles at least would be needed for a modern warhead or bomb), this will save your vision (and you will need it to save your life) and reduce/prevent burns. Also, avoid glass if possible - it will not protect you and will cut you when the blast wave arrives.

* Protect your head with your other arm and/or anything available to do so. If possible, curl up into a fetal position until the blast wave has passed (which will arrive in anywhere from 24 seconds after the flash or less in 5 miles' distance to 3 minutes from the flash 40 miles away) - though if you notice no blast wave within four minutes, you were likely far enough away to be out of blast range.

->I'm going to go out to the site and test the nuclear device which will launch the rocket [because it might fail]. If you see a ''Hiroshima Mushroom'' you ''[[TooDumbToLive do not]]'' come to the site; instead, turn around and leave immediately.

For this discussion, we will detonate a 1 megaton nuclear weapon in UsefulNotes/LosAngeles. [[{{Disney}} 500 South Buena Vista Street, Burbank, California]] ([[LudicrousPrecision Lat 34.155744, Lon -118.326766]]) will be ground zero and the bomb will detonate on the ground.[[note]][[DisproportionateRetribution What, you thought we'd let you get away with Hannah Montana?]][[/note]]

[[IThoughtItMeant No, we don't mean]] PoisonMushroom.