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://rgbrown.org/
Robert G. Brown, a physicist at Duke University, shares an extensive collection of free online textbooks, physics study materials, poetry collections, philosophy essays, and beowulf cluster computing resources. The site is a sprawling intellectual hub covering everything from GPL software tools to metaphysics, all freely licensed under an open public license.
https://astunit.com/astunit_tutorial.php?topic=glossary
The Astronomical Unit is a comprehensive astronomy tutorial site covering everything from choosing a first telescope to positional astronomy, stellar evolution, and debunking pseudoastronomy claims. Visitors will find practical guides, a detailed glossary, book recommendations, DIY telescope projects, and rigorous critiques of popular astronomical myths like the '2012 nonsense' and Apollo conspiracy theories.
https://www.andrews.edu/~burton/mathlinks/coolmathlinks.htm
A curated collection of mathematics education links compiled at Andrews University, organized into sections for teachers, parents, and students across K-12 grade levels. The directory covers lesson plans, interactive activities, problem-solving resources, and NCTM-aligned curriculum materials from across the early web.
http://math2.org/
Math2.org is a comprehensive math reference site offering organized tables, formulas, and identities covering everything from basic arithmetic to calculus, linear algebra, and Fourier transforms. Available in both English and Spanish, it also features a message board for math questions and links to other top math resources on the web.
https://www.qsl.net/vu2msy/LINKS.htm
Compiled by Sandeep Baruah (VU2MSY/VU2MUE), this page catalogs over 200 ham radio links spanning Indian amateur radio clubs, international organizations like IARU and ARRL, digital communication software, antenna resources, and QRP homebrewing sites. It offers a particularly strong focus on the Indian amateur radio community, including regional clubs in Bangalore, New Delhi, and Gujarat, making it a useful snapshot of the early-2000s ham radio web.
https://3towers.com/
The Grasslands Observatory, owned by Tim Hunter and directed by James McGaha, is a working astronomical observatory in operation since 1985 that offers an extensive image gallery covering Messier objects, Arp galaxies, Barnard objects, Caldwell objects, comets, asteroids, and more. With decades of astrophotography, essays on getting started in amateur astronomy, and remote telescope operations, this site is a rich resource for serious backyard astronomers.
https://tonnesoftware.com/
Tonne Software offers a catalog of free and low-cost electrical engineering programs for Windows, covering filter design, meter scale drawing, great-circle mapping, Smith charts, and more. The site also hosts technical articles and tutorials on topics like speech processing, AM demodulators, and CW bandpass filters, many published or submitted to QEX magazine.
http://omnicron.com/~ford/ford.html
Mike Ditto's personal homepage, created in 1993 and barely updated since, covers his life as a software engineer in Austin with interests spanning amateur radio, maps, music, skiing, and computers. A built-in Morse Code Translator and links to his blog with OpenSolaris home networking tips make it a small but charming relic of early web culture.
https://daviddarling.info/encyclopedia/A/40_Eridani.html
David Darling's encyclopedia entry on 40 Eridani covers the nearby trinary star system in Eridanus, including its white dwarf, red dwarf, and orange main-sequence components, with detailed discussion of habitability and its famous role as Vulcan's star in Star Trek. Part of a broader astronomy encyclopedia, this page blends rigorous stellar data with engaging science fiction connections, complete with NASA imagery and comparisons to our own solar system's habitable zone.
https://barriearc.com/
The Barrie Amateur Radio Club (VE3GCB) is a Canadian ham radio club based in Barrie, Ontario, offering monthly meetings, beginner licensing courses, a builders group, and a variety of on-air activities including DMR and HF propagation. The site covers club repeater info, AUXCOMM emergency communications, 3D printing projects, and community events, making it a rich hub for local amateur radio operators of all experience levels.