Today in History: First Man-Made Self-Sustaining Nuclear Chain Reaction Initiated

On December 2, 1942 the first nuclear-chain reaction was initiated under the supervision of Enrico Fermi. The reaction took place in Cook County, Illinois with the Chicago Pile-1, the world’s first nuclear reactor, built as a part of the Manhattan Project. The site is now a U.S. Historic Landmark. From wikipedia:

On 2 December 1942, CP-1 was ready for a demonstration. Before a group of dignitaries, George Weil worked the final control rod while Fermi carefully monitored the neutron activity. The pile “went critical” (reached a self-sustaining reaction) at 15:25. Fermi shut it down 28 minutes later.

After the chain reaction was observed, Arthur Compton, head of the Metallurgical Laboratory, notified James Conant, chairman of the National Defense Research Committee, by telephone. The conversation was in an impromptu code:

Compton: The Italian navigator has landed in the New World.

Conant: How were the natives?

Compton: Very friendly.

Unlike most reactors that have been built since, CP-1 had no radiation shielding and no cooling system of any kind. Fermi had convinced Arthur Compton that his calculations were reliable enough to rule out a runaway chain reaction or an explosion. But, as the official historians of the Atomic Energy Commission later noted, the “gamble” remained in conducting “a possibly catastrophic experiment in one of the most densely populated areas of the nation!”

Read more.


Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here: adafruit.com/editorialstandards

Happy New Year 2025
Happy New Year from Adafruit!

Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7:30pm ET! To join, head over to YouTube and check out the show’s live chat and our Discord!

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Join over 38,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython – The easiest way to program microcontrollers – CircuitPython.org


New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — New Products 11/15/2024 Featuring Adafruit bq25185 USB / DC / Solar Charger with 3.3V Buck Board! (Video)

Python for Microcontrollers – Adafruit Daily — Python on Microcontrollers Newsletter: Open Hardware is In, New CircuitPython and Pi 5 16GB, and much more! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi

EYE on NPI – Adafruit Daily — EYE on NPI Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

Adafruit IoT Monthly — The 2024 Recap Issue!

Maker Business – Adafruit Daily — Apple to build another chip at TSMC Arizona

Electronics – Adafruit Daily — Low power?

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !


No Comments

No comments yet.

Sorry, the comment form is closed at this time.