# Demon Core Demon Core is the nickname for a plutonium sphere from the Manhattan Project that killed two physicists in 1945 and 1946 criticality accidents, one caused by a slipped screwdriver. Starting in 2018, Japanese artists on Twitter and Pixiv turned the deadly incident into fan art of anime girls poking the glowing orb, spawning a lasting dark-humor meme format. ## Origin The real-world catalyst dates to May 21, 1946, when Louis Slotin's screwdriver slipped during a criticality experiment at Los Alamos, dropping a beryllium hemisphere onto the plutonium core and giving him a fatal 1,000-rad dose of radiation[1]. The 1989 film Fat Man and Little Boy dramatized the accident with John Cusack playing Slotin, keeping the story in low-level circulation for decades. The meme format emerged on April 4, 2018, when Japanese artist @nibiqn posted a fan art of Touhou character Aunn Komano using a screwdriver on the core, racking up over 300 retweets and 570 likes[5]. Two weeks later on April 18, 2018, artist @shirosato_town posted a similar piece with Touhou's Koakuma that drew over 220 retweets and 400 likes on Twitter[6], with a matching Pixiv upload picking up more than 540 smiles[7]. These two posts set the Touhou-plus-screwdriver template that the rest of the fandom copied. - **Platform:** Twitter / Pixiv (Japanese fan art spread) - **Creator:** Unknown (earliest known fan art by Twitter artist @nibiqn, April 2018) - **Date:** 2018 ## Overview Demon Core is both a real nuclear artifact and the dark-joke art format it inspired. The physical core was a 6.2-kilogram plutonium sphere used in Los Alamos criticality experiments that killed physicists Harry Daghlian in 1945 and Louis Slotin in 1946[1]. The meme flips that grim history into cute illustrations of anime girls, often Touhou characters, cheerfully holding a flat-head screwdriver over a glowing silver ball while a beryllium hemisphere hovers above it[2]. The visual template is tightly coded. A character leans over the sphere, grips a screwdriver exactly as Slotin did, and the composition hints at the half-second blue flash witnessed during the 1946 accident[3]. The humor hinges on the viewer knowing the real story: the artist draws the moment right before everything goes wrong. Variants expand the gag to idols, VTubers, and generic cute mascots, and the joke scales from single illustrations to short animated loops and comics[4]. ## How It Spread After the April 2018 Touhou posts, drawing characters experimenting with the Demon Core turned into a running Japanese fan art trend across Twitter, Pixiv, and niconico seiga throughout 2018[2]. On December 17, 2018, nuclear historian @wellerstein highlighted the trend to English-speaking audiences in a tweet that pulled over 1,300 retweets and 1,600 likes[8], giving Western viewers their first organized look at the format. YouTube pushed the real history to a much wider audience in parallel. On October 13, 2017, the channel Qxir uploaded an early viral explainer that passed 920,000 views[9], and on November 27, 2020, Kyle Hill published a documentary that cleared 6 million views within months[10]. In March 2019, Japanese YouTuber Karameru posted the comedic short 'Demon Core-kun,' which hit over 3.2 million views and anthropomorphized the sphere itself as a mischievous character[11]. The meme crossed firmly into Western social media in May 2021. On May 6, Twitter user @HellOnEarthIII posted a fan art version that circulated widely[12], followed on May 10 by a @drab_makyo tweet based on a 2020 Tumblr piece by user bepisode[13]. Those two posts, within four days of each other, pulled the Japanese trend into English-language art Twitter where it stuck as a go-to dark-humor template[2]. ## How to Use The typical Demon Core piece shows a single character, usually drawn in anime style, posed over a shiny metal sphere with a flat-head screwdriver in one hand. Common conventions include a beryllium half-dome hovering above the core, a small blue glow or flash effect to reference the 1946 accident, and a casual or unaware facial expression that plays off how dangerous the setup actually is. Captions often skip explanation entirely, trusting viewers to recognize the setup. ## Frequently Asked Questions ### What is Demon Core? Demon Core is both the real plutonium sphere that killed two Los Alamos physicists in 1945 and 1946 and the Japanese fan art meme of anime girls poking that sphere with a screwdriver[1][5]. ### Where did Demon Core come from? The historical core came from the Manhattan Project at Los Alamos, and the meme format started on Japanese Twitter with @nibiqn's April 4, 2018 Touhou fan art[5]. ### What does Demon Core mean? It refers to the nickname given to the deadly plutonium core after the Slotin incident, repurposed online as shorthand for the fan art joke of casually mishandling the sphere[1][2]. ### How do you use Demon Core? Artists typically draw a character holding a screwdriver over a shiny silver sphere with a beryllium hemisphere above, referencing Slotin's 1946 mistake[6][7]. ### Is Demon Core still popular? The format stayed active across both Japanese and Western fan art circles after the May 2021 crossover push by @HellOnEarthIII and @drab_makyo[12][13], and large explainer videos like Kyle Hill's keep introducing new viewers[10]. ## References 1. [https://en.wikipedia.org/wiki/Demon_core]() 2. [https://knowyourmeme.com/memes/demon-core]() 3. [https://en.wikipedia.org/wiki/Fat_Man_and_Little_Boy]() 4. [https://www.youtube.com/watch?v=AQ0P7R9CfCY]() 5. [https://twitter.com/nibiqn/status/981711978598027264]() 6. [https://twitter.com/shirosato_town/status/986570760901689349]() 7. [https://www.pixiv.net/en/artworks/68290937]() 8. [https://twitter.com/wellerstein/status/1074851817333374976]() 9. [https://www.youtube.com/watch?v=-2ayVMf6Xmc]() 10. [https://www.youtube.com/watch?v=aFlromB6SnU]() 11. [https://www.youtube.com/watch?v=6ZIjbX1gj88]() 12. [https://twitter.com/HellOnEarthIII/status/1390380958105415694]() 13. [https://twitter.com/drab_makyo/status/1391886889662107650]() --- Source: https://meme.com/memes/demon-core Published by meme.com — The Internet Meme Library