Science & Nature
1439 sites
Subcategories:
- Astronomy & Space (396)
- Chemistry (8)
- Earth Sciences (26)
- Biology (79)
- Physics (30)
- Mathematics (59)
- Weather & Climate (104)
- Amateur Radio (682)
- Electronics (47)
http://hamgallery.com/
The K8CX Ham Gallery, run by operator K8CX, is a sprawling archive of ham radio history featuring a QSL Card Museum, rare DX sound clips spanning decades from the 1930s onward, and photo galleries from the legendary Dayton Hamvention going back to 1957. With searchable databases, DXCC entity tracking, Hall of Fame lists, and DXpedition galleries, it is an exceptional resource for amateur radio enthusiasts and historians alike.
http://sunstarfrance.com/
Olly Penrice runs this site combining a French gite rental property called Les Granges with a serious passion for astrophotography in the dark skies of Provence. Visitors can browse astro imaging galleries, explore local cycling and climbing, and even book a stay at the gite to experience the region firsthand.
http://joyofpi.com/pilinks.html
A comprehensive link directory dedicated entirely to pi, curated by David Blatner, author of 'The Joy of Pi,' covering everything from basic pi facts and digit downloads to pi music, pi history, and Pi Day celebrations. Visitors will find hundreds of categorized links spanning memorizing pi, calculating digits, pi mysteries, and even wacky pi fun, making it a go-to hub for pi enthusiasts of all levels.
http://faqs.org/faqs/space
The faqs.org Space Index is a comprehensive archive of Usenet FAQs dedicated to astronomy and space topics, covering everything from acronyms and data sources to how to become an astronaut and controversial space questions. Maintained across dozens of indexed documents, it serves as a structured reference hub for space enthusiasts and researchers seeking archived FAQ documents from the early internet era.
https://math.ucr.edu/home/baez
John Baez is a mathematical physicist and emeritus professor at UC Riverside whose sprawling personal site features decades of expository writing on math and physics, including his long-running column 'This Week's Finds in Mathematical Physics.' Visitors can explore course notes, research papers, talks on topics from category theory to the Standard Model, and accessible blog posts bridging cutting-edge science with public engagement.
http://nlsa.com/
Northern Lights Software Associates offers Nova for Windows, a satellite tracking program used by NASA, the U.S. Air Force, and thousands of amateur radio operators worldwide. Now available as freeware, Nova provides real-time tracking of unlimited satellites with detailed maps, ground tracks, and Keplerian element updates.
http://math.ucdavis.edu/~calculus
Calculus.org is a comprehensive educational hub hosted by UC Davis, offering step-by-step calculus problems, Java applets, Maple and Mathematica animations, and sample exams for both students and instructors. The site covers differential, integral, and multivariable calculus with resources ranging from humorous beginner guides to actuarial review problems, making it a well-rounded reference for anyone tackling the subject.
http://schematicsforfree.com/
SchematicsForFree is a volunteer-run archive offering free electronics schematics, circuit diagrams, and service manuals covering audio, video, automotive, and test equipment. Updated regularly since 2022, it embodies the original open-sharing spirit of the web, providing hard-to-find technical documents at no cost.
https://www.qsl.net/k4gc
K4GC Bryan's amateur radio page focuses on the art of building homebrew transmitters and receivers, showcasing projects like a 6L6 tube transmitter. Bryan shares his passion for collecting hard-to-find vintage radio parts including tube sockets, variable capacitors, and boat anchor components accumulated over more than twenty years.
https://dk7ih.de/
DK7IH is Peter Baier's deep-dive engineering site dedicated to building 'hardware defined' ham radio transceivers the old-school way, with analog filters, mixers, and amplifiers rather than software-defined approaches. Dozens of detailed project write-ups cover QRP SSB transceivers, multiband portables, handheld rigs, and homebrew designs spanning HF bands from 1.8 to 28 MHz.