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)
https://tapr.org/
TAPR (Tucson Amateur Packet Radio) is a longstanding amateur radio organization focused on advancing digital communications technology for ham radio operators. The site hosts decades of Digital Communications Conference papers, open hardware licenses, packet radio resources, and membership services for experimenters pushing the boundaries of amateur radio technology.
https://hepdata.net/
HEPData is an open repository for publication-related High-Energy Physics data, hosting experimental datasets from major LHC collaborations including ATLAS, ALICE, CMS, and LHCb. Researchers can search and submit data using advanced query syntax, making it an essential reference tool for particle physics scientists worldwide.
https://nineplanets.org/amateur-astronomical-observatories
The Nine Planets hosts a curated list of amateur astronomical observatories built by individual hobbyists, compiled by the site owner during research for their own backyard observatory project. Visitors will find practical inspiration and design ideas ranging from simple roll-off roof builds to more complex dome structures, all set within a broader astronomy reference site covering planets, stars, comets, and equipment guides.
https://sidewalkastronomers.us/
The Sidewalk Astronomers are a public service amateur astronomy association founded in the tradition of John Dobson, dedicated to bringing telescopes directly to the public in parks, street corners, and busy public spaces. The site features event schedules, telescope plans, newsletters, international projects, and resources for local chapters around the world.
https://dailydx.com/propagation
The Daily DX is a hub for ham radio operators focused on DXing, offering a curated propagation page with links to solar data, space weather forecasts, and VOACAP prediction tools. Visitors can track HF propagation conditions, solar activity, and greyline predictions to optimize their chances of reaching distant or weak-signal stations.
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.
http://cat.boffosocko.com/
A collaborative study group blog documenting UCLA Extension's 2015 Category Theory course led by Professor Michael Miller, covering abstract algebra, functors, and related mathematical structures. Participants followed a structured syllabus across multiple chapters, sharing notes, resources, LaTeX diagrams, and meeting summaries over the summer term.
https://lwca.net/
The Longwave Club of America (LWCA) is a dedicated organization serving enthusiasts of radio frequencies below 500 kilohertz, covering LF, VLF, MedFER, HiFER, and Part 15 experimental beacons. Members receive 'The Lowdown,' a bimonthly publication dating back to 1974, featuring DX loggings, homebrew antenna projects, natural radio phenomena, and news from operators around the world.
http://nmia.com/~roberts/robert.html
Robert Smathers maintains this personal hub dedicated to TVRO (Television Receive Only) satellite reception, featuring links, schedules, mail lists, newsgroups, and dealer resources for satellite hobbyists. The site also touches on visual satellite observing and space topics, making it a useful reference point for backyard dish enthusiasts.
https://www.qsl.net/w4frc
The Ft. McCoy Amateur Radio Club (W4FRC) is a friendly ham radio club based in the Ocala National Forest area of Marion County, Florida, founded in October 1997. The site shares club meeting info, VE testing schedules, member photos, and an open invitation for newcomers to discover the hobby of amateur radio.