Nuclear Weapons

Last modified on December 10th, 2006

Tonight I spent some time in front of the TV, in some nice flannel pants (oh yeah), surfing the web, looking up random events. To that end, I really love wikipedia. I can so easily lose myself in that maze of knowledge, and find I can really learn a pile of new things just by spending an hour or two a week surfing through a pile of links.

Tonight I ended up going through the history of warfare, in particular, related to nuclear weapons. And I guess it kind of interested me, because technically I am a physicist (my undergrad was in Engineering Physics, and I took a few courses related to nuclear energy, atomic structure, solid state physics, and ended up being about three courses shy of an honours mathematics degree as well). Building a nuclear weapon actually isn’t very hard. The hard part is getting access to plutonium or uranium. From there, it’s not hard to do a lot of damage. And that’s really the scary part about nuclear weapons — that the average guy could probably put something together if they had access to the raw material. All you really need to do is take two pieces of plutonium, and put them together so the total mass exceeds the critical mass – kaboom. For plutonium, the amount needed would be a sphere that would fit rather nicely into the palm of your hand. Not very big at all.

Thankfully, it’s next to impossible to get access to uranium and plutonium. For now. But I was thinking to myself tonight that there will probably be a time in the future, and maybe within my lifetime, where those materials won’t be so hard to acquire anymore. It is possible to create almost every type of atom using a cyclotron, but unfortunately the average guy can’t build one of these things. But as technology continues to improve, and people discover new ways to do these sorts of things, I wonder how long it will be before governments aren’t the only ones who will have nuclear technology. And that’s a pretty scary thought.

I really hate violence. I hate wars and the governments who justify warfare. I feel sick to my stomach when I hear the US slamming other countries for trying to acquire nuclear devices when it’s the only country ever to drop a nuclear weapon on another country (in fact it dropped two). People justify that action by saying it saved so many lives, but I don’t understand how you can justify killing hundreds of thousands of ordinary people.

I read a book in high school called Hiroshima that detailed what happened that day. It detailed how the US waited until the early morning, when everyone was cooking breakfast, to drop the bomb. This would maximize the number of people who were using their gas stoves, and cause most of the underground gas pipeline network to explode after the initial blast, killing even more people. And it’s just hard to fathom that things like this occured not that long ago.

The largest US nuclear warhead ever tested was called Castle Bravo, and it also holds its place in history as the worst radiological accident ever in the US. The bomb was only expected to be around 4 megatons, but due to a mistake in the understanding of the how the bomb would work, it actually ended up being more like 15 megatons. The fallout from this blast went over a far wider area, and caused many civilian casualties, mostly on some Japanese fishing boats.

Castle Bravo Nuclear Test

In 1961, in an effort to show its superiority, the USSR created a massive nuclear weapon with a yield of approximately 50 megatons. For comparison, the nuclear weapon dropped on Hiroshima had a yield of around 20 kilotons, so this new russian bomb was 2500 times as powerful. It was named the Tsar Bomba, and here’s some scary facts about it:

The original USA estimate of the yield was 57 Mt, but since 1991 all Russian sources have stated its yield as “only” 50 Mt. Nonetheless, Khrushchev warned in a filmed speech to the Communist parliament of the existence of a 100 Mt bomb (technically the design was capable of this yield). The fireball touched the ground, reached nearly as high as the altitude of the release plane, and was seen 1,000 km away. The heat could have caused third degree burns at a distance of 100 km. The subsequent mushroom cloud was about 60 km high and 30–40 km wide. The explosion could be seen and felt in Finland, even breaking windows there. Atmospheric focusing caused blast damage up to 1,000 km away. The seismic shock created by the detonation was measurable even on its third passage around the earth.

Since 50 Mt is 2.1×1017 joules, the average power produced during the entire fission-fusion process, lasting around 3.9×10-8 seconds or 39 nanoseconds, was a power of about 5.3×1024 watts or 5.3 yottawatts. This is equivalent to approximately 1% of the power output of the Sun. The detonation of Tsar Bomba therefore qualifies, even to this day, as being the single most powerful device ever utilized throughout the history of humanity.

Tsar Bomba

Pretty scary. And these things are sitting in silos, no more than a button press away from launching at any time. The current methodology is nuclear warfare is not to use heavy payloads, but rather to shower the target with multi independent warhards in more of a carpet bombinb approach. This makes the delivery systems cheaper and more reliable.

Thankfully, Canada long ago decided not to develop and support a nuclear weapon’s program (despite having once had nuclear weapons on its soil) — the last nuclear device was removed from Canada in 1984.

2 responses to “Nuclear Weapons”

  1. PBR says:

    I agree with the thrust of your presentation, although I don’t think the cyclotron is the device to use to create significant (or any) quantities of Uranium and Plutonium. However, it certainly is conceivable that other ways to produce these elements will be found — inexpensive ways.

    It would be extremely uplifting if the world could go on a program of significant reduction of nuclear weapons. It seems we have other problems — territorial, religious, etc. to solve first.

  2. Duane says:

    Right. A cyclotron isn’t very practical, but it used to be (a long time ago), one of the only ways to generate plutonium. I believe most weapons grade plutonium today is a by-product of processed nuclear reactor waste.

Leave a Reply

Your email address will not be published. Required fields are marked *