Language Atlas
Things this atlas does not know. Each entry is a question that specialists
have posed and not settled, recorded with what would actually resolve it and which
expertise the answer needs.
These are kept deliberately, rather than quietly omitted. An atlas that shows
only what it is sure of implies a confidence it has not earned, and the gaps are often where
the interesting work is. Several sit exactly where two fields fail to meet: identifying the
hyssop of the Hebrew Bible needs a botanist and a philologist of Biblical Hebrew, and neither
one settles it alone.
Grouped by the field an answer needs. A question sitting between two disciplines appears under both, which is why the group counts add up to more than the number of questions.
Not Yet Classified 10
The Wheel
Who Invented the Wheel
Open The Wheel
Why It Is Open The wheel's earliest archaeological evidence is a potter's wheel and shortly after a wheeled cart from Mesopotamia, roughly 3500 BCE, but similar wheeled vehicles appear in the archaeological record across Central Europe and the Caucasus within a few centuries of each other, and no single inventor or point of origin can be credited from the evidence that survives.
What Would Settle It Additional securely dated archaeological finds that establish a clear chronological and geographic priority among the early Mesopotamian, Central European and Caucasus wheeled-vehicle finds; none exists today.
Expertise Needed Archaeology
Radio
Did Guglielmo Marconi know of Alexander Popov's 7 May 1895 coherer receiver demonstration before filing his own 1896 patent application, or did the two men arrive at similar designs independently from the same published coherer research?
Open Radio
Why It Is Open Popov demonstrated a coherer based receiver to the Russian Physical and Chemical Society on 7 May 1895 but did not patent it or publish it outside Russia in a form clearly available to Marconi at the time. Both men were building on the same coherer research already published by Oliver Lodge and others, so the resemblance between their early receivers does not by itself prove either man copied the other.
What Would Settle It A primary correspondence, laboratory notebook or contemporary press account placing Marconi in direct contact with Popov's published results before Marconi's own 1896 patent filing; none has surfaced in the sources consulted for this entry.
Expertise Needed History of technology
Question posed in
Invention of Radio (Wikipedia), Wikipedia contributors.
Movable Type Printing
Did Knowledge of Chinese and Korean Movable Type Reach Johannes Gutenberg Before His Independent Invention?
Open Movable Type Printing
Why It Is Open Bi Sheng invented ceramic movable type in Song China between 1039 and 1048, and movable metal type was in use in Korea by the fourteenth century, both centuries before Johannes Gutenberg's metal type and mechanical press appeared in Mainz around 1440. No direct documentary link places knowledge of the Asian systems in Gutenberg's hands, and historians remain divided between an independent-invention account and a diffusion account carried along Mongol-era Eurasian trade and diplomatic contacts.
What Would Settle It A documented account, correspondence, or artifact placing knowledge of Chinese or Korean movable type printing in Europe, or specifically before Gutenberg, before his circa 1440 press; none has surfaced in the sources consulted for this entry.
Expertise Needed History of technology
Question posed in
Bi Sheng (Wikipedia), Wikipedia contributors, Body section.
The Mechanical Clock
Does Su Song's 1092 water-driven astronomical clock tower count as the first mechanical clock, or does that title belong to the weight-driven verge-escapement clocks first attested in Europe in the 1280s?
Open The Mechanical Clock
Why It Is Open The two traditions used different power sources, a water clock feeding an escapement-like linkwork versus a purely weight-and-spring drive train, so the answer turns on which feature defines "mechanical clock," not on a missing fact.
What Would Settle It A settled scholarly definition of "mechanical clock" that either includes or excludes an escapement-regulated but water-powered drive train would resolve which tradition holds priority.
Expertise Needed History of technology
Question posed in
History of Timekeeping Devices (Wikipedia), Wikipedia contributors.
The Magnetic Compass
When did the Chinese magnetic compass move from a tool of divination and orientation to genuine sea navigation, and did the practice reach medieval Europe by transmission along existing trade routes or arise there independently?
Open The Magnetic Compass
Why It Is Open Han-dynasty lodestone-spoon use is attested for divination, and Shen Kuo's 1088 description is the first clear account of a directional needle, but no source pins down exactly when navigational use began or documents a transmission route to Europe.
What Would Settle It A dated Chinese or Islamic-world source describing shipboard compass navigation, or documentary evidence of a specific trade contact carrying the technology westward, would settle the timing and the transmission question respectively.
Expertise Needed History of technology
Question posed in
Compass (Wikipedia), Wikipedia contributors.
Radar
Who should be credited as radar's inventor: Christian Hulsmeyer's 1904 patent, Robert Watson-Watt's 1935 Daventry Experiment, or one of the other near-simultaneous 1930s national radar programs in Germany, France, the United States or the Soviet Union?
Open Radar
Why It Is Open At least five countries reached a working radio-echo detection system independently within a few decades of each other, so the question is which milestone, a working principle, a working military system, or an operational network, defines "invention."
What Would Settle It A settled convention for what counts as the invention of a multi-national simultaneous-discovery technology, comparable to how the field already treats the telegraph and telephone priority disputes, would resolve this the same way.
Expertise Needed History of technology
Question posed in
Radar (Wikipedia), Wikipedia contributors.
The Microprocessor
Was Garrett AiResearch's classified Central Air Data Computer chip set (1968-1970), Texas Instruments' 1971 single-chip CPU patent, or Intel's commercially released 4004 (1971) the first true microprocessor?
Open The Microprocessor
Why It Is Open The three claims answer different questions, first working design, first patent, first commercial product, and the classified CADC design was not publicly documented until years after it was built, so the historical record itself was incomplete for years, not merely uncollected.
What Would Settle It A settled convention for whether "first microprocessor" means first working design, first patent or first commercial release would resolve which claim wins under that definition; no new archival evidence is expected to change the underlying facts.
Expertise Needed History of technology
Question posed in
Microprocessor (Wikipedia), Wikipedia contributors.
Vulcanization
Does priority for vulcanization belong to Charles Goodyear, who discovered the sulfur-and-heat process in 1839, or Thomas Hancock, who filed the first patent on it, in Britain, in 1843?
Open Vulcanization
Why It Is Open Goodyear discovered the process first but did not patent it until 1844; Hancock examined a Goodyear sample, independently worked out the same process, and patented it in Britain weeks before Goodyear's own British filing. Neither side has ever produced evidence settling whether Hancock copied or independently rediscovered the process.
What Would Settle It Documentary evidence of exactly what Hancock learned from the Goodyear sample he examined, if any, versus what he derived independently, would settle whether his 1843 patent was an independent rediscovery or a derivative of Goodyear's work.
Expertise Needed History of technology
Question posed in
Vulcanization (Wikipedia), Wikipedia contributors.
Sintering
Should sintering's origin be dated to its ancient craft use in fired ceramics and early sintered-metal artifacts, or to William Coolidge's 1909 patented process, the point it became a deliberately engineered industrial technique?
Open Sintering
Why It Is Open Ancient artisans achieved sintering empirically without understanding or naming the underlying process, so the entity's single origin-year property cannot represent both an ancient craft practice and a specific engineering milestone at once.
What Would Settle It A convention for whether this atlas's "origin-year" property means first craft use or first deliberate engineering formalization would settle which date belongs on this fact, consistent with how the atlas already treats other ancient-craft-to-modern-engineering methods.
Expertise Needed History of technology
Question posed in
Sintering (Wikipedia), Wikipedia contributors.
Aluminum
Does priority for isolating metallic aluminum belong to Hans Christian Orsted, whose 1825 sample was first but impure and never fully confirmed, or to Friedrich Wohler, whose 1827 sample was purer and better documented?
Open Aluminum
Why It Is Open Orsted's 1825 method was not fully published or independently repeated at the time, while Wohler's 1827 work is the first isolation historians can verify in detail; whether "first isolation" should credit priority in time or the first confirmable result is a genuine, unresolved editorial question, not a missing fact.
What Would Settle It A surviving, dated laboratory record of Orsted's exact 1825 method and result, sufficient for modern chemists to confirm what he actually produced, would settle whether his claim meets the same evidentiary bar Wohler's does.
Expertise Needed History of chemistry
Question posed in
Aluminium (Wikipedia), Wikipedia contributors.