Technology and the built world

Jan Koum (Ян Борисович Кум)

Jan Koum (Ян Борисович Кум) is a Ukrainian-American entrepreneur who co-founded WhatsApp with Brian Acton in 2009 and led it through its 2014 sale to Facebook.

Jan Leike

Jan Leike is a German machine learning and AI alignment researcher who leads Anthropic's Alignment Science team, having previously co-led OpenAI's Superalignment team with Ilya Sutskever.

Jan Mayen-class patrol vessel

The Jan Mayen class is a class of three ice-strengthened offshore patrol vessels built for the Norwegian Coast Guard, replacing the Nordkapp class from the early 1980s.

Jan Schroers

Jan Schroers is a materials scientist and mechanical engineer who is the Robert Higgin Professor at Yale University, known for developing thermoplastic forming of bulk metallic glasses.

Jan Seidel

Jan Seidel is a physicist and materials scientist, professor at UNSW Sydney since 2012, known for his 2009 discovery that ferroelectric domain walls conduct electricity.

Jan Šnajder

Jan Šnajder is a Croatian computer scientist and natural language processing researcher, a Full Professor at the University of Zagreb's Faculty of Electrical Engineering and Computing.

Jan Tschichold

Jan Tschichold, born Johannes Tzschichhold (1902–1974), was a German-born typographer whose 1928 book Die neue Typographie codified modernist design and whose typeface Sabon remains in wide use.

Jan van Schilfgaarde (1929–2008) was a Dutch-born American agricultural engineer and soil physicist whose transient drainage theory reshaped subsurface drainage design; he was elected to the National Academy of Engineering in 1989.

Jana Zaumseil

Jana Zaumseil (born 1977) is a German applied physical chemist, Professor of Applied Physical Chemistry at Heidelberg University since 2014, known for organic electronics, carbon nanotube optoelectronics, and light-emitting transistors.

Janbu's method

Janbu's method is a limit-equilibrium procedure of slices for computing the factor of safety of soil or rock slopes, developed by Norwegian engineer Nils Janbu in the 1950s.

Jane McKee Smith

Jane McKee Smith is an American coastal engineer who co-developed the STWAVE wave model and was elected to the National Academy of Engineering in 2019.

Jane's Fighting Ships

Jane's Fighting Ships is an annual reference work cataloging the warships of the world's navies, founded by British journalist Fred T. Jane and first published in 1897.

Oct 10, 2026

Janelle Shane

Janelle Shane is an American laser scientist in Colorado known for the AI humor blog AI Weirdness and the 2019 book You Look Like a Thing and I Love You.

Janet (airline)

Janet, also called Janet Airlines, is the unofficial name for a fleet of unmarked aircraft flying US military and contractor personnel to Area 51 and the Tonopah Test Range.

Jang Yeongsil-class submarine

The Jang Yeongsil-class submarine (장영실함) is a class of three 3,600-ton diesel-electric attack submarines for the Republic of Korea Navy, the second batch of the KSS-III program.

Sep 20, 2026

Jang-wook Choi

Jang-wook Choi (최장욱) is a South Korean battery and materials chemist, professor at Seoul National University, known for elastic and supramolecular binders that stabilize high-capacity battery electrodes.

Jang‐Joo Kim

Jang-Joo Kim (김장주) is a South Korean materials scientist who studies OLED efficiency, a Seoul National University professor from 2003 to 2020 and now emeritus professor.

Jang‐Sik Lee

Jang-Sik Lee (이장식) is a South Korean materials scientist and Mueunjae Chair Professor at POSTECH since 2019, known for charge-trap flash memory and ferroelectric synaptic devices for neuromorphic computing.

Jang‐Ung Park

Jang-Ung Park (박장웅) is a South Korean materials scientist and professor at Yonsei University since 2018, known for smart contact lenses, stretchable transparent electrodes, and liquid-metal retinal implants.

Jangada

A jangada is a traditional sailing fishing raft of northeastern Brazil, built from buoyant logs with a single triangular sail, dominant in artisanal sea fishing for about four centuries.

Jangkrik Oil and Gas Field

Jangkrik is a deepwater natural gas and condensate field in the Makassar Strait off East Kalimantan, Indonesia, which began production in May 2017 through the Jangkrik Floating Production Unit.

Jangwon Seo

Jangwon Seo (서장원) is a South Korean materials scientist at KAIST known for perovskite solar cell research, including a certified 25.2% efficiency cell in Nature in 2021.

JanitorAI

JanitorAI is an AI character-companion platform where users chat with community-created characters, founded by Australian developer Jan Zoltkowski, with 1 million users in its first 17 days after launch.

Janney coupler

The Janney coupler, also known as the knuckle coupler, is the automatic railroad coupler patented by Eli H. Janney of Virginia in 1873, letting cars couple on impact without a worker between them.

Jänschwalde Coal Mine

The Jänschwalde Coal Mine (Tagebau Jänschwalde) was an opencast lignite mine in Brandenburg, Germany, northeast of Cottbus, that extracted about 660 million tonnes of brown coal.

Janschwalde power station

Jänschwalde power station (Kraftwerk Jänschwalde) is a lignite-fired power plant near Cottbus in Brandenburg, Germany, built by East Germany from 1976 and scheduled for complete closure at the end of 2028.

Jantar Mantar, Jaipur

Jantar Mantar in Jaipur is an early-18th-century open-air observatory of monumental masonry astronomical instruments built by Sawai Jai Singh II around 1727, a UNESCO World Heritage Site since 2010.

January 2025 AI market selloff

The January 2025 AI market selloff was a one-day rout on January 27, 2025, triggered by DeepSeek's low-cost AI model, wiping $593 billion from Nvidia.

Janus micromotor

A Janus micromotor is a self-propelled micro- or nanoscale particle with two chemically distinct sides, propelling through fluid by bubble recoil, diffusiophoresis, or electrophoresis for applications like drug delivery.