In 1964, three physicists who just got their PhDs were tasked with developing a working design for a nuclear weapon using only unclassified information. The goal is to see if a country can develop a nuclear weapon without aid. They accomplished it within 2 and a half years.

Nth Country Experiment

Could any country with the right knowledge and technology build a nuclear bomb? From May 1964 to April 1967, the Lawrence Radiation Laboratory (the predecessor to the Lawrence Livermore National Laboratories and the Lawrence Berkeley National Laboratory) set out to answer this question. The Laboratory hired three physicists who only recently received their Ph.Ds in physics to design a nuclear bomb. D.A. Dobson, D.N. Pipkorn, and R.W. Selden had little to no experience with nuclear physics. The Lab wanted to know “if a few capable physicists, unfamiliar with nuclear weapons and with access only to the unclassified technology, could produce a credible weapon design” with “a militarily significant yield.”

If the scientists succeeded in des… Continue Reading (9 minute read)

15 thoughts on “In 1964, three physicists who just got their PhDs were tasked with developing a working design for a nuclear weapon using only unclassified information. The goal is to see if a country can develop a nuclear weapon without aid. They accomplished it within 2 and a half years.”

  1. DontMakeMeCount

    This is why people that don’t want more nukes lying around focus on controlling access to key materials and technology.

  2. Way2trivial

    ever hear of the A bomb kid?


    Phillips was born in August 1955 to [Greek]( [immigrant]( parents and raised in [North Haven, Connecticut](,_Connecticut).[\[1\]]( In 1976, while attending [Princeton University]( as a [junior]( [undergraduate](, he designed a [nuclear weapon]( using publicly available books and papers.[\[2](

  3. Njall

    The only reason it could have taken them that long is no Internet at the time, and they were actually doing other work as well. By the mid-60s the general science of critical mass was already well into general circulation.

  4. duglarri

    In 1978 I took a second-year engineering course, and we had a choice for our term project: either targeting nuclear missiles, or designing a warhead.

    It was easy enough to come up with a workable design from the basic information in the textbook. As our prof remarked, everyone who has tried has succeeded.

    I did the targeting. Which turns out to be harder. Gravity is not uniform; a projectile arcing through space gets pulled in various directions along the route, so it’s not just a matter of physics.

    North Korea, for example, will find it easier to create a working nuclear warhead than they will to deliver it with less than 1-mile circular error probable to a North American destination.

  5. yeroldpappy

    Now they can just google it and order materials from Amazon.

  6. Flight_Harbinger

    I’ve had this bizarre question rolling around in my head for a few weeks now:

    If they had the knowledge (in a hive mind or the queens themselves), how long would it take all the ants on earth to construct a fully functional thermonuclear weapon?

    Stipulations :

    -All ants on earth share effectively the same consciousness
    -They know exactly how make a nuke, but have none of the required infrastructure or resources (they’ll need to mine/create them from scratch)
    -They can’t use any resources, infrastructure, or technology from humans, they effectively don’t exist on earth.

  7. Hemingwavy

    Part of the reason North Korea managed to get nukes was they expected their timeline to develop them to take much longer, forgetting how far computers had advanced.

  8. interminaldecline

    The feasibility isnt the issue – having enough yellowcake u238 is. industrial capacity required, unless you know a guy in chechnya.

  9. The_Fredrik

    The theory is easy.

    Enriching uranium is freaking _hard_.

    Mainly because u-235 has the same chemical _and_ electromagnet properties as u-234 and u-238, so the only way you can separate them is by their very _very_ slight difference in mass.

    Mean lots and lots of expensive centrifuges.

  10. firelock_ny

    I’ve heard it said that the only secret worth keeping is “it can be done”.

  11. CNWDI_Sigma_1

    There is an unclassified version of said report available online. It is heavily redacted, but still contains a lot of interesting details (basically they were attempting to replicate the Fat Man design. Currently, there are many more efficient designs available).

    To repeat their project today, you will need some time-dependent critical geometry calculations (the easy part), and plutonium shock compression hydrodynamic calculations (the hard part; you’ll need to simulate a system conforming to the Mie-Gruneissen equation of state, as well as the interface between the explosives and the tamper). Still, about 90% of input data are available online.

    Among the nuclear security planners, the nuclear weapon design is considered to be readily available. They focus on procurement of nuclear materials.

  12. rosenbergstein

    They could have done it in a week but chose to keep the free money

  13. sofakingon


    “**Born secret**” and “**born classified**” are both terms which refer to a policy of information being [classified]( from the moment of its inception, usually regardless of where it was created, and usually in reference to specific laws in the [United States]( that are related to information that describes the operation of [nuclear weapons](

    It has been extensively used in reference to a clause in the [Atomic Energy Act of 1946](, which specified that all information about [nuclear weapons]( and [nuclear energy]( was to be considered “Restricted Data” (RD) until it had been officially declassified.

    In the [1954 revision of the Act](, the [United States Atomic Energy Commission]( was given the power to declassify entire categories of information.

    The “born secret” policy was created under the assumption that nuclear information could be so important to [national security]( that it would need classification before it could be formally evaluated. The wording of the 1954 act specified as secret:

    >All data concerning (1) design, manufacture, or utilization of atomic weapons; (2) the production of special nuclear material; or (3) the use of special nuclear material in the production of energy, but shall not include data declassified or removed from the Restricted Data category pursuant to section 2162 of this title.[\[1\]](

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