Thing Explainer

Thing Explainer: Complicated Stuff in Simple Words is a 2015 illustrated non-fiction book by Randall Munroe, the creator of the webcomic xkcd, in which he explains complex scientific, technological, and everyday concepts—such as nuclear reactors, the International Space Station, and human cells—using only the 1,000 most common words in English (referred to as "ten hundred" words) and simple line drawings.^[1] Munroe, a former NASA robotics expert, drew inspiration for the book's unique style from his 2012 xkcd comic "Up Goer Five," which famously described the Saturn V rocket using the same restricted vocabulary, demonstrating how even advanced topics can be made accessible without technical jargon.^[1]^[2] Published on November 24, 2015, by Houghton Mifflin Harcourt in the United States, the book features blueprint-style diagrams with annotations in plain language, covering subjects like tectonic plates, airliner cockpits, and the U.S. Constitution.^[1] The book has been widely praised for its innovative approach to science communication, blending humor, precision, and visual clarity to engage readers of all ages and encourage deeper curiosity about the world.^[3] Bill Gates, in particular, commended its ability to demystify intricate ideas while noting that the strict word limit occasionally trades some clarity for creativity, such as substituting "Mars" with "the red world."^[3]

Overview

Synopsis

Thing Explainer: Complicated Stuff in Simple Words is a 2015 illustrated non-fiction book by Randall Munroe, published on November 24 by Houghton Mifflin Harcourt.^[4] The work draws inspiration from Munroe's webcomic xkcd, particularly its "Up Goer Five" strip, to demystify complex subjects through accessible means. The book's core concept revolves around explaining intricate scientific, technical, and everyday phenomena using only the 1,000 most common English words, playfully referred to as the "ten hundred" words.^[5] This constraint forces simplified language while preserving essential details, making advanced topics approachable without jargon.^[4] Spanning 64 pages in a large-format hardcover, the book features 20 standalone explanations, each centered on a single "thing" such as machines, biological structures, or astronomical objects.^[6] These are presented via hand-drawn, labeled diagrams accompanied by concise text, emphasizing visual clarity over dense prose.^[6] Aimed at general readers—including children and adults interested in science communication—the volume promotes curiosity and understanding across diverse audiences.^[7]

Author Background

Randall Munroe is an American author, engineer, and cartoonist best known as the creator of the webcomic xkcd, which he launched on September 30, 2005.^[8] The strip features stick-figure illustrations paired with witty commentary on topics ranging from science and mathematics to technology and language, attracting a dedicated following among enthusiasts of these subjects.^[9] Munroe's work in xkcd often blends humor with rigorous scientific insight, reflecting his expertise and passion for demystifying complex ideas.^[10] Munroe earned a bachelor's degree in physics from Christopher Newport University in 2006.^[8] Prior to fully committing to his creative pursuits, he worked as a roboticist at NASA's Langley Research Center in Virginia, where he contributed to projects involving robotics during and after his studies.^[9] In 2006, shortly after graduation, Munroe left NASA to focus on xkcd full-time, marking a pivotal shift from engineering to artistic and authorial endeavors centered on science communication.^[11] His professional background in physics provided a strong foundation for the accurate yet entertaining explorations that define his output.^[12] Munroe's move into book authorship began with What If?: Serious Scientific Answers to Absurd Hypothetical Questions, published on September 2, 2014, which expanded on his online series addressing whimsical scientific queries with detailed, evidence-based responses.^[13] A significant precursor to Thing Explainer was the 2012 xkcd comic "Up Goer Five," where he illustrated and labeled a diagram of the Saturn V rocket using only the 1,000 most common English words, eschewing technical terms to convey intricate engineering concepts plainly.^[14] This effort exemplified his broader transition from digital comics to print media, where he increasingly emphasized accessible explanations of sophisticated subjects.^[4] Munroe's personal motivation for this work stems from a deep interest in rendering science approachable, viewing explanation as a tool to clarify understanding for oneself and others.^[15] He has described himself as a "chronic explainer" since youth, often rephrasing ideas in the simplest terms possible to overcome jargon barriers that can alienate non-experts, an approach honed through interactions with his xkcd readership who valued clear, jargon-free insights into technical topics.^[16]

Creation

Conception

The concept for Thing Explainer originated in Randall Munroe's 2012 xkcd comic "Up Goer Five," which depicted a blueprint of the Saturn V rocket labeled using only the thousand most common English words, such as describing the engines as the "spot where lots of fire comes out."^[14] This approach was inspired by Munroe's playful naming of spacecraft in the video game Kerbal Space Program, where he escalated to simplistic terms like "up-goer" for rockets, leading him to apply the constraint to a technical diagram as a humorous exercise.^[15] The comic received widespread positive feedback from readers, who appreciated the accessible yet accurate explanation of a complex engineering marvel.^[4] Encouraged by this response, Munroe recognized the potential to extend the simple-word format beyond rocketry to a wider array of scientific and technological subjects, prompted by audience requests for similar treatments of other topics.^[15] He expanded the idea into a book proposal around 2014, pitching it to publishers as a collection of illustrated, blueprint-style explanations constrained to basic vocabulary, leveraging the established popularity of xkcd and his prior book What If?.^[16] The proposal secured a deal with Houghton Mifflin Harcourt, which announced the project in May 2015 for a November release.^[4] Initially, Munroe planned the book to cover everyday wonders, such as teapots, human cells, and launch vehicles, emphasizing large-scale diagrams to convey functionality without jargon.^[3] Early challenges included maintaining scientific accuracy while adhering to the word limit—forcing creative circumlocutions like "bag of meat" for organs—and deciding the balance between textual descriptions and visual elements, where illustrations would bear much of the explanatory load.^[15] Munroe's background as a former NASA roboticist enabled these simplifications to remain faithful to underlying principles.^[16]

Development

The development of Thing Explainer involved a meticulous research phase where Randall Munroe delved into diverse scientific and technical subjects, relying on publicly available resources such as NASA blueprints to ensure factual precision while adhering to the strict vocabulary constraint.^[4]^[15] His background as a former NASA roboticist informed this process, allowing him to verify details on topics ranging from rocketry to biology and engineering.^[15] During the writing phase, Munroe iterated through multiple drafts of each explanation, employing the Up Goer Five Text Editor—a tool that restricts input to the 1,000 most common English words—to enforce the book's linguistic rules and enhance clarity.^[4]^[17] This iterative approach required rewriting sections several times, often substituting complex concepts with everyday analogies, such as referring to bodily organs as "bags" due to the absence of terms like "mass" or "tissue" in the approved vocabulary.^[15] Munroe personally hand-drew all the book's diagrams in a simple line-art style, producing detailed exploded views and labels using only basic words to complement the text; this illustration process, which emphasized clarity over embellishment, extended over a significant portion of the production timeline.^[18]^[15] The overall development occurred primarily from 2014 to 2015, building on the 2012 "Up Goer Five" comic and culminating in the book's announcement on May 13, 2015, ahead of its November publication.^[4]^[14] Key challenges included circumventing technical terminology without losing accuracy—for instance, creatively rephrasing scientific processes to fit the word limit—and sustaining reader interest in a format that deviated from the humor prevalent in Munroe's xkcd comics, opting instead for straightforward, educational prose.^[15] Editorial collaboration with publisher Houghton Mifflin Harcourt focused on layout design, prioritizing oversized pages (9 by 13 inches) to make the central diagrams prominent and integral to each chapter's narrative.^[4] This partnership ensured the visual elements drove the explanations, with text serving as supportive annotations rather than dominant prose.^[18]

Content

Format and Language

The format and language of Thing Explainer are defined by a rigorous constraint on vocabulary, limiting explanations to the 1,000 most common words in English to ensure accessibility for non-experts.^[1] This rule prohibits technical terms, which are instead rephrased using everyday equivalents, such as "food-heating radio boxes" for microwaves.^[4] The vocabulary list was derived from XKCD's Simple Writer tool, an online editor that enforces the word limit by highlighting disallowed terms in red, helping the author adhere to the constraint during writing.^[19] Exceptions are rare and limited to proper names essential for precision, such as "Saturn V" for the rocket, where alternatives would obscure meaning.^[6] Textual elements employ short paragraphs, active voice, and repetitive phrasing to reinforce key ideas and maintain clarity within the vocabulary limits.^[3] Explanations gradually build from foundational concepts to more intricate ones, creating an implied progression in complexity—starting with everyday objects like bridges and washing machines, and advancing to systems like the human body and atomic structures—without explicit labeling of difficulty levels.^[6] This structure prioritizes conceptual buildup, using simple sentences to describe processes step by step, such as labeling rocket components with phrases like "spot where lots of fire comes out" for boosters.^[16] Visually, the book features large, exploded-view diagrams that occupy most of each page, presenting objects and systems in disassembled, blueprint-style illustrations to reveal internal workings.^[3] Text functions primarily as captions and labels integrated into these diagrams, rather than forming a continuous narrative, which allows readers to grasp ideas through visual-spatial relationships.^[16] Accessibility is enhanced by generous white space, bolded labels for parts, and an oversized page layout (approximately 9 by 13 inches), facilitating quick scanning and comprehension for audiences unfamiliar with scientific jargon.^[3] These elements collectively address challenges posed by the word limit, such as conveying precision without complex terminology, by leaning heavily on illustrative clarity.^[16]

Key Explanations

Thing Explainer comprises approximately 44 explanations, each centered on a distinct "thing" that is unpacked through accessible language and detailed diagrams.^[20] Notable examples encompass the Saturn V rocket, dubbed the "Up-Goer Five," which details its structure as stacked cylinders housing fuel tanks and engines for launching payloads into space; cells, portrayed as "bags of stuff inside you" to illustrate biological processes; microwaves, explained as "food-heating radio boxes" detailing how they heat food; wind turbines, explaining blade rotation and energy conversion; and the International Space Station, depicting its modular assembly and life-support systems.^[4]^[1] The thematic scope spans multiple disciplines, including engineering feats such as bridges that span "tall roads" using cables and supports to bear loads, and locks that secure doors via tumbler mechanisms; biological structures like cells as "tiny bags of water" containing DNA described as "bag of meat instructions" for genetic coding, and tectonic plates as "big flat rocks" driving earthquakes and continental drift; physics concepts including atomic bombs that trigger chain reactions in heavy elements, and everyday objects such as pencils that mark paper with graphite leads or bagels formed from dough rings.^[4]^[6] Each explanation employs diagrams to visually decompose the subject into labeled parts and functions, for instance representing the rocket's stages as separable sections with propulsion systems. The progression begins with familiar items like household appliances and builds toward more abstract notions, culminating in an overview of the universe's scale from stars to galaxies. A distinctive feature is the inclusion of a periodic table reimagined with elementary names, such as hydrogen as the "light ball" element essential for water and stars.^[4]^[1]

Reception

Critical Response

Upon its release, Thing Explainer received widespread acclaim from critics for its innovative approach to science communication, particularly its use of simple language and detailed diagrams to demystify complex technologies. Reviewers praised the book's ingenuity in restricting explanations to the thousand most common English words, creating an engaging puzzle-like experience that highlights the creativity required to convey technical ideas accessibly.^[18] The New York Times highlighted how this constraint transforms intricate subjects like rocket launches into straightforward narratives, such as describing boosters as producing "lots of fire."^[16] Bill Gates, in a prominent endorsement on his Gates Notes blog, recommended the book for making science enjoyable and accessible, calling it a "brilliant concept" that serves as a "wonderful guide for curious minds" by sparking interest in everyday phenomena through humor and visuals.^[21] Similarly, The Guardian commended its broad appeal across age groups, noting that the precise, jargon-free descriptions—such as explaining a skyscraper's stability through water flow—offer educational insights without condescension, making it suitable for both children and adults exploring technology together.^[18] Critics emphasized the educational value in fostering curiosity, with diagrams of items like helicopters and human cells providing a visual foundation for deeper learning. However, some reviewers pointed out limitations in the approach, particularly where the vocabulary constraint led to occasional vagueness or oversimplification that could frustrate readers seeking precise details. Gates noted that while inventive, the method sometimes impeded clarity, as seen in circumlocutions like "red world" for Mars instead of direct terms.^[21] A CNET review critiqued the explanations as puzzle-oriented rather than straightforward, arguing that the severe language limits sacrifice nuance in complex topics, rendering it more entertaining than reliably informative for quick learning—such as approximating a porcupine as a "pointy cat" at the expense of accuracy.^[22] The Guardian echoed this, observing that decoding certain phrases, like "stuff in the Earth we can burn" for salt, could take undue effort, potentially undermining the book's goal of simplification.^[18] The book earned recognition in popular awards circuits, nominated for the Goodreads Choice Award in Science & Technology in 2016, reflecting its strong reception in blending comic illustration with scientific explanation.^[23] It did not win major literary prizes but garnered acclaim in science and graphic nonfiction circles for bridging humor and education. Often compared to Munroe's earlier What If? for its witty tone, Thing Explainer stands out through its emphasis on visual diagrams over textual hypotheticals, prioritizing illustrative breakdowns of real-world objects.^[18]

Public and Commercial Impact

Thing Explainer achieved significant commercial success shortly after its November 2015 release, debuting at number one on the New York Times bestseller list for science books and holding positions in the top five for multiple weeks through early 2016. With an initial print run of 300,000 copies, the book sold more than 34,000 copies in its first full week of sales, ranking fourth overall on the Publishers Weekly hardcover nonfiction list.^[24] By December 2015, its year-to-date print sales had reached 184,265 units.^[25] The title remained in print thereafter, sustaining steady sales into 2025 as evidenced by its continued availability through major retailers. As of 2025, specific recent sales figures are not publicly detailed. Among general readers, the book garnered strong public approval, earning an average rating of 4.1 out of 5 on Goodreads from over 25,000 ratings (rating stable as of 2025). Educators have particularly valued its approach for classroom applications, integrating its diagrams and simplified explanations to illustrate topics in disciplines such as chemistry, geology, and physics. The book's publisher, Houghton Mifflin Harcourt, incorporated elements of Munroe's style into high school science textbooks starting in 2016, enhancing visual aids for student comprehension.^[26] Fan communities tied to Munroe's xkcd webcomic have drawn inspiration from the book to develop their own exercises in constrained-language explanations, fostering ongoing engagement with its core concept. The book's emphasis on accessible language and visuals has contributed to broader trends in science communication, promoting initiatives that prioritize clarity for diverse audiences. It has also been highlighted in discussions of effective outreach, including recommendations by public figures like Bill Gates for its role in demystifying technical subjects. No direct sequels to Thing Explainer have been produced, though its constrained-vocabulary technique recurs in Munroe's subsequent book, How To: Absurd Scientific Advice for Troubled Times, published in 2019. The concept has spurred the popularity of online writing tools that limit users to basic word sets, such as those modeled after the "Up Goer Five" prompt that originally inspired the book. By 2025, Thing Explainer endures as a resource valued for breaking down intricate ideas without specialized terminology, particularly for non-native English speakers by relying on universal diagrams alongside its elementary lexicon. Lacking major revisions or new editions, it retains appeal in educational contexts.