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://circuitsarchive.org/
CircuitsArchive is a free, web-based archive of electronic circuit schematics covering everything from audio gear and battery monitors to filters, telephone interfaces, and microprocessor circuits. Maintained by Nicola Asuni since 1998, it offers a well-organized collection of PCB designs and projects useful to hobbyists and engineers alike.
https://members.tripod.com/~Hamnut_2/index.htm
Larry Miller (KB5ITT) shares his adventures installing ham radio repeaters on mountain peaks in the San Juan Mountains of southwestern Colorado, blending technical radio work with exploration of ghost towns and scenic four-wheeling routes. The site covers two specific mountain-top repeater builds near Silverton, historical photography of old mining towns like Animas Forks, and off-road trail information for the region.
https://botanical.com/botanical/mgmh/mgmh.html
A hypertext edition of Mrs. M. Grieve's landmark 1931 reference work 'A Modern Herbal,' covering medicinal, culinary, cosmetic, and economic properties of over 800 herbs and plants. The site includes alphabetical plant indexes, a recipes index, a poisons index, and supplementary reference tools like conversion tables and a medical dictionary.
https://ve3xr.wordpress.com/
The Peel Amateur Radio Club (PARC) serves the ham radio community of Brampton and Caledon, Ontario, with resources covering repeaters, ARES emergency communications, nets, and special interest groups for HF, contesting, packet radio, and Morse code. Members can find meeting schedules, club bylaws, technical notes, and member projects, making it a well-rounded hub for local amateur radio operators.
https://mineralienatlas.de/
Mineralienatlas is a comprehensive German-language encyclopedia and community platform covering mineralogy, geology, paleontology, and mining, supported by thousands of members worldwide. Visitors can search minerals by chemical properties, browse fossil and mineral portraits, explore collecting locations, and dive into crystallography and systematic mineralogy.
https://www.qsl.net/w2vtm
The Victor Amateur Radio Association (VARA), callsign W2VTM, is the employee ham radio club of L-3 Communications Systems East in Camden, NJ, with roots tracing back to the historic Radio Corporation of America (RCA). The site offers club history, hamfest schedules for the South Jersey/Philadelphia metro area, licensing resources, satellite tracking links, HF propagation guides, and a rich heritage connecting members across RCA, GE Aerospace, Martin Marietta, Lockheed Martin, and L-3.
http://cordell.org/
Cordell Expeditions is a site dedicated to exploration and expedition activities, likely covering adventures, field research, or scientific trips into the natural world. The name and framing suggest a group or initiative organized around outdoor discovery and expedition-based work.
https://flame.org/~cdoswell/chasesums/chasesums.html
Chuck Doswell's storm chasing page chronicles over three decades of tornado pursuit, beginning with his first chase in April 1972 and including detailed logs, historical accounts, and safety advice drawn from genuine scientific expertise. Packed with chase summaries, photography links, and connections to fellow chasers and meteorologists, this is a deep and personal record from one of the field's most experienced practitioners.
https://dx4win.com/
DX4WIN is a logging and DX management software site for amateur radio operators, focused on tools to track contacts and DX entities. The site uses a frames-based layout typical of early web design, suggesting it has been around since the early days of the internet.
http://heavens-above.com/
Heavens-Above, developed by Chris Peat, provides real-time satellite tracking and pass predictions customized to your exact location, covering the ISS, Starlink, Hubble, and hundreds of other spacecraft. Beyond satellites, the site offers interactive sky charts, solar eclipse data, comet and asteroid tracking, and deep space mission information, making it an essential tool for backyard astronomers and satellite spotters alike.