Ok, a half life is the time it take for 50% of the mass to decay. Decay meaning move from one state to another... effectively becoming a different element entirely.
Theoretically, that means that matter will NEVER disappear. I.e. if you have 1kg of Uranium235, in 700 million years, you'll have 500g of Uranium235 and 500g of Thorium 231. In another 700 million years you'll have 250g of Uranium235 and 250g of Thorium 231 and the 500g of Thorium 231 from before will have changed into something else. In another 700 million years you'll have 125g etc. It's not quiet as simple as that, but you get the picture.
Now, Uranium 238 has a half life of 4.5 BILLION years.
There is all sorts of radiation and all sorts of half lives. There is all sorts of penetrative ability of radiation. Neutrinos (for example) would be able to penetrate a shield made of lead light-years thick, whereas other radiation is stopped by something as simple as a sheet of paper.
Right now, as you sit where you are sitting you are constantly being bombarded by radiation. Most of it is harmless, others will collide with the DNA in your body causing cancerous cells to grow. It happens every day. Your body is in a constant battle that it generally wins.
SO, in answer to your question, yes, the material the bomb is made out of will affect the kind of radiation that is caused, but none of it is good. Some of it will decay very VERY rapidly. Some of it will be harmful for thousands of years, but also be relatively weak... i.e. you're already being hit by it, but will be hit by it a bit harder in an area where an atomic blast happened.
Just in closing, realize that EVERY explosion has radioactive fallout... it's just that the magnitude is dramatically increased when it's an atomic blast.
SpiltPersonality
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thomasdewitt
9 years ago
In the movie "Blast From The Past," which form of bomb was it, and atomic bomb or a so-called "hydrogen" bomb (fission versus fusion)? Which element was it, also, along with the Isotope? In Hiroshima and in Nagasaki, the two bombs had different elements. In Hiroshima, probably Uranium (Uranium-235?), and in Nagasaki, Plutonium. In Nagasaki and in Hiroshima, I think both bombs may be atomic bombs. I want to find out about the alleged bombs or missiles in the movie "Blast From The Past" with forms of these so-called bombs in Cuba. For example, were those things the equivalence of "atomic" bombs or of the so-called "hydrogen" bombs (fission versus fusion)? Which element in those missiles in Cuba along with the Isotope? I want to find out the method of half-life specifically of thirty-five years (or however many years) in the movie "Blast From The Past."
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SpiltPersonality
9 years ago
There was no atomic bomb in 'Blast from the Past'.
I don't think anyone except maybe the Soviets would be able to tell you what warhead was available in Cuba.
The 35 year half life in 'Blast from the Past' is a 'Hollywood' halflife based on the fact that they wanted the movie to be contemporary, so it was set in 1999 ish after the events in the Cuban Missile Crisis so.... 35 years.
If it was made today the choice would be 55 years etc.
SpiltPersonality
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thomasdewitt
9 years ago
Also, have I found out about the idea of a half-life of somewhere in the hundreds of years in another movie of the radiation from nuclear bombs? It was possible my Father might have said something with reference to another movie with reference to Australia where the half-life of the radiation in that movie had been somewhere in the hundreds of years. I was trying to find the name of the movie in the last several months, and I could only find the movie "On The Beach" with the name of the movie with that description (or with the most proximity of that description).
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DrWhen
8 years ago
I think you're looking for a simple answer when there isn't one. A hydrogen bomb is at least a two stage device with a fission primary that starts a secondary fusion reaction. There can be a variety of materials used and specific designs are secret. The half life applies to the decaying elements and the radiation is a product of the decay and doesn't have a half life itself. In real life the only way to see if something is safe is regular testing and not just setting a timer like in the movie.
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