So what is the site about?

Restricted Data is a blog about the history of nuclear weapons and the efforts policy-makers and scientists have made to try to keep this history secret. Its author is Alex Wellerstein, a historian of science at the Stevens Institute of Technology in New Jersey, US, whose CV includes a one-year stint as the “Edward Teller Graduate Fellow in Science and Security Studies” at the US Department of Energy (“still my best job title” he writes). Wellerstein’s academic research interests lie in the same area, but in the blog, he is writing for a general audience.

What are some of the topics covered?

Most posts on Restricted Data deal with events from the 1940s and 1950s, such as the Manhattan Project to build the first atomic weapons and the US and Soviet hydrogen bomb tests. Over the past decade or so, many formerly secret documents related to this period have been declassified, and others are emerging all the time. Wellerstein is also interested in less-well-studied aspects of nuclear history. One recent post (with the arresting title “How to die at Los Alamos”) focuses on occupational safety at the wartime weapons lab, while another complains about the use of fake “mushroom cloud” photographs (and their associated physical inaccuracies) in books.

Anything else of note?

As well as the blog itself, Wellerstein has also built a tool called Nukemap that models what would happen if a nuclear device were to explode in a certain location. Users of Nukemap can specify the device’s yield (in kilotons), the type of explosion (airburst or surface) and a few other parameters, as well as choosing where the explosion takes place. From a policy perspective it is, perhaps, reassuring to know that if a “crude nuclear terrorist weapon” with a yield of 0.1 kilotons went off in a city centre, few if any people would die in the blast itself, and prompt medical care would save the lives of most of the radiation casualties. But it is quite another thing to look at a map centred on your own house, and imagine what even a “minor” nuclear incident would do to familiar people and landmarks nearby.

Why should I visit?

For those who want to learn more about the history of nuclear weapons, Wellerstein’s blog offers an accessible introduction to a wide range of “science and society” issues, from the morality of the atomic bombings of Hiroshima and Nagasaki during the Second World War to the health risks of radioactive fallout from later nuclear tests. Perhaps more importantly, though, Restricted Data is a good reminder that, like scientists, historians are in the business of analysing data, using it to construct theories, and then checking those theories against new facts that emerge. The declassification of once-secret documents is part of this historical-scientific process, and reading Restricted Data will help you appreciate how perceptions of our scientific past are changing.

Can you give me a sample quote?

From a post about the first Soviet hydrogen-bomb test: “The fully loaded Tu-16 bomber had to abort when the test site was unexpectedly covered by clouds, making them unable to see the target aiming point and rendering the optical diagnostic systems inoperable. The plane was ordered to land, only now it had a fully armed experiment H-bomb on board. There was concern that if it crashed, it could result in a nuclear yield…destroying the airfield and a nearby town. The airfield had meanwhile iced over. Igor Kurchatov, the lead Soviet nuclear-weapons scientist, drove out to the airfield himself personally to see the airfield. [Weapons scientist and later dissident Andrei] Sakharov assured him that even if it crashed, the odds of a nuclear yield were low. An army unit at the airfield quickly worked to clear the runway, and so Kurchatov ordered the plane to land. It did so successfully. Kurchatov met the crew on the field, no doubt relieved. Sakharov recalls him saying, ‘One more test like [this one] and I’m retiring.’ As for Sakharov, he called it ‘a very long day’.”

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